Late Glacial and Holocene Environmental Change Inferred from Sedimentary Archives of Kusawa Lake, Boundary Range Mountains, Yukon Territory, Canada

LATE GLACIAL AND HOLOCENE ENVIRONMENTAL CHANGE INFERRED FROM SEDIMENTARY ARCHIVES OF KUSAWA LAKE, BOUNDARY RANGE MOUNTAINS, YUKON TERRITORY, CANADA

Nicole Angela Chow

A thesis submitted in conformity with the requirements for the degree of Master of Science Graduate Department of Geography University of Toronto

LATE GLACIAL AND HOLOCENE ENVIRONMENTAL CHANGE INFERRED FROM SEDIMENTARY ARCHIVES OF KUSAWA LAKE, BOUNDARY RANGE MOUNTAINS, YUKON TERRITORY, CANADA

M.Sc., 2009

Nicole Angela Chow

Deptartment of Geography, University of Toronto

Abstract

Modern Kusawa Lake (60° 19' 55” N, 136° 4' 48” W, 142 km 2) of southwestern Yukon

Territory drains a 4290 km 2 catchment, 4.7 % of which is glacier covered. Sediment cores show variability both down-lake and within specific sub-basins of the lake. In Regions II -V of

Kusawa Lake, sediments are mainly clastic with massive to weakly laminated silts and clays interrupted by fine sand units, which reflect distinct runoff events into Region IV from glacier sources. In Region I, massive silts, silt-clay couplets are interrupted by thick sand deposits derived from the Primrose River delta. Further up-lake, the sediment record is further interrupted by modern sediment delivery from the Kusawa Campground alluvial fan.

The relatively small accumulation of lake glacial and Holocene sediment input in Kusawa

Lake is similar to other large lakes of the Canadian Cordillera. These patterns reflect a particular style of deglaciation and Holocene sediment inputs.

Frontispiece: Kusawa Lake, looking south from the outlet. July 2007 (Photograph taken by Joe Desloges)

“Field work can be carried out in all weather conditions provided that you are dressed appropriately for it! ” – Dr. Joe Desloges.

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Acknowledgements

First, I would like to thank Dr. Joe Desloges. His passion, enthusiasm and encyclopedic knowledge for geomorphic studies have been inspiring. I would also like to thank Dr. Sarah

Finkelstein for her encouragement and words of wisdom. Both Professors have been a huge support to my academic growth and especially the development of this project. A huge thank you to Mr. Mircea Pilaf, who over looked the splitting of cores, floods, shipments, ceiling collapses, and issues with the photocopier. Life in PGB would be a disaster without him.

I would like to acknowledge the Natural Science and Engineering Research Council of

Canada for their funding. In addition, to Dr. John Westgate and Dr. Mike Gorton in Geology,

Sam Roshdi in Chemical Engineering and Dr. Rolf Beurkens in Physics for access to different laboratory analyses. To Dr. Sharon Cowling, Dr. Tony Davis and Susan Calanza whom have generously provided guidance throughout my time here at U of T.

Muddy times spent in the field with Dr. Bob Gilbert, and Tim Phillpot were certainly fun and memorable. Thank you, Monique Stewart and Dr. Gilbert for the acquisition of the cores and to Krish Chakraborty for the analysis of diatoms.

Fellow graduate PGBers also provided a source of diversion: Carlos Avendaño, Cameron

Balfour, Feng Deng and Lisa Zhang who made lunch hours a multi-cultural (tri-lingual) experience. For times of laughter and advice during those mind-boggling times: Jen Adams,

Nyssa Clubine Jane Devlin, Anastasia Gousseva, J-P Iamonaco, Vito Lam, Kathy Miller, Young-

Lan Shin, Rebecca Snell, Roger Philips, and Jenn Weaver.

Many written pages, figures and tables of thanks to David Pabke who provided a solution to laptop woes six days before this thesis was due.

Finally, my parents Joyce Yeo and Chow Lok Leung have loved and supported me unconditionally. Armed with a B.Ed, and a Dip-Ing in Civil Engineering respectively, they listened to me patiently natter on about the significance of mud and flipped the phone bill regardless. Thank you!

Table of Contents

Abstract ii

Frontispiece iii

Acknowledgements iv

Table of Contents vi

List of Figures ix

List of Tables xiii

Chapter 1 – Introduction 1 1 Introduction 1 1.2 Research objective 4

Chapter 2 – Literature review 5 2 Introduction 5 2.1 Glaciations 6 2.1.1 Late Pleistocene 7 2.1.2 Late Wisconsin glaciation of northwestern Canada 8 2.1.3 Early Holocene sedimentary environment of the upper Takhini River drainage basin 11 2.2 The Holocene climate record of northwestern Canada 15 2.3 Pro-glacial fluvial hydrology and sediment transport 18 2.4 Lacustrine processes 19 2.4.1 Thermal stratification 20 2.4.2 Inflow behaviour 21 2.4.3 Turbidity current dynamics 22 2.4.4 The effect of turbidity currents upon lake bottoms 25 2.5 Varves 27 2.5.1 Varve formation 27 2.5.2 Varves as inferences of past climates 28

Chapter 3 – Study Area 30 3.1 Physiography of the Yukon Territory 30 3.2 Upper Takhini River drainage basin morphology 34 3.2.1 Primrose River sub-basin 34 3.2.2 Upper-most Takhini River sub-basin 35 vi

3.2.3 Kusawa River sub-basin 35 3.2.4 Jo-Jo Creek sub-basin 35 3.2.5 Devilhole Creek sub-basin 36 3.2.6 Kusawa Campground alluvial fan-delta complex 36 3.3 Bedrock and surficial geology 37 3.4 Glacial cover 38 3.5 Hydrology 39 3.6 Climate 42 3.7 Vegetation 45

Chapter 4 – Methods 46 4.1 Field Methods 46 4.1.1 Acoustic Profiling 46 4.1.2 Sediment cores 46 4.1.3 CTD’s 46 4.1.4 Geographic Information Systems 47 4.2 Laboratory methods 49 4.2.1 Sediment core properties 49 4.2.2 Loss on Ignition 50 4.2.3 Laser particle analysis 52 4.2.4 Geology – X-ray fluorescence 53 4.2.5 Microprobe tephra glass analysis 54 4.2.6 Radiocarbon-14 Analysis 54 4.3 Secondary data 55 4.3.1 Pb 210 and Cs 137 55

Chapter 5 – Results 56 5 Introduction 56 5.1 CTD’s 56 5.1.1 Temperature 56 5.1.2 Turbidity 58 5.1.3 Conductivity 60 5.2 Aerial imagery 63 5.3 Acoustic records and lake bathymetry 68 5.4 The sedimentology of Kusawa Lake 74 5.4.1 Sediment structure and grain size 74 5.4.2 Stratigraphy and grain size trends 87 5.4.3 Loss on Ignition 93 5.4.4 X-ray fluorescence 98 5.5 Chronology 99 5.5.1 Lead 210 and Caesium 137 99 vii

5.5.2 Radiocarbon-14 100 5.5.3 White River Ash 101 5.5.4 Rate of sediment deposition 103

Chapter 6 – Discussion 105 6.1 The Kusawa lacustrine system 105 6.2 Post-glacial sedimentary environment of Kusawa Lake 106 6.3 Sediment as a proxy for Holocene environmental change in Kusawa Lake 109 6.3.1 Late-glacial, early Holocene (10.5 – 7.0 ka cal. BP) 110 6.3.1.1 Sedimentary environment 110 6.3.1.2 Kusawa Lake diatoms 112 6.3.1.3 Climate 113 6.3.2 The Neo-glacial (7.0 – 2.0 ka cal. BP) 114 6.3.2.1 Sedimentary environment 114 6.3.2.2 Climate 115 6.3.3 Little Ice Age (1200 – 1900 AD) 117 6.3.3.1 Sedimentary environment 117 6.3.3.2 Climate 118 6.3.4 Post-LIA to present (1900 – present) 120 6.4.1 Specific Sediment Yield of Kusawa Lake 121 6.4.2 Sediment trapping 124

Chapter 7 – Conclusion 127 7.1 Spatial conclusions 127 7.2 Temporal conclusions 128 7.3 Future directions 130

List of Citations 131

Appendix A – Mean annual discharge of the lower Takhini River 141

Appendix B – CTD profiles 142

Appendix C – Laser particle size results 144

Appendix D – Loss on Ignition results 187

Appendix E – X-ray Fluorescence results 191

Appendix F – Chronology: Pb 210 and Cs 137 results, Microprobe tephra glass results 192

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List of Figures:

Frontispiece Kusawa Lake, July 2007 ii Figure 2.1 Conceptual model of the pro-glacial system generating lacustrine sediment 5 Figure 2.2 Glacial ice limits and ice flow directions of the Cordilleran Ice Sheet of southern Yukon Terriotry 10

Figure 2.3 Southewestern Yukon showing names referred to in the text 14

Figure 2.4 Schematic subdivision of a turbidity current 24

Figure 3.1 Southwestern Yukon showing names referred to in the text 32

Figure 3.2 The upper Takhini River drainage basin of Kusawa Lake and sub-basins 33

Figure 3.3 Mean annual discharge of the lower Takhini River 1950 – 2007 40

Figure 3.4 Annual hydrograph for the lower Takhini River at the outlet of Kusawa Lake 1986 41

Figure 3.5 Annual hydrograph for the lower Takhini River at Highway Bridge 1986 42

Figure 3.6 Temperature precipitation graph of Whitehorse based on 1971 – 2000 averages 44

Figure 3.7 Monthly rainfall normals for the Takhini River Branch based on 1971 – 2000 averages 44

Figure 3.8 Monthly snowfall normals for the Takhini River Ranch based on 1971 – 2000 averages 45

Figure 4.1 Kusawa Lake vibra core sample locations 48

Figure 5.1a Temperature profiles of Kusawa Lake taken on July 19 th , 20 th and 21 st , 2004 (southern region) 58

Figure 5.1b Temperature profiles of Kusawa Lake taken on July 19 th , 20 th and 21 st , 2004 (northern region) 58

Figure 5.2a Turbidity profiles of Kusawa Lake taken on July 19 th , 20 th and 21 st , 2004 (southern region) 60

Figure 5.2b Turbidity profiles of Kusawa Lake taken on July 19 th , 20 th and 21 st , 2004 (northern region) 60

Figure 5.3 Conductivity profiles of Kusawa Lake taken on July 19 th , 20 th and 21 st , 2004 62

Figure 5.4 Aerial photo A27149-12 of Hendon River and surrounding glacial features 64

Figure 5.5a Aerial photo of A27149-100 Upper most Takhini River sub-basin mouth 65

Figure 5.5b Aerial photo A27149-63 Takhini Lake 65

Figure 5.6 Aerial photos A27217-136 and A27217-134 Primrose River sub-basin delta 66

Figure 5.7 Aerial photo A27327-52 Campground Alluvial fan 67

Figure 5.8 Locations of Regions, Lake bathymetry and CHIRP Acoustic transects 69

Figure 5.9 Acoustic section from southern Kusawa Lake near the upper-most Takhini River mouth 70

Figure 5.10 Acoustic section from Region II, south of Primrose River delta 72

Figure 5.11 Acoustic section from Region I, proximal to the Primrose River delta 73

Figure 5.12 Acoustic section from Region I, northern Kusawa Lake 73

Figure 5.13 Core stratigraphy characteristics 75

Figure 5.13a KUS324 76

Figure 5.13b KUS322 76

Figure 5.13c KUS325 76

Figure 5.13d KUS326 77

Figure 5.13e KUS319 77

Figure 5.13f KUS327 78

Figure 5.13g KUS328 78

Figure 5.13h KUS318 78

Figure 5.13i KUS330 78

Figure 5.13j KUS331 79

Figure 5.13k KUS329 79

Figure 5.14 Major sand units with laminations core KUS324 (2.65 – 2.74m) 81

Figure 5.15 Silt – clay laminations core KUS322 (0.84 – 0.93 m) 82

Figure 5.16 KUS319 (2.1 – 2.2 m) 83

Figure 5.17 KUS326 (2.24 – 2.31 m) 83

Figure 5.18 KUS327 (2.14 – 2.22 m) 83

Figure 5.19 KUS318 (1.04 – 1.15 m) 85

Figure 5.20 KUS331 (1.03 – 1.14 m) 85

Figure 5.21 KUS330 (0.24 – 0.44 m) 86

Figure 5.22a Percentage grain size of cores taken in Regions II and IV 89

Figure 5.22b Percentage of grain size of cores taken in Region I 89

Figure 5.23a Cross reference of major sand units in cores (0 – 1 m) 90

Figure 5.23b Cross reference of major sand units in cores (1 – 2 m) 91

Figure 5.23c Cross reference of major sand units in cores (2 – 3 m) 92

Figure 5.24 Mean organic matter relative to increasing distance from the upper Takhini River outlet 93

Figure 5.25a Percentage organic matter KUS324 &322 96

Figure 5.25b Percentage organic matter KUS325, 326 & 319 96

Figure 5.25c Percentage organic matter KUS327, 328 & 318 97

Figure 5.25d Percentage organic matter KUS330, 331 & 329 97

Figure 5.26 Major element geochemical composition of Kusawa Lake 98

Figure 5.27 Kusawa Lake down-core profiles of lead-210 and caesium-137 100

Figure 5.28 Ilmentie geochemical plots of KUS324-20 and KUS322-8 in relation to White River Ash – eastern lobe (WRA-E) and the northern lobe (WRA-N) 102

Figure 5.29 Age – depth curve of core KUS324 using radio-carbon -14 and White River eastern-lobe dates 104

Figure 6.1 Stratigraphic log of core KUS324, arbitrary climate record and Jelly Bean Lake 18 O Aleutian Low 116

Figure 6.2 Specific sediment yield comparison for glacier-fed lakes in the Canadian Cordillera, plotted by percent glacier cover 123

Figure 6.3 Specific sediment yield comparison for glacier-fed lakes in the Canadian Cordillera, plotted by drainage basin area 123 Figure B 1 a & b Close-up of top (15 m) of figures 5.2a and 5.2b 142

Figure B.2 Close-up (top 30 m) of figure 5.3 143

Figure F.3 Major Element geochemistry on Kusawa Lake and Duke River White River Ash layers referring to figure 5.28 194

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List of Tables:

Table 3.1 Glacial cover distribution within the Kusawa Drainage Basin 38

Table 3.2 Site characteristics of Lower Takhini River discharge stations. 40 Mean annual discharge (m 3/s) figures based on 1955 – 2005 averages

Table 3.3 Climatic characteristics for Whitehorse based on 1971 – 2001 averages Lat / Long: 60° 43' N, 135° 4' W. Elevation: 706.2 m. Climate ID: 2101300. WMO ID: 71964 43

Table 4.1 Site characteristics and core sample lengths taken in July 5 – 8th 2006 49

Table 4.2 Cores and site characteristics of Pb 210 and Cs 137 analyses 55

Table 5.1 Radiocarbon dates and calibrated calendar ages from core KUS324 101

Table A.1 Mean annual discharge of the lower Takhini River 1950 – 2007 referring to Figure 3.3 141

Table C.1 Percentage grain size of cores taken, referring to figures 5.22 a – d 144

Table C.2 Laser particle size results of cores, referring to figures 5.22 a-d 147

Table D.1 Loss on Ignition results referring to figures 5.24 and 5.25 a – d 187

Table E.1 Major element geochemical composition of Kusawa Lake, H 20 calibrated, referring to figure 5.26 191

Table F.1 Kusawa Lake down-core profiles of lead-210 and caesium-137 , referring to figure 5.27 192

Table F.2 Average percentage major element composition of glass shards from two Kusawa Lake cores 193

Table F.3 Average percentage magnetite and ilmenite composition of glass shards from two Kusawa Lake cores referring to figure 5.26 194

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I – Introduction

1.1 Introduction

Within the last 50 years, there has been a rapidly increasing concern regarding global climate change and its impact on water resources. Glaciers in Canada and Alaska cover ~ 90,000 km 2 (13 %) of mountain glacier area on the earth’s surface. More than 50 % of the Canadian landmass is underlain by permafrost. Of that 50 %, approximately 60 % is at temperatures just a few degrees below the melting point (Bockheim, 2006). Environmental scientists have noted that continual increases in mean annual air temperatures in the Arctic latitudes have induced dramatic changes (Arendt et al., 2002; Moore, 2002a). Warmer temperatures can gradually lead to thawing and destabilization of perennially frozen grounds (Camil, 2005; Hinzman et al.,

2006b). Since the 20 th C., glaciers in the Canadian Cordillera have lost 25% of their area

(Luckman, 2000).

Glacial melt in northwestern Canada and Alaska can exert critical controls upon the landscape, most notably, hillslope processes and hydrology including surface and sub-surface ground water regimes and fluvial – lacustrine processes. Glacier and ground ice melt have contributed to a rise in rates of watershed discharge. With an increase in surface glacier melt, a decrease in snowpack accumulation there is a noticeable increase in, surface water discharge increases and, as a result, an elevated hydrologic base-flow in the summer. As glacial ice degrades to the point of becoming discontinuous, surface water infiltration through soils to groundwater can eventually enter the stream drainage network and provide base-flow during both the dry and winter periods (Burn, 2002; Camil, 2005; Hinzman et al. 2006a). Consequently, coastal and lacustrine environments have experienced an increase in the magnitude and frequency of higher-level discharge (Arendt et al. 2002; Lowey, 2002; Gilbert et al. 2006).

In order to put contemporary climatic warming and the current state of glaciers in northwest North America into context, past climatic conditions prior to the onset of anthropogenic influences must be understood. Unfortunately, Canada only holds approximately 70 years worth of detailed metrological data and the availability of climatic data for remote locations such as the glacial mountains of northwestern Canada is limited. Consequently, and especially within the last three decades, there has been a surge in the study of paleoenvironmental reconstruction for northwestern North America (Serink 2004). Current research challenges the fundamentals of unveiling historical climatic variation using proxies such as O 18 – 16 isotopes from ice cores, tree rings, marine sediment and clastic sediments from glacier-fed lakes, and diatoms (Last & Smol.

2001; Menounos et al., 2004; Anderson, 2005).

Paleolimnological records from large glacier-fed lakes have contributed significantly to our understanding of Pleistocene and Holocene environments. Studies regarding glacial lake environments within western Canada by Gilbert (1975), Desloges & Gilbert (1994a, 1994b

1998), Lamoureux et al. (1996), Dirszowsky & Desloges (1997, 2004), Menounos et al. (2005),

Menounos (2006), Gilbert et al. (2006) and Hodder et al. (2006) have all shown that lacustrine deposits offer a potentially continuous archive of sediment production from a contributing drainage basin. This in turn has the potential to help infer past climatic variability. Clastic sedimentary deposits can reveal information regarding sediment source characteristics, sediment transport and depositional mechanisms, extreme depositional events and lake conditions. This form of study is not limited to Canada. Similar approaches in reconstructing environmental change in glaciated mountain regions have also been pursued in Sweden (Anderson et al., 1996), in the Swiss Alps (Ohlendorf et al.1997), in Argentina (Strelin & Malagino 2000), and in Central

Finland (Ojala & Saarnisto 1999).

Relatively little research has examined the potential to reconstruct paleoenvironments from clastic sediment records in large glaciated lakes within the southwestern Yukon Territory.

Kusawa Lake, located within the Dezadeash Region of the Boundary Ranges, was selected for this purpose. It is 70 km in length and has a total area of 142 km 2. Kusawa Lake is part of the

Takhini River basin, in which the upper part (feeding Kusawa Lake) has a total area of 4292 km 2. Glaciers cover 4.7% of the drainage basin. Glacial history of the Dezadeash Region has played a considerable role in determining the morphology of Kusawa Lake. Once occupied by ice-dammed Glacial Lake Champagne during the Late Pleistocene deglaciation, the onset of climatic warming during the early Holocene caused ice-dam breakage, regional flooding, and the deposition of thick and fast sediment (Eyles, 1990; Gilbert & Desloges, 2005).

Significant shifts in climate were experienced within the region throughout the Holocene.

Research carried out within the northwest of Canada has shown this variability. Paleo proxies from neighbouring environments to Kusawa Lake such as Pyramid Lake and Jellybean Lake

(Anderson et al., 2005; Mazzaucchi et al., 2003) of the Y.T. have shown that the Aleutian Low played a profound role in controlling northwest Pacific Holocene climates. Flood events generated from incursions of warmer and moist Pacific air masses have resulted in numerous synchronous glacial activities in the St. Elias and Coast Mountain Ranges, such as the Little Ice

Age advance, which brought about instability of both sub-aerial and subaqueous terraces in

Kusawa Lake. Given the continual shift in water levels throughout the Holocene, these changes have had a significant effect upon the rate of sediment delivery into Kusawa Lake.

More recently, catastrophic flood experienced at the Kusawa Lake Campground alluvial fan show how rapid climatic changes acts as a factor in determining the morphology of present day glaciolacustrine environments. Throughout the summer of 1982, the persistence of above average precipitation within the Kusawa Lake region caused permafrost thawing and hillslope 3 failure in the basin above the alluvial fan. Approximately 6.7 x 105 m 3 of unconsolidated sediment was transported downslope and deposited on the alluvial fan-delta (Lowey 2002).

Private property and recreational facilities within the area were flooded and destroyed. Along with previous studies using proxies such as tree-ring evidence, Lowey (2002), Gilbert &

Desloges (2005), and Lipovsky (2006) have shown that relatively smaller flood events have occurred more frequently within the last 150 years. Although the torrent system is presently less active, there is still the potential for future flood events and landslide dam failures.

Using the lacustrine sediment accumulation record from Kusawa Lake as a proxy evidence for understanding environmental change may help in understanding shifting climatic patterns throughout Holocene.

1.2 Research Objective

The central focus of this research is to determine how the sedimentary record of glacially- fed Kusawa Lake has varied throughout the Late Glacial and Holocene intervals and subsequently whether these variations are tied to known regional climatic fluctuations.

The more specific research objectives are:

a) Examine how the Cordilleran Ice Sheet and de-glacial events have determined the shape

of the lake basin and, subsequently, the inherent sediment properties of Kusawa Lake

deposits.

b) To characterise the spatial variability of clastic depositional sequences and relate these to

possible sediment sources and delivery processes.

c) To examine Holocene changes in the rate and character of deposition, and relate this to

possible local and regional hydroclimatic forcing.

II – Literature Review

2. Introduction

A number of factors influence the relation between glacier activity and lacustrine sedimentation. In some cases, these factors are linked in unidirectional or bidirectional ways

(Fig. 2.1). Fig. 2.1 is a conceptual model, which summarizes the process – network of a typical pro-glacial system generating lacustrine sediment (Hodder et al., 2007). Six inter-related systems are specified leading to the ultimate product of lacustrine sediment deposits.

Fig. 2.1 Conceptual model of the pro-glacial system generating lacustrine sediment.

Dotted lines = connections between lacustrine sediment and the fluvial, climate and / or glacial system

(Hodder et al. 2007) 5

Given the complexities associated with the range of processes that control lacustrine sediment yield, it is important to simplify individual components that act as contributors (Fig.

2.1). Due to the nature of this project, this chapter will focus on the processes and interactions between climate, glacial, fluvial and lacustrine systems in northwestern Canada.

This chapter will begin by briefly examining the Late Pleistocene glacial episode and its impacts, particularly relating to the advance and retreat of the Cordilleran Ice Sheet in northern

British Columbia (B.C.), and southwestern Yukon Territory (Y.T.) during the Late Wisconsinan.

This is followed by a review of the climatic and geomorphic conditions throughout the Holocene up until the present day. Because of heavy modification of the regional topography by the

Cordilleran Ice Sheet, the relevant climatic and geomorphic elements controlling sediment yield will be reviewed to provide context for subsequent inferences from, and discussion of, lacustrine sediments.

2.1 Glaciations

During the Pleistocene epoch (1.65 M.Y – 10 ka cal. BP), a series of warming and cooling events have led to extensive ice sheets that covered up to 35 % of the earth’s high altitude and high latitude regions (Easterbrook, 1999). Causes of these climatic shifts include plate tectonics and intermittent volcanic activity, the Milankovitch insolation cycles and carbon and methane cycling (MacDonald et al., 2000; Hodder et al., 2007). These climatic shifts triggered glacial events, which have had a significant impact upon the landscape in North

America. At a regional scale, glaciations during the Late Pleistocene played a large role in the erosional and depositional landscapes in the southwestern Yukon Territory. Of particular importance to the lacustrine system was the formation of Glacial Lake Champagne during the last deglaciation. 6

2.1.1 Late Pleistocene

The Late Pleistocene (130 – 10 ka BP) began at the Eemian interglacial phase before the final glacial episode of the Pleistocene known as the Holocene (Easterbrook, 1999). The Late

Pleistocene demonstrated distinctive climatic characteristics that included repeated advances and retreats of the continental ice sheets (Flint, 1957; Clague et al. 1987). There have been indications that more than twelve glacial cycles have occurred within northwest Canada alone.

The most notable glacial episode was the Wisconsinan Glaciation, which dominated North

America (Flint, 1957; Fulton, 1991; Easterbrook, 1999). The last glacial stage can be subdivided into the early (~ 75 – 64 ka), middle (64 – 26 ka) and late (26 – 10 ka) Wisconsinan sub-stages

(Easterbrook, 1999; Trenhaile, 2004). During the Late Wisconsinan, the continental ice sheet had three main components. These included the Laurentide ice sheet in central and eastern North

America, the glacial complex in the High Arctic, and the Cordilleran glacial complex (Trenhaile,

2004). Stratigraphic and sedimentological studies supported by C 14 dating show that the

Cordilleran Ice Sheet formed sometime between 29 – 25 ka cal. BP (Ryder & Maynard, 1991;

Easterbrook, 1999). The Cordilleran Ice sheet spanned north – south from the Northwest

Aleutian Islands, to Mt. Adams near the Columbia River in Washington State, and was approximately 900 km wide from the Pacific to the foothills of the Rockies (Fulton, 1991). C 14 dating of organic lacustrine deposits and the characteristic presence of loess deposits has shown that the maximum glacier extent to the south occurred at ~ 18 ka cal. BP and had extended to

Montana, and Washington States (Hobbs, 1947). The extreme northwest Yukon remained ice free.

2.1.2 Late Wisconsin glaciation of northwestern Canada

Bostock (1966) identified four advances of the Cordilleran Ice Sheet, within the southern

– central Yukon: the Nansen (oldest), Klaza, Reid, and McConnell (youngest and the latest) glaciations. During the preceding interglacials, upland areas were ice-free. Since the more recent ice advances were the most extensive and most erosive, landforms found throughout southern – central Yukon are predominantly from the Reid and McConnell glaciations (Kerr,

1934; Hughes 1987).

Based on stratigraphic and geomorphic evidence, the Late Wisconsin Reid – McConnell glacial advance began circa 25 – 29 ka cal. BP and covered a vast region from the Pelly and

Selwyn Mountains in the east, to south central Yukon, and from the Cassiar Lobe and to the eastern Coast Mountains of B.C. (Jackson et al. 1991) (Fig. 2.2). Glacial ice from the Cassiar and Coastal Mountains converged and flowed 1600 km in a north and northwesterly through the

Yukon and Teslin River Valleys and ceased north of the Yukon Plateau (Gilbert & Desloges

2005). Westward ice flow from the Pelly and Selwyn Mountains was contiguous with an eastward piedmont glacier complex from the St. Elias Mountains. Ice from the Lowell and

Dusty Glacier lobes, which constituted the main mass of the St Elias complex, flowed east, northeasterly, and north into the valleys of the Slims, Kaskawulch, Dusty, and Alsek rivers (Fig.

2.2) (Kindle, 1953; Clague, 1989; Braher et al., 2008). Glacial ice reached the Shakwak Valley in the Dezadeash Region through the Denali fault line. At Much Lake, ice flow continued in a northerly direction along the Duke Depression through Alder Creek and eastwards towards

Dezadeash Lake where it accumulated (Kindle, 1953; Jackson et al, 1991; Gilbert & Desloges,

2005). This ice subsequently merged with the densely compact glacial ice flowing from the

Klukshu and Takhanne River Valleys. The enlarged ice field flowed northeast along the

Dezadeash Valley and Shakwak Trench into the Kusawa Lake area.

Prominent glacial positions of the glacial maximum can be traced through moraines and erratic boulders. Evidence of glacial scouring can be found at elevations up to 2000 m a.s.l.

(Kindle, 1953; Gilbert & Desloges, 2005) suggesting this was the maximum ice thickness.

Kindle (1953) noted Shakwak till exposures 120 km northeast of the present divide in the Ice

Field Ranges between the Kaskawulsh and Hubbard glaciers. Isolated nunataks, which protruded through the ice, suggest ice elevations in the southern Dezadeash, Ruby, and Kluane

Ranges reached 1700 m a.s.l. Based upon the floor elevations of the lowest cirques in the Ruby

Range of the Yukon Territory, which once supported cirques – glaciers, paleo-firn lines fell as low as 1500 m a.s.l. (Jackson et al., 1991). Kame terraces found at elevations of 1050 – 1350 m a.s.l. near Jo-Jo Lake and Dezadeash River indicate the long-term presence of the ice. The movement of ice, in the Shakwak Trench and Takhini River valley caused bedrock scouring that resulted in the deepening of the valley system. Glacial Lake Champagne was formed towards the end of the McConnell glaciation, when valley glaciers still occupied the large valleys of the

Kluane Ranges west of the Shakwak Valley, Takhanne, and Klukhu river Valleys south of

Dezadeash Lake (Kerr, 1934; Kindle; 1953). The Kusawa Valley remained glaciated to the early

Holocene (Jackson et al., 1991; Gilbert & Desloges, 2005).

Fig. 2.2 Glacial ice limits and ice flow directions of the Cordilleran Ice Sheet of southern Yukon Territory.

EL = Eastern Coast Ranges Lobe; EC = Eastern Coast Ranges; CL = Cassiar Lobe; C = Cassiar Mountains; LL =

Liard Lobe; P = Pelly Mountains; S = Selwyn Mountains, SL = Selwyn Lobe. Arrows = flow directions. Red dash line = Ice sheet divide. NTS Digital Elevation Model (Hillshade) at 500 m intervals.

Ages documenting the retreat of the Cordilleran Ice Sheet in the Yukon have been limited. The C 14 dating of organic – rich silt in lacustrine sediments derived from the terminus of the St. Elias piedmont lobe complex has provided an estimated age of 13,660 +/- 180 yr BP

(Rampton, 1971 in Jackson et al. 1991). The end of McConnell de-glaciation marked the start of the Holocene, which encompasses approximately the past 10.5 ka BP. A major feature of the

McConnell de-glaciation were the large ice-dammed lakes that occupied the interior valleys of the Yukon River drainage basin. Thick sequences of glaciolacustrine sediments were deposited and these have shaped the valley morphology we see today (Gilbert & Desloges 2005).

2.1.3 Early Holocene sedimentary environment of the upper Takhini River drainage basin

Due to the large spatial extent of the strandlines (indicators of water levels) along the

Dezadeash Valley from the Takhini River to the south-east of Haines Junction, and in the valleys of the Dezadeash, Kathleen and Frederick Lakes, it is possible that Glacial Lake Champagne was dammed by glaciers from the west in close proximity to the St. Elias ice complex (Gilbert &

Desloges 2005) during the early Holocene. Glaciers in the Primrose Valley and glaciers near the

Kusawa Lake outlet (Fig. 2.3) formed large deltas in Glacial Lake Champagne (Gilbert &

Desloges, 2005). Because a trunk glacier occupied the southern portion of Kusawa Lake, the majority of sediment accumulation was derived in response to the early Holocene deglaciation and the complete drainage of Glacial Lake Champagne.

An assessment of strandlines by Gilbert & Desloges (2005) showed that water levels once stood at ~ 772 m a.s.l. in the northern (outlet) part of Kusawa Lake during the early

Holocene (contemporary lake level is 671 m a.s.l). This was coincident with a persistent high – level of Glacial Lake Champagne (Gilbert & Desloges, 2005). Less prominent strandlines were found at 853 m a.s.l, which suggests that an early phase of Glacial Lake Champagne once stood a higher level. Subsequently, the lake grew and levels fell. Glacial-lake elevation data suggests that the most prominent strandlines along valley walls occur at 765 and 725 m a.s.l. with lesser strandlines occurring between 725 and 765 m a.s.l and down to 701 m a.s.l. This indicates that water levels had fluctuated significantly throughout the deglaciation process.

Throughout this drainage process, Lake levels were controlled by both a spillway floored at 756 m a.s.l at the north of the Nordenskiold River along with a continual down-cutting of the sediment plug at the outlet of Kusawa Lake. This indicates differential isostatic rebound of 0.2 m/km from south to north (Kindle, 1953; Gilbert & Desloges, 2005). Uniformly thick glaciolacustrine fine sand, silt and clay sediment were deposited on the Takhini and Dezadeash valley floors (Fig. 2.3) (Lowey, 2002; Gilbert & Desloges, 2005). Using acoustic records,

Gilbert & Desloges (2005) noted three distinct sediment facies within Kusawa Lake. They propose that the first facies was deposited when the glacier was positioned in the middle of

Kusawa Lake, and another glacier had occupied the Primrose Valley. The second sediment facies was deposited over facies 1 as the lake level continued to decrease and was found to be discontinuous and thickest near Primrose River delta. However, this facies is not continuous.

The third facie is finely layered and found to lie conformably over facie 2 and extends to the modern sediment surface.

However, Gilbert & Desloges (2005) noticed that reflectors are stronger near the surface and the sediment is more focused towards the deeper parts of the lake. Given the acoustic records, they estimate that the total glaciolacustrine sediment thickness is greater than 100 m, with the majority of it related to immediate de-glaciation and glacial lake draining. This thick and fast process of sedimentation conforms to the thick and acoustically stratified sediment found in other large lakes in B.C. such as Okanagan and Lillooet Lakes (Eyles, 1990; Desloges

& Gilbert, 1994)

Repeated glacial advances and retreats have shaped the regional topography, and have a significant influence upon lacustrine sedimentation processes (Fig. 2.1). Unfortunately, due to the remoteness and limited accessibility of glaciated regions, archives of climate change within the Cordillera are hard to develop. Therefore, there has been an emphasis on interpretation of 12 small sites (ponds, bogs etc.) that hopefully provide a regional picture of hydrologic forcing.

Assessing late glacial and Holocene climate impacts on large watersheds have been more problematic, but such an approach has the potential to identify regional wide geomorphic effects of climate change. Kusawa Lake and the upper Takhini River drainage basin provide the opportunity to assess the utility of large lake records in reconstructing Holocene climate change.

In order to achieve this, the next section will discuss the Holocene climate record within northwestern Canada.

Fig. 2.3 Southwestern Yukon, showing names referred to in the text. Spot height elevations from Gilbert & Desloges (2005) Arrows

indicate large deltas built into Kusawa Lake

2.2 The Holocene climate record of northwestern Canada

Scientists use multi-proxies to reconstruct Pleistocene and Holocene paleoenvironmental conditions at a variety of resolution scales. Most common analyses include: isotopic δ018 derived from snow pack or sediment accumulation, dendrochronology (Alley et al., 1993;

Gedalof & Smith, 2001; Moore, G.W.K et al., 2002; Anderson et al., 2005), lithostratigraphic analyses, pollen records, and biochemical remains of past phototropic communities preserved in lake sediments (Pienitz et al., 2000; Menounos, 2006). However, due to response and lag-time of glacier movement and sudden shifts in atmospheric – oceanic processes, determining climatic conditions during the Holocene can be extremely complex. In northwest Canada, it is possible to recognize a series of minor Holocene glacial advances and retreats that characterize the impact of the Holocene climate change.

During the late Pleistocene and into the early Holocene (ca. 14 – 10.5 ka cal. BP), rapid shifts in the sea surface temperature and temperature gradients in the atmospheric circulation occurred over the northwest Pacific and Arctic Oceans. The Aleutian Low (AL); a semi- permanent low-pressure system located over the Gulf of Alaska, controlled northwest Pacific

Holocene climates (Moore, G.W.K et al., 2002; Anderson et al., 2005) and was a major factor in explaining glacial activity. Regional factors such as topography and proximity to the Pacific

Ocean led to the decay of the Cordilleran Ice Sheet (Jackson et al. 1991). By the end of the

McConnell glaciation, the Cordilleran Ice Sheet decayed rapidly via of down wasting and stagnation and exposed large areas of the continental shelf (MacDonald et al., 2000).

The Holocene (10.5 ka cal. BP – present) is associated with a series of climatic warming and cooling events that are known to affect lacustrine sedimentary records. Multi-proxy analysis of pro-glacial lakes within northwestern Canada showed periods of high temperatures and dry 15

conditions between 10.5 – 7.0 ka cal. BP (Johnson, 1992; Wiles et al., 2002; Anderson, 2005).

Higher rates of sedimentary accumulation and more variable inputs of sediment were recorded in many Cordilleran lakes (Barber & Finney, 2000; Hodder et al., 2006, Gilbert et al., 2006).

Clastic material inputs into several lakes across the interior of B.C. were also high and nutrient levels were poor (MacDonald et al., 2000). Within the Y.T, an analysis of fossil pigments, diatoms and lake stratigraphy on Lake U60 in the Pelly Mountains showed that primary productivity of chlorophytes and cyanobacteria were greatest following the retreat of the glaciers and the occurrence of fine sediment lamination was indicative of meromitic water conditions

(Pienitz et al., 2000). This coincides with a peak in Populus found in late glacial sediments across the Y.T. (Lacourse & Gajewski, 2000). All results obtained suggest that these dry conditions persisted until ~ 7.0 ka cal. BP.

The mid-Holocene (~ 7.0 – 2.0 ka cal. BP.) also known as the Neoglacial is characterized by a slightly cooler and wetter climate due to an increase in effective moisture content from the

Aleutian Low and an increased intensity of the Pacific air mass (Last, 2002; Spooner, 2002;

Mazzucchi et al., 2003). High levels of exotic western hemlock pollen were noticed in

Waterdevil Lake, northwestern B.C. Similarly, a profusion of white spruce, poplar and willow pollen were found in glacial lakes across southwest Yukon and the Mackenzie Mountains

(Lacourse & Gajewski, 2000). This suggests an increase in effective moisture, which encouraged growth and subsequently the distribution of pollen. In addition, this corresponds with sedimentation rates in Lake U60 of the Y.T., which varied by an order of magnitude reflecting an increased variability of sediment and organic matter input from the watershed due to a moister climate (Pienitz et al., 2000). Using isotopic δ 18 0 analyses of sediment cores excavated out of Jellybean Lake, Anderson et al. (2005) noted a significant increase in atmospheric circulation intensity from the southwest Pacific between 4.5 – 3.5 ka cal. BP. The 16

Aleutian Low is theorised to have been intense and is estimated to have been situated eastward over Alaska and the Y.T.. This eastward shift had a profound orographic influence upon precipitation and subsequent lake levels and increased rates of sedimentation (Moore, G.W.K et al., 2002).

During the onset of the Neoglacial warming phase (~ 3.5 – 2.0 ka cal. BP), the Aleutian

Low was signified as weak (Moore, G.W.K. et al., 2002; Anderson et al., 2005). The westward shift in the Beaufort Gyre allowed the counter-flowing Mackenzie Current to reposition, strengthen, and persist until present day (Dyke & Savelle, 2001; Wiles et al., 2002). Once again, this abrupt change in circulation patterns had an impact upon glaciolacustrine environments across northwestern Canada. The slightly warmer temperatures and distinctive varves were recorded in Lake C2 of northern Ellesmere Island between the years 3.3 – 3.1 ka cal. BP.

(Lamoureaux & Bradley, 1996). Last et al. (2002) recorded similar results in Oro Lake, B.C.

Likewise, Brahney et al., (2008) noted that distinct sequences of rhythmic sediment laminae in

Kluane Lake at around 2.8 ka cal. BP corresponds to sediment exhaustion from preceeding glacial advances in the St. Elias Mountains (Denton & Stuiver, 1966).

The end of the Neoglacial was marked by an intensification of the Aleutian Low and shifts in the North Pacific Index ~ 1.2 ka cal. B.P. (MacDonald et al., 2000; Anderson et al.,

2005) which brought about a warmer and moister climate. Subsequently, glaciers retreated

(Denton & Stuiver, 1996). This corresponds with the profusion of western hemlock ( Tsuga heterophylla ), which extended into the eastern ranges near Pyramid Lake ~1.5 ka cal. BP

(Mazzucchi et al., 2003). Likewise, a sudden high influx of Duke River sediment into Kluane

Lake ~ 1.3 ka cal. BP. also coincides with the presence of a warmer climate (Brahney et al.,

2008).

The ‘Little Ice Age’ (LIA) is a climatic cooling period, which is thought to have occurred between the 12 th and 13 th Centuries, and the early 18 th to mid 19 th Centuries throughout most of northern B.C and Y.T. Dendrochronology, lichenometry and radiocarbon dates show that at least three cooling periods occurred during the 18 th – 19 th C. (1650, 1700 and 1850 A.D), each separated by slightly warmer intervals (Luckman, 2000; Loso et al., 2006). The Aleutian Low moved eastward and intensified over northwest North America, which brought cooler temperatures during the spring and periods of increased precipitation throughout the summer

(Luckman, 2000; Wiles et al. 2002). The increase in effective moisture triggered episodes of synchronous glacier advances in the Coast and St. Elias Mountain Ranges ~1850 A.D. (Johnson,

1992; Lacourse & Gajewski, 2000; Anderson et al., 2005).

2.3 Pro-glacial fluvial hydrology and sediment transport

Lake sedimentation processes are closely related to the temporal and regional variation in hydrology and the topography of the drainage basin (Fig. 2.1) (Håkanson, 1983). In order to understand the relationships, this section will discuss, with relevant examples, the interaction between pro-glacial fluvial environments, which ultimately leads to the sedimentation of lakes.

Major sources of sediment into a fluvial and lacustrine environment of northwest Canada typicaly include glacier-derived sediment, rockfall / slide material and peri-glaical slumped from lateral valley sides. Studies conducted at Lillooet Lake, B.C. and the surrounding regions indicate that glacier derived debris alone can contribute up to 75 – 83% of the fine sediment load

(Desloges & Gilbert, 1994). However, not all sediment is deposited directly into the lake. In some cases, sediment traps within the upper reaches of the drainage basin (Smith, 1981), and alluvial fans (Parker et al., 1998; Lipowsky, 2006) act as storage sites. The trapping of sediment introduces a lag effect into the sediment cascade (Brierley et al., 2006; Hodder et al., 2007). In a 18

study of Small River Glacier basin in the Canadian Rockies Orwin & Smart (2004) discovered that at least 80% of the downstream sediment load is derived from the storage in the pro-glacial area and not from contemporary glacier bed erosion.

The mobilization of sediment from stored sediments within a pro-glacial environment is controlled by the hydrology during a given year (Marren, 2005). In addition, the pro-glacial area can function as both a source and a sink of sediment during a melt season or period within a melt season (Brierley et al., 2006). However, a transport-limited sediment system occurs when sediment size and sediment supply is greater than the energy available to move it. Within a sediment-rich pro-glacial system, each flood event of a given magnitude has approximately the same ability of mobilizing and thus transporting the same volume of sediment. If the system is supply-limited, then the sediment supply may become exhausted over time and hydrologic changes will not be recorded in the downstream and lake sedimentary records. Supply limitations may occur when the channel sediment recharge rate becomes lower than the rate of sediment mobilization in the channels (Knighton, 1998; Marren, 2005). Pleistocene glaciations have ensured a mostly transport-limited situation during the Holocene for many of the glacially covered terrains of the western Cordillera (Church & Ryder, 1972). A transport-limited situation offers better understanding of the magnitude-frequency relation in comparison to a supply- limited system. Temporal lags in the availability of sediment may mean that floods of similar magnitudes yield different amounts and sizes of sediment due to the exhaustion effect (Leopold et al., 1964; Knighton 1998; Trenhaile, 2004). A number of studies have shown the importance of pro-glacial sediment sources during the onset of a high magnitude-flooding event (Eyles,

1990; Warburton, 1990; Desloges & Gilbert, 1994).

2.4 Lacustrine processes

Sedimentation patterns are determined by seasonal and diurnal changes within the lacustrine environment. This section will discuss the theory behind water circulation, its control on the distribution of sediments, and in particular, the formation of turbidity currents (see box in

Fig. 2.1). This section will conclude by looking at the effects of turbidity currents upon lake bottom sediments.

2.4.1 Thermal stratification

Glacier-fed lakes of northwestern Canada are commonly diamictic (Crookshanks, 2008).

Water and sediment circulation patterns are dependent on the thermal structure of the water column and the Coriolis Effect (Hodder et al., 2007). This ultimately influences the characteristics and distribution of sediment throughout the lake (Drewry, 1986). The physical structure of lakes is governed by seasonal changes in temperature. In general, there is often a difference between the density of lake water near the bottom and the top of the water column.

The thermocline separates the warmer water above from the colder and denser water below

(density of water is greatest at ~ 4°C) during a warm season (Hodder et al., 2007). The Coriolis

Effect also has an important control upon internal waves. This occurs only when the Coriolis

Effect is balanced by the force of gravity. As a result, a standing wave rotates around the basin along the thermocline and contributes to significant mixing, which can then influence the distribution of energy and particulates within the water column (Smith & Ashley, 1985; Drewry,

1986; Hodder et al. 2007).

In a pro-glacial environment, direct heating and runoff from surrounding tributaries in the spring and early summer encourages lake water temperatures to rise and gradually become denser, which ensures some mixing. Pro-glacial lakes are commonly stratified by the early 20

summer. During the autumn, the fall in lake temperatures encourages lake turnover. There is also the potential for the entire lake to become isothermal at several intervals of the year. This occurs when the lake surface water cools to approximately 4 oC and the density of the lake water becomes highest at the surface allowing the upwelling of less dense colder water from the bottom. It is unclear if all large glacier-fed, high latitude, lakes are diamictic, but at least one major turnover event probably would occur (Drewry, 1986; Knighton, 1998; Hodder et al.,

2007).

2.4.2 Inflow behaviour

When a river enters a pro-glacial lake, three spatial patterns of inflow may be observed.

These are overflows (hypocycnal), interflows (homopycnal) or underflows (hyperpycnal). The difference between these types of flows is dependent on the hydrostatic pressure of the lake, the density difference between the lake and river water and changes in temperature gradients

(Middleton & Hampton, 1973; Leeder, 1982; Lowe, 1982; Edwards, 1992; Knighton, 1998).

Overflow occurs when inflow density is less than the density of the lake epilimnion.

Wind stress also influences the surface current flow velocity and in some cases, the Coriolis force deflects the dispersal of sediment towards the right (Smith & Ashley, 1985; Drewry, 1986).

Overflows are normally observed during times of low sediment input when thermal properties control the density difference between the two water masses (Smith & Ashley, 1985). In glacial lakes with low rates of fine-sediment input, the process of interflow may occur where the density of inflowing river water is equal to the density of unstratified lake water. In the case of thermally stratified pro-glacial lakes with high sediment input, interflow at the thermocline may alternate with underflow on a seasonal basis. The concentration of suspended silts and clays in overflows and interflows are typically low (5 – 30 gm/l). Consequently, sediment deposition via 21

settling from the water column, accumulations on the lake bed are thin, regular, have sharp contacts and display no current structures (Gilbert, 1975; Smith & Ashley, 1985; Middleton,

1993).

Underflows are widely recognised as the principal mechanism of sediment distribution in pro-glacial lakes. There are two types of underflows which are typical of glacier-fed lakes and these are disintegrated by differences in density and velocity. The first type is quasi-continuous flows, where bottom currents form when high-density river water “underflows” the hypolimnion of the lake (Lowe, 1982; Smith & Ashley, 1983). Sediment deposits are a mixture of fine sands and silts (i.e.: little upward fining) because sediment delivery persists over a long period of time with intermittent pulses. The second type of underflow is from a more catastrophic source such as slumps from mass movement processes that generate surge-type currents (Middleton &

Hampton, 1976; Edwards, 1992). Sediment deposits display upward thinning and fining due to the short-lived nature of sediment input. They become more ‘local’ in their effects. Since high inflow densities are often caused by high-suspended sediment concentrations, both types of underflows are a type of turbidity current (Smith & Ashley, 1983; Middleton, 1993; Serink,

2004).

2.4.3 Turbidity current dynamics

Turbidity currents are particle-laden underflows, which travel along the lake or ocean bed. Because turbidity currents involve the transport of water and sediment, they can be classified as both fluid and sediment gravity flows. In a fluid context, turbidity currents are classified as stratified gravity currents (or density currents). Flow takes place below, above or between ambient fluids because of a difference in hydrostatic pressure-force between the two.

The difference in hydrostatic pressure-force may be due to differences in sediment composition, 22

temperature or salinity (Allen, 1970; Middleton, 1993; Kneller & Buckee, 2000). In a sedimentary context, turbidity currents are classified as a type of sediment gravity flow where grain suspension is mainly supported by the upward component of fluid turbulence due to water circulation in the sediment water mixture. Sediment gravity flows can be distinguished from other types of flow i.e.: debris flows where sediment is dispersed by other mechanisms

(Middleton, 1993).

The vertical concentration structure of the turbidity current is a critical factor in understanding flow and sediment dynamics (Allen, 1971). Depending on the height at which maximum velocity is achieved, the turbidity current can be divided into the inner and outer regions. Both regions have separate flow processes: within the inner region, turbulence is created by bed friction, whereas in the outer region turbulence is created by friction due to the entrainment of ambient fluid (Fig. 2.4). The height of the velocity maximum is a function of the ratio of the drag forces at the upper and lower boundaries (Middleton, 1976; Allen, 1971) and in many experimental studies, this height is typically 0.2 – 0.3 ratio of the current depth (Edwards,

1992; Middleton, 1993; Kneller & Buckee, 2000).

Fig. 2.4 Schematic subdivision of a turbidity current flow pattern and structure of the turbidity current head where y is the height from the lake bed and u is the velocity (modified from: Middleton, 1993; Kneller & Buckee, 2000)

In terms of a latitudinal concentration structure of a turbidity current, turbidity currents are found to have three distinct parts: the head, the body and the tail. The head of a density surge is lobate in form and possesses a characteristic ~ 10% overhang (Fig. 2.4) (Allen, 1970;

Middleton, 1993). Unlike the body and the tail, the head is denser and has a higher concentration of coarse material (Bouma, 1964; Middleton & Hampton, 1976). In order for the head to advance, it must have more gravitational potential energy to displace the ambient fluid which produces resistance to the flow (Middleton, 1993). Large eddies within the head are usually found to have velocities that exceed 50% of the maximum mean downstream velocity (Kneller &

Buckee, 2000). Due to the friction experienced at the base of the current, the head is a region in which erosion takes place (Middleton, 1993).

Flow within the body region of the current is found to be uniform in thickness and less dense in terms of sediment concentration. In order to achieve a constant rate of flow, the average velocity in the body must be greater than that of the head. However, this is dependent on the rate 24

of loss of fluid from the head and slope of the bed (Leeder, 1982; Edwards, 1992; Middleton,

1993). In a study carried out in a flume setting, Kneller & Buckee (2000) note that high magnitude inflow velocity maybe up to 40% higher than the maximum mean velocity in the body. This maximum inflow velocity may therefore be equivalent to the velocities in the current head. With increased Reynolds stress (Re>2500) there is the potential for sediment entrainment within the body and subsequently bed erosion.

A gradual thinning of flow depth and sediment concentration is found at the tail of the current (Bouma, 1962; Allen, 1970). The mixing of the current and the water above produces an entrained layer.

Sediment sorting in turbidity currents is highly dependent on clastic properties such as size and weight (Edwards, 1992). The sediment particle entrained within a turbidity current must overcome the gravity component and have the energy to overcome the flow of the fluid drag

(friction) exerted at the bed boundary of the lake. Turbidity currents can travel over long periods

(days) and over a great distance (10's of kilometres) until energy (velocity) is lost (Edwards,

1992; Hånkanson, 1983). The deposition of sediment commences with the coarsest material, typically from the head of the turbidity current, with finer particulates deposited above the initial deposit or further up lake, as the body and tail of the turbidity current passes (Lowe, 1982;

Edwards, 1992; Middleton, 1993).

2.4.4 The effect of turbidity currents upon lake bottoms

In general, the concentration of suspended sediment in the water column of glacier-fed lakes is, on average, much greater than in freshwater or marine environments. The inflow of sediment is largely inorganic with low concentrations of dissolved sediment loads (Gilbert, 1975;

Smith & Ashley, 1983). As discussed in section 2.4.3, any abrupt changes in lake temperature 25

variations and / or inflowing water have the ability to create turbidity currents and induce sedimentation (Serink, 2004; Edwards, 1992).

The effects of turbidity currents in a glaciolacustrine environment can be identified in a number of pro-glacial lakes. When a river reaches peak discharge, turbidity currents entering the lake can create trenches at the bottom. In a study carried out by Lamoureux et al. (2002) on Bear

Lake in Devon Island, large vortex-like underflows eroded and created trenches in the deep basin as seen today. Underflows deposited rhythmic sediments and these were dominant in the proximal reaches. Interflows, associated with a decrease in energy and settling from suspension, were found to be the main sedimentation processes in the more shallow and distal locations of the lake. Turbidity processes were recorded in Atlin Lake, B.C. by Gilbert et al. (2006). They noted that sediment ponding along the thalweg of a lake may be due to turbidity currents following the deepest part of the lake. However, the greater depths of Atlin lake resulted in more isolation from the vigorously circulating interflows which created an evenly distributed and quieter form of deposition. In terms of sedimentary deposition, Desloges & Gilbert (1994) noticed that sediments found in the large basin of Lillooet Lake, B.C. were unconformable, which indicated that the turbidity currents originating off the delta had travelled as underflows and as a result, eroded and flattened the underlying surface. Areas where sediments were found to be more conformable, suggested lower energy conditions and the deposition of sediments was through the process of settling from suspension.

2.5 Varves

One of the first analyses of varve chronologies was by de Geer in 1912. de Geer (1912) suggested that annually laminated lacustrine sediment deposits from deep-water lakes have the ability to provide us with detailed and continuous chronological data about the rate of sediment production from a contributing drainage basin (Ohlendorf, 1997; Dirszowsky et al., 2002).

Regional studies of varve thicknesses carried out within Cordilleran lakes by Desloges et al.

(1994, 1998, 2002), Lamoureux et al. (1996), Slaymaker (2003), Dirszowsky et al. (1997, 2004), and Menounos (2004, 2006) have all demonstrated that the composition and deposition of lake sediments in glacial environments are closely related to climatic changes within that region.

Studies have also demonstrated varve formations can be used to infer seasonal or sub-annual climatic changes leading back to the late Holocene (Last, 2002; Hodder et al., 2006). Varve analysis is therefore a potentially important parameter for measuring environmental change in a drainage basin (Desloges et al., 2002; Menounos, 2006).

2.5.1 Varve formation

The formation of varved structures depends greatly on the type and characteristics of the lake such as its tropic state, its morphology, and the physical setting of the lake (Serink, 2004).

Under regular circumstances, a single varve will consist of two distinctive layers forming a couplet. The first is a thick and light coloured layer of silt and sand rich laminae, which forms in the summer through inflow pulses associated with, melt water during the nivial or subsequent rain events. Turbidity currents may deliver part of these higher energy laminae. A thin dark - coloured layer of silty-clay forms during the autumn and winter periods. This reflects the decrease in the sediment supply and quieter water conditions under a frozen lake surface. Low water temperatures delay the settling of clay particles, resulting in the formation of clastic varves 27

which are thinly laminated (Desloges & Gilbert, 1994; Lamoreux, 1996; Slaymaker et al., 2003).

Below average thickness in a varve sequence may be indicative of cooling and / or limited sediment supplies. Extreme flood events from high temperature induced snow and ice melt and high rates of precipitation are noticeable factors that contribute to the formation of thick and above average varves.

Desloges & Gilbert (1994) noted that smaller runoff events, which follow larger flows, might reflect a hysteresis in the supply of sediment. As the melt season progresses, sediment exhaustion leads to thinner, less frequent and finer grained laminations. The thickening of a varve indicates a period of increased sediment delivery rates. Extreme events in particular lead to a reduction in storage and consequently an increase in sediment supply. It is thought that availability and sediment transport capacity would both be at their highest just as glacier retreat begins (Desloges & Gilbert, 1994; Dirszowsky, 2004).

2.5.2 Varves as inferences of past climates

Although numerous studies have demonstrated statistically significant relationships between hydro-climatic records and varve thicknesses, Hodder et al. (2007) question the universal accuracy of this proxy analysis and refer to many “marginal correlations” between varve thicknesses and climate. Using a previously studied glacier-fed lake in the Cordillera of

British Columbia, Hodder et al. (2006), found that, despite the overall physical connection between varve correlations thicknesses and seasonal temperatures and discharge (Fig. 2.1), there is no significant information regarding the processes by which temperature anomalies translate into thicker varves. The “marginal” correlations found at Mud Lake, B.C. demonstrate an incomplete understanding of drainage basin sediment cascades. Hodder et al. (2007) conclude

that each varve is not a unique situation as numerous non-linear relationships and feedbacks exist among processes. These situations are either unknown or stochastic.

III – Study Area

3. 1 Physiography of the Yukon Territory

The Yukon Territory is within the Canadian Cordilleran region and topography ranges from rolling uplands in the interior to the rugged Coast and St. Elias Mountains (Hughes, 1987).

The Dezadeash region of the southwestern Yukon Territory encompasses three distinct physiographic subdivisions of the Cordilleran region. The Boundary Ranges of the Coast

Mountains occupy the southeast region; the St. Elias Mountains cover the southwest area; and the southeast part of the Kluane Plateau, which is part of the greater Yukon Plateau (Fig. 3.1)

(Kerr, 1934; Kindle, 1953). The Shakwak Trench is a structural trench created by the Denali fault line. The Shakwak Trench extends northwest along the eastern side of the St. Elias

Mountain ranges through to the Kluane Lake drainage basin (Gilbert, 2004) and separates the

Kluane Plateau from the St. Elias Mountains. The St. Elias Mountains are predominantly comprised of the Ice Field Ranges, which lie west of the Alsek River, and the Alsek Ranges, which forms the front of the St. Elias Mountains. The Duke Depression, which occupies the southwest corner of the Dezadeash Range, trends northwestwardly and separates the Kluane

Ranges from the St. Elias Mountains (Fig. 3.1) (Kerr, 1934; Kindle, 1953).

The Takhini River is a tributary of the Yukon River west of Whitehorse. It drains northwest from the Coast Mountains and the Yukon Plateau (Hamilton, 1995). The upper

Takhini River drainage basin straddles the border between the Boundary Range Mountains of southern Yukon and northern British Columbia, with a very small segment in southeast Alaska

(Fig. 3.1, 3.2). The upper Takhini River basin outlet that flows into Kusawa Lake is 60 km east of Haines Junction and 37 km east of the Dezadeash Range. Kusawa Lake (60° 19' 55” N, 136°

4' 48” W), which means “long, narrow lake” in the Tlingit language, is 65 km southwest of

Whitehorse. Kusawa Lake occupies the central – southern portions of the structural Shakwak

Trench east of the Boundary Ranges within the upper Takhini River basin. Mountains around

Kusawa Lake are as high as 2000 m a.s.l. (Fig 3.1) (Kindle 1953, Gilbert, 2004).

Fig. 3.1 Southwestern Yukon showing names referred to in the text. Spot height elevations determined by Gilbert & Desloges (2005). Arrows = major drainage networks into the Upper Takhini River drainage basin 32

Fig. 3.2 The upper Takhini drainage basin of Kusawa Lake (dark blue bold line) and the sub-basin divides (dark blue dashed line). Glaciated regions are shaded in grey. Contour intervals at 1000 m.

3.2 Upper Takhini River drainage basin morphology

Kusawa Lake is 70 km in length and has a total area of 142 km 2. The total drainage of the upper Takhini River basin above Kusawa Lake is 4292 km 2. The basin area to lake area ratio is a modest 30.2, according to the index established by Gilbert (2004). Lake water flows from the south to the north. There are three major sub-drainage basins of the upper Takhini River basin: the Primrose River, Kusawa River, and the upper-most Takhini River, which account for

62.50 % of the total upper Takhini River basin (Gilbert, 2004). Two smaller sub-basins: Jo-Jo

Creek and Devilhole Creek, along with small tributaries found on the west side of the lake, account for the 37.5 % of the entire basin. In proximity to the outlet of Kusawa Lake, is an active alluvial fan complex known as the Kusawa Campground alluvial fan.

3.2.1 Primrose River sub-basin

The Primrose River sub-basin covers an area of 1466 km 2, or 34 % of the upper Takhini

River basin. 3.0 % is glacier covered (Table 3.1) and it has significant sediment traps between the glaciers and outlet. Within the Primrose River basin is Primrose Lake (23 km long, 0.7 km wide) and Rose Lake (8 km long, 1 km wide). In addition, within the upper valleys of the

Primrose River basin, an 8 km long sandur named Silt Lake can be found (Gilbert, 2004). Given the presence of sediment traps, and in comparison to the Kusawa and upper-most Takhini River basins, it was assumed that the Primrose contributes less sediment to Kusawa Lake due to its diminutive glacial cover (Table 3.1). Near the Primrose River outlet are a number of minor debris aprons off the valley walls. The Primrose River fan-delta is approximately 0.8 km 2, is terraced and pro-grades into Kusawa Lake creating lake narrows with the opposite shoreline

(Fig. 3.2)

3.2.2 Upper-most Takhini River sub-basin

The upper-most Takhini River sub-basin covers an area of 545 km 2 (12.7 % of the entire basin) and is the smallest of the three major sub-basins (Gilbert 2004). However, it has the greatest proportion of glacial cover of 13.9 % (Table 3.1). In proximity to the mouth of the upper-most Takhini basin is Takhini Lake (9 km long and 0.6 km wide at 800 m a.s.l.). Takhini

Lake probably acts as a significant sediment trap. A very small delta of approximately 0.4 km 2 is found at the mouth of the upper-most Takhini River as it flows into Kusawa Lake (Fig. 3.2).

3.2.3 Kusawa River sub-basin

The Kusawa River sub-basin covers an area of 677 km2 (15.8% of the upper Takhini basin). Glaciers cover an area of 75 km 2 (or 11.2%) of the sub-which is 1.8 % of the entire

Upper Takhini River basin. Unlike the Primrose and the upper-most Takhini River sub-basins, the Kusawa River basin does not appear to have significant sediment traps. However, there is a large (13 km 2) unnamed lake in the headwaters of the Kusawa River. This region of the lake denotes rising valley sides, which are narrow (Gilbert, 2004). The Kusawa River delta is confined to the steep valley sides and is 6 km long. The nature of the delta is braided and the presence of eyots suggests that the Kusawa River acts as a primary sediment source into Kusawa

Lake (Fig. 3.2).

3.2.4 Jo-Jo Creek sub-basin

Jo-Jo Creek sub-basin is the most distal sub-basin and covers an area of 330 km 2 (7.7 % of the entire basin). Jo-Jo Creek sub-basin has no glacial cover. Jo-Jo Lake found at 953 m a.s.l. probably forms a significant sediment trap. The overall length of Jo-Jo Lake is ~12 km but its average width is 1.6 km as it occupies a narrow, steep-walled valley. A massive kame moraine, 35

~ 70 m high found 3.5 km north of the lake, and stratified gravel, sand and silt deposits found south of the lake, suggest that Jo-Jo Lake was once dammed (Fig. 3.2).

3.2.5 Devilhole Creek sub-basin

The Devilhole Creek sub-basin is situated west of Kusawa Lake and covers an area of

244.5 km 2 (5.7% of the entire basin). Like the Kusawa River sub-basin, the region denotes steep valley sides. Glaciers occupy 5 km 2 (Table 3.1) of the headwaters and a number of moraines can be found (Fig. 3.2).

3.2.6 Kusawa Campground alluvial fan-delta complex

The total catchment the alluvial fan-delta complex occupies an area of 32 km 2 (Lipovsky,

2006), or 0.0075 % of the entire Upper Takhini River basin. The fan and delta features act as the primary sediment source into Kusawa Lake (Fig. 3.2).

Recent field studies conducted by Lowery (2002), Yukon Parks and the Yukon Geological

Survey, showed that sediment in the upper valleys and on exposed land at the northern end of the lake is comprised of a complex of kames, kame terraces and kettles. Sedimentary debris deposited in the valley floor of the Kusawa floodplain consists of gravelly muddy sand: 20% gravel, 55 % sand, 19 % silt and 6 % clay (Lowey, 2002). The composition of the terrain around

Kusawa Lake varies with changing elevation. Slopes at high elevation display steep rock outcrops, occasionally covered by thin moraine or colluvial deposits. Moraine deposits, with permafrost present in local areas, cover slopes at mid-elevation. At lower elevations and on valley floors it is comprised of glaciofluvial sand and gravel. Colluvial deposits found in higher elevations consist mainly of cobbley and bouldery diamicton (a finer grained matrix with permafrost common at shallow depths), which is susceptible to creep, solifluction, gullying and 36 active layer detachment flows. The till normally found at mid-elevations is also composed of diamicton, yet with a higher amount of sand, silt and clast content (Lowey, 2002; GeoProcess

NTS 115A, 2002).

3.3 Bedrock and surficial geology

The bedrock geology of Kusawa Valley consists primarily of crystalline rocks of the

Coast Plutonic Complex, essentially comprised of 100 – 55 million year old (M.Y.) granodiorite and granite intrusions. The Yukon – Tanana Terrane includes pre – 570 M.Y quartz mica schist, gneiss, slate, quartzite, limestone, and greenstone. The occurrence of mineral deposits within these rock types include platinum group elements, copper, gold, silver, lead and zinc most commonly found along the region near the Denali Fault line and towards the east of Kusawa

Lake (GeoProcess NTS 115A, 2002).

Glacial, glaciofluvial, colluvial, and fluvial processes have contributed to the formation of the rugged topography found in the Kusawa Valley. Kames, kame terraces, and kettles are located north of the Kusawa Lake outlet. Steep rock outcrops are dominant at high elevations above 1500 m a.s.l. Thin ground moraine or colluvial deposits which are comprised of cobbly, boulder diamicton may also be found throughout the basin. Slopes are susceptible to creep and solifluction from permafrost effects. Gullying, and under extreme circumstances, avalanches and rockslides may occur. Streamlined or crested moraine deposits of sand and gravel cover the mid elevation slopes (1000 – 1500 m a.s.l.) in the region of active glacier cover. Permafrost may also be present at these elevations and is extremely susceptible to creep and thermokarst (Gilbert,

2004). Glaciofluvial silts, sands, and gravel deposits are abundant at the lower elevations (680 –

1000 m a.s.l.) and throughout the valley floors. The relative coarseness of these sedimentary

37 deposits allows for stable well-drained surfaces. Glaciolacustrine deposits of fine sand, silts, and clays are dominant at lake level (GeoProcess NTS115A 2002; Lowey 2002).

3.4 Glacial cover

The distribution of glacial cover within the upper Takhini River drainage basin has been heavily influenced by coastal – atmospheric interactions. The total glacier area in 2005 is ~ 200 km 2, which accounts for 4.7 % of the total basin area (Table 3.1). The majority of the glaciers are small, with the largest being 8 km in length. The southern region is influenced by cool maritime climate conditions, which has a profound influence upon winter accumulation and summer ablation. As a result, it is assumed that the glaciers are relatively active (Gilbert, 2004).

Sub-basin / Location Glacial Cover % of % of Upper Takhini area (km 2) sub-basin River Drainage Basin Primrose River 44 3.0 1.0 Upper-most Takhini River 76 13.9 1.8 Kusawa River 75 11.2 1.8 Devilhole Creek Headwaters 5 0.07 0.1 TOTAL 200 - 4.7

Table 3.1 Glacial cover distribution within the Kusawa Drainage Basin (Gilbert, 2004)

3.5 Hydrology

Hydrometric stations associated with the Takhini River watershed are situated at the

Kusawa Lake outlet (09AC004) and along the lower Takhini River, 40 km downstream of the outlet near Whitehorse (09AC004) (Fig. 3.3). The Kusawa Lake outlet station was commissioned in 1952 and recorded discharge between 1955 – 1986. Since then, it has ceased operation. The downstream gauge, known as Highway Bridge, was installed in 1948 and is still in operation (Table 3.2) (WSC Hydat 2008).

Rivers north of the 60 th parallel typically exhibit a nival hydrologic regime: high flows in the spring and summer, which are associated with glacial and nival-melt and rainstorms respectively, and low flows throughout the winter. Throughout the year, the mean annual

o o discharge (Qm) of the lower Takhini River at Highway Bridge (60 51’ 0” N, 135 43’ 47.9” W)

3 is on average 10 m /s greater than the Qm at the Kusawa Lake outlet (Table 3.2, Fig. 3.3, 3.4 &

3.5) as it drains additional sub-basins: Ibex River, Mendenhall River and Arkell Creek. During the winter, discharge is limited to baseflow at the Kusawa Lake outlet due to ice formation.

Moore, R.D et al. (2002) studied winter streamflow variability at both sites and discovered that under extreme winter conditions (i.e.:1965 and 1994) ice can plug the lower Takhini channel for

2 months and discharge levels do not return to a pre-freeze stage until March. Late spring melt in mid-April caused minor increases in both stage and discharge. However, the marked rise in discharge during late April - May corresponded with a sudden decline in stage. The authors believe that this occurrence was consequence of ice break-up and the associated decrease in frictional flow resistance. The rise in discharge levels was a result of channel storage release caused by backwater effect of ice cover. Throughout May – August, snow and ice melt and storm water feed into Kusawa Lake. Up to 220 m3/s of water can be discharged at the lake outlet

(Moore, R.D et al., 2002b). 39

Takhini River Site coordinates (DMS) Station Drainage Qm Number Area (km 2) (m 3/s) Highway Bridge 60 o 51’ 0” N, 135 o 43’ 47.9” W 09AC001 6990 61.9 Kusawa Lake outlet 60 o 36’ 35.9” N, 136 o 7’ 12.1” W 09AC004 4292 51.7

Table 3.2 Lower Takhini River discharge stations. Mean annual discharges (m 3/s) are based on 1955 – 2005 averages (WSC Hydat 2008)

Fig. 3.3 Mean annual discharge of the lower Takhini River 1950 – 2007 (App. 3A) (WCS 2008)

Peaks in mean annual discharge (Q m) of the lower Takhini River are cyclic in nature. At

3 Highway Bridge, Qm peaks greater than 70 m /s occur approximately every 6.1 years and have a

16.4% chance of doing so in any given year. This is typically followed by a significant decrease

3 to < 60 m /s in Q m within the next year. Qm values at the Kusawa Lake outlet resemble those at

3 Highway Bridge although values are ~ 10 m /s lower. Qm values above the overall mean of 51.8 m3/s at the Kusawa Lake outlet have a 57.7 % recurrence probability (Fig. 3.3).

Fig. 3.4 Annual hydrograph (mean daily discharge) for the lower Takhini River at the outlet of Kusawa Lake

(09AC004) for 1986 (WSC 2008). 1986 data are shown in red. The maximum and minimum values for the entire record are shown in green and blue respectively.

Fig. 3.5 Annual hydrograph for the lower Takhini River at Highway Bridge (09AC001) 1986 (WSC2008).

1986 data are shown in red. The maximum and minimum values for the entire record are shown in green and blue respectively.

3.6 Climate

The Dezadeash region has a sub-arctic climate. Average temperatures rise above 10 oC for approximately three months of the summer (Table 3.3). The warm air mass from the Pacific moderates temperatures within the region. As Kusawa lies within the regions of the Boundary

Range Mountains, temperature and precipitation received is considerably lower due to the orographic effects from the Coastal and St. Elias mountain ranges (Lowey, 2002).

Temperatures in January can range between -22 oC to -13.3 oC with an average of -17 oC. In July, the average temperature is 14 oC although temperatures may dip to 7 oC and peak to 20.5 oC

(Environment Canada, 2008).

The total annual precipitation is low and averages 267 mm. Most precipitation occurs in the winter rather than in the summer. The average depth of winter snow is 22 cm. The months of July and August are considered some of the wettest months with an average rainfall of 26 mm 42

(Table 33, Fig. 3.6, 3.7 & 3.8) (Pienitz, 1997; Environment Canada, 2008). Lakes in the southern part of Yukon have protracted periods of ice cover. This usually extends from

November to May, with the mean number of days between the clearing of ice and initial ice formation being around 150 days in the Whitehorse area (Pienitz et al., 1997).

Average Average Average Total Total Total Average Rainfall Snowfall Precipitation Month Temp ( oC) (mm) (cm) (mm) Jan -17.7 0.2 23.7 16.7 Feb -13.7 0.1 16.8 11.4 March -6.6 0 14.9 10.4 April 0.9 1.3 8 7.0 May 6.9 13 2.4 15.2 June 11.8 29.7 0.5 30.3 July 14.1 41.4 0 41.4 Aug 12.5 38.5 1 39.4 Sept 7.1 29.3 5.1 34.1 Oct 0.6 8.8 18.9 23.8 Nov -9.4 0.7 27.3 19.2 Dec -14.9 0.3 26.4 18.5 Year -0.7 163.1 145 267.4

Table 3.3 Climatic characteristics for Whitehorse based on 1971 – 2001 averages

Lat / Long: 60° 43' N, 135° 4' W. Elevation: 706.2 m. Climate ID: 2101300. WMO ID: 71964

(Environment Canada 2008).

Fig. 3.6 Temperature precipitation graph of Whitehorse based on 1971 – 2000 averages.

(Environment Canada 2008).

Fig. 3.7 Monthly rainfall normals for the Takhini River Ranch 1971 – 2000 averages

(Environment Canada 2008).

Fig. 3.8 Monthly snowfall normals for the Takhini River Ranch 1971 – 2000 averages

(Environment Canada 2008).

3.7 Vegetation

The outlet of Kusawa Lake is at 750 m a.s.l. Due to the influence of both coastal and arctic air masses, conifers and some mixed forest trees are dominant up to 1300 m a.s.l. In the very compressed sub-alpine zone, white spruce and fir are present although white spruce is the dominant tree species in the valleys. An under-story of feather-moss in the forested areas is also common along the valley floor. Balsam poplar may also be found on the margins of the lake.

Above tree line (~ 1200m a.s.l) herbs, dwarf shrubs, shrub birch, willow, moss, and lichen dominate the alpine tundra terrain (GeoProcess NTS 115A, 2002).

IV – Methods

4.1 Field methods

4.1.1 Acoustic profiling

During the summer of 2004, all of Kusawa Lake was surveyed using a Datasonics Dual –

Frequency CHIRP II sub-bottom acoustic profiler. Sixty-eight oblique cross – lake transects from the northern (outlet – Takhini River outlet from Kusawa Lake) to the southern reaches of the lake (inlet of Kusawa River) were completed covering 125 km worth of line work. The profiler can penetrate up to 100 m of thick silt and clay muds and produce sub-bottom imagery with a maximum resolution of 0.5 m. Data derived from the acoustic records allowed for the mapping of lake bathymetry and sediment depths (Gilbert & Desloges 2005).

4.1.2 Sediment cores

Nine cores in the northern region of the lake and two cores in the central and southern regions were extracted from the lake using a Rossfelder submersible vibra corer (Table 4.1).

Core tubes were 6 m in length, 0.75 cm in diameter and were made of aluminium. A core catcher was riveted into the bottom of the tube and the top was inserted into the vibra corer head.

Cores were extracted at mid-points in the lake to avoid local slope effects. The lengths of cores obtained ranged from 0.8 to 5.5 m and were cut into smaller sections for shipment.

4.1.3 Conductivity Turbidity and Density Profiles

CTD profiles of Kusawa Lake were measured using a Hydrolab DataSonde 4a. Sixteen sites at approximately 1.5 to 1.6 km intervals from the source to the outlet of the Lake were surveyed during the summer of 2004 measuring primarily temperature, turbidity and conductivity with depth. Identifying where water columns become unstable is an integral part of 46 understanding how Kusawa Lake mixes vertically (James, 2004). Regions of mixing can be easily identified from density profiles where density inversions occur. How this changes throughout the long profile of the lake will also determine sediment distribution as abrupt changes in lake temperature variations and / or inflowing water have the ability to create turbidity currents and induce sedimentation (Serink, 2004).

4.1.4 Geographic Information Systems

A GARMIN Geographic Positioning System (GPS) recorded acoustic track lines, coring locations and CTD measurement locations. The metadata was transferred onto the Earth Science

Research Institute’s (ESRI) ArcGIS and visually displayed using ArcMap. The ArcMap file contains recorded data indicating the water depth, length of core, maximum thickness of sediment from the sub-bottom acoustic records and surface water temperature of each coring location (Fig. 4.1; Table 4.1)

Fig. 4.1 Kusawa Lake vibra core sample locations

Vibra Site Coordinates Lake Depth Surface Vibra core core # (D.M.S) (m) Water Temp length (m) (oC) 318 60 o 20’ 15.216” N, 136 o 4’ 39.755” W 30 .0 11.1 2.14 319 60 o 19’ 10.847” N, 136 o 4’ 55.559” W 28.4 11.6 3.34 322 60 o 15’ 35.423” N, 136 o 6’ 29.627” W 47 .0 13.8 1.10 324 60 o 10’ 11.639” N, 136 o 10’ 5412” W 135 .0 11.6 2.78 325 60 o 18’ 21234” N, 136 o 4’ 22.583” W 24.7 12.1 2.87 326 60 o 18’ 32.327” N, 136 o 4’ 42.239” W 30.2 13.3 2.96 327 60 o 19’ 17.759” N, 136 o 4’ 32.663” W 29.6 13.4 2.70 328 60 o 19’ 52.860” N, 136 o 4’ 48.071” W 32.4 11.0 1.70 32 9 60 o 21’ 18.971” N, 136 o 4’ 42.780” W 32.2 10.8 5.48 330 60 o 20’ 54.239” N, 136 o 4’ 35.940” W 34.7 10.8 0.80 331 60 o 21’ 4.7874” N. 136 o 4’ 45.551” W 33.5 10.9 2.90

Table 4.1 Site characteristics and core sample lengths taken in July 5 – 8th 2006.

4.2 Laboratory methods

4.2.1 Sediment core properties

In the laboratory, core sections were stood upright to separate interstitial water. Any surfacing water was removed with the use of a pipette. The cores were split longitudinally by incising the aluminium tube and passing a steel wire through to separate the mud. The lengths of the sediment in the cores were measured and recorded. One-half of the core was wrapped in saran wrap and aluminium foil and stored in the cooler at 4 oC for archival purposes.

The different stages of drying (which were primarily controlled by temperature and moisture content) were logged through digital photography. The process of drying allowed the rhythmic laminations to become clearly visible (Lamoreaux, 1996). Photographs of the cores in a semi- dried state were developed and manually cross-referenced with other cores. The physical characteristic of each core (i.e.: grain size, volcanic ash layers, organics, colour etc.) were logged manually. This was graphically displayed on Corel Draw 12 as a schematic core section for visual interpretation. 49

Couplets of silt overlain by clay were analysed extensively through the measurement of thickness. Counts were conducted from high – quality photographic close-ups. Where the sections of the core showed couplets less than 2 mm in thickness, the use of a high precision microscope with x40 the magnification (the Increment Measurer System) was calibrated to conduct couplet counts. Thickness and couplet counting were carried out as consistently as possible but the possibility of error arises from the possible presence of sub-annual (sub-event) layers.

4.2.2 Loss on Ignition

The Loss on Ignition (LOI) method was used to determine the percentage of organic matter and carbonate content (Dean, 1974; Heiri, et al., 2001). LOI was carried out with approximately 2 g of sediment sample taken from all different sedimentary units within the cores. Samples were oven dried at 105 oC for 24 hours to exonerate excess moisture and reweighed. The first reaction occurs when the organic matter is oxidized after burning at a temperature of 550 oC to carbon dioxide and ash for one hour. Following a cooling period the samples were then reweighed to determine the percentage loss:

OM = LOI 550 {[MS 105 – MS 550 ] /MS 105 }*100

Where:

OM = Organic Matter %

C = Carbonate %

o LOI 550 = Loss on Ignition at 550 C

o MS 105 = Mass of Dried Sample at 105 C

o MS 550 = Mass of Dried Sample after LOI at 550 C

Given the bedrock geology, no major sources of carbonate content were expected.

However, the LOI procedure on determining the carbonate content was followed anyway to test error on the OM content.

The second reaction occurred when samples were burned at a temperature of 1100 oC and here, the carbonate was lost leaving oxide residuals. The sample was reweighed and the percentage loss from the initial sample weight was calculated:

C = LOI 1100 {[MS 550 – MS 1100 ] / MS 550 }*100

Where:

OM = Organic Matter %

C = Carbonate %

o LOI 550 = Loss on Ignition at 550 C

o LOI 1100 = Loss on Ignition at 1100 C

o MS 105 = Mass of Dried Sample at 105 C

o MS 550 = Mass of Dried Sample after LOI at 550 C

o MS 1100 = Mass of Dried Sample after LOI at 1100 C

(Dean, 1974; Håkanson 1995; Heiri et al. 1999)

Results obtained from the LOI procedure were used as a proxy for the clastic content of lake sediments. In lakes draining glacial environments, changes in LOI appear to reflect the changes in the fraction of clastic sedimentation (Menounos et al. 2004) where sediment sequestration occurs. Periods of high OM content may reflect possible periods of high deposition from a flooding and / or outwash event or changes in lake primary productivity levels

(Håkanson 1995; Heiri et al. 1999; Lacourse & Gajewski, 2000).

4.2.3 Laser particle analysis

Evaluating the sediment particle size is an important textural parameter of glaciolacustrine sedimentology as it supplies information on the conditions of transport, sorting, and deposition of the sediment. In addition, it provides some information on the history of events such as floods that occurred at the depositional site (Lowey 2002; Schnurrenberger et al.,

2003). Determining the percentage of clay and silt allows for possible inferences of inputs from glaciolacustrine deposits in the Kusawa Lake drainage basin.

Laser Particle Size (LPS) Analysis was conducted using two different instruments from two different laboratories: The Coutler Counter from the Department of Geography, Queen’s

University and the Malvern Laser Sizer from the Department of Chemical Engineering,

University of Toronto. The Coulter Counter was used for cores KUS318, 330, 331, and 329.

The Malvern Laser Sizer was used for cores KUS319, 322, 324, 325, 326, 327 and 332.

Sedimentary units within the core section, which displayed distinctive thick silt and clay deposits, thick sand events or a distinctive amalgamation of sandy fine silt over a sand layer, were selected for grain size distribution analysis. Approximately 20 samples were taken from each core with the exception of cores KUS330 and 332. Ten samples were taken from these cores, as cores were 0.8 and 1.0 m in length respectively.

The best form of data regarding fine particle size distributions, hence the clay – silt fraction, was obtained from samples which do not contain any organic matter. Approximately

250 mg of clay – silt and 150 mg of fine sand fractions were placed in glass vials and 7 pipette drops of 32.5 % concentrated hydrogen peroxide (H 202) were used in each sample to remove any organic matter. Samples were left to evaporate and dry for one week in the fume hood.

The sample was mixed with distilled water and further disaggregated using ultrasonics when passed through the refractor. The Coulter and the Malvern instruments were set to read

52 grain size intervals ranging from 0.375 m to 2000 m and from 0.00582 m to 880 m respectively. The mean, median, mode, standard deviation, variance, skewness in a normal distribution, kurtosis, D 10 , D 50 and D 90 and the specific surface area of a particle were all recorded. A replicate of three readings were conducted for each sample. The standard cut off for fluvial geomorphic classification of particle size was used: clay (4 m), Silt (63 m), Sand (2000

m). The LPS results were then graphed and cross –referenced to other core samples within the region (Singer et al., 1988, McCave et al., 2006).

To compare whether there was a difference between LPS results obtained from the

Coutler Counter and the Malvern Laser Sizer, 2 samples (one sand and the other silt) were conducted on both machines. Results obtained showed no significant difference.

4.2.4 Geology – X-ray fluorescence

X-Ray fluorescence (XRF) analysis was used on clastic sediment samples to determine if there were down-lake and temporal differences down-core in geochemical composition. Five grams of clay and fine sand from the top and bottom of two cores (one proximal and one distal) were analysed. Organic matter was removed by burning the samples at 550 o C for 1 hour.

Dried samples were pulverised into a fine powder using a mortar and pestle. The samples were then briquetted into pellets for heavy elements (above iron) and analysed using the Phillips

2404 XRF at the XRF Spectrometry Laboratory Department of Geology, University of Toronto.

A semi-quantitative scan was used to measure major-elements in the sample. This method uses a high power X-ray tube to bombard a solid sample with X-rays. The secondary (fluorescent) X- rays released by the sample throughout this process determines the elements present and their concentrations. A semi-quantitative scan was carried out on 2 samples (one of sand and the other of clay) for Rare Earth Elements (REE). Results derived showed no trace of REEs.

Determining the geochemical composition of sediment through XRF analysis can help infer how the regional geology may have influence the distribution of Kusawa Lake sediments.

4.2.5 Microprobe tephra glass analysis

White coloured ash was found in two cores that were confirmed to be volcanic in origin.

To determine the constituents of the volcanic ash, Microprobe Tephra Glass Analysis was conducted by the Department of Geology, University of Toronto. The major- element composition of glass shards was analysed using a wave-dispersive Cameca SX-50, which operated at a 15 kV accelerating voltage, a 6nA beam current and a 10 m defocused beam. The calibration performed was based on mineral and glass standards and compared against research conducted by Jensen et al. (2005).

4.2.6 Radiocarbon-14 Analysis

Woody debris and re-worked organic matter were found at multiple depths in one core.

These samples were submitted to the Isotrace Mass Spectrometry Laboratory, University of

Toronto for C 14 analysis. Using an average of two separate analysis under normal precision, the results derived were corrected for natural and sputtering isotope fractionation using 13 C / 12 C ratios. The sample ages obtained were calibrated to conventional radiocarbon dates in years B.P. using the Libby C 14 mean-life of 8033 years.

4.3 Secondary data

4.3.1 Pb 210 and Cs 137

Rawn et al. (2006) and Lockhart et al. (2006) measured Pb 210 and Cs137 activity on short cores for Kusawa Lake taken in March 1992. The authors estimated mean ages of the core on sample slices from the regression of unsupported Pb210 and Cs 137 and calculated it against accumulated dry weight. Pb 210 and Cs 137 were assayed by α – counting and γ – counting.

(Lockhart et al., 1998; Rawn et al., 2006). Peaks which occurred during the late – 1950’s and early – 1960’s would provide estimation on age structure and rates of sediment deposition in

Kusawa Lake. The researchers kindly provided the raw data for our use (Table 4.2).

Short Site Coordinates Lake Depth # Sample Proximity to 2006 cores Core # (D.M.) (m) slices KUS -1 60 o 25’ N, 136 o10 W 49 29 South of the Primrose Delta near core KUS332 KUS -2 60 o 15’ N, 136 o10 W 78 18 Bet ween the Takhini River and core KUS324

Table 4.2 Cores and site characteristics of Pb 210 and Cs 137 analyses (Lockhart et al., 1998)

V – Results

5. Introduction

Geomorphic processes of the past and present define the distribution and composition of sediments deposited in Kusawa Lake. In order to understand these processes, this chapter will discuss the results obtained from field measurements and sediment core samples taken at

Kusawa Lake over two field seasons: the summers of 2004 and 2006. Aerial imagery from the

National Air-photo Library and analysis of secondary data on Pb210 and Cs137 acquired directly from Lockhart et al. (1998) and Rawn et al. (2006) will also assist in explaining the processes and chronology of sedimentation at Kusawa Lake.

5.1 CTD’s

CTD profiles of the water column can provide insight into the circulation and distribution of sediments within Kusawa Lake. In July 2004, sixteen sites measuring CTD at ~1.5 to 6 m depth intervals from the source to the outlet of the Lake were surveyed. For the purpose of discussion here, temperature and turbidity profiles of Kusawa Lake were spatially divided in half: the northern region (35 – 72 km from the Upper Takhini River outlet) and the southern reigon (0 –

35 km from the Upper Takhini River outlet).

5.1.1 Temperature

The temperature profiles show a strong down-lake pattern of thermal stratification (Fig. 5.1 a).

Within the southern half of Kusawa Lake from 2.1 to 33 km, the surface water temperature ranges from 8.4 to 13.3oC. The thermocline near the headwaters starts at ~5 m, is 17 m thick and decreases at a rate of 0.12 oC/m. The epilimnion is at a depth of 7 m near the headwaters and

56 increases in thickness to 20 m at 33 km. Between 21 and 33 km of the lake, the thermocline is shallow-graded. The thermocline begins at ~ 18 m, is 20 m in thickness and experiences a total change of 6oC (Fig. 5.1a).

Within the northern half of the lake (~ 39 and 52 km), the thermocline decreases gradually at an approximate rate of 0.26 oC m (Fig. 5.1b). Below the thermocline, temperatures decrease to roughly 5.4 oC and the lake in this region is isothermal. Surface water temperatures of roughly

16 oC are typically found north of the Primrose River delta. An epilimnion at approximately 9 m in thickness is found and this is followed by a steeply graded yet shallow thermocline (9 – 16 m).

The hypolimnion is similar to patterns found south of the Primrose delta (Fig. 5.1b).

As these temperature profiles were taken in July, these temperatures probably represent maximum heating of Kusawa Lake for the summer. Higher surface temperatures contribute to the warm cap of water. Therefore a thicker epilimnion, a steeply-graded thermocline and a hypolimnion are found throughout the lake (James, 2004).

a) Southern Region b) Northern Region

Fig. 5.1 Temperature profiles of Kusawa Lake taken on July 19th, 20th and 21st 2004

5.1.2 Turbidity

Turbidity, a measure of suspended particulate matter in a water column does not follow a down- lake pattern. The epilimnion of proximal waters between 2.1 and 3.8 km from the lake head is higher in turbidity (19 – 31 mg/L) with a steeply – graded interflow between 5 – 16 m of water depth. Below the interflows, turbidity decreases to ~ 12 mg/L (Fig. 5.2 a & b). From the proximal sites (Regions IV and V) to the centre of the lake (Regions II and III), turbidity ranges

58 from 8 – 10 mg/L below the thermocline. However, lateral in-feeding tributaries significantly affect the turbidity between 0 and 35 m water depths. The epilimnion at the foot of Ark

Mountain tributary (16.7 – 21.0 km from source) and Devilhole Creek (27.6 km) is no greater than 2 m. Sediment concentrations at these sites are higher (~ 15 mg/L) than at sites without the influence of tributaries (10 – 12 mg/L) (Fig. 5.2a).

Similar turbidity patterns are displayed by the profiles taken within Region I of Kusawa Lake.

Turbidity throughout the water column is relatively constant at the outlets of Jo-Jo Lake (39.1 km and 43.0 km from source) and Sandpiper Creek (52.2 km from source) ranging from 12.1 –

14.1 mg/L and 10.8 – 12.9 mg/L, respectively. This illustrates a condition where the lake is not stratified and tributary density is similar to that of lake water. However, turbidity increases in concentration at sites north of the Primrose River delta. These sites have interflows at 4 – 10 m depth with turbidity in the range of 13 to 25 mg/L. Turbidity in the hypolimnion ranges between

12.3 – 14 mg/L (Fig. 5.2b).

This turbidity pattern suggests that the numerous lateral tributaries along the length of

Kusawa Lake are an important localised source for sediment input. Much of the sediment appears to remain within the epilimnion during the summer when the lake is stratified.

a) Southern Region b) Northern Region

Fig. 5.2 Turbidity profiles of Kusawa Lake taken on July 19th, 20th and 21st 2004. Turbidity was measured in NTU units and converted to mg/L using the calibration developed by Hodder et al. (2006) for this instrument

(For more detail, inset diagrams of turbidity profiles at 0 – 15 m depths are found within Appendix B)

5.1.3 Conductivity

Conductivity is a measure of total dissolved solids in water and the drainage basin geology of a lake establishes the normal ranges for conductivity in the lake. Conductivity can also provide information regarding water quality. Changes in conductivity levels are normally

60 due to pollution discharges especially if the pollutants include inorganic dissolved solids such as bicarbonate, chloride, magnesium, phosphate, calcium and sodium ions (O’Sullivan et al., 2004).

Conductivity is lowest in the epilimnion of proximal waters (21.6 µS/cm) and gradually increases with increasing depth reaching a maximum chemocline of 26.8 µS/cm at 28.2 m water depths (Fig. 5.3). These values show that throughout the summer months, photosynthesis and respiration of aquatic species within this region is high (O’Sullivan et al., 2004). Within the epilimnion, photosynthesis dissolves carbon dioxide, which reduces bicarbonate ions. As the rate of photosynthesis decreases with increasing depth (the chemocline), an excess of carbon dioxide is produced resulting in an increase in bicarbonate ions (O’Sullivan et al., 2004). As distance increases from the source up to 33.0 km of the lake, conductivity levels rises. The epilimnion is thin and the chemocline is 35 m thick. Below 40 m water depths, conductivity maintains a value of ~ 27.5 µS/cm. Within the centre of the lake (33.0 – 52.2 km), conductivity ranges from 25 – 28.9 µS/cm throughout the water column. These near-vertical profiles suggest that the water is holomitic (Fig. 5.3) (James, 2004; O'Sullivan et al., 2004).

Conductivity values north of the Primrose River delta are at a minimum of 5 µS/cm higher than the conductivity values south of the delta. The epilimnion is 10 m thick and conductivity in the epilimnion ranges from 33.1 – 34.2 µS/cm. Conductivity in the chemocline increases at a rate of 0.13 µS/cm/ m and reaches its maximum value of ~ 34.7 µS/cm at 18 m water depths. Below the chemocline, there is a slight decrease in conductivity to an average of

34 µS/cm (Fig. 5.3). The higher conductivity levels found north of the Primrose River delta is due to human activity. The Kusawa Campground (alluvial fan) is densely occupied throughout the summer months. Recreational activities increase the level of pollutants (inorganic dissolved solids) both onshore and in-lake.

Fig. 5.3 Conductivity profiles for Kusawa Lake (north and south) taken on July 19th, 20th and 21st 2004

(For more detail, inset diagrams of conductivity profiles at 0 – 30 m depths are found within Appendix B)

5.2 Aerial imagery

Excursions to the upper parts of the drainage basin were not carried out during the field season. As a result, aerial imageries were acquired from National Air photo Library, Natural

Resources Canada to help in the identification of surficial conditions and primary sediment sources into Kusawa Lake. These aerial imageries were taken in the summer of 1998.

Sediment throughout the Upper Takhini River basin is mobilized by a combination of glacial, fluvial and hillslope processes. Mass wasting events are predominant in the upper glacial reaches of the basin and these vary from avalanches, to debris flows. Evidence of these physical processes includes bedrock outcrops and deeply incised gullies on hillsides.

It is probable that most of the sediment into southern Kusawa Lake originates from the

Kusawa River sub-basin. Permafrost covers 11.2 % of the sub-basin. Tarns and a complicated network of incised tributaries are indicative of degradation and sediment excavation. Debris aprons off the valley walls of Hendon River flank the lower reaches. An alluvial fan is found to be aggrading faster than the Hendon River can excavate, causing an upstream lake and delta

(Fig. 5.4). The Hendon River meanders tortuously before flowing into the Kusawa River.

Kusawa River is sinuosity and anabranches within the steep and narrow valley walls. In proximity to Kusawa Lake, the channel decreases in gradient and braids significantly. All this suggests that he Kusawa River carries a high sediment load, which is subsequently deposited into

Kusawa Lake with decreasing momentum (Fig. 5.4).

Fig. 5.4 Aerial photo A27149-12 of Hendon River and surrounding glacial features

(Red arrows = sediment flow; Yellow arrows = labels)

Glacial cover accounts for 13.9% of the upper-most Takhini River sub-basin. Much of the colluvial deposits found in higher elevations consist of cobbley and bouldery diamicton (a finer grained matrix with permafrost common at shallow depths), which is susceptible to creep, solifluction, gullying and active layer detachment flows. Debris aprons as seen on the lower slopes are common. Takhini Lake, 8.5 km upriver from the outlet of the upper-most Takhini

River into Kusawa Lake, acts as a significant sediment trap for coarse material. The braided channel and sediment plumes flowing into Takhini Lake are indicative of deposition (Fig. 5 5b).

A portion of the silt and clay from the upper-most Takhini River sub-basin is deposited into

Takhini Lake while a portion would be further transported into Kusawa Lake and deposited up-

lake (Fig. 5.5a). Despite the significant glacial cover, it is therefore assumed that the upper-most

Takhini River contributes less sediment than Kusawa River.

Fig. 5.5 Aerial photos of Upper-most Takhini River a) Aerial photo A27149-100 showing: i) main sediment b) Aerial photo A27149-63, plumes entering Takhini plume from Kusawa Lake inputs; ii) right hand Lake deflected (coriolis force) sediment plume from the upper-most Takhini River

It may be assumed that the Primrose River sub-basin contributes less sediment into

Kusawa Lake due to its diminutive glacial cover (3%), the presence of two sediment traps and a long sandur. However, hillslope failures, chutes, bedrock outcrops and a braided river delta at the outlet of the Primrose River indicate that mass wasting processes are a direct sediment source

(Fig. 5.6). The Primrose River delta extends into Kusawa Lake depositing sands, silts and clays and as a result, a number of high terraces formed during the drainage of Glacial Lake

Champagne. It also appears that during a late stage of deltaic development, the Primrose River

65 avulsed from a westerly course to a south-westerly course. This might be due to high water levels during extreme flood events. The delta has extended far out into the lake and is close to reaching the opposite shoreline. Water depth within the narrow is ~ 1 m at normal summer levels. Low lake levels dropping by 2 m water depth combined with freezing in the winter months, have the ability to cut off lake circulation entirely (Fig. 5.6).

Fig. 5.6 Aerial photos A27217-136 and A27217-134 Primrose River sub-basin delta,

photograph taken at summer high water levels

The Kusawa Campground alluvial fan complex is a torrent system and probably accounts for a significant amount of the modern sediment delivered into the northern most region of

Kusawa Lake. Lowery (2002) and Lipovsky (2006) provided information regarding the surficial geology of the catchment. Field excursions to the upper reaches of the catchment showed that at high elevations, sediments consist of fluvial-glacial deposits from late glacial deposition. High gradient slopes in the upper section of the Campground basin enable the mobilization and

66 transport of vast amounts of debris through two steeply cut gorges, which act as debris channels

(named here the northern and southern channel) (Fig. 5.7). A layer of discontinuous permafrost is overlain by thick glacial sediment. During the summer months the active layer (~1 m in depth), depending on the climate, can thaw and result in slope failure. As a result, sediment from the slope failures coalesce with colluvium and is transported downslope into the channels.

Sediment is either stored in the alluvial fan or deposited in Kusawa Lake following extreme floods (Lipovsky, 2006).

Fig. 5.7 Aerial photo A27327-52 Campground Alluvial fan

5.3 Acoustic records and lake bathymetry

During the summer of 2004, all of Kusawa Lake was surveyed using a Datasonics Dual –

Frequency CHIRP II sub-bottom acoustic profiler (Gilbert, 2004; Gilbert & Desloges, 2005).

Sixty-eight oblique cross – lake transects from the north (outlet – Takhini River) to the southern reaches of the lake (source – Kusawa Lake Delta) were completed covering 125 km. Depth in water and sediment was based on a sound velocity of 1430 m/s, corresponding to 5.5 oC. The information obtained was used to create a bathymetric map of the lake (Fig. 5.8).

For the purpose of analysis, Kusawa Lake will be divided into five regions. This was determined by Gilbert & Desloges (2005) who noted regions of similar morphology, acoustic character of sediments and, by inference, the sedimentary environment.

Fig. 5.8 Locations of Regions, Lake bathymetry and CHIRP Acoustic transects. Isobath intervals at 20m, dashed

lines at 10 m. Maximum depths in each section of the lake are indicated (From Gilbert & Desloges, 2005).

Acoustic records indicate that the upper-most sediment fill within Kusawa Lake is characterised by mostly silts and clays. These well-layered sediments have accumulated to a thickness of at least 60 m in the southern portion of the lake.

Acoustics within Regions IV and V depict a U-shaped valley following the Shakwak

Trench. High mountains on both sides extend deep into the sides of the lake. Digital Elevation

Models (DEM) of the area show that slopes of 30 o or more can be found within 200 m of the valley shoreline. This region consists of a single basin with a maximum depth of 135 m (Fig.

5.9). Gilbert (2004) suggests that the lacustrine sediment has infilled the basin to a maximum water depth of 82 m. The sediment fill smoothes the underlying basement rather than lying conformably on it. In addition, the acoustic records indicated that one facies consisted of well layered sediment with reflectors parallel to the present lake floor (Fig. 5.9) (Gilbert & Desloges,

2005). This suggests that a long period of deposition, largely from low-density turbidity currents

(possibly originating from the Upper-most Takhini River delta) has been distributing the sediment along the length of the lake floor (Fig. 5.9).

Fig. 5.9 Acoustic section from southern Kusawa Lake near the upper-most Takhini River mouth (Region IV).

View is from east to west. Core KUS324 was obtained along this transect (see Fig. 5.8 for location).

Lake depths within Region III (also known as the elbow region) of Kusawa Lake are ~ 40 m. A thin sediment cover of < 20 m overlies an irregular hard basement. Here, the Shakwak

Trench cuts through the Upper Takhini basin and Kusawa Lake bends in a north-westerly direction. The displacement of the Shakwak Trench created the “S” shape of Kusawa Lake.

Before tectonic faulting, Kusawa Lake may have been connected with Federick Creek and

Federick Lake (Kindle, 1934; Gilbert, 2004). CHIRP Acoustics within the elbow region shows no vertical displacement of the basin from one side of the depression to the other. Hard bedrock outcrops surround the valley sides at various locations and protrude through the bed. It is unsure whether this basement is thick glaciolacustrine sands and gravels or bedrock.

Further up lake within Region II, the maximum sediment depth is 84 m in the southeast and 40 m in the northeast (Fig. 5.10). Proximal to the elbow, sediment is moderately well layered and a number of irregular depressions occur. Mounds of sediment rise up to ~40 m in depth. Shorelines along the upper valley sides are absent in this region. Given the presence of the Shakwak Trench, the emergent riegel at the boundary of Regions II and III, and the irregular, submerged bedrock basement along the east side of the lake, this region may not have experienced heavy glacial erosion. Consequently, Gilbert & Desloges (2005) propose two causes for the depressions either sedimentation was spatially variable due to stagnant ice, or a tectonic strike – slip off-set motion caused the intermittent depressions.

Fig. 5.10 Acoustic section from Region II, south of Primrose River delta. View is from east to west. Core

KUS322 was obtained along this transect (see Fig. 5.8 for location)

Although depressions were found in the central and southern regions of the lake, they are not as constant as those discovered in Region I, north of the Primrose River delta. Rippled sand dominates the base of the Primrose delta. Unfortunately, this more reflective sediment has prevented the assessment of the total thickness of lacustrine sediment in the southern part of

Region I. Sub-bottom record shows conformably deposited sediments to at least 60 m below the sediment surface. Acoustic facies along this transect (Fig. 5.8 & 5.11) consists of up to 25 m of well-layered sediment with reflectors parallel to the present lake floor overlying less well stratified layers below. This suggests that a long period of deposition, largely from suspension had occurred throughout the Holocene.

Fig. 5.11 Acoustic section from Region I, proximal to the Primrose River delta. View is from east to west. Core

KUS326 was taken along this transect (see Fig. 5.8 for location)

Further up lake in Region I, trenches in the lake bottom range from 10 - 54 m in depth.

These trenches appear to be channels scoured and entrenched into the lacustrine sediment. Some depressions appear less exaggerate due to progressive infill by other sources (Fig. 5.12). It is possible that these depressions were created during the retreat of Glacial Lake Champagne by pro-glacial turbidity currents when flow velocity was supercritical (Gilbert & Desloges, 2005).

Fig. 5.12 Acoustic section from Region I, northern Kusawa Lake. View is from east to west. Core KUS318 was

taken along this transect (see Fig. 5.8 for location). 73

Gilbert & Desloges (2005) and Chow (2007) indicate that modern (Holocene) depositional rates in Kusawa Lake are low. This suggests that the vast majority of the sediment thickness presented here in the acoustic profiles, perhaps up to 95 %, is of de-glacial or of early

Holocene origin. Thick silts and clay deposits of up to 60 m found in the Regions II - V of

Kusawa Lake demonstrate the onset of thick and fast sedimentation in response to deglaciation: the drainage of ice-dammed Glacial Lake Champagne. Throughout the Holocene, localized inputs of sediment from small and medium tributary basins and other unstable hillslopes have also contributed towards the total sediment package of Kusawa Valley.

5.4 The sedimentology of Kusawa Lake

5.4.1 Sediment structure and grain size

Overall, sediments from the 11 cores taken displayed significant differences in structure and composition both spatially and temporally. The stratigraphic sequences at the core sites generally consist of poor to well-defined laminated clays and silts with intermittent sand deposits. Due to the variability in structure and composition throughout the cores and between cores, the stratigraphic sequences of each core were graphically reconstructed according to the characteristics displayed. Figure 5.13 is a detailed legend showing this classification. Sediment logs showing core stratigraphy individual cores were constructed according to the classification.

Fig. 5.13 Core stratigraphy characteristics. Legend for figures 5.13 a – k

Fig. 5.13 Core stratigraphy from south (proximal) to north (distal) in Kusawa Lake: a) KUS324; b) KUS322; c) KUS325

Fig. 5.13 Core stratigraphy from south (proximal) to north (distal) in Kusawa Lake: d) KUS326; e) KUS319

Fig. 5.13 Core stratigraphy from south (proximal) to north (distal) in Kusawa Lake: f) KUS327; g) KUS328; h) KUS318; i) KUS330

Fig. 5.13 Core stratigraphy from south (proximal) to north (distal) in Kusawa Lake: j) KUS331; k) KUS329

79 Core KUS324 is 2.78 m in length and was taken in Region IV of the main lake in 135 m water depths. Overall, core 324 is comprised of approximately 19.1 % clay, 60.2 % silt and 20.7

% fine sand (Fig. 5.22a). The core is characterised by three distinct facies. The first facies is found in the deeper sediments below 0.8 m of the core and is characterised by light coloured, clastic-rich fine silt (D 50 of 14.2 µm at 1.89 m) deposits that are capped by dark-coloured clay units (Fig. 5.13a; App. C). This is an indication of deposition by seasonal underflow or turbidity currents and winter settling from suspension. The second facies type is found within the top 0.8 m of the core and is also characterised by light coloured clastic-rich silt deposits but with thin (0

< x < 2 mm) intermittent dark coloured weakly defined clay laminae. The third facies is found intermittently throughout the core. There are at least 15 major and 25 minor units of fine sand deposits ranging from 0.5 cm thick laminae up to 24.5 cm beds. The average thickness of sand units is 1.2 cm and the D max is 409.5 µm (Fig. 5.13a; App. C). Sand units below 2 m of the core display distinct internal laminations, which is indicative of separate depositional episodes. Sand units found within the medial part of the core are generally mixed with silt forming more homogenous units. Grading from fine sands to clays also occurs above major sand deposits (Fig.

5.14). These deposits in core 324 demonstrate the influence of density currents, which gradually deposit heavier particulates as each event loses momentum with increasing distance.

Fig. 5.14 Major sand units with laminations in core KUS324 (2.65 – 2.74 m)

Sediment core KUS322 (Fig. 5.13b and 5.15) is 1 m in length and was obtained from the northeast portion of Region II (Fig. 5.8). Clays (52.2 %) and silts (42.6 %) particles dominate the entire core. Two dominant facies are found: below 0.7 m the sediment is primarily grey, well-laminated silts and clays and inorganic (Fig. 5.15). Although there is not a distinctive sand layer within the facie, the D max is 878.7 µm at 0.8 m core depth. In addition, the percentage of sand content was also greatest: 11.2 % (Fig. 5.22b; App. C). Above 0.7 m, the sediment is thick clay with no visible laminae. Between 0.7 – 0.6 m and at 0.1 – 0 m, a massive unit of silt is found (Fig. 5.13b). At 8 cm of the core, a thin 0.2 cm layer of white – coloured silt is found

(Section 5.5.3). This unit is thought to be volcanic ash. This region denotes steep valley sides and very minor lateral tributary inputs. This is consistent with the agreement with the overall fine-grained nature of sedimentary deposits in this region. Thin laminations may reflect lake- wide seasonal deposition and upper basin sediment sources. Settling from suspension dominates this core.

Fig. 5.15 Silt - clay laminations in core KUS322 (0.84 – 0.93 m)

Four sediment cores, KUS325, 326, 319 and 327 (Fig. 5.13 c, d, e and f respectively), ranging from 2.2 – 3.0 m in length, were taken in the southern portion of Region I up-lake from the Primrose River delta. Sediment structure shows that within this shallow northern region of the lake, the sediment has been heavily influenced by a constant influx of sediment emanating from the Primrose River. These cores display three distinctive facies.

Below 1.7 m core depth in cores 325, 327 and 319 and below 2.22 m in core 326, sequences of finely laminated silts (0.2 ± 0.078 cm) and clays (1.17 ± 0.8 cm) are interrupted by at least four beds of thick sand (5.2 ± 4.1 cm) (Fig. 5.16, 5.17 & 5.18). Of the four sand bed units, the D max is 878.7 µm in cores 325 and 327, although a greater proportion of particles are fine sand (D 50 = 120.7 µm). In cores 319 and 326, sand particles are found to be slightly finer, with a D 50 of 88.9 µm (App. C).

Beds show sharp (likely to be erosive) lower contacts and some fine sand units display distinct ripple / cross-bedding structure composed of centimetre scaled light coloured sands alternating with darker millimetre scale sand laminae (Fig. 5.17 & 5.18). However, there is no

82 evidence of fine sand grading upwards into the overlying clay deposit. It is believed that these massive sand deposits are due to large flood events from the Primrose River.

Fig. 5.16 KUS319 (2.1 – 2.2 m) Fig. 5.17 KUS326 (2.24 – 2.31 m) Fig. 5.18 KUS327 (2.14 – 2.22 m)

From 1.7 m to 0.7 m of cores 319 and 325, from 1.7 – 0.9 m of core 327 and 2.22 – 1.35 m of core 326 is also distinctive in terms of determining continuous up-lake stratigraphy. The sediments in 326 and 319 are characterised by thick, clastic-rich silt deposits with thin, dark coloured well-defined clay laminants. Within this unit, the silt content is approximately 15% more than the clay content (Fig. 5.22b). However, the sediment in 325 and 327 is dominated by a slightly higher (~ 5%) clay content with intermittent thin silt laminations. Despite the dominance of silts and clays, the D max is 260 µm (medium sand) which is found in core 319 at

1.67 m (App. C).

The third sediment facies occurs at the top of all four cores. The sediment is thick clastic- rich medium silt with no apparent laminations. However, at least three ~ 0.2 cm thick and thirteen ~ 0.8 cm thick clay deposits break this sequence (Fig. 5.13 c & f). Although clay is present, no visible grading may be seen. With the exception of core 325 at 0.1 m and of core 319 at 0.66 m, the sand is generally fine to medium grained and exceeds no more than 4 % of the sample. At 0.66 m of core 319, the fine sand content (D 50 = 65.5 µm) is 26.5 % and at 0.1 m of

83 core 325, the sand content is 10.3 % despite having a D 50 of 3.8 µm (Fig. 5.22b; App. C). Within the top 0.4 m of all four cores, at least five 0.33 ± 0.24 cm dark, organic rich, deposits interrupt the silt.

Core KUS328 was obtained from the centre of Region I, is 1.64 m in length and taken in

32.4 m of water. Core 328 displays stratigraphic characteristics that are transitional between the sediment found proximal to the Primrose River delta and those surrounding the Kusawa

Campground alluvial fan-delta (Fig. 5.13g).

Core 328 is primarily silt (65.5 %) with thin, well-defined clay (21.8 %) laminations (Fig.

5.22b), which resembles the second facies of cores 325, 326, 319 and 327. However, the sequence is interrupted by twenty-nine ~ 1.5 ± 0.7 of thick clay laminae, five sand units with distinct laminations, and one thick (4.8 cm) deposit of silt with fine sand (Fig. 5.13g). Fine sand content averages ~ 5 % throughout the core with the exception of a peak of 29.3 % at 1.1 m. The

Dmax at this peak is 351.5 µm (App. C). This may be the same sand layer (event) found in cores

325 and 319 at 1.0 m, and in core 318 at 1.3 m. The sediment may have originated from the

Kusawa Campground alluvial fan as a similar peak is not found in the more distal core 327.

The sedimentary sequence of the northern half of Region I is further interrupted by probable inputs from the Kusawa Campground alluvial fan. Cores KUS318 and 331 are 2.04 m and 2.9 m in length respectively and were taken in approximately 32 m of water adjacent to the alluvial fan-delta. Both cores display similar depositional characteristics and layering. Below 1.3 m in each core, sedimentary features resemble that of the Primrose cores: clay with silt laminations, and alternating bands of clays and silts that are interrupted by at least four thick (3.4

± 1.2 cm) sand deposits (Fig. 5.13 h & i). Of the four thick sand deposits, core 318 displays a higher percentage of sand than in core 331. The D max (373.1 µm) is found at 1.75 m of core 318 and the D50 is 64.5 µm (fine sand). Despite the lower percentage sand content, coarser sand 84 particles are found (D max = 717 µm at 1.76 m) in core 331. Fine silt (D 50 = 9.45 µm) is dominant

(App. C).

The top 1.3 m consists of eight distinctive coarser units of sand and silt within more thinly layered sections of the core (Fig. 5.13h & k, 5.19, 5.20). Between those units, are zones of intermittently well-defined, but weakly visible, silt laminae. The coarsest sand is found at 0.37 m of core 318 and at 0.32 m in core 331, where the D max = 1822 µm and 1512 µm respectively.

Relative to the rest of the 0 – 1.3 m section of the core, both layers have a high percentage sand content (23 % and 39 % respectively). The distinct sand units are thought to originate from high- energy flood events off the alluvial fan coupled with delta front slope failures.

Fig. 5.19 KUS318 (1.04 – 1.15 m) Fig. 5.20 KUS331 (1.03 – 1.14 m)

Core KUS330 is 0.8 m in length and was taken in 35 m of water, directly in front of the two debris feeding alluvial channels between cores 318 and 331. Primarily clastic-rich silts with thin, weakly visible, laminae dominate the core. There are seven distinctive bands of sand laminae ranging from 0.5 – 1.8 cm in thickness and 2 sand beds ~ 10 cm thick. Between 0.42 and

0.26 m is a 16 cm thick bed of organic debris mixed with sand (Fig. 5.13j & 5.21). At both 0.39 m and 0.28 m of the core, the percentage of sand content is 67.8 % and 64.0 % respectively, with

85 a Dmax of 1512 µm. It is speculated that this difference in sediment stratigraphy and grain size in comparison to the surrounding cores is due to the effects of sub-aqueous deltaic channelization.

Fig. 5.21 KUS330 (0.24 – 0.44 m)

The longest core (KUS329) is 5.4 m in length was taken in 32.2 m of water approximately 1.5 km south of the Takhini River outlet from Kusawa Lake. It is the most distal to the two debris-feeding alluvial channels and is the most distal core from the whole lake.

Thick silts with well-defined thin and thick laminations dominate the bottom 2.5 m of 329 and five distinctive sand peaks ranging from 11.3 % to 55.0 % in sand content interrupt this sequence

(Fig. 5.13k, 5.22b). However, at both 5.21 m and 4.35 m of 329, clays and silts account for 100

% of the layer. Both of these layers occur after a massive sand deposit, which indicate the onset of lower energy and uniformity after a major flooding event. However, medium silt, is slightly more dominant in this unit. Clastic-rich silts with thin, yet distinctive, laminae dominate the top

2.5 m of the core (Fig. 5.13k) although intermittent layers of silty fine sand are found within this unit. At 1.5 m, 53.5 % of the layer is sand whereas by 1.13 m clayey – silt accounts for 97.4 %

86 of the layer (Fig. 5.22b). These structural characteristics are similar to those found in cores 318 and 331 at similar depths. There are a large number of distinct sand deposits, including including nine major sand beds ranging from 2 – 32 cm in thickness, and thirty-six sand laminae

(1.8 ± 1.3 cm). An average of 69.0 % of fine sand content with a D max of 11660 µm is found between 0.95 and 0.3 m (App. C). The immense outwash of sediment in a likely single event demonstrates the spatial extent of flooding from the alluvial fan torrent system. Within the top

0.2 m, there is a significant increase in clayey-silt content with a D 50 of 11.83 µm (fine silt) at

0.09 m (App. C).

5.4.2 Stratigraphy and grain size trends

No common stratigraphic or grain size trends in the two south-lake cores (KUS324 and

322) or with those taken north of the Primrose River delta (Fig. 5.22a; 5.23 a, b, c). Cores taken north of the Primrose River delta (Region I), display some similar characteristics in terms of structure and grain size (Fig. 5.22b; Fig 5.23 a, b, c).

In Region I, there is an up-lake trend in sand content between the bottom to ~ 1.5 m of cores KUS325, 326, 319, 327 and 318. The distinctive sequence of thick sands, silts and clay deposits (Fig. 5.13, 5.16, 5.17, 5.18) suggest these sand layers (Fig.5.23a, b & c) are correlated.

This trend is supported by a number of sand content peaks (Fig. 5.22b) where grain sizes fell within the fine – medium sand range. The intermittent flux of sand, most likely from the

Primrose River, appears to spread uniformly northward into Region I of Kusawa Lake. The top

~ 1.5 m of cores 325 to 327 are predominantly clayey-silt. Core 328 shows a transition between the stratigraphy found in cores proximal to the Primrose River delta, and those found near the

Campground Alluvial fan-delta. Relative to cores 327 and 318, the percentage silt content is significantly higher (~ 80 %), the percentage sand content is more than in core 327 but less than 87 that found in core 318 (Fig. 5.22b). However, the grain size and stratigraphy found in the bottom

1.5 m of core 318 resembles those proximal to the Primrose, whereas the top resembles those cores surrounding the alluvial fan. Therefore, the Campground alluvial fan has significantly influenced the sedimentary sequence of Kusawa Lake.

The intermittent silty fine sand deposits found within the top 2.5 m of core 329 resemble the fine sand layers in 318 and 331 at the same core depth. These layers are believed to be remnants of sand deposited furthest away from the Campground fan-delta. Within the top 1.5 m of cores 318, 330, 331 and 329, all sand beds have sharp lower contacts and sand content constitutes at least 20 % of the layer. These sand layers are believed to originate from intermittent pulses of high energy and erosive flood events off the alluvial fan-delta, coupled with lateral slope failures. Given the high percentage sand content at 0.4 – 0.3 m of cores 330,

331 and 329 (68 %, 39 %, and 65 % respectively) it is speculated that this is due to the 1982

Campground alluvial fan flooding event. However, core 318 displays a lesser sand content (23

%) at 0.37 m (Fig.5.22b). This is due to a greater distance from the alluvial fan relative to the rest of the cores. In addition, sand particulates travelled in the opposite direction of water flow.

Fig. 5.22a Percentage grain size of cores taken in Regions IV and II (App. C)

Fig. 5.22b Percentage grain size of cores taken in Region I (App. C)

Fig. 5.23a Cross reference of major sand units in the 0 to 1m interval of cores in a transect form. South (proximal) to north (distal) of Kusawa Lake.

Fig. 5.23b Cross reference of major sand units in the 1 to 2 m interval of cores in a transect form. South (proximal) to north (distal) of Kusawa Lake.

Fig. 5.23c Cross reference of major sand units in the 2 to 3m interval of cores in a transect form. South (proximal) to north (distal) of Kusawa Lake. Core KUS329 is 5.4 m in length. All other cores are less than 3 m in length.

5.4.3 Loss on Ignition

Loss on Ignition (LOI) was measured throughout all cores as described in Chapter 3.

Overall, there is no significant relationship between mean (within core) organic matter content with increasing distance down lake (r 2 = 0.012, y = 0.0113x + 2.483). However, LOI values for cores surrounding the Campground alluvial fan are slightly higher than elsewhere in the lake

(Fig. 5.24).

Fig. 5.24 Mean organic matter relative to increasing distance from the Upper Takhini River outlet.

Error bars at ± 1 standard deviation (App. D)

Fluctuations of organic matter content within the cores suggest temporal variability. The

OM content in core 324 increases with decreasing core depth up to 0.5 m. OM varies between

1.2 % and 6.7 % with a mean of 3.37 % with three major peaks in OM at 1.60, 1.35, and 0.5 m

(5, 5.7 and 6.7 % respectively) (Fig. 5.25a). These peaks correspond to the fine sand (section

5.4.1 and 5.4.2) deposited by high energy floods emanating from the upper-most Takhini River watershed. However, OM content decreases significantly to ~ 2.5% within the top 0.25 m of the core. OM in core 322 increases with decreasing core depth. Values range from 1.52 – 3.08 % with a mean of 2.3 % (Fig. 5.25a).

Within Region I, OM is constant throughout core 325, which is the closest to the Primrose River delta. Values range from 0.94 % to 4.40 % with a mean of 2.48 %. In cores 326, 319, 327 and

328, which were taken within the southern half of Region I, the OM means are 2.5, 3.28, 3.71 and 2.88 % respectively. In general, the cores show a gradual increase in OM content with decreasing core depth. However, specifically within cores 319 and 327, there is considerable variability in OM between 2.3 m and 1.5 m (3.0 < OM < 6.0 %), which indicate changes in classic input (Fig.5.25b & c).

Core 330, of all Region I cores, taken in proximity to the Kusawa Campground alluvial-fan delta, had the highest OM content. Within the bottom 0.57 – 0.80 m of the core, OM content does not fluctuate much and has a mean of 3%. However, by 0.42 and up to 0.28 m of the core, the OM content varies between 7.0 to 25.8 %. This high OM content may be due to the 1982 flooding episode resulting outwash of OM from the fan-delta surface. Within the upper most 0.25 m of the core, OM content decreases to an average of 5.5% (Fig. 5.25d)

Cores 318 and 331 were also taken near the outskirts of the Kusawa Campground alluvial fan – delta and both cores show an increase in OM content with decreasing core depth. The lower 1.4 m of both cores shows OM content varies between 0.77 % and 4.54 %. The upper 1 m of 318 and 331 resembles core 330. From 1.0 to 0.55 m of 318, the mean OM is ~ 2.5%. Between 0.55 m and the top of the core, OM varies between 0.9% and 7.7% (Fig. 5.25c & d). Core 329 is the longest and most distal of all cores taken from the Primrose River delta. Like core 325, OM is 94

constant throughout. At 5.33 m, the percentage OM ranges from 0.5 and 2.8% and there is a slight decrease to 1.82% at 3.1 m. At ~ 2 m, there is considerable variability in the OM ranging from 0.8 – 3.84 % and this continues to the top section of the core (Fig. 5.25d).

a) b)

Fig. 5.25 Percentage organic matter content: a) cores 324 & 322, b) cores 325, 326 & 319

c) d)

Fig. 5.25 Percentage organic matter content: c) cores 327, 328 & 318, d) cores 330, 331 & 329 (App. D)

5.4.4 X-Ray Fluorescence

X-Ray Fluorescence (XRF) analysis was used to determine if there were spatial (down-lake) and temporal (down-core) differences in geochemical composition. Two samples of clay and fine sand from the top and bottom of cores KUS324 (Region IV, most proximal – southern) and

KUS329 (Region I, most distal – northern), and three samples (two of clay, one of sand) were taken from the top and bottom of KUS326 (Region I, near the Primrose River delta).

In general, the XRF data of all cores show there is no major variation in geochemical composition temporally and spatially within Kusawa Lake. SiO 2 is dominant with a mean of 60

%. This is followed by 16.1 % of Al 2O3, 8.12 % of Fe 2O3 and 3.9 % of MgO. Trace amounts of other elements are also found (Fig. 5.26). One noteworthy difference is the Fe 2O3 content in cores 324 at 52 cm and 326 at 297 cm, which are 5.48 % and 4.58 % respectively, are higher than the average (Fig. 5.26; App.E).

Fig. 5.26 Major element geochemical composition of Kusawa Lake sediments. H 2O calibrated (App. E)

5.5 Chronology

The chronology of sediment deposition in two cores (KUS324 and 322) was determined using Pb 210 , Cs 137 , C 14 dating as well as microprobe analysis of volcanic ash.

5.5.1 Lead 210 and Caesium 137

Lockhart et al. (1998) and Rawn et al. (2001) provided primary data on age the structure and rates of sediment deposition in Kusawa Lake by the means of testing for Pb 210 and Cs 137 .

Rawn et al. (2002) took one core (their KB1) from the southern region of Kusawa Lake (0.42 km south of core KUS324). Their Pb 210 curve (Fig. 5.27) shows a nearly constant trend in excess

Pb 210 . Application of a constant rate model allows for a good estimate of ages with depth. Fig.

5.27 shows that deposition over the last ~ 130 years resulted in about 0.18 m of constant sediment input. Cs 137 results confirm this with a peak in activity at 0.06 m, corresponding to the

1954 – 1963 peak of inputs. They concluded that the average sedimentation rate over the last

130 years was uniform at approximately 227 g/m 2/yr.

Fig. 5.27 Kusawa Lake down-core profiles of lead-210 and caesium-137 .

Modified from Lockhart et al. (1998) (See App. F)

5.5.2 14 C

An isolated deposit of reworked woody debris and three isolated deposits of organic matter were found in core KUS324. Radiocarbon-14 dating was processed by the Isotrace Mass

Spectrometry Laboratory at the University of Toronto. Table 5.1 shows the age results for core

KUS324.

100

Depth Material dated Weight Conventional Calibrated Median Lab code (cm) (mg) 14 C age (14 C age, 2-sigma calibrated year BP) range age (year BP) 53 Disseminated 2500 2180 ± 50 2052 – 2332 2205 TO - organic matter and 13665 needles 135 Disseminated 782 4740 ± 60 5440 – 5589 5480 TO - organic matter 13664 178 Woody d ebris 277 7050 ± 100 7670 – 8043 7872 TO - (reworked) 13415 214 Disseminated 423 8460 ± 80 9278 – 9554 9468 TO - organic matter 13414

Table 5.1 Radiocarbon dates and calibrated calendar ages from core KUS324. The median probability from the 2- sigma range is given and is used in the construction of the age- depth curve (Fig. 5.29). Dates were calibrated using

CALIB v5.0.1 (Stuiver et al. 1993) and the INTCAL04 calibration curve (Stuiver et al., 1998)

14 C dates derived from core KUS324 are statistically significant at a p = 0.05 level. As core depth decreases, age decreases (y = 0.0219x + 8.052; r 2 = 0.995, t = 20.66, P = 0.078).

Extrapolation of the age trends to the base of core 324, where thick sand refusal prevented further core penetration, indicates post Glacial Lake Champagne deposition stood around 10.5 ka cal B.P.

5.5.3 White River Ash

Microprobe Tephra Glass analysis was conducted on white – coloured volcanic ash (tephra) found in cores KUS322 at 8 cm and KUS324 at 20 cm. Sample 322-8 contains frothy pumice with feldspar (plagioclase), green amphibole, magnetite and ilmenite. Sample 324-20 contains frothy pumice with plagioclase, green amphibole, ilmenite, magnetite and trace amounts of apatite and climopyroxene.

101

Major element geochemistry on 322-8 and 324-20 tephra samples show that both samples have high concentrations of SiO 2 (75%) and Al 2O3 (14%). Other elements are Na 2O and K 2O, which constitutes 4% and 3.5% of the sample respectively (App. F).

Geochemical analysis of Magnetite (Fe 3O4) and Ilmenite (FeTiO 3) determined the mineral assemblage in both samples. Looking specifically at Fe-Ti concentrations from the analyses,

TiO 2 in magnetite is low in 322-8 and 324-20: 4.49 % and 4.43 % respectively. The concentration of Fe 2 O3 is high (322-8: 58.05 %; 324-20: 57.44 %) and FeO constitutes nearly one third of the total sample. The total FeO (FeO t) is 85.87% and 87.99% respectively. High concentrations of TiO 2 is found within ilmenite (322-8: 28.3%; 324-20: 29.23%). Fe 2 O3 and

FeO content is also high, bring the FeO t to 65.45% in 322-8 and 64.39% in KUS324-20. Trace elements of SiO 2, Cr 2O3,CaO and NiO are also found in magnetite and ilmenite (App. F).

Fig. 5.28 Ilmentie geochemical plots of KUS324-20 and KUS322-8 in relation to White River Ash – eastern lobe

(WRA-E) and the northern lobe (WRA-N). Data for WRA-E and WRA-N are from Richter et al. (1995) (App. F)

102

Richter et al. (1995) studied tephra from Mt. Churchill, Alaska, which is the source of the late Holocene White River Ash (WRA) and identified two source lobes: an eastern lobe and a northern lobe. TiO 2 - FeO t percentages derived from illmentite analysis were plotted along with percentages obtained by Richter et al. (1995) to see where in relation to other WRA – eastern and northern lobe ash deposits the samples from 322-8 and 324-20 lie. Fig. 5.29 shows that 322-8 and 324-20 fall within the WRA-eastern lobe group. Although the sample size is insufficient for statistical analyses (n=2), the major elements from the White River tephra obtained by Jensen et al. (2005) at Duke River fan show similar results to those that obtained from Kusawa Lake. This confirms the origin of tephra found in Kusawa cores is from the WRA– eastern lobe. Based on the research by Froese et al. (2007), it is estimated that both the northern and eastern lobes of Mt.

Churchill erupted and deposited tephra in 1155 cal. B.P (1140 – 1200 cal. B.P. 95% C.I).

5.5.4 Rate of sediment deposition

Although there were no C 14 dates available for core KUS322, White River Ash indicates an average rate of sediment deposition in the upper 20 cm of this core to be ~ 0.1 mm / year. As mentioned in section 5.4.1, the core consists of only fine silt and clay laminae, thus it is possible to assume that the rate of sediment deposition throughout the 1 m long core is approximately constant. This would put the basal date of 322 at ~ 10 ka cal B.P.

As discussed in section 5.5.2, there is a linear relationship between both age and depth from four

C14 ages for KUS324. Mt. Churchill White River Ash – eastern lobe dates were incorporated and at a p = 0.05 level, there is a significant linear relationship between core depth and cal. B.P. dates (r = 0.997. r 2 = 0.994, y = 0.023x – 0.23, P = 0.561, p < 0.001) (Fig. 5.29; App. F). As a result, the long-term average sediment accumulation rate at this more proximal location of

Kusawa Lake site is estimated to be 0.25 – 0.48 mm/yr. Given this assumption, the bottom of 103 core 324 (at 2.8 m) is circa 10.5 ka cal B.P. This is the similar to the basal date estimated for

KUS322 and thus, both cores represent the complete record of Holocene deposition. Constant rates of accumulation were not observed in 324 as thick fine sand units were unevenly distributed throughout the core. Periods where average sediment accumulation rates of 0.48 mm/year are coincident with high magnitude flooding events. Low or no sand intervals have an average rate of ~ 0.25 mm/year.

Fig. 5.29 Age – depth curve of core KUS324 using C14 and White River Ash eastern-lobe dates. The median

probability from the 2-sigma range is given (Table 5.1) and is used in the construction of the age- depth curve

(App. F). White River eastern-lobe dates are used with accordance to research carried out by Frose et al. (2007).

104

VI - Discussion

6.1 The Kusawa lacustrine system

Underflows are widely recognised as the principal mechanism of sediment distribution in pro-glacial lakes. Underflows occur when there is a difference in density between the lake and inflowing river water, and changes in temperature and temperature gradients (Middleton &

Hampton, 1976; Leeder, 1982; Lowe, 1982; Hodder et al., 2007). Core samples and CTD profiles showed that turbidity currents dominate the sedimentary environment of Kusawa Lake.

As discussed in section 2.4.1, turbidity currents are formed typically by the introduction of colder glacial melt water into warmer lake water. This can be identified by the change in turbidity levels, especially where there are lateral in-feeding tributaries feeding into the lake.

Within Regions II – V of Kusawa Lake, lateral in-feeding tributaries affect turbidity levels between 0 – 35 m water depths. At sites north of the Primrose River delta sediment concentration levels were also found to be higher. Numerous sections of sediment cores obtained from both the northern and southern regions of Kusawa Lake showed deposits of fine sand grading upwards into the overlying clay deposit (Fig. 5.14 & 5.20). Suspended sediment was transported above the epilimnion and slightly finer sediment particles reached sites 326, 319 and 327 by transport of interflow or overflow currents. It is possible that sediment delivery is dominated by underflow currents generated from catastrophic events such as slumps from mass movement processes off the delta that generate surge-type currents (Middleton & Hampton,

1976; Edwards, 1992) off the delta. This would explain the presence of thick sand layers found predominantly in cores KUS326, 319 and 327. Therefore, CTDs and core stratigraphy results suggest that not only are lateral tributaries an important localised source for sediment input, but much of the sediment remains within the epilimnion during the summer when the lake is stratified.

105 Conductivity levels were lowest in the epilimnion of proximal waters and gradually increased with increasing depth reaching a maximum chemocline at 28.2 m water depths. This is not uncommon for deep water lakes. Throughout the summer months, photosynthesis of aquatic species is high and as the rate of photosynthesis, decreases with increasing depth (the chemocline) an increase in bicarbonate ions is produced (O’Sullivan et al., 2004).

Conductivity values north of the Primrose River delta were at least 5 µm/cm higher than the values found south of the delta (Fig. 5.3). Conductivity levels were highest for all of Kusawa

Lake near the Kusawa Campground alluvial fan (Fig. 5.3). The CTD profiles were recorded in

July. The campground is densely occupied throughout the summer months and recreational activities increased the level of pollutants (inorganic dissolved solids) both onshore and in-lake

(O'Sullivan et al., 2004).

6.2 Post-glacial sedimentary environment of Kusawa Lake

Glacier flow indicators mapped by Kindle (1953), Hughes et al. (1969), Jackson et al.

(1991) and Gilbert & Desloges (2005), and streamlined-bedrock forms along the Shakwak

Trench line and the valleys of Kathleen, Dezadeash and Federick Lakes, all indicate that the major flow of Pleistocene ice was northward into the Kusawa Valley. Throughout the

McConnell Glaciation, large valley glaciers from the St. Elias complex flowed east, northeasterly and north into the valleys of the Slims, Kaskawulch, Dusty and Alsek River, coalescing with ice from the Cassiar region. Kerr (1934), Kindle (1953), Jackson et al. (1991) and Gilbert

& Desloges (2005) all indicate that the mountain glacier complex decayed rapidly (< 2000 yr) ending no later than circa 10.5 ka cal. BP.

Eyles (1990) suggested that during the late glacial, many glacial lake valleys in northwestern Canada were affected by sediment, which was deposited quickly and in large

106 quantities forming thick deposits. Gilbert (1975) recorded thick (>180 m) acoustically stratified sediment in Lillooet Lake, and identified these as being deposited throughout the entire Holocene but the thickest package was de-glacial in origin. Hodder et al. (2006) also noted similar early

Holocene and late glacial accumulations in Mud Lake of British Columbia. Similarly, deposits about 120 m thick were recorded in the proximal lake basins of Willison Bay and Llewellyn Inlet of Atlin Lake in northern British Columbia, which were also identified to be de-glacial in origin

(Serink, 2004; Gilbert et al., 2006).

Gilbert & Desloges (2005) interpreted acoustic records that show conformably deposited sediments to at least 60 m below the sediment surface of Kusawa Lake. Facies 1 (the lowermost facies) provides evidence for the final lowering of Kusawa Lake following the last drainage of the Glacial Lake Champagne ice dam. A second facies, which lies conformably over facies 1 extends to the modern sediment surface. Facies 2 can also be found in Region I of the lake.

However, Gilbert & Desloges (2005) noticed that the reflectors of facies 2 are more concentrated towards the deeper parts of the lake such as Region IV (Fig. 5.9). The acoustic records also show that the upper-most (recent) facies consists of well-layered sediment with reflectors parallel to the present lake floor (Fig. 5.9).

The presence of a thinner and more opaque third facies in Kusawa Lake provides evidence for the drainage of Glacial Lake Champagne, and indicates the following:

1) significant erosion, transport and deposition of sediment, where thick glaciolacustrine deposits were laid down (Eyles, 1990), 2) significant sediment availability in and around the lake during de-glaciation; 3) rapid ice withdrawal, and 4) despite the presence of sediment traps within the upper watershed, sediment supply into the lake was abundant during, and immediately after deglaciation suggesting a well connected sediment cascade.

107 As a result, we may infer from the acoustic evidence that the sediment regime of Kusawa

Lake was similar to lakes within northwestern Canada, which delivered “thick and fast” sediment throughout the early Holocene (Eyles, 1990).

Although stratified acoustic records can be traced up lake, acoustic facies from Regions II

– V of the lake are not distinguished in Region I. The acoustically layered sediment (~ 40 m thick) found in Region I may have been deposited primarily during the post – Lake Champagne drainage period (Gilbert & Desloges 2005). Although acoustic penetration in this region was limited by thick sand, records did show up to 25 m of thick rippled sand at the bottom. The majority of sediment originated from the Primrose River sub-basin, where the incision of the deltas delivered large loads of coarse-grained sediment to the falling lake, some in episodic events associated with slope failures. The Primrose River delta was created by a reworking of large, high level delta terraces. The entrenched Primrose River falls steeply through a series of rapids across the older deposit. The Primrose River delta is terraced and has pro-graded into

Kusawa Lake, which now creates a “narrow” with the opposite shoreline (Fig. 5.6). At low water levels (~ 1 m), a large part of the narrows region is emergent (Fig. 5.6).

The Kusawa Campground alluvial fan complex has progressed into the northern half of

Region I, further affecting the top ~ 1.5 m of lake bottom sediment observed in cores. However, acoustics show no record of this, which suggests that the alluvial fan-delta complex was formed relatively recently.

Acoustic records of Kusawa Lake also show numerous and isolated lake bottom depressions. Reasons for the presence of depressions in Kusawa Lake were suggested by Gilbert

& Desloges (2005) to include tectonic factors and turbidity currents.

108 Plate tectonics determined the shape of Kusawa Lake, where the displacement of the

Shakwak trench created the distinct “S” shape of Kusawa Lake. Given the presence of strandlines along the Dezadeash Valley, old drainage patterns before faulting may have connected Kusawa Lake with Federick Creek and Federick Lake. Region III of Kusawa Lake lies in the Shakwak Trench, which is known to be actively faulting (Kerr, 1934; Kindle, 1953).

However, acoustics within Region III show a slight displacement from one side of the depression to the other (Gilbert, 2004) due to the presence of a mound ~ 40 m in depth. Either this displacement is due to a strike – slip motion, which may have caused some intermittent depressions within the lake, or it is the consequence of super critical turbidity currents.

Turbidity currents are known to create trenches at the bottom of lake beds. Gilbert

(2004) suggested that the size of depressions found in Kusawa Lake is comparable to the largest trenches that have been reported elsewhere (cf. Desloges & Gilbert, 1998; Lamoreaux et al.

2002). When the trunk glacier retreated from the southern portion of Kusawa Lake large amounts of sediment were pumped into the lake (Gilbert, 2004). Where velocity was highest

(supercritical flow), large vortex-like underflows scoured deep trenches in the lake bottom.

Acoustic records and sampled sediments – for example, the sedimentological differences between cores KUS324 and 322 – demonstrate that down-lake sediment movement is through a combination of underflow and interflow carrying sediments in suspension. The deposition of sediments from turbidity currents and the scavenging of lake bed account for the conformable deposition along the thalweg (Fig. 5.8). The turbidity currents generated from the upper lake areas travel the length of the main basin depositing graded sediments at decreasing rates with increasing distance from the Kusawa and Takhini River outlets. However, currents flowing from south to north do not travel past the Primrose delta.

109 6.3 Sediment as a proxy for Holocene environmental change in Kusawa Lake

The reconstruction of changes in sedimentary environment of Kusawa Lake allows some inferences regarding Holocene watershed processes and associated sediment delivery. Varves are annual deposits and are thought to provide annual to sub-annual resolution insight into variations in depositional processes over long periods (Desloges, 1994; Slaymaker, 2003). As noted in the conceptual model by Hodder et al. (2007), typical varved records from a glaciated environment indicate that the ‘Climate System’ is controlled regionally by latitude, elevation, continentality and atmospheric-oceanic interactions (Fig. 2.1). As a result, periods of increased varve thickness could be interpreted as periods of “warm” (recession) or “cold” (ice advance) conditions from these stands. Because varves can be derived from different processes, it becomes difficult to base climatic reconstructions on varve records alone: to determine exactly which season within a particular year played a greater role in climatic changes or, specifically, which meteorological conditions/events were most significant in driving lacustrine deposition in

Kusawa Lake.

While only portions of the Kusawa cores are varved, some coarse resolution evidence for late glacial retreat and Holocene climate change in the upper Takhini River drainage basin is preserved in the sediments of Kusawa Lake. It must, however, be noted that compaction of sediments is inherent due to continuous burial and coring effects. Void ratio, porosity and water content can decrease with depth below the sediment surface as bulk density increases by as much as 33 % below 1m sediment depths (Gilbert, 1975; Desloges & Gilbert, 1994). Despite errors involved, the measurements of sand, silt and clay laminae from the cores are believed to be representative of undisturbed sediment from the coring depths.

110 6.3.1 Late-glacial, early Holocene (10.5 ka cal. BP – 7.0 ka cal. BP)

6.3.1.1 Sedimentary environment

Given the five dates (four C 14 dates and a tephra layer) obtained from core KUS324 and the age-depth model (Fig. 5.29), the 2.8 m long sediment record indicates an average accumulation rate of 0.25 mm/yr and up to 0.48 mm/yr during high-energy depositional events.

This is in contrast to the Kusawa Lake acoustic records, which show a “thick and fast” early phase of deposition during de-glaciation starting prior to ~ 10.5 ka cal. BP, whereas the upper most 3 m of lake sediment documents the very low Holocene sediment input. These overall

Holocene rates are in agreement with estimates made from core KUS322 taken in Region II of the lake.

The early Holocene is represented in the lower most sections (Fig. 6.1) of core KUS324 and is characterised by a direct delivery of sediment from the upper-most Takhini River sub- basin and the Kusawa River sub-basin into Regions V and IV. Laminated sand deposits suggested high-energy transport via underflow currents. The thick sand layer observed at the bottom of core KUS324 (2.6 – 2.8 m; ~ 10 ka cal. BP) (Fig. 5.14 & 6.1) is probably final deposition resulting from the drainage of Glacial Lake Champagne during the McConnell deglaciation period terminating at 10.5 ka cal. BP. Silt alternating with laminated sand deposits between 2.6 – 2.0 m of core 324 (~ 10.5 – 9.0 ka cal. BP) suggests periods of climatic variability

(intermittent warm and cool intervals) throughout the Holocene Thermal Maximum (HTM).

Contacts between the silt and laminated sands were sharp, indicating the dominance of discrete underflow currents. Within the units of laminated sand deposits, higher levels of organic matter content (~ 3.4 %) probably indicate how high energy floods emanating from the upper-most

Takhini River watershed may have eroded and transported surrounding hillslope and floodplain vegetation, and how a possible increase in temperatures may have influenced lake productivity

111 levels (Lacourse & Gajewski, 2000; Chakraborty, 2008).

A change is reflected in the sediments of core 324 between 2.0 – 1.78 m (Fig. 6.1), where thinner, less frequent bands of laminated sand with sharp contacts were found within the silt deposits. However, three massive beds of sand, coupled with sand laminae were found between

1.78 and 1.5 m (6.0 ka cal. BP) (Fig. 6.1) signalling a return to high-energy events. The presence of such units indicated episodic high-magnitude flooding. Contacts between the silt and sand were sharp, indicating underflow currents as a primary driving force within the lacustrine environment. Possible generating mechanisms of these sand deposits include high-magnitude snowmelt or summer rainstorm events that generate large floods and / or sub-aerial or subaqueous hillslope failures around the lake margin.

Between 1.5 and 1.25 m (C 14 : 5480 cal. BP at 1.35 m) (Fig. 6.1) of the core, sand deposits became infrequent and decrease in thickness and average grain size (Fig. 5.13a, 5.22a &

App. C). The upward grading of silt deposits capped with clay are indicative of interflow currents followed by a period of quiet discharge (Last & Vance, 2002; Smith & Ashley, 1983).

These sedimentological results may indicate that the termination of the HTM in the Kusawa

Lake region which, based on the age-depth model, would be around 7.0 ka cal. BP.

6.3.1.2 Kusawa Lake diatoms

Chakraborty (2008) produced a high-resolution sequence of paleolimnological change through the analysis of diatoms and measurement of biogenic silica in core 324. Both benthic and planktonic diatom species found throughout the core were well preserved although planktonic species Cyclotella ocellata and Cyclotella pseudostelligera dominated . Chakraborty

(2008) found that Cyclotella ocellata was most abundant between 10.5 – 8.0 ka cal. BP., reaching its peak of 54 % relative abundance at ~ 8.6 ka cal. BP. Conversely, Cyclotella

112 pseudostillegera , experienced its lowest abundance levels during this period, which ranged from

1-5%.

Between 8.0 – 5.0 ka cal. BP., Chakraborty (2008) noted a change in diatom species assemblages in Kusawa Lake with a 25 % decrease in the relative abundance of Cyclotella ocellata and a 41 % increase in Cyclotella pseudostelligera. This significant shift in planktonic primary production suggests that the Holocene Thermal Maximum (HTM) began ~ 9.0 ka cal.

BP., and terminated at ~7.0 ka cal. BP. Given the limnological record of Kusawa Lake,

Chakraborty (2008) suggests that the termination of the HTM in the Kusawa Lake area was earlier in the Yukon Territory.

Between 5.0 ka cal. BP, Cycotella ocellata displayed a decrease in relative abundance from 27.1 % at 5.0 ka cal. BP. to 17.5 % at 200 cal. BP. Meanwhile, Cycotella pseudosteligera dominated and increased in relative abundance from 42.2 % at 5.0 ka cal. BP. to 65.2 % at 200 cal. BP. at 2.2 ka cal. BP. However, Cycotella pseudosteligera decreased significantly, to 50 % at 200 cal. BP (Chakraborty, 2008). The rise in Cycotella pseudosteligera after 5.0 ka cal. BP reflected the milder conditions following the HTM. Cyclotella ocellata, which has a higher temperature optimum, would be expected to decrease in abundance during this period

(Chakraborty, 2008).

6.3.1.3 Climate

Sedimentological and limnological results obtained from Regions V – II of Kusawa Lake are comparable to other pro-glacial lakes of northwestern Canada. Sedimentary characteristics of the early Holocene reflected in the bottom of core KUS324 are similar to those of some other glacier-fed lakes in the Canadian Cordilleran, confirming the effect of the regional climate upon glaciolacustrine processes. Sediment core VC1, taken from Mud Lake, B.C. showed sharp

113 contacts of sand deposits above silt, and high levels of organic matter content at ~ 9.6 ka cal. BP.

(Hodder et al., 2006). Likewise, Barber & Finney (2000) recorded higher and more variable rates of sediment accumulation in Kluane Lake, Y.T. between 10.5 – 8.0 ka cal. BP., which is a reflection of the early Holocene deglaciation.

The sedimentary characteristics between 2.0 – 1.78 m of core 324 (Fig. 6.1) and diatom assemblages mark the HTM termination at ca. 7.0 ka cal. BP. This date is also confirmed by

Spooner (2002) and Mazzucchi et al. (2003), who noted that at ~ 7.5 ka cal. BP, the regional climate within the Yukon Territory began to cool due to an increase in effective moisture content from the Aleutian Low and also due to an increase in the intensity of the Pacific air mass.

6.3.2 The Neo-glacial (7.0 – 2.0 ka cal. BP)

6.3.2.1 Sedimentary environment

Distinctively thick clay-silt couplets were found between 1.78– 0.98 m of the core (Fig.

5.21a) and this was followed by a thick (~ 4 cm), laminated sand deposit at 0.95 m. An increase in organic matter content was also noted (Fig. 5.13a & 5.22a), which suggests an increase in lake productivity due to a shift in the hydroclimatic regime to slightly warmer climatic conditions in

Kusawa Lake. This was followed by a unit of rhythmic silt with thin, well-defined laminae found between 0.8 and 0.55 m of core 324 (Fig. 5.21a, Fig. 6.1). The top 0.5 m of core 324 (Fig.

6.1) and the top 0.1 m of core 322 of Regions IV and II respectively, showed no variation in sediment deposition: deposits were thick massive silt. The thin layer of white-coloured tephra found at 20 cm of core 324 and at 8 cm of 332 was confirmed to be White River Ash. The eruption of both the northern and eastern lobes of Mt. Churchill, Alaska in 1155 cal. BP deposited tephra across southwestern Yukon (Froese et al., 2007). The very low late Holocene

114 inputs of sediments could be climatic driven (i.e. drier) or a sediment-exhaustion / sediment- shortage effect from the upper basin. The latter cause is more likely.

6.3.2.2 Climate

The sedimentary characteristics of the 1.78 – 0.98 m (Fig. 6.1) of core 324 marked a climatic cooling period coupled with sediment abundance as seen by the occurrence of low magnitude, high frequency sedimentary outwash events. Similar processes and climatic controls discussed by Mazzucchi et al. (2003), Anderson et al. (2005) and Brahney et al. (2008) correspond to results found in Kusawa Lake. Between 4.5 – 3.5 ka BP, a significant increase in atmospheric circulation intensity from the southwest Pacific had a profound influence upon precipitation in northwestern Canada (Anderson, 2005). The effect of the Aleutian low was also reflected in the sediments of Pyramid Lake in the Cassiar Mountains and in Kluane Lake of Y.T.

(Brahney et al., 2008). Mazzucchi et al. (2003) discovered a rise in the sedimentation rates with an increase in both the thickness and frequency of fine sand laminae indicating a possible increase in the rate of spring snowmelt or a rise in number of high-magnitude convective rainstorm events.

In Kusawa Lake, the thinly laminated sediments between 0.8 and 0.55 m of core 324 were a direct reflection of sediment exhaustion from the upper basins (Fig. 6.1). Similar results were obtained from sediment cores of Kluane Lake, where Brahney et al., (2008) noted distinct sequences of rhythmic sediment laminae at this time. Sediment records from Jellybean Lake of southwestern Yukon showed that after 2.5 ka BP, the Aleutian Low was situated westward and therefore its effects in the southwestern Y.T were weakened, creating cooler and wetter conditions Anderson et al. (2005).

115 The unit of rhythmic silt with thin, well-defined laminae found between 0.8 and 0.55 m of core 324 also confirm that by ~ 2.0 ka BP, the position of the Aleutian Low was the furthest west and weakest than at any time within the last 7500 years. The westward shift in the Beaufort

Gyre allowed an increase in moisture delivery into the interior regions of the Yukon Territory

(Gajewski & Lacourse, 2000; Pienitz et al., 2000, Last & Vance, 2002) and had a substantial effect upon the glaciolacustrine sediment delivery within the region, exhausting all sediments from the upper reaches creating a shortage. Similar results were yielded in Kluane Lake

(Brahney et al., 2008).

Figure 6.1 Stratigraphic log of core KUS324, arbitrary climate record and Jelly Bean Lake 18 O Aleutian

Low (modified from Anderson et al., 2005) ‘+ve’ denotes a “warmer” climate, whereas ‘–ve’ denotes a “cooler” climate”.

116 6.3.3 Little Ice Age (1200 – 1900 AD.)

6.3.3.1 Sedimentary environment

As discussed in section 6.2, Region I is heavily influenced by the Primrose River delta extending into Kusawa Lake. This began as the delta formed during the Glacial Lake

Champagne phase and continued after drainage well into the Holocene. Given the size of the delta and tributary watershed, much coarse sediment (sand) was delivered into region. Cores extracted from Region I showed no recorded presence of White River Ash or dateable organic matter material, as found in cores 324 and 322. This suggests surface sediments of Region I are more recent in origin. Organic matter content, laminae thickness and acoustic results all point to very much higher rates of sediment input into this distal region of Kusawa Lake. The average sedimentation rates, based on assumed varve deposition, and the absence of White River Ash suggest that all core records north of the Primrose River delta have basal dates younger than

1155 cal. BP. Average, long-term, rates of sediment accumulation are probably up to 3.3 mm/yr and in some intervals, as high as 5.0 mm/yr.

Between the bottom of sediment cores KUS325, 326, 327 and 319 there are four correlated beds of thick sand (Fig. 5.16, 5.17 & 5.18), which interrupt sequences of thicker silts and clays. These distinctive sand beds can be traced between the four cores (Fig. 5.23a, b, & c).

Beds show sharp (erosive) lower contacts and some fine sand units display distinct ripple / cross- bedding structure composed of centimetre-scaled light coloured sands alternating with darker millimetre-scale sand laminae (Fig. 5.13 c, d, e, f and h). It is believed that these sand deposits are turbidites probably due to large flood events emanating from the Primrose River (Bouma,

1964; Middleton & Hampton, 1976). However, there was no evidence of fine sand grading upwards into the overlying clay deposit. Silt deposits are abrupt and thin (typically half the width of a varve), followed by a ~ 0.8 cm thick deposit of clay. The assumption here is that

117 these are varves. Couplet counts suggest thick sand deposits are cyclic in nature occurring about once between every 10 - 20 silt-clay couplets. The cyclic nature of silt-clay and sand deposits suggests high-energy discharge events, with recurrence intervals of ~ 15 varve years, persisted for a period of about 60 varve years (Fig. 5.13 c, d, e, f and h). Unfortunately, there are no absolute dates to place this sequence in a proper time context.

Silt – clay couplets, possibly varves, are recorded between 1.7 m to 0.7 m of cores 325 and 319 and from 1.7 – 0.9 m of core 327 and from 2.22 – 1.35 m of core 326 (Fig. 5.13c – f).

On the whole, the couplet units suggest a period of less energetic conditions without major turbidities but with very distinct seasonal contrasts in discharge and sediment input. Assuming

3.3 mm/year sedimentation rates, this sequence of couplet formation occurred circa 1650 – 1800

AD, which is coincident with climatic cooling during the Little Ice Age.

A third sediment facies occurs at the top of all four of these cores in Region I. The sediment is thick, clastic-rich, medium silt with no apparent laminations. The presence of six thin sand layers, which interrupt this sequence of thick silt suggest intermittent flood events emanating from the Primrose River delta. The sudden increase in OM content by approximately

3 % at ~ 0.3 to 0.2 m of all cores is probably the result of inputs during the waining stages of the

1982 flood.

6.3.3.2 Climate

Evidence for the occurrence of the Little Ice Age (LIA) is well preserved in lake sediments across northwestern Canada. Unlike the preceding ~ 9000 years, the climate throughout the LIA was variable with intense cooling periods. The Aleutian Low was situated westward at around 1200 and 1900 AD, and eastward at ~ 1700 AD. The intensification

(eastward shift) of the Aleutian Low usually results in a brief periods of cooler spring

118 temperatures (Wiles et al. 2002; Anderson, 2005). Geomorphic indicators, such as results from ice-cored moraines, the development of nivation terraces in the Dezadeash Range from persistent snow banks, and blockage of the Alsek River by fluctuating ice fronts coincide with the occurrence of glacier advances between 1200 – 1300 AD, and more significantly, advances between 1700 and 1900 AD (GeoProcess NTS 115A, 2002).

Based on stratigraphic evidence and the inferred average sedimentation rates in cores taken proximal to the Primrose River delta, it is probable that the well-defined varved sequences are associated with the LIA. Other pro-glacial lake studies report similar LIA effects on sedimentation. The varve chronology of Iceberg Lake, south-central Alaska, showed a cooler period between 1500 and 1850 AD (Loso et al., 2006). Lake levels rose in Kluane Lake due to the advance of the Kaskawulsh Glacier in the St. Elias Mountains between 1680 and 1700 AD., and produced rhythmic sediments (Brahney et al.,2008). Serink (2004) noted a variable period of varve thicknesses delivered from the Juneau Ice Fields into the Llewellyn Inlet of northwestern B.C. ~ 1725 – 1775 and 1850 - 1900 AD., which were coincident with known LIA advances of glaciers situated in the adjacent Wrangell Mountains (Wiles et al., 2002). Similarly,

Hodder et al. (2006) recorded well-defined varves over the last 129 years (~ 1876 AD) which clearly showed the recession of glaciers from the LIA maxima at Mud Lake. In terms of clastic sediments, Menounos (2009) recorded a series of well-defined varves in Green Lake of southcentral B.C. and in Red Barrel Lake of northern B.C. between 1700 – 1850 AD. (Menounos,

2009). Lakes draining glacial environments show an increase in the fraction of clastic sedimentation during fully advanced ice (Håkanson 1995; Menounos et al. 2004). The subsequent increase in variability of sediment deposition (massive to varved) recorded in proglacial lakes across northern B.C and the southwestern Y.T marked the termination of the

119 LIA. This is coincident with the end of glacial advances in coastal southern B.C. (Clague &

Evans, 1998; Luckman, 2000; Wiles et al., 2002; Anderson et al., 2005).

6.3.4 Post – LIA to present (1900 – present)

Based on the presence of organic matter identified within the top 0.5 m of all 9 cores in

Region I, it is estimated that the average rate of sediment deposition across the four cores surrounding the Kusawa Campground alluvial fan (cores KUS318, 330, 331 and 329) is approximately 5 mm/yr. The 5 cm of fine sand found at 2 m of all cores surrounding the Kusawa

Campground alluvial fan (with the exception of core 330) suggested that the Kusawa alluvial fan experienced a high magnitude flood event approximately 400 years ago (Chow, 2007). Prior to the 1600’s (400 – 1100 years ago), the sand layers of core 329 suggests that extreme flooding events may have been at ~ 100 year cycles (Fig. 5.1k). Between 3.1 – 1.85 m of core 329, four thin (< 1 cm) laminated sand layers interrupt the well-defined silt laminations and may indicate intermittent major flooding events.

Using dendrochronology and lichenometry methods, Lowey (2000) and Lipvosky (2006) provided evidence that a catastrophic flood occurred in the Kusawa Campground alluvial fan complex approximately 200 years ago. Sand deposits found at 1.28 m of core 331 (Fig. 5.13j &

5.21j) and at 0.8 m of core 329 (Fig. 5.13k & 5.21k) may be related to the sequence of fine-sand and silt laminae found between 1.3 - 1.47 m of core 318 (Fig. 5.13h & 5.21h). This deposition may have occurred sometime between 160 - 260 years ago and is most likely to be correlated with the event as described above. The 2 – 5 cm thick fine sand deposits found at roughly 0.6 m of the four cores surrounding the Kusawa Campground alluvial fan probably date back to approximately 120 years.

120 It must be noted that not every coarse layer of sand deposited in the cores necessarily represents a separate event or separate year. In addition, the cause of each high-energy event may differ. For example, the occurrence of snowmelt or rainstorm floods generated in the upper

Campground alluvial basin relate to different climate forces. Overloading and failure of the alluvial fan-delta front can be intrinsically triggered and be only indirectly related to climate specific climate affects.

Although a specific magnitude of flooding can not be determined from the cores, the recurrence interval of major flooding events can be estimated. Studies regarding hillslope failure in permafrost environments estimate that landslides and debris flows occur on a 10-year to 100- year recurrence interval (Leopold et al., 1983; Clague & Evans, 1998; Knighton, 1998). Lowey

(2002) estimated that the recurrence interval of flooding events within the Kusawa Campground alluvial complex is approximately every 150 – 200 years. However, from core 329 (5.5 m in core length) a recurrence interval of circa 100 years may be determined up until the last 400 years (1600’s). The highest frequency of sandy deposits in all cores appear to occur in the interval prior to 250 years ago, followed by a reduction in high energy deposition up until 120 years ago . Within the last 120 years, there was a notable return to higher frequency events, with an estimated 25-year recurrence event (Chow, 2007).

6.4.1 Specific Sediment Yield of Kusawa Lake

Using the average accumulation rate (AAR), lake wide sediment accumulation rates can be estimated for Kusawa Lake. The total drainage basin area for Kusawa Lake is 4292 km 2. The

AAR of Regions II to V is ~ 0.25 mm/yr, and up to 0.48 mm/yr during high energy internals.

The AAR of Region I is ~ 3.3 mm/yr and up to 5.0 mm/yr during high energy periods. The lower values for AAR for the two regions are used here to estimate minimum total sediment

121 loads. Assuming an average specific density of 1.1 g/cc for the laminated silts and clays, the total annual sediment load is 277,000 tonnes in Regions II - V, and 104,500 tonnes for Region I.

This equates to a specific sediment yield of ~ 11 t/km 2/yr for the 2496 km 2 sub-basins of Regions

II – V, and 58 t/km 2/yr for the 1796 km 2 sub-basins of Region I. The percentage glacier cover in the Kusawa watershed feeding Regions II – V is 3.7 % and 3.0 % for Region I. Therefore, the

Primrose River sub-basin delivers sediment into Kusawa Lake at a different rate, relative to the

Kusawa River sub-basin and the upper-most Takhini River sub-basin.

Studies from other large lakes in the coastal regions of the Canadian Cordillera (c.f.

Chilko Lake, Desloges & Gilbert, 1998; Atlin Lake, Gilbert et al., 2005) show highly variable sediment loads both spatially and temporally. These patterns reflect particular styles of deglaciation in large watersheds and regional climate variability over the Holocene. The amount of glacier cover in a watershed and total drainage basin size is thought to be positively correlated with sediment production rates. Figure 6.2 and 6.3 compare recent (last 100 years) specific sediment yield vs. glacier cover and specific sediment yield vs. total drainage area respectively, for glacier-fed lakes throughout the Canadian Cordillera. In general, there is a declining ratio of sediment yield with an increase in the size of a drainage basins (Fig.6.3). Much of this is thought to relate to greater storage effects in larger watersheds. Glacier-fed lakes receive from 33 – 386 t/km 2/yr of sediment (Hodder et al., 2006). Relative to other glacier-fed lakes studied within the

Canadian Cordillera, the modern (last 100 years) sediment yield to Kusawa Lake is very low, at least within the main body of the lake. Unlike glacier-fed lakes of the Rocky Mountains, those found in the coastal regions of the Cordillera tend to have highly variable sediment yield rates that are related not only to glacier cover but also geology and the influence of maritime-Pacific climates (Fig. 6.2). Therefore, low rates of sediment delivery to Kusawa Lake would be

122 consistent with one or more of climate, low erodibility (i.e. high resistance) of the bedrock lithologies or trapping of sediment in the upper watershed.

Fig. 6.2 Specific sediment yield comparison for glacier-fed lakes in the Canadian Cordillera, plotted by percent

glacier cover. For specific locations, see Hodder et al. (2006)

Fig. 6.3 Specific sediment yield comparison for glacier-fed lakes in the Canadian Cordillera, plotted by drainage

basin area. For specific locations, see Hodder et al. (2006). 123 Overall, there was no major variation in sediment geochemical composition either down core or temporally or spatially throughout the cores affected by inputs from the Upper Takhini drainage basin. The greatest variation was Fe 2O3 in sand deposits from Region IV and from the southern half of Region I were there was ~ 5 % higher than average Fe 2O3 (Fig. 5.26). Core geochemistry is consistent with the overall bedrock geology of the Upper Takhini River watershed, which is comprised of granodiorite, granite intrusions, quartz mica schist, gneiss, slate, quartzite, limestone, and greenstone. Little to no variation in geochemical composition down the cores suggest either no strong differential inputs from various source areas in the basin or that there is insufficient bedrock and surficial material variability to discriminate. The latter hypothesis is more likely but cannot be tested with confidence in this study.

6.4.2 Sediment trapping

Hodder et al. (2007) discussed the influence of intervening sediment traps in the upper reaches of drainage basins. The trapping of sediment enroute from glacier sources to the lake can result in lag effects in the sediment cascade (Brierley et al., 2006; Hodder et al., 2007) and can have a significant effect upon the lacustrine depositional pattern. For example, Dirszowsky

& Desloges (2004) reported the presence of a thick alluvial cap on the Moose Lake delta, which acted as a major sediment storage site for most of the Holocene. This resulted in lower yields to the lake and less Holocene variability in the lake sediment record. A number of large sediment traps within the upper reaches of the upper Takhini River basin have affected the distribution of sediments into Kusawa Lake. Takhini Lake, just upstream of the Takhini River outlet into

Kusawa Lake, acts as a major sediment trap for this portion of the drainage basin. Aerial imageries (Fig. 5.5a & b) showed a braided channel and sediment plumes flowing into Takhini

Lake indicating that both coarse and fine sediment are stored there. The upper-most Takhini

124 River delta entering into Kusawa Lake is small (0.4 km 2) for the size of the watershed (Chow,

2007) also suggesting upper basin sediment storage is significant. Other storage sites include alluvial fans and cirque basins in the upper reaches of the upper Takhini River basin.

Smith (1981) documented a 40 % reduction in sediment rates following the formation of a pond at the terminus of Bow Glacier upstream from Bow Lake, Alberta. Any flushing of the small sediment trap system would only occur when very high-energy flood events or glacier advances helped scour out the trap (Smith, 1981).

Despite significant sediment storage in the upper Kusawa Lake drainage basin, intermittent thick sand deposits found throughout core 324 provided evidence for high-energy turbidites. It is most likely that these sand deposits are derived from the upper Takhini River outlet where today right hand deflected surface sediment plumes are commonly observed (Fig.

5.5a & b). Core KUS322 taken north of Jo-Jo Creek outlet of Region II showed thin, weakly to well-defined silt-clay laminations throughout. Sand fractions accounted for no more than 5 % of the core and the average sediment accumulation rate was very low. The absence of sand in core

KUS322 suggests turbidite transport is limited to the upper lake regions and therefore the headwater region in the major sediment source for all of Regions II - VI (cf. Edwards, 1992;

Hånkanson, 1983).

When compared to other Cordilleran lakes, both the Holocene and contemporary specific sediment yield to Regions II – V is very low relative to the size of the sub-basin and percentage glacier cover. Thin, weakly to well-defined, silt-clay laminae may be indicative of a shift in the climatic regime, sediment exhaustion and the opening of intervening sediment storage sites in

Kusawa Lake (cf. Hodder et al., 2006). However, intermittent sand deposits found throughout core 324 provided evidence for higher magnitude discharge events. Their frequency seems highest during the late-glacial, early Holocene and Neoglacial interval (Fig. 6.1).

125 In the large Primrose River sub-basin (area = 1466 km 2; 34 % of the entire Upper-

Takhini basin), glacial cover is low (3%) and there are two major sediment traps: Primrose Lake flowing consecutively into Rose Lake (Fig. 3.2) and a long sandur (Silt Lake) (Fig. 3.2). The initial assumption was that storage in this basin would produce low rates of sediment input into the northern region of Kusawa Lake. However, ~ 3.3 mm/yr sediment accumulation rates suggest much higher rates compared to Regions II – V. It is most probable that the Primrose River delta itself is a major source of sediment along with tributaries downstream of Rose Lake. The delta is

0.8 km 2 in area and is extensively terraced with many sub-aerial slumping banks.

The Kusawa Campground alluvial-fan delta complex was found to be a small and localised site for sediment storage. Sediments from slope failures in the upper basin, are transported downslope into the steep gorge-like channels. Sediment storage of coarser sediment in this fan-delta complex is also significant. Relative to the rest of Kusawa Lake, the rate of sediment accumulation off the fan-delta edge is high at around ~ 5 mm/yr. This is good evidence that local sediment inputs are very important in the north region of the lake. This is not the case in other regions of Kusawa Lake.

126 VII - Conclusion

Overall, Kusawa Lake and the Upper Takhini River drainage basin have provided the opportunity to assess the utility of large lake records in reconstructive Holocene climate change in both a spatial and temporal context. Due to their difference in scale, the conclusions of this chapter will be discussed according to context.

7.1 Conclusions about spatial variations

1) XRF results suggest that basin-wide bedrock composition does not help discriminate the source of lake sediments because of the uniformity in lithology throughout the watershed, as seen in the sediment cores derived.

2) The Kusawa River and uppermost Takhini River sub-basins are the dominant sources of sediment for Regions II – V where recent accumulation rates have been uniformly low. The large lake size, shape and bathymetry all contribute to limit the down lake extent (energy) of turbidity currents, which are mostly focussed in Regions IV and V.

3) The presence of a large sediment traps means that the upper Primrose basin has not likely been a significant source of sediment during the Holocene but the lower basin and raised delta have been. Region I has much higher sedimentation rates associated with inputs from the

Kusawa Campground alluvial fan – delta and Primrose delta complexes. They are important local sources of sediments and the turbidity currents that flow northward into Region I.

Progradation of the Primrose delta has effectively separated Region 1 from major sediment fluxes in the rest of the lake except for the finest silts and clays in overflow currents.

4) Some lateral tributaries along the main lake are likely important local sources, however, in general, sediment delivery today from the upper portions of the watershed is very limited due to significant sediment traps including large lakes and floodplains. This disruption in

127 the sediment cascade results in poor “connections” between source areas (hillslope, glacial, fluvial) and the lake and this has persisted throughout the Holocene. This somewhat limits the strength of inferences that can be made about basin-wide climate change impacts on sediment delivery.

5) The relatively small accumulation of Holocene sediments in Kusawa Lake is similar to other large lakes within the Canadian Cordillera and fits the pattern of lower specific sediment yield with the increasing size of drainage basins. Large lakes, with large contributing sub-basins and their tributaries do not provide a single archive of sediment inputs but can present a more complex spatial organization of sediment accumulation histories. Major tributaries such as the

Primrose River can be important sources of sediment but the timing and nature of upper basin sediment traps can be an important factor in explaining changes

7.2 Conclusions about temporal variations

1) Acoustic records and the basal sections of cores record “thick and fast” deposition following the drainage of Glacial Lake Champagne. During deglaciation and the Lake

Champagne phase, connections in the sediment cascade were likely much stronger, and overall sediment volume delivery to the lake was much greater.

2) Sediment accumulation rates were more variable throughout the early Holocene with a subsequent middle Holocene decline in variability followed by a Neoglacial increase. Cores taken in Region I of the lake showed only a continuous record of the Little Ice Age phase and more modern depositional events.

3) Stratigraphic evidence from core 322 and the acoustic profiles taken in Regions IV and II respectively, help verify that the Holocene core record at the 324 site is very likely representative of processes and accumulation rates for most of the lake. The acoustic records

128 show three distinctive sediment facies documenting the drainage of Glacial Lake Champagne.

This was mainly high-energy turbidity currents in a proximal glaciolacustrine environment. The decline in melt-water levels and availability of sediments throughout the HTM allowed for the deposition of thinner, concordant, packages of sediment by way of interflow currents with a lower magnitude, yet higher frequency of turbidites. The subsequent deposition of thicker laminae (varves) and well-laminated sediments throughout the Neoglacial phase marks the renewal of glacial activity with a shift to more variable discharge regimes and an overall increase in rates of sediment accumulation thereafter.

4) Cores KUS325, 326, 319, and 327 taken proximal to the Primrose River delta record the Little Ice Age phase. Renewed sediment inputs follow closely the pattern of glacier expansion throughout the LIA where rhythmic sediment deposits match the recession from LIA maximums within the St. Elias and Wrangell Mountains. This is also coincident with the end of known glacial advances in coastal southern B.C.

5) Cores near the Kusawa Campground alluvial fan-delta indicate localised high magnitude flood events. Prior to the 1600’s (400 – 1100 years ago), the sand layers of core 329 suggests that extreme flooding events may have been at ~ 100 year cycles. The highest frequency of sandy deposits appears to occur in the interval of 250 - 400 years ago, followed by a reduction in high energy deposition up until about 120 years ago. Since then, it is estimated that flood events occur at least once in every 25 years. All four cores show indications of the

1982 flooding event, where levels of organic matter content and sand fractions peak significantly.

129 7.3 Future directions

Faced with increasing concern regarding global climate change and its impact on water resources, the need for long-term paleoenvironmental records is recognised by researchers

(Dirszowsky & Desloges, 2004; Menounos et al., 2005; Gilbert et al., 2006; Hodder et al., 2006).

Despite the surge in the study of paleoenvironmental reconstruction for northwestern Canada within the last three decades, the focus remains on lakes situated in British Columbia. Further research needs to be conducted within the Yukon Territory in order to determine more precisely the role of regional climate in driving sediment delivery throughout the Holocene, especially where glacier-derived sediments are abundantly available. The potential complexity of large lakes suggests that a range of basin sizes and lake sizes are important to study to sort out local effects from regional conditions.

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140 Appendix A

Takhini R at Takhini R at Takhini R at Highway Bridge Highway Bridge Kusawa outlet Mean Mean Mean Annual Q Annual Q Annual Q Year (m^3/s) Year (m^3/s) Year (m^3/s) 1950 62.80 1985 55.80 1952 54.13 1951 48.10 1986 64.80 1953 65.50 1952 60.20 1987 61.60 1954 47.10 1953 76.10 1988 71.10 1955 1954 54.10 1989 64.90 1956 1955 56.20 1990 67.40 1958 1956 50.90 1991 1959 50.30 1957 73.00 1992 66.20 1960 49.30 1958 49.60 1993 75.90 1961 1959 58.20 1994 64.70 1962 1960 56.30 1995 56.50 1963 1961 72.20 1996 46.30 1964 1962 1997 64.60 1965 43.70 1963 1998 53.10 1966 50.60 1964 68.40 1999 59.20 1967 59.00 1965 52.90 2000 81.80 1968 1966 58.50 2001 69.30 1969 53.20 1967 70.60 2002 54.40 1970 37.40 1968 62.60 2003 50.20 1971 55.20 1969 63.80 2004 60.30 1972 54.50 1970 43.20 2005 65.90 1973 39.70 1971 64.70 2006 62.40 1974 50.90 1972 62.50 2007 72.10 1975 57.60 1973 47.10 Mean 60.55 1976 52.70 1974 62.50 1977 59.00 1975 69.30 1978 46.20 1976 63.30 1979 56.30 1977 68.90 1980 53.20 1978 53.70 1981 64.50 1979 68.30 1982 54.50 1980 60.50 1983 49.50 1981 71.10 1984 40.00 1982 64.60 1985 47.30 1983 57.00 1986 54.90 1984 46.80 Mean 51.78

Table A.1 Mean annual discharge of the lower Takhini River 1950 – 2007 referring to Figure 3.3

141

Appendix B

CTD Profiles

Southern Region Northern Region

Fig. B.1a & b Close-up (top 15 m) of figures 5.2a and 5.2b: Turbidity profiles of Kusawa Lake taken on July 19 th ,

20 th and 21 st 2004. Turbidity was measured in NTU units and converted to mg/L using the calibration developed by

Hodder et al. (2006) for this instrument.

142

Fig. B.2 Close-up (top 30 m ) of figure 5.3: Conductivity profiles of Kusawa Lake (north and south) taken on July

19 th , 20 th and 21 st 2004

143

Appendix C

Laser particle size results

KUS324 KUS325 KUS326 Depth % % % Depth % % % Depth % % % (cm) Clay Silt Sand (cm) Clay Silt Sand (cm) Clay Silt Sand 4 24.37 59.79 15.84 10 39.66 50.09 10.25 11 43.90 55.46 0.64 26 12.01 63.73 24.25 20 38.46 58.72 2.82 29 31.37 68.63 0.00 38 44.76 50.08 5.16 24 38.23 59.51 2.25 49 54.47 44.24 1.29 51 5.31 45.76 48.93 34 29.98 68.94 1.09 66 19.84 79.91 0.24 70 22.00 71.58 6.42 40 34.32 62.67 3.01 82 23.93 75.21 0.86 100 4.48 55.02 40.50 53 29.33 68.81 1.86 89 17.96 81.01 1.02 115 31.30 58.03 10.67 60 40.85 55.03 4.12 109 31.07 66.75 2.18 135 5.67 63.88 30.44 70 68.13 28.47 3.40 120 26.36 73.31 0.34 147 17.47 65.71 16.83 80 65.34 32.28 2.38 130 20.75 79.25 0.00 151 6.68 61.31 32.01 90 56.62 40.41 2.97 163 64.32 35.62 0.06 169 32.86 60.01 7.13 100 73.83 10.57 15.60 184 38.67 60.94 0.39 174 5.83 51.33 42.84 110 91.31 4.67 4.02 191 55.56 44.44 0.00 189 28.79 70.19 1.02 120 82.22 12.96 4.82 206 52.74 47.26 0.00 200 21.39 78.60 0.01 130 71.98 22.17 5.85 215 58.26 40.70 1.03 215 5.64 54.89 39.47 140 68.23 31.09 0.68 237 2.68 41.36 55.96 235 31.63 62.40 5.96 150 65.62 34.38 0.00 242 40.29 57.83 1.88 261 3.37 61.90 34.73 158 83.66 9.48 6.86 253 0.51 44.71 54.78 265 53.99 43.43 2.57 168 18.88 27.10 54.02 277 12.30 84.47 3.23 272 5.82 66.61 27.57 178 37.81 48.41 13.77 288 0.55 27.66 71.79 KUS322 188 2.18 26.84 70.98 KUS328 Depth % % % Depth % % % (cm) Clay Silt Sand 198 81.40 13.63 4.97 (cm) Clay Silt Sand 10 45.64 53.39 0.97 206 5.90 36.95 57.15 6 44.25 55.75 0.00 20 57.87 36.11 6.02 218 70.48 24.77 4.74 16 10.18 84.50 5.32 30 46.05 50.06 3.90 223 3.00 31.90 65.11 26 10.15 83.86 5.99 40 50.85 45.96 3.19 228 80.10 10.77 9.13 35 16.69 80.06 3.25 50 51.43 45.32 3.25 238 33.17 52.06 14.77 99 10.68 81.58 7.73 60 29.72 64.52 5.76 258 2.82 40.66 56.53 110 3.19 67.46 29.35 70 29.72 64.52 5.76 268 25.94 36.06 38.00 121 58.07 38.34 3.59 80 61.48 27.05 11.47 278 15.05 37.90 47.05 131 12.01 84.62 3.37 90 79.82 13.43 6.74 151 27.58 71.29 1.14 100 69.82 25.35 4.83

Table C.1 Percentage grain size of cores taken referring to Figures 5.22a and b

144

KUS319 KUS327 Depth % % % Depth % % % (cm) Clay Silt Sand (cm) Clay Silt Sand 7 21.89 76.42 1.69 5 36.36 63.37 0.27 20 14.13 84.89 0.98 23 39.20 60.02 0.79 32 9.77 89.08 1.15 28 27.06 71.43 1.51 48 16.60 83.13 0.28 32 29.47 66.86 3.67 58 29.33 69.84 0.83 42 21.05 78.95 0.00 66 20.22 53.32 26.46 53 42.37 57.63 0.00 78 65.04 34.87 0.09 68 40.52 58.67 0.81 94 41.96 57.82 0.22 81 63.94 35.05 1.01 106 44.39 55.61 0.00 99 68.48 31.44 0.09 119 38.65 61.35 0.00 112 71.84 28.08 0.07 125 60.18 39.07 0.75 156 71.48 28.52 0.00 137 47.03 51.98 1.00 166 44.75 37.57 17.68 148 50.94 48.95 0.12 172 1.29 24.40 74.30 163 50.62 49.38 0.00 188 32.09 65.89 2.02 167 0.45 28.79 70.76 206 2.98 28.14 68.89 185 2.00 52.79 45.20 215 71.01 28.96 0.03 195 60.92 36.70 2.38 225 0.91 16.84 82.26 196 13.25 86.55 0.19 241 87.84 11.12 1.05 213 30.84 68.25 0.91 254 3.08 60.97 35.95 KUS330 KUS318 Depth % % % Depth % % % (cm) Clay Silt Sand (cm) Clay Silt Sand 2 7.27 62.22 30.07 12 31.56 63.76 4.70 8 36.17 52.22 9.83 20 46.29 51.99 1.46 22 23.79 58.17 16.78 31 12.41 75.08 12.52 28 2.84 32.96 64.03 37 5.38 71.63 22.95 39 2.56 29.46 67.80 41 9.08 84.87 6.07 45 29.04 53.43 16.09 46 30.78 69.09 0.00 48 7.64 59.79 32.16 66 36.87 59.61 3.54 62 10.68 34.07 54.70 82 55.10 43.56 1.37 71 3.95 41.69 54.13 90 14.34 76.95 8.70 110 19.32 71.49 9.15 130 5.92 64.82 29.27 141 33.31 60.77 5.93 145 6.82 65.08 28.09 161 7.10 76.85 16.06 175 3.41 45.59 50.98 191 29.29 66.66 4.08

Table C.1 Percentage grain size of cores taken referring to Figures 5.22a and b

145

KUS331 KUS329 Depth % % % Depth % % % (cm) Clay Silt Sand (cm) Clay Silt Sand 3 32.33 58.37 9.31 9 31.40 63.66 4.94 12 4.95 65.08 29.94 14 3.88 63.84 32.26 20 7.80 62.18 30.01 28 4.45 68.48 27.06 32 8.32 52.77 38.92 50 2.82 31.66 65.52 60 3.82 62.57 33.64 76 1.93 24.99 73.09 82 25.00 68.95 6.06 95 2.72 28.74 68.59 111 2.68 42.46 54.88 113 31.86 65.57 2.56 125 4.35 67.09 28.55 150 3.93 42.54 53.49 136 2.03 24.01 73.95 164 24.35 60.57 15.08 148 35.68 61.21 3.11 190 5.36 72.20 22.47 160 12.02 79.99 7.99 230 4.08 57.39 38.57 176 32.16 54.32 13.55 250 41.79 54.81 3.43 189 15.94 61.98 22.12 273 35.76 58.66 5.61 192 5.36 72.35 22.29 315 3.43 45.57 51.04 202 4.07 58.24 37.64 335 30.26 56.76 12.99 218 45.06 49.09 5.88 363 36.26 61.78 1.94 234 65.86 34.12 0.05 383 35.26 53.36 11.36 250 2.33 34.49 63.18 396 4.90 64.18 30.88 267 10.20 79.65 10.16 419 45.06 49.09 5.88 278 43.33 56.04 0.64 435 69.02 31.02 0.02 290 3.96 61.81 34.26 453 10.03 78.64 11.31 481 45.27 53.33 1.40 502 11.15 34.01 54.87 521 29.88 70.11 0.00 536 2.66 42.44 54.93

Table C.1 Percentage grain size of cores taken referring to Figures 5.22a and b

146

KUS324 Grain Size (um)/ Depth (cm) 4 26 38 51 70 100 115 135 147 0.0582 0.000 0.000 0.020 0.000 0.000 0.000 0.008 0.000 0.001 0.0679 0.000 0.000 0.042 0.000 0.001 0.000 0.017 0.000 0.002 0.0791 0.001 0.000 0.066 0.000 0.002 0.000 0.028 0.000 0.004 0.0921 0.001 0.000 0.094 0.000 0.005 0.000 0.042 0.000 0.008 0.1073 0.003 0.000 0.125 0.001 0.010 0.000 0.059 0.000 0.013 0.125 0.005 0.000 0.161 0.002 0.018 0.000 0.079 0.000 0.020 0.1456 0.010 0.000 0.203 0.005 0.028 0.000 0.103 0.000 0.030 0.1697 0.016 0.000 0.254 0.008 0.041 0.000 0.132 0.003 0.042 0.1977 0.027 0.001 0.319 0.013 0.057 0.000 0.169 0.009 0.059 0.2303 0.045 0.006 0.406 0.019 0.076 0.001 0.219 0.017 0.080 0.2683 0.075 0.017 0.528 0.026 0.100 0.004 0.290 0.027 0.109 0.3125 0.124 0.039 0.699 0.035 0.129 0.012 0.390 0.038 0.148 0.3641 0.197 0.078 0.895 0.045 0.165 0.031 0.509 0.050 0.198 0.4242 0.281 0.128 1.066 0.066 0.225 0.058 0.625 0.075 0.263 0.4941 0.357 0.170 1.128 0.079 0.275 0.074 0.684 0.095 0.314 0.5757 0.449 0.217 1.218 0.101 0.351 0.090 0.763 0.126 0.382 0.6707 0.627 0.317 1.522 0.145 0.484 0.142 0.978 0.173 0.507 0.7813 0.769 0.381 1.689 0.164 0.589 0.158 1.108 0.201 0.595 0.9103 1.023 0.509 2.090 0.221 0.809 0.208 1.396 0.256 0.758 1.0604 1.239 0.607 2.385 0.259 0.997 0.234 1.616 0.294 0.889 1.2354 1.518 0.748 2.804 0.323 1.254 0.287 1.923 0.350 1.064 1.4393 1.754 0.856 3.094 0.361 1.474 0.311 2.150 0.384 1.200 1.6767 2.017 0.986 3.409 0.413 1.741 0.349 2.406 0.431 1.359 1.9534 2.283 1.123 3.409 0.474 2.035 0.393 2.662 0.486 1.529 2.2757 2.545 1.262 3.409 0.536 2.338 0.442 2.911 0.547 1.703 2.6512 2.789 1.397 3.409 0.601 2.643 0.496 3.141 0.617 1.880 3.0887 3.014 1.527 3.409 0.671 2.940 0.558 3.355 0.699 2.063 3.5983 3.205 1.646 3.409 0.744 3.216 0.628 3.539 0.795 2.246

Table C.2 Laser particle size results of cores, referring to figures 5.22 a-d

Table C.2 Continues until page 186

147

KUS324 Grain Size (um)/ Depth (cm) 4 26 38 51 70 100 115 135 147 4.192 3.354 1.749 3.409 0.820 3.458 0.703 3.686 0.902 2.423 4.8837 3.453 1.837 3.409 0.898 3.655 0.784 3.790 1.019 2.592 5.6895 3.497 1.911 3.409 0.976 3.804 0.868 3.846 1.143 2.749 6.6283 3.482 1.974 3.409 1.052 3.901 0.954 3.847 1.271 2.888 7.7219 3.409 2.036 3.409 1.124 3.949 1.043 3.794 1.405 3.008 8.996 3.289 2.110 3.409 1.193 3.962 1.142 3.691 1.551 3.113 10.4804 3.138 2.215 3.409 1.264 3.958 1.263 3.550 1.722 3.209 12.2096 2.983 2.374 3.409 1.351 3.960 1.430 3.389 1.946 3.311 14.2242 2.852 2.608 3.409 1.473 3.985 1.668 3.224 2.251 3.431 16.5712 2.774 2.935 3.409 1.654 4.042 2.009 3.072 2.667 3.580 19.3055 2.774 3.367 3.409 1.931 4.135 2.488 2.948 3.224 3.766 22.4909 2.862 3.894 3.409 2.330 4.253 3.124 2.855 3.927 3.983 26.2019 3.036 4.490 3.409 2.875 4.381 3.918 2.789 4.755 4.215 30.5252 3.282 5.109 3.409 3.579 4.466 4.850 2.738 5.661 4.442 35.5618 3.573 5.687 3.409 4.424 4.428 5.857 2.754 6.558 4.637 41.4295 3.882 6.164 3.409 5.360 4.216 6.842 2.757 7.358 4.785 48.2654 4.078 6.515 3.409 6.305 3.808 7.705 2.714 8.009 4.891 56.2292 4.069 6.760 3.409 7.144 3.222 8.369 2.589 8.514 4.681 65.507 3.812 6.318 3.409 7.837 2.519 8.867 2.368 8.048 4.252 76.3157 3.325 5.509 3.409 8.375 1.794 8.346 2.056 7.043 3.636 88.9077 2.682 4.455 3.409 8.009 1.145 7.295 1.685 5.675 3.020 103.5775 1.992 3.319 3.409 7.165 0.643 5.901 1.301 4.181 2.404 120.6678 1.362 2.258 3.409 5.951 0.316 4.366 0.951 2.769 1.788 140.578 0.878 1.395 3.409 4.558 0.000 2.918 0.676 1.608 1.172 163.7733 0.576 0.798 3.409 3.220 0.000 1.746 0.497 0.792 0.557 190.7959 0.430 0.200 3.409 2.111 0.000 0.936 0.397 0.328 0.000 222.2773 0.362 0.000 3.409 1.272 0.000 0.126 0.330 0.000 0.000 258.953 0.282 0.000 3.409 0.433 0.000 0.000 0.246 0.000 0.000 301.68021 0.138 0.000 3.409 0.000 0.000 0.000 0.161 0.000 0.000 351.45749 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 409.44791 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 3.409 0.000 0.000 0.000 0.000 0.000 0.000

148

KUS324 Grain Size (um)/ Depth (cm) 151 169 174 189 200 215 235 261 265 272 0.0582 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.000 0.153 0.000 0.0679 0.000 0.002 0.000 0.000 0.000 0.000 0.005 0.000 0.270 0.000 0.0791 0.000 0.004 0.000 0.000 0.000 0.001 0.010 0.000 0.353 0.000 0.0921 0.000 0.010 0.000 0.000 0.001 0.002 0.018 0.000 0.411 0.001 0.1073 0.000 0.021 0.001 0.000 0.002 0.003 0.031 0.000 0.459 0.002 0.125 0.000 0.039 0.003 0.000 0.007 0.006 0.050 0.000 0.510 0.003 0.1456 0.000 0.065 0.006 0.000 0.015 0.009 0.074 0.000 0.573 0.005 0.1697 0.000 0.100 0.010 0.000 0.029 0.014 0.104 0.000 0.661 0.008 0.1977 0.000 0.142 0.017 0.000 0.049 0.021 0.140 0.000 0.784 0.013 0.2303 0.000 0.189 0.025 0.006 0.074 0.031 0.185 0.007 0.965 0.021 0.2683 0.003 0.237 0.035 0.026 0.107 0.044 0.239 0.016 1.233 0.033 0.3125 0.014 0.285 0.046 0.071 0.146 0.064 0.306 0.024 1.605 0.051 0.3641 0.038 0.338 0.059 0.152 0.192 0.090 0.387 0.030 1.986 0.077 0.4242 0.073 0.453 0.087 0.260 0.280 0.125 0.514 0.048 2.183 0.110 0.4941 0.101 0.561 0.105 0.356 0.340 0.143 0.609 0.062 2.037 0.129 0.5757 0.130 0.723 0.133 0.465 0.432 0.168 0.745 0.086 1.925 0.154 0.6707 0.199 0.951 0.185 0.693 0.596 0.226 0.987 0.120 2.203 0.211 0.7813 0.233 1.141 0.209 0.844 0.676 0.245 1.145 0.134 2.208 0.234 0.9103 0.304 1.468 0.269 1.144 0.871 0.299 1.455 0.169 2.567 0.289 1.0604 0.350 1.744 0.306 1.379 1.004 0.326 1.690 0.188 2.762 0.320 1.2354 0.425 2.090 0.369 1.718 1.217 0.376 2.013 0.221 3.121 0.372 1.4393 0.471 2.361 0.401 1.990 1.355 0.393 2.239 0.231 3.282 0.397 1.6767 0.533 2.667 0.448 2.321 1.552 0.420 2.499 0.253 3.452 0.433 1.9534 0.603 2.972 0.501 2.682 1.798 0.450 2.763 0.282 3.581 0.475 2.2757 0.677 3.249 0.556 3.069 2.082 0.482 3.015 0.312 3.667 0.522 2.6512 0.755 3.496 0.617 3.465 2.424 0.518 3.253 0.348 3.702 0.577 3.0887 0.842 3.700 0.685 3.874 2.834 0.563 3.477 0.392 3.696 0.647 3.5983 0.932 3.852 0.761 4.273 3.311 0.618 3.679 0.447 3.642 0.735

149

KUS324 Grain Size (um)/ Depth (cm) 151 169 174 189 200 215 235 261 265 272 4.192 1.022 3.939 0.843 4.644 3.848 0.683 3.849 0.509 3.547 0.843 4.8837 1.110 3.959 0.930 4.970 4.430 0.760 3.979 0.581 3.419 0.978 5.6895 1.194 3.912 1.021 5.230 5.029 0.848 4.061 0.664 3.266 1.144 6.6283 1.271 3.803 1.111 5.401 5.598 0.947 4.085 0.762 3.094 1.345 7.7219 1.347 3.646 1.198 5.465 6.084 1.059 4.048 0.882 2.914 1.587 8.996 1.432 3.460 1.286 5.417 6.437 1.189 3.954 1.039 2.731 1.877 10.4804 1.545 3.271 1.383 5.267 6.627 1.347 3.817 1.251 2.550 2.220 12.2096 1.717 3.106 1.506 5.041 6.671 1.551 3.664 1.547 2.445 2.624 14.2242 1.980 2.988 1.681 4.776 6.618 1.822 3.517 1.953 2.403 3.092 16.5712 2.366 2.931 1.935 4.393 6.096 2.184 3.392 2.495 2.409 3.620 19.3055 2.906 2.938 2.303 3.994 5.395 2.664 3.296 3.198 2.431 4.202 22.4909 3.605 2.997 2.807 3.577 4.568 3.275 3.216 4.053 2.419 4.812 26.2019 4.446 3.084 3.459 3.140 3.688 4.014 3.208 5.032 2.330 5.414 30.5252 5.380 3.240 4.253 2.686 2.831 4.859 3.187 6.068 2.143 5.963 35.5618 6.326 3.342 5.146 2.220 2.048 5.755 3.115 7.052 1.862 6.408 41.4295 7.195 3.337 6.060 1.754 1.376 6.618 2.960 7.855 1.516 6.708 48.2654 7.933 3.184 6.890 1.309 0.833 7.368 2.705 8.378 1.150 6.863 56.2292 8.534 2.867 7.518 0.905 0.422 7.947 2.350 8.583 0.805 6.908 65.507 8.193 2.412 7.921 0.566 0.011 8.388 1.923 8.568 0.516 6.383 76.3157 7.297 1.875 8.133 0.310 0.000 7.938 1.469 7.577 0.303 5.597 88.9077 5.998 1.333 7.426 0.143 0.000 7.008 1.042 6.250 0.169 4.644 103.5775 4.521 0.859 6.331 0.000 0.000 5.746 0.686 4.792 0.103 3.639 120.6678 3.078 0.504 4.995 0.000 0.000 4.328 0.430 3.376 0.158 2.680 140.578 1.855 0.149 3.618 0.000 0.000 2.964 0.281 2.159 0.177 1.854 163.7733 0.973 0.000 2.402 0.000 0.000 1.836 0.132 1.251 0.221 1.218 190.7959 0.091 0.000 1.471 0.000 0.000 1.033 0.000 0.669 0.260 0.789 222.2773 0.000 0.000 0.539 0.000 0.000 0.231 0.000 0.088 0.264 0.520 258.953 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.217 0.250 301.68021 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.133 0.000 351.45749 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.047 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

150

KUS322 Grain Size (um)/ Depth (cm) 10 20 30 40 50 60 70 80 90 100 0.0582 0.000 0.129 0.000 0.000 0.000 0.000 0.000 0.000 0.434 0.000 0.0679 0.000 0.227 0.000 0.000 0.000 0.000 0.000 0.000 0.763 0.000 0.0791 0.000 0.306 0.000 0.000 0.000 0.000 0.000 0.000 1.018 0.000 0.0921 0.000 0.379 0.000 0.000 0.000 0.000 0.000 0.000 1.232 0.000 0.1073 0.000 0.456 0.000 0.000 0.000 0.000 0.000 0.000 1.425 0.000 0.125 0.000 0.542 0.000 0.000 0.000 0.000 0.000 0.000 1.610 0.000 0.1456 0.000 0.645 0.000 0.045 0.060 0.000 0.000 0.000 1.792 0.000 0.1697 0.000 0.766 0.000 0.129 0.147 0.000 0.000 0.000 1.968 0.000 0.1977 0.000 0.910 0.012 0.242 0.263 0.000 0.000 0.000 2.135 0.000 0.2303 0.000 1.077 0.138 0.389 0.413 0.000 0.000 0.167 2.292 0.063 0.2683 0.000 1.266 0.304 0.573 0.600 0.000 0.000 0.422 2.459 0.360 0.3125 0.012 1.473 0.508 0.790 0.822 0.052 0.052 0.736 2.676 0.731 0.3641 0.232 1.690 0.742 1.030 1.066 0.177 0.177 1.097 2.923 1.168 0.4242 0.485 1.920 1.003 1.295 1.334 0.320 0.320 1.500 3.190 1.664 0.4941 0.802 2.185 1.313 1.615 1.658 0.508 0.508 1.976 3.447 2.231 0.5757 1.137 2.447 1.631 1.941 1.986 0.708 0.708 2.464 3.702 2.823 0.6707 1.509 2.714 1.966 2.286 2.333 0.939 0.939 2.972 3.946 3.432 0.7813 1.890 2.967 2.293 2.624 2.672 1.182 1.182 3.460 4.157 4.017 0.9103 2.327 3.165 2.599 2.936 2.983 1.478 1.478 3.875 4.245 4.483 1.0604 2.729 3.338 2.882 3.218 3.262 1.751 1.751 4.241 4.298 4.899 1.2354 3.115 3.483 3.145 3.470 3.512 2.015 2.015 4.548 4.300 5.247 1.4393 3.505 3.591 3.385 3.683 3.720 2.273 2.273 4.783 4.239 5.508 1.6767 3.880 3.664 3.599 3.854 3.885 2.516 2.516 4.936 4.117 5.672 1.9534 4.235 3.710 3.796 3.994 4.017 2.748 2.748 5.013 3.948 5.741 2.2757 4.566 3.733 3.977 4.104 4.118 2.968 2.968 5.014 3.744 5.714 2.6512 4.863 3.733 4.136 4.183 4.184 3.178 3.178 4.940 3.515 5.593 3.0887 5.098 3.707 4.265 4.224 4.208 3.369 3.369 4.786 3.272 5.381 3.5983 5.254 3.650 4.352 4.223 4.189 3.537 3.537 4.555 2.974 5.096

151

KUS322 Grain Size (um)/ Depth (cm) 10 20 30 40 50 60 70 80 90 100 4.192 5.310 3.557 4.384 4.174 4.118 3.679 3.679 4.252 2.646 4.770 4.8837 5.257 3.424 4.352 4.072 3.994 3.792 3.792 3.887 2.293 4.239 5.6895 5.097 3.249 4.251 3.918 3.820 3.876 3.876 3.474 1.928 3.640 6.6283 4.839 3.036 4.082 3.715 3.601 3.930 3.930 3.027 1.564 3.008 7.7219 4.505 2.794 3.852 3.473 3.348 3.954 3.954 2.564 1.218 2.381 8.996 4.097 2.530 3.578 3.203 3.077 3.957 3.957 2.092 0.908 1.800 10.4804 3.643 2.255 3.275 2.923 2.804 3.946 3.946 1.663 0.650 1.301 12.2096 3.180 2.006 2.960 2.645 2.537 3.933 3.933 1.298 0.454 0.910 14.2242 2.775 1.811 2.685 2.422 2.343 3.923 3.923 1.008 0.320 0.636 16.5712 2.446 1.674 2.467 2.253 2.208 3.916 3.916 0.791 0.241 0.466 19.3055 2.194 1.584 2.305 2.131 2.119 3.912 3.912 0.638 0.203 0.378 22.4909 1.996 1.519 2.178 2.032 2.049 3.903 3.903 0.531 0.187 0.340 26.2019 1.826 1.451 2.060 1.930 1.969 3.798 3.798 0.452 0.179 0.324 30.5252 1.659 1.360 1.929 1.805 1.859 3.594 3.594 0.388 0.170 0.309 35.5618 1.471 1.233 1.766 1.644 1.705 3.281 3.281 0.331 0.155 0.285 41.4295 1.252 1.070 1.562 1.445 1.504 2.868 2.868 0.275 0.134 0.244 48.2654 1.033 0.879 1.321 1.213 1.264 2.385 2.385 0.217 0.107 0.190 56.2292 0.813 0.675 1.054 0.960 1.000 1.874 1.874 0.159 0.077 0.126 65.507 0.594 0.477 0.784 0.710 0.734 1.386 1.386 0.103 0.048 0.063 76.3157 0.375 0.303 0.538 0.483 0.493 0.970 0.970 0.051 0.021 0.009 88.9077 0.000 0.165 0.337 0.302 0.299 0.661 0.661 0.001 0.000 0.000 103.5775 0.000 0.071 0.197 0.175 0.165 0.467 0.467 0.000 0.000 0.000 120.6678 0.000 0.023 0.120 0.107 0.094 0.371 0.371 0.000 0.000 0.000 140.578 0.000 0.023 0.105 0.094 0.082 0.666 0.666 0.000 0.000 0.000 163.7733 0.000 0.079 0.146 0.129 0.122 0.524 0.524 0.000 0.000 0.000 190.7959 0.000 0.194 0.228 0.198 0.198 0.375 0.375 0.000 0.000 0.034 222.2773 0.000 0.353 0.320 0.269 0.276 0.221 0.221 0.034 0.047 0.144 258.953 0.000 0.530 0.377 0.302 0.315 0.093 0.093 0.237 0.200 0.287 301.68021 0.000 0.682 0.360 0.263 0.280 0.027 0.027 0.578 0.407 0.444 351.45749 0.000 0.768 0.248 0.141 0.158 0.000 0.000 1.026 0.646 0.589 409.44791 0.000 0.758 0.135 0.019 0.035 0.000 0.000 1.505 0.879 0.691 477.00681 0.000 0.653 0.000 0.000 0.000 0.000 0.000 1.898 1.057 0.725 555.71301 0.000 0.483 0.000 0.000 0.000 0.000 0.000 2.074 1.128 0.681 647.40558 0.000 0.313 0.000 0.000 0.000 0.000 0.000 1.911 1.052 0.566 754.22748 0.000 0.143 0.000 0.000 0.000 0.000 0.000 1.395 0.816 0.398 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.656 0.443 0.202

152

KUS325 Grain Size (um)/ Depth (cm) 10 20 24 34 40 53 60 70 80 90 0.0582 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.357 0.662 0.056 0.0679 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.645 1.024 0.093 0.0791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.884 1.214 0.126 0.0921 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.092 1.328 0.162 0.1073 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.280 1.415 0.209 0.125 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.451 1.496 0.271 0.1456 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.603 1.575 0.353 0.1697 0.035 0.000 0.000 0.000 0.000 0.000 0.000 1.727 1.648 0.462 0.1977 0.109 0.000 0.000 0.000 0.000 0.000 0.000 1.817 1.708 0.603 0.2303 0.210 0.000 0.000 0.000 0.000 0.000 0.084 1.872 1.756 0.780 0.2683 0.342 0.050 0.091 0.000 0.000 0.000 0.232 1.929 1.814 0.993 0.3125 0.500 0.200 0.235 0.076 0.121 0.042 0.416 2.074 1.938 1.234 0.3641 0.674 0.376 0.400 0.183 0.272 0.151 0.620 2.284 2.095 1.487 0.4242 0.866 0.572 0.583 0.302 0.443 0.273 0.844 2.539 2.281 1.760 0.4941 1.105 0.823 0.823 0.465 0.660 0.439 1.131 2.745 2.462 2.091 0.5757 1.346 1.079 1.067 0.630 0.885 0.612 1.418 2.980 2.653 2.414 0.6707 1.607 1.363 1.342 0.823 1.134 0.815 1.731 3.213 2.855 2.749 0.7813 1.867 1.649 1.621 1.022 1.389 1.030 2.040 3.432 3.050 3.063 0.9103 2.142 1.985 1.953 1.304 1.691 1.322 2.356 3.540 3.190 3.321 1.0604 2.396 2.292 2.258 1.565 1.974 1.592 2.636 3.625 3.302 3.540 1.2354 2.640 2.593 2.557 1.836 2.253 1.864 2.888 3.666 3.378 3.717 1.4393 2.871 2.891 2.849 2.132 2.538 2.147 3.104 3.653 3.405 3.843 1.6767 3.083 3.175 3.126 2.441 2.819 2.429 3.279 3.590 3.385 3.916 1.9534 3.280 3.447 3.395 2.767 3.101 2.720 3.425 3.492 3.333 3.949 2.2757 3.459 3.701 3.653 3.108 3.383 3.021 3.546 3.372 3.256 3.946 2.6512 3.611 3.928 3.895 3.454 3.655 3.328 3.642 3.236 3.158 3.910 3.0887 3.724 4.107 4.105 3.784 3.898 3.627 3.709 3.092 3.041 3.838 3.5983 3.791 4.228 4.279 4.086 4.103 3.915 3.751 2.944 2.910 3.732

153

KUS325 Grain Size (um)/ Depth (cm) 10 20 24 34 40 53 60 70 80 90 4.192 3.804 4.280 4.406 4.342 4.250 4.178 3.768 2.792 2.767 3.589 4.8837 3.759 4.263 4.483 4.546 4.334 4.412 3.762 2.637 2.614 3.413 5.6895 3.663 4.185 4.510 4.695 4.354 4.610 3.736 2.478 2.457 3.208 6.6283 3.525 4.061 4.486 4.787 4.312 4.764 3.693 2.316 2.297 2.982 7.7219 3.357 3.910 4.411 4.823 4.221 4.859 3.631 2.133 2.136 2.744 8.996 3.180 3.756 4.291 4.810 4.098 4.890 3.554 1.943 1.976 2.502 10.4804 3.013 3.620 4.135 4.756 3.965 4.853 3.464 1.754 1.850 2.260 12.2096 2.873 3.516 3.955 4.671 3.842 4.756 3.367 1.582 1.761 2.090 14.2242 2.768 3.444 3.763 4.566 3.734 4.611 3.268 1.436 1.713 1.988 16.5712 2.697 3.390 3.536 4.446 3.637 4.436 3.167 1.323 1.697 1.953 19.3055 2.651 3.385 3.298 4.244 3.591 4.155 3.080 1.242 1.697 1.969 22.4909 2.619 3.328 3.039 3.968 3.514 3.832 2.985 1.184 1.687 2.001 26.2019 2.590 3.178 2.752 3.609 3.365 3.471 2.865 1.136 1.646 2.011 30.5252 2.489 2.920 2.435 3.174 3.123 3.079 2.703 1.087 1.560 1.964 35.5618 2.303 2.559 2.084 2.676 2.779 2.658 2.484 1.023 1.422 1.835 41.4295 2.015 2.119 1.703 2.139 2.346 2.210 2.198 0.933 1.234 1.615 48.2654 1.628 1.641 1.308 1.597 1.855 1.747 1.850 0.811 1.008 1.316 56.2292 1.158 1.168 0.920 1.087 1.350 1.292 1.457 0.660 0.761 0.969 65.507 0.648 0.745 0.571 0.651 0.882 0.878 1.056 0.493 0.515 0.621 76.3157 0.161 0.408 0.292 0.321 0.498 0.537 0.689 0.329 0.297 0.316 88.9077 0.000 0.179 0.103 0.113 0.227 0.293 0.397 0.188 0.130 0.088 103.5775 0.000 0.060 0.007 0.000 0.076 0.149 0.202 0.086 0.027 0.000 120.6678 0.000 0.062 0.000 0.000 0.054 0.004 0.109 0.032 0.000 0.000 140.578 0.000 0.124 0.041 0.000 0.101 0.000 0.179 0.030 0.011 0.000 163.7733 0.455 0.226 0.127 0.000 0.201 0.000 0.255 0.082 0.082 0.037 190.7959 1.131 0.302 0.219 0.000 0.283 0.000 0.342 0.179 0.179 0.174 222.2773 1.762 0.307 0.281 0.000 0.295 0.000 0.367 0.298 0.271 0.316 258.953 2.112 0.236 0.280 0.000 0.229 0.000 0.302 0.403 0.320 0.421 301.68021 1.972 0.124 0.205 0.000 0.120 0.000 0.173 0.450 0.294 0.445 351.45749 1.325 0.048 0.129 0.000 0.046 0.000 0.048 0.409 0.183 0.363 409.44791 0.679 0.000 0.000 0.000 0.000 0.000 0.000 0.276 0.072 0.185 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.142 0.000 0.007 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

154

KUS325 Grain Size (um)/ Depth (cm) 100 110 120 140 150 158 168 178 188 198 0.0582 0.782 1.240 0.248 0.000 0.000 0.862 0.000 0.000 0.000 0.900 0.0679 1.202 2.080 0.433 0.000 0.000 1.475 0.000 0.000 0.000 1.545 0.0791 1.421 2.631 0.580 0.000 0.000 1.907 0.000 0.000 0.000 2.005 0.0921 1.551 3.012 0.712 0.000 0.000 2.230 0.000 0.000 0.000 2.353 0.1073 1.655 3.303 0.847 0.000 0.000 2.496 0.000 0.000 0.000 2.638 0.125 1.758 3.554 0.999 0.000 0.000 2.732 0.000 0.000 0.000 2.890 0.1456 1.868 3.783 1.175 0.000 0.000 2.952 0.000 0.000 0.000 3.119 0.1697 1.981 3.991 1.383 0.000 0.000 3.153 0.000 0.000 0.000 3.325 0.1977 2.093 4.171 1.627 0.000 0.000 3.332 0.000 0.000 0.000 3.502 0.2303 2.201 4.310 1.908 0.000 0.000 3.482 0.000 0.000 0.000 3.640 0.2683 2.321 4.399 2.222 0.000 0.000 3.596 0.000 0.000 0.000 3.732 0.3125 2.489 4.432 2.562 0.000 0.000 3.674 0.000 0.000 0.000 3.777 0.3641 2.671 4.386 2.909 0.092 0.084 3.699 0.041 0.082 0.006 3.756 0.4242 2.868 4.285 3.269 0.471 0.438 3.689 0.165 0.282 0.016 3.690 0.4941 3.078 4.183 3.674 0.974 0.906 3.685 0.318 0.532 0.032 3.619 0.5757 3.276 4.034 4.056 1.537 1.433 3.652 0.488 0.815 0.047 3.511 0.6707 3.479 3.882 4.421 2.208 2.063 3.626 0.679 1.140 0.066 3.404 0.7813 3.657 3.725 4.732 2.934 2.747 3.601 0.880 1.493 0.084 3.297 0.9103 3.753 3.564 4.879 3.815 3.588 3.564 1.084 1.903 0.112 3.200 1.0604 3.808 3.388 4.972 4.591 4.335 3.506 1.271 2.293 0.133 3.093 1.2354 3.811 3.203 4.994 5.268 4.994 3.425 1.438 2.663 0.150 2.980 1.4393 3.751 3.008 4.931 5.900 5.618 3.310 1.585 3.027 0.168 2.858 1.6767 3.624 2.758 4.785 6.416 6.140 3.163 1.706 3.365 0.185 2.730 1.9534 3.448 2.500 4.575 6.765 6.511 2.995 1.794 3.664 0.201 2.603 2.2757 3.229 2.243 4.320 6.945 6.730 2.816 1.849 3.916 0.216 2.480 2.6512 2.974 1.992 4.042 6.971 6.809 2.590 1.876 4.116 0.234 2.360 3.0887 2.691 1.747 3.679 6.822 6.725 2.349 1.872 4.242 0.253 2.255 3.5983 2.387 1.506 3.281 6.524 6.502 2.095 1.836 4.283 0.274 2.145

155

KUS325 Grain Size (um)/ Depth (cm) 100 110 120 140 150 158 168 178 188 198 4.192 2.072 1.267 2.852 6.138 6.197 1.828 1.774 4.232 0.298 2.019 4.8837 1.756 1.032 2.402 5.399 5.542 1.554 1.689 4.091 0.327 1.869 5.6895 1.449 0.807 1.948 4.572 4.789 1.284 1.588 3.871 0.363 1.693 6.6283 1.159 0.600 1.512 3.720 3.991 1.027 1.480 3.591 0.406 1.492 7.7219 0.887 0.416 1.114 2.899 3.202 0.794 1.371 3.273 0.458 1.273 8.996 0.657 0.265 0.774 2.165 2.477 0.593 1.271 2.950 0.519 1.049 10.4804 0.460 0.152 0.509 1.557 1.857 0.434 1.188 2.650 0.590 0.836 12.2096 0.344 0.080 0.326 1.097 1.372 0.319 1.129 2.402 0.674 0.650 14.2242 0.275 0.047 0.219 0.781 1.023 0.245 1.101 2.222 0.777 0.501 16.5712 0.240 0.000 0.173 0.584 0.793 0.204 1.104 2.114 0.905 0.392 19.3055 0.224 0.000 0.165 0.473 0.654 0.186 1.141 2.074 1.074 0.322 22.4909 0.213 0.000 0.174 0.408 0.569 0.179 1.212 2.084 1.302 0.280 26.2019 0.197 0.000 0.180 0.359 0.503 0.173 1.317 2.125 1.613 0.256 30.5252 0.175 0.000 0.176 0.309 0.438 0.165 1.461 2.179 2.041 0.241 35.5618 0.149 0.000 0.158 0.253 0.360 0.153 1.649 2.236 2.613 0.226 41.4295 0.123 0.000 0.129 0.190 0.282 0.135 1.888 2.214 3.348 0.206 48.2654 0.102 0.000 0.093 0.125 0.204 0.114 2.187 2.125 4.254 0.179 56.2292 0.088 0.000 0.056 0.061 0.126 0.090 2.553 1.979 5.277 0.145 65.507 0.080 0.000 0.023 0.003 0.000 0.066 2.989 1.804 6.370 0.106 76.3157 0.072 0.000 0.000 0.000 0.000 0.042 3.488 1.627 7.392 0.065 88.9077 0.054 0.000 0.000 0.000 0.000 0.017 4.034 1.477 8.226 0.027 103.5775 0.015 0.000 0.000 0.000 0.000 0.000 4.607 1.371 8.841 0.000 120.6678 0.000 0.000 0.000 0.000 0.000 0.000 5.176 1.306 9.192 0.000 140.578 0.000 0.000 0.000 0.000 0.000 0.000 5.722 1.275 8.401 0.000 163.7733 0.000 0.000 0.000 0.000 0.000 0.000 5.993 1.251 7.154 0.000 190.7959 0.000 0.000 0.000 0.003 0.000 0.000 5.955 1.197 5.715 0.000 222.2773 0.000 0.000 0.050 0.063 0.000 0.055 5.531 1.063 4.266 0.064 258.953 0.079 0.062 0.162 0.121 0.000 0.208 4.682 0.816 2.913 0.181 301.68021 0.471 0.180 0.310 0.160 0.000 0.417 3.440 0.467 1.730 0.332 351.45749 1.020 0.332 0.476 0.158 0.000 0.659 1.947 0.119 0.784 0.496 409.44791 1.671 0.496 0.633 0.110 0.000 0.893 0.454 0.000 0.000 0.646 477.00681 2.319 0.636 0.748 0.061 0.000 1.068 0.000 0.000 0.000 0.748 555.71301 2.815 0.717 0.791 0.000 0.000 1.134 0.000 0.000 0.000 0.773 647.40558 2.960 0.702 0.736 0.000 0.000 1.052 0.000 0.000 0.000 0.702 754.22748 2.554 0.572 0.575 0.000 0.000 0.811 0.000 0.000 0.000 0.536 878.67499 1.493 0.327 0.319 0.000 0.000 0.439 0.000 0.000 0.000 0.293

156

KUS325 Grain Size (um)/ Depth (cm) 206 218 223 228 238 258 268 278 0.0582 0.000 0.356 0.000 0.503 0.000 0.000 0.000 0.000 0.0679 0.000 0.692 0.000 0.888 0.000 0.000 0.000 0.000 0.0791 0.000 1.009 0.000 1.188 0.000 0.000 0.000 0.000 0.0921 0.000 1.307 0.000 1.439 0.000 0.000 0.000 0.000 0.1073 0.000 1.580 0.000 1.665 0.000 0.000 0.000 0.000 0.125 0.000 1.819 0.000 1.881 0.000 0.000 0.000 0.000 0.1456 0.000 2.006 0.000 2.091 0.000 0.000 0.000 0.000 0.1697 0.000 2.117 0.000 2.297 0.000 0.000 0.000 0.000 0.1977 0.000 2.129 0.000 2.496 0.000 0.000 0.000 0.000 0.2303 0.000 2.042 0.000 2.686 0.085 0.000 0.000 0.000 0.2683 0.000 1.938 0.000 2.875 0.223 0.000 0.050 0.000 0.3125 0.025 2.015 0.000 3.079 0.393 0.000 0.196 0.000 0.3641 0.065 2.242 0.018 3.278 0.577 0.008 0.361 0.020 0.4242 0.107 2.565 0.036 3.476 0.775 0.024 0.539 0.102 0.4941 0.164 2.723 0.064 3.675 1.035 0.046 0.760 0.204 0.5757 0.219 2.953 0.090 3.854 1.290 0.069 0.972 0.320 0.6707 0.277 3.168 0.121 4.020 1.568 0.097 1.193 0.452 0.7813 0.331 3.367 0.149 4.150 1.836 0.124 1.393 0.593 0.9103 0.385 3.432 0.188 4.161 2.093 0.158 1.575 0.754 1.0604 0.425 3.496 0.214 4.132 2.307 0.185 1.725 0.906 1.2354 0.454 3.531 0.234 4.051 2.479 0.206 1.852 1.048 1.4393 0.474 3.537 0.249 3.908 2.599 0.226 1.961 1.188 1.6767 0.486 3.519 0.259 3.707 2.664 0.243 2.052 1.320 1.9534 0.491 3.488 0.264 3.468 2.691 0.256 2.131 1.440 2.2757 0.492 3.452 0.268 3.203 2.688 0.268 2.206 1.548 2.6512 0.495 3.405 0.273 2.924 2.664 0.283 2.276 1.646 3.0887 0.499 3.341 0.280 2.640 2.624 0.301 2.332 1.726 3.5983 0.508 3.254 0.291 2.362 2.579 0.324 2.368 1.786

157

KUS325 Grain Size (um)/ Depth (cm) 206 218 223 228 238 258 268 278 4.192 0.523 3.133 0.308 2.088 2.536 0.352 2.375 1.824 4.8837 0.545 2.975 0.333 1.815 2.502 0.387 2.348 1.838 5.6895 0.574 2.794 0.365 1.544 2.484 0.428 2.285 1.830 6.6283 0.609 2.500 0.402 1.278 2.481 0.474 2.188 1.803 7.7219 0.649 2.165 0.438 1.021 2.492 0.522 2.063 1.761 8.996 0.693 1.816 0.471 0.782 2.517 0.573 1.923 1.714 10.4804 0.745 1.485 0.497 0.572 2.554 0.633 1.783 1.671 12.2096 0.813 1.202 0.521 0.403 2.605 0.715 1.658 1.645 14.2242 0.913 0.984 0.558 0.278 2.673 0.841 1.561 1.648 16.5712 1.069 0.838 0.635 0.195 2.761 1.041 1.503 1.691 19.3055 1.314 0.755 0.796 0.146 2.872 1.358 1.493 1.782 22.4909 1.682 0.715 1.088 0.121 3.003 1.830 1.535 1.926 26.2019 2.205 0.694 1.560 0.109 3.149 2.494 1.633 2.121 30.5252 2.911 0.672 2.266 0.101 3.302 3.380 1.792 2.361 35.5618 3.805 0.632 3.254 0.095 3.453 4.487 2.013 2.636 41.4295 4.855 0.567 4.544 0.086 3.594 5.764 2.292 2.928 48.2654 5.989 0.477 6.108 0.075 3.606 7.099 2.623 3.221 56.2292 7.056 0.370 7.753 0.060 3.479 8.278 2.988 3.498 65.507 7.928 0.259 9.316 0.044 3.202 9.162 3.367 3.754 76.3157 8.460 0.157 10.537 0.025 2.794 9.640 3.734 3.985 88.9077 8.631 0.072 11.363 0.003 2.306 9.805 4.062 4.195 103.5775 8.548 0.005 10.503 0.000 1.804 8.724 4.333 4.385 120.6678 7.457 0.000 8.764 0.000 1.348 7.144 4.414 4.549 140.578 6.046 0.000 6.569 0.000 0.987 5.334 4.313 4.695 163.7733 4.636 0.000 4.429 0.000 0.740 3.620 4.013 4.769 190.7959 3.225 0.000 2.684 0.000 0.586 2.239 3.511 4.694 222.2773 1.815 0.014 0.939 0.000 0.470 0.857 2.798 4.359 258.953 0.404 0.120 0.000 0.127 0.334 0.000 2.085 3.675 301.68021 0.000 0.257 0.000 0.384 0.198 0.000 1.372 2.626 351.45749 0.000 0.409 0.000 0.719 0.000 0.000 0.000 1.330 409.44791 0.000 0.553 0.000 1.087 0.000 0.000 0.000 0.035 477.00681 0.000 0.663 0.000 1.420 0.000 0.000 0.000 0.000 555.71301 0.000 0.710 0.000 1.629 0.000 0.000 0.000 0.000 647.40558 0.000 0.672 0.000 1.620 0.000 0.000 0.000 0.000 754.22748 0.000 0.540 0.000 1.325 0.000 0.000 0.000 0.000 878.67499 0.000 0.310 0.000 0.748 0.000 0.000 0.000 0.000

158

KUS326 Grain Size (um)/ Depth (cm) 11 29 49 66 82 89 109 120 130 0.0582 0.000 0.000 1.219 0.000 0.000 0.000 0.000 0.000 0.000 0.0679 0.000 0.000 2.065 0.000 0.000 0.000 0.000 0.000 0.000 0.0791 0.000 0.000 2.484 0.000 0.000 0.000 0.000 0.000 0.000 0.0921 0.000 0.000 2.537 0.000 0.000 0.000 0.000 0.000 0.000 0.1073 0.000 0.000 2.369 0.000 0.000 0.000 0.000 0.000 0.000 0.125 0.000 0.000 2.148 0.000 0.000 0.000 0.000 0.000 0.000 0.1456 0.000 0.000 1.997 0.000 0.000 0.000 0.000 0.000 0.000 0.1697 0.000 0.000 1.976 0.000 0.000 0.000 0.000 0.000 0.000 0.1977 0.000 0.000 2.107 0.000 0.000 0.000 0.000 0.000 0.000 0.2303 0.000 0.000 2.373 0.000 0.000 0.000 0.000 0.000 0.000 0.2683 0.000 0.000 2.669 0.000 0.000 0.000 0.000 0.000 0.000 0.3125 0.034 0.030 2.790 0.000 0.000 0.026 0.000 0.000 0.000 0.3641 0.221 0.148 2.613 0.022 0.024 0.077 0.041 0.000 0.024 0.4242 0.438 0.279 2.296 0.090 0.106 0.136 0.174 0.085 0.124 0.4941 0.722 0.457 2.056 0.181 0.213 0.220 0.342 0.203 0.253 0.5757 1.029 0.639 1.861 0.284 0.334 0.308 0.525 0.341 0.386 0.6707 1.386 0.848 1.602 0.409 0.478 0.414 0.736 0.511 0.536 0.7813 1.765 1.064 1.439 0.547 0.638 0.529 0.958 0.705 0.681 0.9103 2.228 1.354 1.380 0.740 0.868 0.700 1.238 0.986 0.849 1.0604 2.656 1.621 1.371 0.925 1.094 0.863 1.508 1.258 0.994 1.2354 3.066 1.892 1.400 1.116 1.332 1.035 1.784 1.535 1.131 1.4393 3.462 2.182 1.457 1.330 1.606 1.226 2.093 1.849 1.286 1.6767 3.824 2.488 1.520 1.566 1.913 1.433 2.440 2.189 1.478 1.9534 4.150 2.827 1.586 1.828 2.251 1.661 2.831 2.545 1.719 2.2757 4.435 3.209 1.667 2.127 2.627 1.910 3.282 2.925 2.043 2.6512 4.675 3.640 1.752 2.477 3.042 2.182 3.800 3.332 2.483 3.0887 4.851 4.101 1.832 2.874 3.479 2.469 4.364 3.745 3.041 3.5983 4.961 4.586 1.901 3.324 3.925 2.770 4.952 4.151 3.722

159

KUS326 Grain Size (um)/ Depth (cm) 11 29 49 66 82 89 109 120 130 4.192 4.997 5.063 1.957 3.819 4.355 3.079 5.518 4.528 4.496 4.8837 4.961 5.504 1.996 4.354 4.752 3.396 6.013 4.864 5.327 5.6895 4.859 5.876 2.025 4.911 5.095 3.724 6.382 5.145 6.145 6.6283 4.696 6.139 2.050 5.455 5.362 4.061 6.571 5.354 6.854 7.7219 4.480 6.264 2.079 5.939 5.533 4.406 6.551 5.477 7.354 8.996 4.226 6.262 2.125 6.320 5.601 4.757 6.345 5.510 7.588 10.4804 3.950 6.175 2.202 6.566 5.567 5.105 6.025 5.462 7.563 12.2096 3.621 5.684 2.319 6.682 5.447 5.437 5.230 5.355 7.382 14.2242 3.296 5.038 2.478 6.712 5.263 5.730 4.338 5.218 6.530 16.5712 2.979 4.294 2.664 6.268 5.039 5.955 3.450 4.941 5.492 19.3055 2.680 3.524 2.950 5.620 4.677 6.114 2.656 4.594 4.409 22.4909 2.390 2.780 3.212 4.822 4.250 6.214 2.004 4.156 3.376 26.2019 2.104 2.107 3.373 3.948 3.761 5.886 1.512 3.625 2.470 30.5252 1.820 1.536 3.365 3.080 3.225 5.285 1.171 3.025 1.732 35.5618 1.534 1.071 3.142 2.277 2.659 4.449 0.946 2.390 1.162 41.4295 1.243 0.702 2.707 1.577 2.082 3.460 0.795 1.763 0.738 48.2654 0.952 0.416 2.120 1.002 1.524 2.442 0.678 1.190 0.429 56.2292 0.670 0.199 1.478 0.559 1.015 1.512 0.567 0.706 0.206 65.507 0.417 0.000 0.880 0.245 0.589 0.767 0.457 0.336 0.000 76.3157 0.212 0.000 0.410 0.000 0.274 0.258 0.352 0.000 0.000 88.9077 0.008 0.000 0.000 0.000 0.000 0.000 0.262 0.000 0.000 103.5775 0.000 0.000 0.000 0.000 0.000 0.000 0.194 0.000 0.000 120.6678 0.000 0.000 0.000 0.000 0.000 0.000 0.149 0.000 0.000 140.578 0.000 0.000 0.000 0.000 0.000 0.000 0.127 0.000 0.000 163.7733 0.000 0.000 0.000 0.000 0.000 0.000 0.127 0.000 0.000 190.7959 0.000 0.000 0.000 0.000 0.000 0.000 0.139 0.000 0.000 222.2773 0.000 0.000 0.000 0.000 0.000 0.000 0.145 0.000 0.000 258.953 0.000 0.000 0.000 0.000 0.000 0.000 0.125 0.000 0.000 301.68021 0.000 0.000 0.000 0.000 0.000 0.000 0.075 0.000 0.000 351.45749 0.000 0.000 0.000 0.000 0.000 0.000 0.025 0.000 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

160

KUS326 Grain Size (um)/ Depth (cm) 184 191 206 215 237 242 253 277 288 0.0582 0.192 0.159 0.397 0.293 0.000 0.198 0.000 0.000 0.000 0.0679 0.388 0.323 0.791 0.589 0.000 0.395 0.000 0.000 0.000 0.0791 0.587 0.491 1.176 0.884 0.000 0.590 0.000 0.000 0.000 0.0921 0.790 0.665 1.545 1.176 0.000 0.781 0.000 0.000 0.000 0.1073 0.997 0.848 1.893 1.466 0.000 0.966 0.000 0.000 0.000 0.125 1.212 1.044 2.216 1.753 0.000 1.144 0.000 0.000 0.000 0.1456 1.436 1.256 2.507 2.037 0.000 1.313 0.000 0.000 0.000 0.1697 1.670 1.488 2.758 2.315 0.000 1.470 0.000 0.000 0.000 0.1977 1.902 1.732 2.955 2.573 0.000 1.606 0.000 0.000 0.000 0.2303 2.100 1.955 3.076 2.782 0.000 1.706 0.000 0.000 0.000 0.2683 2.196 2.077 3.085 2.881 0.000 1.737 0.000 0.000 0.000 0.3125 2.104 1.990 2.948 2.793 0.000 1.663 0.000 0.000 0.000 0.3641 1.808 1.666 2.661 2.502 0.007 1.476 0.000 0.000 0.000 0.4242 1.414 1.226 2.276 2.093 0.018 1.218 0.000 0.000 0.000 0.4941 1.031 0.798 1.854 1.671 0.032 0.944 0.000 0.000 0.000 0.5757 0.677 0.404 1.425 1.271 0.047 0.678 0.000 0.000 0.000 0.6707 0.337 0.056 0.999 0.884 0.065 0.432 0.000 0.000 0.000 0.7813 0.080 0.000 0.645 0.602 0.083 0.265 0.000 0.000 0.000 0.9103 0.112 0.228 0.585 0.712 0.106 0.396 0.000 0.027 0.000 1.0604 0.200 0.576 0.595 0.916 0.128 0.594 0.000 0.084 0.000 1.2354 0.390 1.145 0.713 1.267 0.151 0.900 0.000 0.203 0.001 1.4393 0.716 2.001 0.957 1.787 0.178 1.330 0.002 0.418 0.006 1.6767 1.175 3.096 1.311 2.429 0.207 1.852 0.009 0.738 0.017 1.9534 1.742 4.305 1.743 3.118 0.241 2.416 0.028 1.144 0.039 2.2757 2.394 5.489 2.222 3.778 0.280 2.968 0.063 1.634 0.072 2.6512 3.075 6.455 2.706 4.314 0.326 3.448 0.112 2.171 0.112 3.0887 3.703 6.992 3.154 4.636 0.376 3.798 0.150 2.699 0.146 3.5983 4.243 7.095 3.542 4.740 0.430 4.003 0.149 3.184 0.158

161

KUS326 Grain Size (um)/ Depth (cm) 184 191 206 215 237 242 253 277 288 4.192 4.699 7.052 3.857 4.685 0.487 4.092 0.166 3.687 0.178 4.8837 5.265 7.381 4.132 4.619 0.545 4.163 0.403 4.475 0.296 5.6895 5.603 6.722 4.295 4.346 0.605 4.088 0.649 5.120 0.398 6.6283 5.661 5.609 4.354 3.942 0.670 3.901 0.694 5.515 0.430 7.7219 5.601 4.495 4.378 3.406 0.747 3.705 0.688 5.819 0.450 8.996 5.462 3.508 4.180 2.915 0.847 3.535 0.926 6.122 0.552 10.4804 5.150 2.573 3.879 2.479 0.987 3.375 0.977 6.180 0.600 12.2096 4.638 1.838 3.515 2.137 1.184 3.270 1.157 6.183 0.699 14.2242 4.034 1.284 3.103 1.884 1.456 3.203 1.315 6.012 0.802 16.5712 3.431 0.912 2.677 1.703 1.814 3.165 1.625 5.813 0.968 19.3055 2.837 0.677 2.254 1.567 2.262 3.209 1.986 5.531 1.170 22.4909 2.296 0.541 1.854 1.448 2.783 3.228 2.467 5.077 1.439 26.2019 1.826 0.463 1.490 1.323 3.349 3.181 3.094 4.575 1.793 30.5252 1.433 0.407 1.169 1.182 3.914 3.035 3.870 4.033 2.248 35.5618 1.109 0.351 0.891 1.023 4.428 2.778 4.772 3.462 2.812 41.4295 0.842 0.280 0.651 0.852 4.843 2.414 5.739 2.871 3.485 48.2654 0.619 0.210 0.412 0.678 5.136 1.968 6.688 2.279 4.255 56.2292 0.430 0.140 0.173 0.513 5.307 1.521 7.490 1.716 5.081 65.507 0.274 0.000 0.000 0.369 5.389 1.074 8.092 1.214 5.926 76.3157 0.118 0.000 0.000 0.256 5.429 0.628 8.454 0.805 6.723 88.9077 0.000 0.000 0.000 0.176 5.473 0.181 8.651 0.508 7.429 103.5775 0.000 0.000 0.000 0.127 5.552 0.000 7.983 0.317 8.044 120.6678 0.000 0.000 0.000 0.105 5.656 0.000 6.901 0.213 8.579 140.578 0.000 0.000 0.000 0.000 5.715 0.000 5.530 0.172 8.358 163.7733 0.000 0.000 0.000 0.000 5.574 0.000 4.079 0.000 7.649 190.7959 0.000 0.000 0.000 0.000 5.165 0.000 2.768 0.000 6.562 222.2773 0.000 0.000 0.000 0.000 4.460 0.000 1.697 0.000 5.228 258.953 0.000 0.000 0.000 0.000 3.512 0.000 0.626 0.000 3.802 301.68021 0.000 0.000 0.000 0.000 2.428 0.000 0.000 0.000 2.431 351.45749 0.000 0.000 0.000 0.000 1.345 0.000 0.000 0.000 1.060 409.44791 0.000 0.000 0.000 0.000 0.262 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

162

KUS319 Grain Size (um)/ Depth (cm) 7 20 32 48 58 66 78 94 119 0.0582 0.000 0.000 0.000 0.000 0.001 0.107 0.316 0.000 0.000 0.0679 0.000 0.000 0.000 0.000 0.002 0.215 0.632 0.000 0.000 0.0791 0.001 0.000 0.000 0.000 0.005 0.322 0.944 0.000 0.000 0.0921 0.003 0.000 0.000 0.000 0.010 0.430 1.247 0.000 0.000 0.1073 0.006 0.000 0.000 0.000 0.019 0.536 1.540 0.000 0.000 0.125 0.013 0.000 0.000 0.000 0.032 0.642 1.819 0.000 0.001 0.1456 0.022 0.000 0.000 0.000 0.049 0.748 2.082 0.001 0.003 0.1697 0.035 0.000 0.000 0.000 0.071 0.850 2.322 0.006 0.009 0.1977 0.051 0.000 0.000 0.000 0.097 0.945 2.526 0.016 0.019 0.2303 0.070 0.000 0.000 0.000 0.128 1.016 2.666 0.036 0.040 0.2683 0.090 0.000 0.000 0.000 0.164 1.036 2.693 0.075 0.081 0.3125 0.113 0.000 0.000 0.000 0.207 0.971 2.551 0.147 0.159 0.3641 0.140 0.000 0.000 0.000 0.259 0.819 2.232 0.263 0.287 0.4242 0.196 0.000 0.000 0.000 0.350 0.619 1.805 0.409 0.438 0.4941 0.250 0.000 0.000 0.000 0.425 0.417 1.356 0.542 0.554 0.5757 0.333 0.000 0.000 0.000 0.538 0.223 0.921 0.701 0.682 0.6707 0.463 0.000 0.000 0.000 0.732 0.045 0.528 1.024 0.976 0.7813 0.575 0.000 0.000 0.000 0.880 0.000 0.271 1.273 1.154 0.9103 0.800 0.013 0.004 0.015 1.178 0.035 0.545 1.746 1.539 1.0604 0.997 0.050 0.019 0.057 1.426 0.101 0.937 2.139 1.839 1.2354 1.258 0.150 0.069 0.170 1.761 0.228 1.525 2.667 2.285 1.4393 1.485 0.379 0.200 0.429 2.031 0.440 2.332 3.100 2.647 1.6767 1.757 0.779 0.457 0.884 2.350 0.735 3.292 3.587 3.094 1.9534 2.055 1.349 0.857 1.536 2.689 1.083 4.287 4.070 3.580 2.2757 2.356 2.039 1.375 2.346 3.023 1.458 5.192 4.528 4.092 2.6512 2.656 2.732 1.926 3.190 3.345 1.813 5.878 4.922 4.597 3.0887 2.946 3.235 2.351 3.842 3.646 2.097 6.250 5.244 5.080 3.5983 3.219 3.409 2.508 4.125 3.914 2.293 6.351 5.463 5.496

163

KUS319 Grain Size (um)/ Depth (cm) 7 20 32 48 58 66 78 94 119 4.192 3.464 3.660 2.768 4.497 4.139 2.448 6.350 5.564 5.810 4.8837 3.682 4.924 4.074 6.147 4.316 2.697 5.881 5.545 5.995 5.6895 3.876 5.711 5.042 7.200 4.448 2.816 5.086 5.412 6.033 6.6283 4.051 5.739 5.272 7.231 4.535 2.803 4.105 5.176 5.920 7.7219 4.214 5.646 5.365 7.032 4.584 2.768 3.149 4.858 5.681 8.996 4.379 5.976 5.995 7.258 4.606 2.756 2.304 4.484 5.370 10.4804 4.553 5.869 6.094 6.848 4.610 2.703 1.612 4.082 4.805 12.2096 4.741 5.902 6.359 6.589 4.609 2.678 1.116 3.661 4.208 14.2242 4.934 5.822 6.434 5.925 4.607 2.669 0.811 3.281 3.626 16.5712 5.117 5.815 6.576 5.307 4.601 2.699 0.659 2.945 3.091 19.3055 5.281 5.639 6.599 4.588 4.537 2.763 0.610 2.648 2.618 22.4909 5.421 5.341 6.307 3.873 4.368 2.867 0.609 2.364 2.199 26.2019 5.284 4.900 5.805 3.191 4.057 3.008 0.607 2.073 1.823 30.5252 4.922 4.304 5.092 2.547 3.602 3.178 0.576 1.764 1.479 35.5618 4.336 3.583 4.222 1.955 3.025 3.364 0.504 1.455 1.156 41.4295 3.573 2.788 3.268 1.420 2.375 3.547 0.401 1.146 0.833 48.2654 2.719 1.993 2.324 0.951 1.713 3.710 0.297 0.837 0.510 56.2292 1.874 1.276 1.485 0.567 1.104 3.842 0.193 0.528 0.187 65.507 1.130 0.693 0.810 0.279 0.599 3.946 0.089 0.220 0.000 76.3157 0.557 0.284 0.340 0.000 0.235 3.870 0.000 0.000 0.000 88.9077 0.000 0.000 0.000 0.000 0.000 3.674 0.000 0.000 0.000 103.5775 0.000 0.000 0.000 0.000 0.000 3.369 0.000 0.000 0.000 120.6678 0.000 0.000 0.000 0.000 0.000 2.975 0.000 0.000 0.000 140.578 0.000 0.000 0.000 0.000 0.000 2.536 0.000 0.000 0.000 163.7733 0.000 0.000 0.000 0.000 0.000 2.097 0.000 0.000 0.000 190.7959 0.000 0.000 0.000 0.000 0.000 1.657 0.000 0.000 0.000 222.2773 0.000 0.000 0.000 0.000 0.000 1.218 0.000 0.000 0.000 258.953 0.000 0.000 0.000 0.000 0.000 0.778 0.000 0.000 0.000 301.68021 0.000 0.000 0.000 0.000 0.000 0.339 0.000 0.000 0.000 351.45749 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

164

KUS319 Grain Size (um)/ Depth (cm) 125 137 148 163 167 185 195 196 213 0.0582 0.378 0.285 0.222 0.238 0.000 0.000 0.425 0.000 0.000 0.0679 0.754 0.570 0.446 0.477 0.000 0.000 0.847 0.000 0.000 0.0791 1.120 0.851 0.672 0.716 0.000 0.000 1.259 0.000 0.000 0.0921 1.470 1.125 0.896 0.953 0.000 0.000 1.656 0.000 0.000 0.1073 1.801 1.388 1.121 1.188 0.000 0.000 2.032 0.000 0.000 0.125 2.107 1.640 1.346 1.420 0.000 0.000 2.381 0.000 0.000 0.1456 2.381 1.876 1.571 1.649 0.000 0.000 2.699 0.000 0.000 0.1697 2.617 2.092 1.794 1.873 0.000 0.000 2.978 0.000 0.000 0.1977 2.801 2.274 2.003 2.081 0.000 0.000 3.202 0.000 0.000 0.2303 2.910 2.399 2.165 2.247 0.000 0.000 3.350 0.000 0.000 0.2683 2.911 2.426 2.221 2.323 0.000 0.000 3.384 0.000 0.018 0.3125 2.767 2.308 2.096 2.246 0.000 0.000 3.265 0.000 0.078 0.3641 2.474 2.039 1.778 1.998 0.000 0.000 2.986 0.000 0.195 0.4242 2.080 1.677 1.356 1.650 0.000 0.000 2.599 0.000 0.356 0.4941 1.649 1.295 0.927 1.289 0.000 0.000 2.172 0.000 0.501 0.5757 1.216 0.918 0.516 0.944 0.000 0.000 1.740 0.000 0.658 0.6707 0.802 0.555 0.138 0.615 0.000 0.000 1.311 0.000 0.974 0.7813 0.486 0.275 0.000 0.380 0.000 0.000 0.963 0.000 1.165 0.9103 0.584 0.321 0.139 0.501 0.000 0.001 0.946 0.022 1.497 1.0604 0.776 0.442 0.372 0.705 0.000 0.005 1.005 0.071 1.728 1.2354 1.124 0.689 0.781 1.045 0.002 0.017 1.181 0.181 2.060 1.4393 1.647 1.084 1.424 1.546 0.006 0.046 1.484 0.395 2.274 1.6767 2.309 1.608 2.280 2.175 0.015 0.098 1.882 0.731 2.529 1.9534 3.038 2.215 3.267 2.873 0.031 0.172 2.324 1.176 2.794 2.2757 3.756 2.858 4.286 3.580 0.055 0.270 2.760 1.738 3.066 2.6512 4.374 3.472 5.191 4.218 0.085 0.377 3.136 2.374 3.343 3.0887 4.810 3.983 5.816 4.697 0.115 0.473 3.404 3.000 3.645 3.5983 5.037 4.360 6.111 4.996 0.139 0.544 3.553 3.566 3.958

165

KUS319 Grain Size (um)/ Depth (cm) 125 137 148 163 167 185 195 196 213 4.192 5.085 4.606 6.210 5.143 0.170 0.634 3.592 4.179 4.271 4.8837 5.059 4.819 6.456 5.293 0.255 0.841 3.573 5.320 4.571 5.6895 4.897 4.832 6.388 5.215 0.339 1.008 3.434 6.254 4.836 6.6283 4.320 4.655 5.609 4.941 0.397 1.097 3.204 6.744 5.039 7.7219 3.675 4.403 4.759 4.640 0.449 1.186 2.949 7.084 5.157 8.996 3.029 4.126 3.961 4.215 0.543 1.338 2.615 7.457 5.179 10.4804 2.420 3.685 3.167 3.742 0.601 1.456 2.291 7.392 5.105 12.2096 1.905 3.264 2.507 3.308 0.677 1.628 2.006 7.298 4.956 14.2242 1.503 2.873 1.986 2.892 0.748 1.832 1.771 6.981 4.765 16.5712 1.216 2.540 1.607 2.512 0.854 2.128 1.590 6.340 4.424 19.3055 1.028 2.259 1.340 2.144 1.001 2.510 1.459 5.500 4.046 22.4909 0.914 2.025 1.152 1.785 1.234 3.010 1.369 4.593 3.638 26.2019 0.844 1.819 1.004 1.425 1.595 3.644 1.307 3.693 3.205 30.5252 0.789 1.623 0.856 1.066 2.128 4.409 1.259 2.841 2.751 35.5618 0.730 1.419 0.708 0.707 2.866 5.271 1.207 2.079 2.280 41.4295 0.652 1.214 0.561 0.348 3.814 6.161 1.136 1.426 1.800 48.2654 0.552 1.010 0.413 0.000 4.946 6.989 1.035 0.891 1.331 56.2292 0.451 0.806 0.265 0.000 6.174 7.648 0.901 0.482 0.901 65.507 0.351 0.601 0.117 0.000 7.398 8.116 0.744 0.194 0.538 76.3157 0.251 0.397 0.000 0.000 8.486 8.411 0.578 0.000 0.268 88.9077 0.150 0.000 0.000 0.000 9.379 7.782 0.422 0.000 0.102 103.5775 0.000 0.000 0.000 0.000 10.121 6.719 0.292 0.000 0.000 120.6678 0.000 0.000 0.000 0.000 9.616 5.368 0.198 0.000 0.000 140.578 0.000 0.000 0.000 0.000 8.431 3.939 0.146 0.000 0.000 163.7733 0.000 0.000 0.000 0.000 6.792 2.639 0.000 0.000 0.000 190.7959 0.000 0.000 0.000 0.000 5.152 1.623 0.000 0.000 0.000 222.2773 0.000 0.000 0.000 0.000 3.513 0.608 0.000 0.000 0.000 258.953 0.000 0.000 0.000 0.000 1.874 0.000 0.000 0.000 0.000 301.68021 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 351.45749 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

166

KUS327 Grain Size (um)/ Depth (cm) 5 23 28 32 42 53 68 81 99 0.0582 0.000 0.000 0.041 0.000 0.000 0.000 0.000 0.000 0.000 0.0679 0.000 0.000 0.084 0.000 0.000 0.000 0.000 0.000 0.000 0.0791 0.000 0.000 0.131 0.000 0.000 0.000 0.000 0.000 0.000 0.0921 0.000 0.000 0.186 0.000 0.000 0.000 0.000 0.000 0.000 0.1073 0.000 0.000 0.252 0.000 0.000 0.000 0.000 0.000 0.000 0.125 0.000 0.000 0.337 0.000 0.000 0.000 0.000 0.000 0.000 0.1456 0.000 0.000 0.452 0.000 0.000 0.000 0.000 0.000 0.000 0.1697 0.000 0.000 0.611 0.000 0.000 0.000 0.000 0.000 0.000 0.1977 0.000 0.000 0.829 0.000 0.014 0.000 0.000 0.000 0.000 0.2303 0.000 0.000 1.107 0.000 0.039 0.000 0.000 0.000 0.000 0.2683 0.027 0.034 1.400 0.005 0.077 0.000 0.013 0.000 0.000 0.3125 0.117 0.121 1.588 0.069 0.127 0.000 0.121 0.138 0.000 0.3641 0.226 0.228 1.577 0.149 0.180 0.000 0.252 0.409 0.119 0.4242 0.350 0.353 1.435 0.242 0.239 0.083 0.403 0.730 0.357 0.4941 0.523 0.523 1.289 0.366 0.332 0.249 0.612 1.151 0.694 0.5757 0.705 0.711 1.142 0.502 0.425 0.455 0.833 1.614 1.110 0.6707 0.921 0.936 0.954 0.662 0.541 0.720 1.097 2.154 1.648 0.7813 1.154 1.191 0.823 0.840 0.666 1.042 1.383 2.737 2.294 0.9103 1.497 1.565 0.802 1.103 0.864 1.536 1.789 3.442 3.204 1.0604 1.828 1.937 0.816 1.369 1.049 2.030 2.177 4.096 4.086 1.2354 2.181 2.338 0.878 1.660 1.245 2.538 2.577 4.715 4.955 1.4393 2.569 2.778 0.990 1.991 1.457 3.112 3.001 5.294 5.802 1.6767 2.978 3.244 1.126 2.359 1.680 3.718 3.429 5.790 6.554 1.9534 3.412 3.734 1.275 2.764 1.917 4.319 3.858 6.176 7.165 2.2757 3.857 4.230 1.455 3.199 2.164 4.909 4.270 6.423 7.584 2.6512 4.296 4.703 1.641 3.646 2.421 5.464 4.642 6.511 7.779 3.0887 4.693 5.120 1.828 4.077 2.677 5.929 4.936 6.416 7.715 3.5983 5.027 5.450 2.010 4.465 2.937 6.266 5.131 6.145 7.412

167

KUS327 Grain Size (um)/ Depth (cm) 5 23 28 32 42 53 68 81 99 4.192 5.266 5.661 2.196 4.778 3.203 6.435 5.203 5.734 6.963 4.8837 5.395 5.731 2.389 4.991 3.488 6.424 5.149 5.244 6.014 5.6895 5.406 5.657 2.611 5.091 3.810 6.246 4.980 4.477 4.946 6.6283 5.300 5.441 2.877 5.076 4.178 5.909 4.713 3.680 3.853 7.7219 5.084 5.098 3.199 4.951 4.591 5.437 4.377 2.916 2.825 8.996 4.786 4.664 3.586 4.744 5.042 4.879 4.010 2.244 1.939 10.4804 4.437 4.182 4.029 4.489 5.506 4.190 3.650 1.706 1.242 12.2096 4.067 3.639 4.512 4.219 5.957 3.538 3.325 1.324 0.752 14.2242 3.729 3.169 5.011 3.952 6.376 2.969 3.030 1.091 0.452 16.5712 3.448 2.798 5.499 3.692 6.751 2.498 2.916 0.975 0.301 19.3055 3.210 2.527 5.975 3.517 6.662 2.122 2.868 0.936 0.253 22.4909 2.972 2.321 6.071 3.347 6.201 1.809 2.822 0.923 0.261 26.2019 2.694 2.137 5.844 3.150 5.398 1.529 2.717 0.897 0.289 30.5252 2.354 1.939 5.305 2.903 4.369 1.262 2.520 0.837 0.313 35.5618 1.954 1.698 4.509 2.594 3.258 0.995 2.218 0.735 0.320 41.4295 1.516 1.408 3.560 2.220 2.205 0.729 1.829 0.599 0.300 48.2654 1.077 1.118 2.578 1.796 1.315 0.462 1.391 0.444 0.248 56.2292 0.674 0.828 1.678 1.349 0.644 0.195 0.950 0.288 0.167 65.507 0.271 0.538 0.947 0.923 0.000 0.000 0.556 0.151 0.085 76.3157 0.000 0.248 0.431 0.564 0.000 0.000 0.251 0.044 0.000 88.9077 0.000 0.000 0.134 0.310 0.000 0.000 0.000 0.000 0.000 103.5775 0.000 0.000 0.000 0.171 0.000 0.000 0.000 0.000 0.000 120.6678 0.000 0.000 0.000 0.317 0.000 0.000 0.000 0.000 0.000 140.578 0.000 0.000 0.000 0.313 0.000 0.000 0.000 0.028 0.000 163.7733 0.000 0.000 0.000 0.333 0.000 0.000 0.000 0.089 0.000 190.7959 0.000 0.000 0.000 0.311 0.000 0.000 0.000 0.144 0.000 222.2773 0.000 0.000 0.000 0.236 0.000 0.000 0.000 0.176 0.000 258.953 0.000 0.000 0.000 0.135 0.000 0.000 0.000 0.171 0.000 301.68021 0.000 0.000 0.000 0.050 0.000 0.000 0.000 0.126 0.000 351.45749 0.000 0.000 0.000 0.010 0.000 0.000 0.000 0.081 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

168

KUS327 Grain Size (um)/ Depth (cm) 156 166 172 188 206 215 225 241 254 0.0582 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.151 0.000 0.0679 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.293 0.000 0.0791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.424 0.000 0.0921 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.546 0.000 0.1073 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.670 0.000 0.125 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.811 0.000 0.1456 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.996 0.000 0.1697 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.258 0.000 0.1977 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.639 0.000 0.2303 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.161 0.000 0.2683 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.772 0.000 0.3125 0.027 0.000 0.001 0.000 0.000 0.000 0.000 3.281 0.000 0.3641 0.193 0.051 0.007 0.000 0.006 0.000 0.005 3.504 0.001 0.4242 0.442 0.269 0.014 0.178 0.020 0.324 0.011 3.542 0.020 0.4941 0.812 0.549 0.024 0.408 0.039 0.774 0.018 3.667 0.044 0.5757 1.281 0.876 0.033 0.665 0.059 1.299 0.026 3.879 0.071 0.6707 1.892 1.268 0.044 0.959 0.084 1.949 0.035 3.982 0.101 0.7813 2.626 1.709 0.055 1.270 0.111 2.683 0.042 4.244 0.132 0.9103 3.579 2.251 0.068 1.610 0.144 3.653 0.049 4.524 0.165 1.0604 4.517 2.769 0.079 1.921 0.174 4.525 0.056 4.861 0.193 1.2354 5.425 3.262 0.089 2.201 0.201 5.307 0.061 5.181 0.214 1.4393 6.273 3.739 0.099 2.482 0.229 6.080 0.067 5.440 0.235 1.6767 6.996 4.166 0.108 2.755 0.255 6.751 0.072 5.573 0.255 1.9534 7.514 4.511 0.117 3.009 0.280 7.239 0.078 5.622 0.274 2.2757 7.760 4.757 0.125 3.261 0.304 7.544 0.084 5.375 0.295 2.6512 7.745 4.895 0.133 3.525 0.329 7.689 0.092 5.004 0.323 3.0887 7.469 4.903 0.142 3.791 0.357 7.665 0.100 4.514 0.358 3.5983 6.926 4.777 0.153 4.054 0.388 7.529 0.110 3.925 0.398

169

KUS327 Grain Size (um)/ Depth (cm) 156 166 172 188 206 215 225 241 254 4.192 6.216 4.533 0.168 4.303 0.424 6.839 0.120 3.267 0.446 4.8837 5.395 4.200 0.189 4.532 0.469 5.926 0.131 2.582 0.502 5.6895 4.594 3.821 0.220 4.730 0.523 4.877 0.145 1.920 0.569 6.6283 3.816 3.440 0.262 4.881 0.586 3.779 0.164 1.319 0.652 7.7219 3.063 3.096 0.318 4.971 0.655 2.724 0.190 0.813 0.762 8.996 2.341 2.816 0.389 4.992 0.725 1.797 0.227 0.423 0.912 10.4804 1.654 2.604 0.473 4.940 0.791 1.059 0.279 0.155 1.124 12.2096 1.012 2.446 0.572 4.830 0.849 0.539 0.350 0.004 1.427 14.2242 0.435 2.304 0.686 4.684 0.898 0.227 0.444 0.000 1.848 16.5712 0.000 2.137 0.817 4.360 0.949 0.083 0.561 0.000 2.412 19.3055 0.000 1.914 0.977 3.967 1.028 0.126 0.706 0.000 3.141 22.4909 0.000 1.613 1.185 3.517 1.170 0.160 0.882 0.045 4.025 26.2019 0.000 1.241 1.470 3.032 1.422 0.198 1.097 0.079 5.030 30.5252 0.000 0.821 1.869 2.539 1.838 0.200 1.367 0.096 6.087 35.5618 0.000 0.417 2.420 2.054 2.460 0.170 1.715 0.101 7.084 41.4295 0.000 0.144 3.154 1.593 3.314 0.126 2.169 0.101 7.891 48.2654 0.000 0.018 4.079 1.170 4.398 0.082 2.765 0.103 8.419 56.2292 0.000 0.000 5.157 0.795 5.636 0.045 3.524 0.107 8.634 65.507 0.000 0.000 6.323 0.480 6.933 0.022 4.453 0.106 8.643 76.3157 0.000 0.000 7.463 0.235 8.136 0.008 5.521 0.092 7.656 88.9077 0.000 0.000 8.472 0.067 9.152 0.002 6.660 0.063 6.344 103.5775 0.000 0.000 9.306 0.000 10.002 0.000 7.772 0.025 4.914 120.6678 0.000 0.000 9.978 0.000 9.546 0.000 8.743 0.000 3.526 140.578 0.000 0.000 9.371 0.000 8.368 0.000 9.505 0.000 2.318 163.7733 0.000 0.000 8.078 0.061 6.726 0.000 10.078 0.000 1.380 190.7959 0.000 0.000 6.378 0.171 4.969 0.000 9.334 0.017 0.754 222.2773 0.000 0.000 4.678 0.270 3.327 0.000 7.914 0.072 0.391 258.953 0.000 0.053 2.978 0.313 1.685 0.000 6.062 0.131 0.028 301.68021 0.000 0.235 1.278 0.268 0.042 0.000 4.067 0.174 0.000 351.45749 0.000 0.633 0.000 0.141 0.000 0.000 2.072 0.175 0.000 409.44791 0.000 1.340 0.000 0.015 0.000 0.000 0.077 0.123 0.000 477.00681 0.000 2.363 0.000 0.000 0.000 0.000 0.000 0.071 0.000 555.71301 0.000 3.391 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 3.987 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 3.421 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 2.260 0.000 0.000 0.000 0.000 0.000 0.000 0.000

170

KUS328 Grain Size(um)/ Depth (cm) 6 16 26 35 99 110 121 131 151 0.0582 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0679 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0921 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.1073 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.125 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.1456 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.1697 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.1977 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2303 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2683 0.000 0.000 0.000 0.000 0.000 0.000 0.027 0.000 0.000 0.3125 0.000 0.000 0.000 0.009 0.000 0.000 0.283 0.000 0.000 0.3641 0.114 0.000 0.010 0.064 0.007 0.003 0.589 0.033 0.029 0.4242 0.317 0.038 0.056 0.127 0.053 0.019 0.941 0.103 0.156 0.4941 0.579 0.097 0.117 0.211 0.114 0.039 1.375 0.195 0.322 0.5757 0.877 0.165 0.184 0.302 0.181 0.061 1.840 0.292 0.508 0.6707 1.231 0.248 0.263 0.408 0.261 0.087 2.355 0.403 0.730 0.7813 1.625 0.340 0.346 0.520 0.346 0.114 2.887 0.516 0.971 0.9103 2.121 0.456 0.453 0.680 0.458 0.145 3.435 0.644 1.285 1.0604 2.595 0.564 0.547 0.831 0.561 0.172 3.936 0.751 1.573 1.2354 3.057 0.664 0.635 0.988 0.658 0.197 4.387 0.843 1.843 1.4393 3.515 0.769 0.728 1.162 0.766 0.222 4.771 0.931 2.125 1.6767 3.942 0.877 0.826 1.349 0.881 0.249 5.064 1.012 2.403 1.9534 4.328 0.979 0.927 1.550 0.999 0.279 5.264 1.085 2.663 2.2757 4.662 1.079 1.039 1.767 1.127 0.315 5.361 1.157 2.911 2.6512 4.935 1.186 1.172 2.000 1.269 0.363 5.349 1.241 3.149 3.0887 5.127 1.300 1.329 2.240 1.421 0.424 5.221 1.340 3.362 3.5983 5.230 1.421 1.516 2.482 1.581 0.501 4.985 1.463 3.548

171

KUS328 Grain Size (um)/ Depth (cm) 156 166 172 188 206 215 225 241 254 4.192 5.242 1.558 1.741 2.720 1.747 0.596 4.656 1.626 3.703 4.8837 5.170 1.723 2.014 2.954 1.921 0.708 4.256 1.846 3.838 5.6895 5.030 1.933 2.345 3.187 2.108 0.839 3.811 2.143 3.965 6.6283 4.836 2.206 2.740 3.426 2.315 0.991 3.349 2.534 4.094 7.7219 4.603 2.564 3.203 3.677 2.556 1.169 2.891 3.031 4.229 8.996 4.345 3.027 3.729 3.955 2.849 1.382 2.446 3.634 4.374 10.4804 4.070 3.600 4.303 4.266 3.214 1.644 2.103 4.326 4.525 12.2096 3.820 4.281 4.906 4.617 3.672 1.981 1.846 5.075 4.673 14.2242 3.581 5.041 5.497 4.995 4.229 2.417 1.673 5.821 4.804 16.5712 3.330 5.819 6.023 5.369 4.869 2.974 1.565 6.484 4.906 19.3055 3.036 6.550 6.443 5.717 5.560 3.677 1.501 7.014 4.989 22.4909 2.663 7.154 6.714 6.008 6.231 4.510 1.453 7.379 4.854 26.2019 2.200 7.599 6.839 6.245 6.815 5.442 1.398 7.618 4.551 30.5252 1.737 7.924 6.873 6.044 7.281 6.404 1.324 7.180 4.086 35.5618 1.273 7.476 6.395 5.540 7.640 7.291 1.225 6.399 3.482 41.4295 0.810 6.599 5.664 4.764 7.209 8.019 1.099 5.358 2.784 48.2654 0.000 5.400 4.735 3.803 6.308 8.535 0.952 4.175 2.057 56.2292 0.000 4.046 3.693 2.777 5.059 8.881 0.793 2.983 1.370 65.507 0.000 2.713 2.646 1.807 3.658 8.116 0.634 1.901 0.786 76.3157 0.000 1.581 1.711 1.005 2.329 6.844 0.490 1.033 0.350 88.9077 0.000 0.759 0.975 0.437 1.247 5.308 0.372 0.431 0.000 103.5775 0.000 0.267 0.473 0.000 0.498 3.773 0.286 0.000 0.000 120.6678 0.000 0.000 0.188 0.000 0.000 2.421 0.233 0.000 0.000 140.578 0.000 0.000 0.000 0.000 0.000 1.364 0.326 0.000 0.000 163.7733 0.000 0.000 0.000 0.000 0.000 0.673 0.307 0.000 0.000 190.7959 0.000 0.000 0.000 0.000 0.000 0.321 0.300 0.000 0.000 222.2773 0.000 0.000 0.000 0.000 0.000 0.201 0.276 0.000 0.000 258.953 0.000 0.000 0.000 0.000 0.000 0.178 0.213 0.000 0.000 301.68021 0.000 0.000 0.000 0.000 0.000 0.134 0.120 0.000 0.000 351.45749 0.000 0.000 0.000 0.000 0.000 0.018 0.032 0.000 0.000 409.44791 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 477.00681 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 555.71301 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 647.40558 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 754.22748 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 878.67499 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

172

KUS318 Grain size (um) / Depth (cm) 12 20 31 37 41 46 0.375 0.200 0.500 0.054 0.029 0.047 0.200 0.412 0.360 0.730 0.095 0.052 0.084 0.290 0.452 0.530 1.020 0.140 0.077 0.120 0.410 0.496 0.740 1.250 0.200 0.110 0.180 0.510 0.545 0.910 1.430 0.250 0.140 0.220 0.600 0.598 1.050 1.570 0.300 0.160 0.260 0.680 0.656 1.160 1.700 0.350 0.180 0.300 0.760 0.721 1.260 1.780 0.390 0.210 0.340 0.840 0.791 1.330 1.830 0.430 0.230 0.370 0.890 0.868 1.360 1.840 0.460 0.240 0.390 0.950 0.953 1.380 1.840 0.490 0.250 0.410 1.000 1.047 1.380 1.830 0.520 0.260 0.430 1.040 1.149 1.370 1.830 0.540 0.260 0.440 1.090 1.261 1.360 1.830 0.560 0.270 0.440 1.140 1.384 1.340 1.840 0.570 0.260 0.440 1.190 1.52 1.330 1.860 0.580 0.260 0.440 1.250 1.668 1.330 1.900 0.600 0.250 0.430 1.320 1.832 1.330 1.950 0.600 0.250 0.420 1.400 2.011 1.350 2.010 0.610 0.240 0.410 1.480 2.207 1.370 2.060 0.620 0.230 0.400 1.580 2.423 1.400 2.120 0.630 0.230 0.390 1.690 2.66 1.430 2.170 0.640 0.230 0.390 1.810 2.92 1.480 2.240 0.660 0.230 0.400 1.940 3.205 1.530 2.310 0.680 0.230 0.410 2.080 3.519 1.600 2.390 0.700 0.240 0.440 2.240 3.863 1.680 2.460 0.740 0.260 0.480 2.400 4.24 1.770 2.530 0.780 0.290 0.540 2.560 4.655 1.860 2.580 0.830 0.320 0.610 2.730 5.11 1.950 2.610 0.900 0.370 0.720 2.890 5.61 2.040 2.620 0.970 0.420 0.840 3.050 6.158 2.120 2.620 1.060 0.490 0.990 3.210 6.76 2.210 2.610 1.160 0.570 1.170 3.350 7.421 2.300 2.600 1.280 0.670 1.380 3.490 8.147 2.390 2.590 1.410 0.790 1.620 3.610 8.943 2.500 2.580 1.560 0.930 1.900 3.710 9.818 2.610 2.550 1.740 1.090 2.230 3.780 10.78 2.700 2.460 1.930 1.290 2.590 3.800 11.83 2.760 2.300 2.140 1.520 3.000 3.750 12.99 2.760 2.100 2.360 1.790 3.430 3.630 14.26 2.710 1.900 2.600 2.090 3.860 3.440 15.65 2.630 1.760 2.840 2.430 4.290 3.230 17.18 2.560 1.690 3.100 2.790 4.680 3.010 18.86 2.530 1.670 3.370 3.170 5.010 2.810 20.71 2.530 1.660 3.650 3.540 5.240 2.620 22.73 2.540 1.620 3.920 3.890 5.340 2.420

173

KUS318 Grain size (um) / Depth (cm) 66 90 110 130 141 145 161 175 191 24.95 2.120 3.950 3.380 2.790 2.250 2.750 3.890 1.670 2.710 27.39 2.000 4.000 3.520 3.010 2.250 3.010 4.390 1.940 2.650 30.07 1.820 3.960 3.600 3.260 2.210 3.320 4.880 2.250 2.520 33.01 1.610 3.820 3.600 3.540 2.130 3.710 5.300 2.610 2.320 36.24 1.400 3.610 3.550 3.830 2.050 4.170 5.620 3.000 2.090 39.78 1.230 3.360 3.450 4.120 1.970 4.660 5.780 3.430 1.850 43.67 1.110 3.100 3.300 4.400 1.880 5.100 5.770 3.890 1.630 47.94 1.040 2.830 3.090 4.620 1.760 5.410 5.570 4.380 1.410 52.62 1.010 2.550 2.800 4.750 1.590 5.500 5.190 4.870 1.190 57.77 0.990 2.240 2.440 4.760 1.370 5.350 4.650 5.340 0.970 63.41 0.950 1.920 2.030 4.650 1.130 4.970 4.010 5.740 0.780 69.61 0.860 1.610 1.620 4.410 0.900 4.430 3.330 6.010 0.620 76.42 0.720 1.320 1.250 4.070 0.720 3.820 2.680 6.110 0.520 83.89 0.520 1.080 0.960 3.640 0.600 3.200 2.090 5.990 0.480 92.09 0.310 0.870 0.760 3.160 0.530 2.600 1.560 5.650 0.470 101.1 0.140 0.700 0.600 2.630 0.480 2.040 1.100 5.090 0.450 111 0.035 0.530 0.470 2.080 0.390 1.540 0.700 4.370 0.380 121.8 0.004 0.360 0.340 1.540 0.270 1.140 0.380 3.530 0.250 133.7 0.000 0.200 0.230 1.040 0.150 0.890 0.160 2.680 0.110 146.8 0.000 0.085 0.140 0.650 0.070 0.770 0.041 1.910 0.022 161.2 0.000 0.022 0.100 0.390 0.048 0.730 0.006 1.290 0.002 176.9 0.000 0.003 0.110 0.260 0.069 0.690 0.000 0.860 0.000 194.2 0.000 0.000 0.130 0.210 0.120 0.590 0.000 0.590 0.000 213.2 0.000 0.000 0.150 0.190 0.160 0.410 0.000 0.430 0.000 234 0.000 0.000 0.140 0.170 0.150 0.200 0.000 0.330 0.000 256.9 0.000 0.000 0.085 0.120 0.096 0.063 0.000 0.230 0.000 282.1 0.000 0.000 0.032 0.053 0.039 0.010 0.000 0.120 0.000 309.6 0.000 0.000 0.006 0.011 0.008 0.000 0.000 0.044 0.000 339.9 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.008 0.000 373.1 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 409.6 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 449.7 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 493.6 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 541.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 594.8 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 653 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 716.8 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 786.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 863.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 948.3 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1041 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1143 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1255 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1377 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1512 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

174

KUS330 Grain size (um) / Depth (cm) 2 8 22 28 39 45 48 62 71 0.375 0.035 0.260 0.150 0.013 0.012 0.200 0.037 0.069 0.018 0.412 0.063 0.460 0.260 0.022 0.021 0.360 0.067 0.120 0.033 0.452 0.093 0.680 0.380 0.033 0.032 0.530 0.099 0.180 0.049 0.496 0.130 0.950 0.540 0.047 0.045 0.750 0.140 0.250 0.070 0.545 0.170 1.160 0.670 0.059 0.057 0.920 0.180 0.310 0.087 0.598 0.200 1.330 0.770 0.070 0.067 1.050 0.210 0.360 0.100 0.656 0.220 1.460 0.860 0.080 0.077 1.160 0.240 0.410 0.120 0.721 0.250 1.570 0.950 0.090 0.087 1.260 0.270 0.450 0.130 0.791 0.270 1.640 1.010 0.099 0.095 1.330 0.290 0.480 0.140 0.868 0.290 1.670 1.050 0.110 0.100 1.360 0.310 0.490 0.150 0.953 0.310 1.670 1.070 0.110 0.110 1.370 0.320 0.500 0.160 1.047 0.320 1.640 1.070 0.120 0.110 1.350 0.340 0.510 0.170 1.149 0.330 1.610 1.080 0.120 0.120 1.330 0.350 0.500 0.180 1.261 0.340 1.570 1.070 0.130 0.120 1.300 0.350 0.500 0.180 1.384 0.340 1.530 1.050 0.130 0.120 1.260 0.350 0.490 0.180 1.52 0.340 1.490 1.040 0.130 0.120 1.220 0.360 0.470 0.180 1.668 0.340 1.470 1.030 0.130 0.120 1.200 0.360 0.460 0.180 1.832 0.340 1.470 1.020 0.130 0.120 1.180 0.360 0.450 0.190 2.011 0.340 1.470 1.020 0.140 0.120 1.170 0.360 0.450 0.190 2.207 0.340 1.480 1.030 0.140 0.120 1.170 0.360 0.440 0.190 2.423 0.350 1.500 1.040 0.140 0.120 1.180 0.360 0.440 0.190 2.66 0.350 1.530 1.060 0.150 0.130 1.200 0.360 0.450 0.200 2.92 0.360 1.570 1.080 0.150 0.130 1.230 0.370 0.450 0.200 3.205 0.370 1.610 1.120 0.160 0.130 1.270 0.380 0.470 0.210 3.519 0.380 1.660 1.160 0.170 0.140 1.320 0.400 0.480 0.220 3.863 0.400 1.720 1.210 0.170 0.140 1.370 0.420 0.500 0.230 4.24 0.420 1.780 1.270 0.190 0.150 1.440 0.450 0.530 0.250 4.655 0.450 1.830 1.330 0.200 0.160 1.500 0.480 0.550 0.270 5.11 0.480 1.880 1.390 0.210 0.170 1.560 0.520 0.580 0.290 5.61 0.520 1.930 1.450 0.230 0.190 1.620 0.560 0.610 0.320 6.158 0.560 1.960 1.510 0.250 0.200 1.680 0.610 0.640 0.350 6.76 0.610 1.990 1.580 0.260 0.220 1.740 0.660 0.670 0.380 7.421 0.660 2.020 1.650 0.280 0.230 1.800 0.720 0.700 0.420 8.147 0.730 2.060 1.720 0.310 0.260 1.860 0.780 0.730 0.460 8.943 0.800 2.100 1.800 0.330 0.280 1.930 0.860 0.760 0.500 9.818 0.880 2.150 1.890 0.360 0.300 2.010 0.940 0.800 0.550 10.78 0.980 2.180 1.970 0.390 0.330 2.070 1.040 0.830 0.600 11.83 1.090 2.180 2.040 0.420 0.370 2.110 1.140 0.860 0.670 12.99 1.230 2.120 2.080 0.460 0.410 2.110 1.260 0.880 0.730 14.26 1.380 2.030 2.100 0.510 0.450 2.060 1.390 0.900 0.810 15.65 1.570 1.920 2.110 0.560 0.500 2.000 1.540 0.910 0.890 17.18 1.790 1.830 2.130 0.620 0.560 1.950 1.720 0.920 0.990 18.86 2.050 1.780 2.170 0.700 0.640 1.940 1.920 0.950 1.100 20.71 2.360 1.770 2.240 0.790 0.730 1.960 2.160 1.000 1.240 22.73 2.700 1.770 2.330 0.910 0.830 2.010 2.440 1.080 1.400

175

KUS330 Grain size (um) / Depth (cm) 2 8 22 28 39 45 48 62 71 24.95 3.080 1.790 2.420 1.060 0.970 2.040 2.760 1.170 1.590 27.39 3.470 1.790 2.480 1.240 1.130 2.030 3.100 1.290 1.810 30.07 3.830 1.770 2.520 1.460 1.330 2.000 3.450 1.430 2.060 33.01 4.160 1.760 2.530 1.740 1.580 1.940 3.780 1.590 2.350 36.24 4.410 1.740 2.530 2.070 1.870 1.900 4.070 1.780 2.680 39.78 4.570 1.720 2.520 2.470 2.230 1.890 4.300 1.990 3.040 43.67 4.640 1.680 2.510 2.940 2.640 1.910 4.440 2.220 3.430 47.94 4.590 1.610 2.470 3.470 3.110 1.940 4.480 2.470 3.840 52.62 4.440 1.500 2.400 4.060 3.620 1.950 4.410 2.740 4.260 57.77 4.190 1.360 2.300 4.660 4.150 1.920 4.260 3.020 4.660 63.41 3.880 1.220 2.170 5.250 4.670 1.850 4.040 3.330 5.030 69.61 3.540 1.090 2.040 5.780 5.150 1.750 3.790 3.660 5.330 76.42 3.200 0.990 1.930 6.170 5.560 1.660 3.530 4.000 5.530 83.89 2.880 0.910 1.830 6.380 5.840 1.590 3.280 4.300 5.590 92.09 2.580 0.840 1.740 6.360 5.960 1.530 3.010 4.520 5.470 101.1 2.290 0.740 1.600 6.080 5.890 1.420 2.710 4.600 5.160 111 1.990 0.610 1.370 5.560 5.630 1.220 2.360 4.500 4.640 121.8 1.670 0.460 1.040 4.860 5.180 0.890 1.980 4.220 3.970 133.7 1.350 0.350 0.650 4.060 4.580 0.500 1.600 3.810 3.230 146.8 1.050 0.310 0.330 3.250 3.910 0.240 1.250 3.360 2.530 161.2 0.810 0.340 0.160 2.520 3.220 0.160 0.970 2.960 1.970 176.9 0.640 0.410 0.130 1.920 2.580 0.230 0.760 2.620 1.560 194.2 0.510 0.470 0.210 1.450 2.020 0.440 0.610 2.320 1.280 213.2 0.420 0.450 0.340 1.100 1.550 0.680 0.500 1.980 1.060 234 0.340 0.350 0.450 0.820 1.170 0.770 0.390 1.570 0.830 256.9 0.260 0.200 0.410 0.590 0.860 0.630 0.270 1.080 0.560 282.1 0.190 0.074 0.260 0.400 0.620 0.370 0.180 0.610 0.280 309.6 0.160 0.014 0.100 0.270 0.450 0.130 0.130 0.290 0.092 339.9 0.170 0.001 0.019 0.200 0.360 0.024 0.110 0.140 0.015 373.1 0.210 0.000 0.001 0.180 0.330 0.002 0.130 0.120 0.001 409.6 0.270 0.000 0.000 0.200 0.340 0.000 0.160 0.160 0.000 449.7 0.310 0.000 0.000 0.210 0.360 0.000 0.170 0.210 0.000 493.6 0.300 0.000 0.000 0.190 0.350 0.000 0.130 0.190 0.000 541.9 0.250 0.000 0.000 0.140 0.310 0.000 0.074 0.110 0.000 594.8 0.180 0.000 0.000 0.069 0.250 0.000 0.025 0.034 0.000 653 0.120 0.000 0.000 0.022 0.190 0.000 0.004 0.005 0.000 716.8 0.094 0.000 0.000 0.003 0.140 0.000 0.000 0.000 0.000 786.9 0.085 0.000 0.000 0.000 0.110 0.000 0.000 0.000 0.000 863.9 0.084 0.000 0.000 0.000 0.086 0.000 0.000 0.000 0.000 948.3 0.078 0.000 0.000 0.000 0.063 0.000 0.000 0.000 0.000 1041 0.064 0.000 0.000 0.000 0.041 0.000 0.000 0.000 0.000 1143 0.047 0.000 0.000 0.000 0.021 0.000 0.000 0.000 0.000

176

KUS331 Grain size (um) / Depth (cm) 3 12 20 32 60 82 111 125 136 148 0.375 0.240 0.025 0.038 0.043 0.021 0.120 0.015 0.023 0.010 0.150 0.412 0.420 0.045 0.068 0.076 0.037 0.220 0.028 0.041 0.018 0.270 0.452 0.620 0.067 0.100 0.110 0.055 0.320 0.047 0.061 0.026 0.390 0.496 0.870 0.096 0.140 0.160 0.079 0.460 0.063 0.087 0.037 0.560 0.545 1.070 0.120 0.180 0.200 0.098 0.570 0.079 0.110 0.047 0.710 0.598 1.230 0.140 0.210 0.230 0.120 0.670 0.092 0.130 0.055 0.830 0.656 1.360 0.160 0.240 0.270 0.130 0.750 0.100 0.150 0.063 0.950 0.721 1.470 0.180 0.270 0.300 0.150 0.840 0.110 0.160 0.071 1.070 0.791 1.550 0.200 0.290 0.320 0.160 0.900 0.120 0.180 0.078 1.170 0.868 1.590 0.210 0.320 0.340 0.170 0.960 0.120 0.190 0.083 1.260 0.953 1.590 0.220 0.330 0.360 0.180 1.000 0.130 0.200 0.087 1.340 1.047 1.570 0.230 0.340 0.370 0.190 1.030 0.130 0.200 0.091 1.410 1.149 1.540 0.230 0.360 0.380 0.190 1.060 0.130 0.210 0.094 1.480 1.261 1.500 0.240 0.360 0.380 0.190 1.080 0.130 0.210 0.095 1.540 1.384 1.450 0.240 0.370 0.380 0.190 1.090 0.120 0.210 0.096 1.600 1.52 1.390 0.230 0.370 0.380 0.190 1.110 0.120 0.200 0.096 1.650 1.668 1.350 0.230 0.370 0.380 0.180 1.120 0.120 0.200 0.096 1.700 1.832 1.310 0.230 0.370 0.380 0.180 1.150 0.120 0.200 0.096 1.750 2.011 1.290 0.230 0.370 0.380 0.170 1.170 0.110 0.190 0.095 1.800 2.207 1.260 0.220 0.370 0.380 0.170 1.200 0.110 0.190 0.095 1.840 2.423 1.250 0.220 0.370 0.390 0.160 1.230 0.110 0.190 0.095 1.890 2.66 1.250 0.220 0.370 0.390 0.160 1.270 0.110 0.190 0.096 1.930 2.92 1.250 0.230 0.380 0.400 0.160 1.320 0.110 0.190 0.098 1.990 3.205 1.270 0.230 0.390 0.420 0.160 1.380 0.110 0.200 0.100 2.050 3.519 1.300 0.250 0.400 0.440 0.160 1.450 0.120 0.210 0.100 2.130 3.863 1.340 0.260 0.420 0.460 0.170 1.530 0.130 0.230 0.110 2.220 4.24 1.390 0.290 0.440 0.500 0.180 1.620 0.140 0.250 0.120 2.320 4.655 1.450 0.320 0.470 0.540 0.190 1.720 0.150 0.280 0.130 2.430 5.11 1.510 0.350 0.500 0.580 0.210 1.820 0.160 0.320 0.140 2.550 5.61 1.580 0.400 0.530 0.630 0.230 1.930 0.180 0.360 0.150 2.670 6.158 1.650 0.450 0.570 0.690 0.260 2.040 0.200 0.420 0.160 2.790 6.76 1.720 0.510 0.620 0.760 0.300 2.150 0.220 0.480 0.180 2.910 7.421 1.800 0.580 0.670 0.830 0.340 2.270 0.240 0.550 0.200 3.030 8.147 1.890 0.660 0.730 0.910 0.390 2.380 0.280 0.630 0.220 3.130 8.943 1.990 0.760 0.790 1.000 0.440 2.500 0.320 0.720 0.240 3.210 9.818 2.100 0.870 0.870 1.110 0.520 2.610 0.360 0.830 0.260 3.270 10.78 2.200 0.990 0.960 1.220 0.600 2.700 0.420 0.950 0.290 3.270 11.83 2.270 1.140 1.060 1.340 0.700 2.760 0.490 1.100 0.320 3.200 12.99 2.290 1.300 1.180 1.480 0.830 2.790 0.560 1.270 0.360 3.040 14.26 2.270 1.490 1.320 1.620 0.980 2.780 0.630 1.460 0.400 2.810 15.65 2.230 1.700 1.480 1.770 1.160 2.740 0.710 1.690 0.450 2.530 17.18 2.190 1.940 1.680 1.930 1.380 2.700 0.800 1.950 0.500 2.270 18.86 2.180 2.210 1.910 2.110 1.650 2.680 0.920 2.260 0.560 2.070 20.71 2.210 2.500 2.180 2.300 1.980 2.680 1.080 2.600 0.640 1.920 22.73 2.250 2.820 2.500 2.480 2.360 2.690 1.290 2.980 0.720 1.810

177

KUS331 Grain size (um) / Depth (cm) 3 12 20 32 60 82 111 125 136 148 24.95 2.280 3.160 2.860 2.660 2.810 2.710 1.550 3.390 0.830 1.680 27.39 2.300 3.510 3.240 2.790 3.300 2.690 1.840 3.810 0.950 1.520 30.07 2.280 3.860 3.620 2.890 3.840 2.630 2.160 4.230 1.090 1.320 33.01 2.250 4.200 3.990 2.940 4.390 2.530 2.510 4.600 1.260 1.120 36.24 2.210 4.500 4.310 2.960 4.910 2.410 2.900 4.910 1.470 0.940 39.78 2.160 4.750 4.580 2.960 5.370 2.280 3.370 5.130 1.730 0.820 43.67 2.100 4.930 4.770 2.950 5.710 2.160 3.910 5.210 2.040 0.740 47.94 2.020 5.020 4.850 2.950 5.900 2.070 4.480 5.150 2.410 0.680 52.62 1.880 5.000 4.820 2.940 5.910 2.000 5.040 4.950 2.850 0.620 57.77 1.720 4.870 4.680 2.930 5.730 1.910 5.550 4.610 3.340 0.540 63.41 1.530 4.640 4.440 2.920 5.380 1.780 5.940 4.180 3.870 0.440 69.61 1.350 4.340 4.120 2.910 4.900 1.560 6.170 3.710 4.420 0.330 76.42 1.200 3.980 3.750 2.920 4.340 1.230 6.230 3.240 4.930 0.250 83.89 1.080 3.580 3.350 2.920 3.750 0.840 6.190 2.810 5.370 0.200 92.09 0.950 3.130 2.920 2.910 3.160 0.450 6.020 2.420 5.680 0.190 101.1 0.770 2.650 2.470 2.860 2.590 0.170 5.600 2.080 5.830 0.190 111 0.540 2.130 2.010 2.730 2.050 0.031 4.850 1.750 5.780 0.180 121.8 0.300 1.620 1.540 2.500 1.570 0.002 3.880 1.440 5.550 0.150 133.7 0.150 1.140 1.130 2.200 1.170 0.000 2.860 1.150 5.160 0.100 146.8 0.098 0.760 0.800 1.870 0.860 0.000 1.890 0.890 4.680 0.057 161.2 0.140 0.510 0.590 1.590 0.640 0.000 1.130 0.680 4.150 0.036 176.9 0.240 0.380 0.470 1.380 0.500 0.000 0.770 0.530 3.630 0.041 194.2 0.330 0.310 0.420 1.250 0.420 0.000 0.810 0.420 3.130 0.073 213.2 0.320 0.280 0.390 1.150 0.350 0.000 1.070 0.350 2.650 0.120 234 0.210 0.240 0.340 1.030 0.280 0.000 1.020 0.290 2.190 0.170 256.9 0.085 0.160 0.250 0.860 0.200 0.000 0.420 0.230 1.730 0.190 282.1 0.016 0.070 0.150 0.660 0.140 0.000 0.034 0.190 1.300 0.170 309.6 0.001 0.015 0.089 0.480 0.100 0.000 0.000 0.160 0.940 0.130 339.9 0.000 0.001 0.068 0.360 0.092 0.000 0.000 0.160 0.660 0.068 373.1 0.000 0.000 0.086 0.330 0.110 0.000 0.000 0.180 0.480 0.025 409.6 0.000 0.000 0.130 0.350 0.140 0.000 0.000 0.210 0.380 0.005 449.7 0.000 0.000 0.170 0.390 0.160 0.000 0.000 0.240 0.310 0.000 493.6 0.000 0.000 0.160 0.400 0.150 0.000 0.000 0.240 0.260 0.000 541.9 0.000 0.000 0.110 0.350 0.110 0.000 0.000 0.220 0.210 0.000 594.8 0.000 0.000 0.048 0.260 0.076 0.000 0.000 0.180 0.150 0.000 653 0.000 0.000 0.010 0.180 0.054 0.000 0.000 0.140 0.110 0.000 716.8 0.000 0.000 0.001 0.140 0.051 0.000 0.000 0.120 0.092 0.000 786.9 0.000 0.000 0.000 0.140 0.065 0.000 0.000 0.110 0.082 0.000 863.9 0.000 0.000 0.000 0.170 0.087 0.000 0.000 0.100 0.074 0.000 948.3 0.000 0.000 0.000 0.210 0.082 0.000 0.000 0.076 0.061 0.000 1041 0.000 0.000 0.000 0.220 0.049 0.000 0.000 0.041 0.045 0.000 1143 0.000 0.000 0.000 0.170 0.012 0.000 0.000 0.010 0.029 0.000 1255 0.000 0.000 0.000 0.086 0.001 0.000 0.000 0.001 0.015 0.000

178

KUS331 Grain size (um) / Depth (cm) 160 176 189 192 202 218 234 250 267 278 290 0.375 0.058 0.160 0.069 0.031 0.022 0.320 0.390 0.013 0.055 0.240 0.023 0.412 0.100 0.280 0.120 0.055 0.039 0.560 0.680 0.025 0.099 0.430 0.042 0.452 0.150 0.420 0.180 0.082 0.058 0.810 0.990 0.042 0.150 0.630 0.062 0.496 0.220 0.590 0.260 0.120 0.082 1.130 1.390 0.057 0.210 0.890 0.088 0.545 0.280 0.740 0.330 0.150 0.100 1.380 1.700 0.071 0.260 1.100 0.110 0.598 0.330 0.860 0.390 0.170 0.120 1.570 1.950 0.084 0.310 1.280 0.130 0.656 0.370 0.970 0.450 0.200 0.140 1.730 2.160 0.094 0.350 1.430 0.150 0.721 0.420 1.080 0.500 0.220 0.150 1.850 2.350 0.100 0.390 1.570 0.160 0.791 0.460 1.170 0.550 0.240 0.170 1.940 2.500 0.110 0.420 1.680 0.180 0.868 0.490 1.240 0.600 0.250 0.180 1.970 2.610 0.120 0.450 1.760 0.190 0.953 0.510 1.290 0.630 0.260 0.180 1.970 2.700 0.120 0.470 1.810 0.190 1.047 0.530 1.340 0.670 0.270 0.190 1.950 2.780 0.120 0.480 1.860 0.200 1.149 0.550 1.380 0.700 0.270 0.190 1.930 2.880 0.120 0.490 1.890 0.200 1.261 0.550 1.420 0.720 0.270 0.190 1.910 2.990 0.120 0.490 1.920 0.200 1.384 0.560 1.450 0.740 0.270 0.190 1.890 3.100 0.120 0.490 1.950 0.200 1.52 0.550 1.480 0.760 0.260 0.190 1.880 3.220 0.110 0.480 1.970 0.190 1.668 0.550 1.510 0.770 0.250 0.190 1.890 3.330 0.110 0.470 2.000 0.180 1.832 0.550 1.540 0.790 0.240 0.180 1.910 3.420 0.100 0.460 2.030 0.180 2.011 0.540 1.560 0.800 0.230 0.180 1.940 3.470 0.098 0.440 2.060 0.170 2.207 0.540 1.590 0.810 0.220 0.180 1.980 3.460 0.093 0.430 2.080 0.160 2.423 0.540 1.610 0.820 0.210 0.180 2.010 3.390 0.088 0.430 2.100 0.160 2.66 0.560 1.630 0.830 0.210 0.180 2.040 3.250 0.084 0.430 2.110 0.150 2.92 0.580 1.660 0.840 0.210 0.180 2.070 3.070 0.082 0.440 2.120 0.150 3.205 0.620 1.690 0.850 0.210 0.190 2.100 2.880 0.081 0.460 2.130 0.150 3.519 0.670 1.730 0.870 0.220 0.200 2.140 2.690 0.082 0.500 2.140 0.160 3.863 0.740 1.770 0.890 0.240 0.220 2.190 2.510 0.084 0.550 2.150 0.180 4.24 0.830 1.830 0.910 0.260 0.240 2.230 2.350 0.088 0.610 2.170 0.190 4.655 0.950 1.900 0.930 0.300 0.270 2.270 2.200 0.093 0.700 2.180 0.220 5.11 1.090 1.960 0.950 0.340 0.300 2.290 2.040 0.099 0.800 2.190 0.250 5.61 1.260 2.030 0.980 0.400 0.340 2.290 1.870 0.100 0.930 2.190 0.290 6.158 1.450 2.100 1.010 0.470 0.390 2.270 1.680 0.110 1.070 2.180 0.330 6.76 1.660 2.170 1.050 0.550 0.440 2.240 1.500 0.120 1.240 2.180 0.380 7.421 1.890 2.230 1.090 0.640 0.500 2.200 1.360 0.130 1.420 2.180 0.440 8.147 2.150 2.290 1.140 0.750 0.570 2.170 1.280 0.150 1.630 2.200 0.510 8.943 2.420 2.330 1.190 0.880 0.650 2.150 1.280 0.170 1.870 2.250 0.590 9.818 2.700 2.360 1.260 1.030 0.740 2.140 1.310 0.200 2.120 2.310 0.680 10.78 2.990 2.350 1.330 1.210 0.840 2.110 1.350 0.240 2.400 2.370 0.790 11.83 3.260 2.290 1.420 1.410 0.950 2.030 1.360 0.280 2.690 2.410 0.910 12.99 3.510 2.200 1.510 1.650 1.080 1.900 1.310 0.320 2.990 2.400 1.050 14.26 3.700 2.080 1.610 1.910 1.230 1.750 1.220 0.370 3.290 2.350 1.210 15.65 3.830 1.960 1.720 2.210 1.390 1.600 1.130 0.420 3.560 2.270 1.390 17.18 3.890 1.890 1.850 2.530 1.580 1.490 1.060 0.480 3.820 2.200 1.590 18.86 3.900 1.850 2.000 2.880 1.790 1.440 1.030 0.570 4.040 2.170 1.830 20.71 3.850 1.850 2.190 3.240 2.030 1.440 1.020 0.690 4.220 2.170 2.100 22.73 3.760 1.830 2.410 3.610 2.300 1.450 1.020 0.860 4.350 2.150 2.410 179

KUS331 Grain size (um) / Depth (cm) 160 176 189 192 202 218 234 250 267 278 290 24.95 3.660 1.770 2.640 3.960 2.610 1.430 1.010 1.080 4.410 2.090 2.760 27.39 3.540 1.650 2.890 4.290 2.950 1.370 0.980 1.340 4.400 1.960 3.160 30.07 3.420 1.500 3.140 4.560 3.320 1.280 0.940 1.650 4.290 1.770 3.590 33.01 3.320 1.370 3.390 4.780 3.690 1.190 0.890 2.000 4.100 1.560 4.040 36.24 3.210 1.300 3.620 4.910 4.060 1.120 0.810 2.400 3.860 1.370 4.490 39.78 3.110 1.300 3.820 4.970 4.410 1.090 0.710 2.880 3.590 1.220 4.910 43.67 2.980 1.360 3.970 4.950 4.690 1.090 0.580 3.450 3.290 1.110 5.250 47.94 2.810 1.450 4.050 4.820 4.900 1.070 0.430 4.080 2.980 0.990 5.470 52.62 2.570 1.540 4.020 4.590 5.000 1.030 0.270 4.740 2.660 0.830 5.540 57.77 2.280 1.580 3.890 4.250 4.980 0.960 0.130 5.380 2.320 0.620 5.440 63.41 1.960 1.560 3.660 3.840 4.850 0.860 0.042 5.910 1.980 0.390 5.180 69.61 1.650 1.490 3.340 3.370 4.630 0.770 0.007 6.280 1.650 0.180 4.800 76.42 1.350 1.390 2.970 2.900 4.340 0.710 0.000 6.470 1.370 0.057 4.320 83.89 1.090 1.280 2.560 2.440 4.000 0.690 0.000 6.510 1.140 0.009 3.780 92.09 0.840 1.170 2.110 2.010 3.620 0.700 0.000 6.400 0.970 0.001 3.240 101.1 0.590 1.040 1.640 1.620 3.210 0.690 0.000 6.070 0.830 0.000 2.710 111 0.340 0.880 1.140 1.260 2.760 0.620 0.000 5.510 0.710 0.000 2.200 121.8 0.140 0.670 0.660 0.920 2.310 0.470 0.000 4.770 0.570 0.000 1.750 133.7 0.028 0.440 0.280 0.620 1.860 0.260 0.000 3.960 0.430 0.000 1.360 146.8 0.003 0.230 0.074 0.390 1.450 0.094 0.000 3.120 0.280 0.000 1.050 161.2 0.000 0.120 0.026 0.240 1.110 0.016 0.000 2.320 0.150 0.000 0.820 176.9 0.000 0.092 0.044 0.180 0.820 0.001 0.000 1.690 0.061 0.000 0.650 194.2 0.000 0.140 0.140 0.170 0.590 0.000 0.000 1.320 0.015 0.000 0.530 213.2 0.000 0.250 0.280 0.200 0.410 0.000 0.000 1.150 0.002 0.000 0.440 234 0.000 0.380 0.400 0.230 0.260 0.000 0.000 0.960 0.001 0.000 0.350 256.9 0.000 0.430 0.460 0.250 0.170 0.000 0.000 0.570 0.000 0.000 0.260 282.1 0.000 0.380 0.460 0.240 0.120 0.000 0.000 0.160 0.000 0.000 0.180 309.6 0.000 0.290 0.430 0.220 0.110 0.000 0.000 0.009 0.000 0.000 0.130 339.9 0.000 0.190 0.380 0.220 0.140 0.000 0.000 0.000 0.000 0.000 0.110 373.1 0.000 0.150 0.330 0.220 0.180 0.000 0.000 0.000 0.000 0.000 0.110 409.6 0.000 0.150 0.290 0.220 0.210 0.000 0.000 0.000 0.000 0.000 0.110 449.7 0.000 0.200 0.230 0.210 0.210 0.000 0.000 0.000 0.000 0.000 0.091 493.6 0.000 0.250 0.140 0.170 0.160 0.000 0.000 0.000 0.000 0.000 0.058 541.9 0.000 0.220 0.062 0.100 0.089 0.000 0.000 0.000 0.000 0.000 0.024 594.8 0.000 0.120 0.013 0.040 0.030 0.000 0.000 0.000 0.000 0.000 0.005 653 0.000 0.031 0.001 0.008 0.005 0.000 0.000 0.000 0.000 0.000 0.000 716.8 0.000 0.003 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 786.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 863.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 948.3 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1041 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

180

KUS329 Grain size (um) / Depth (cm) 9 14 28 50 76 95 113 150 0.375 0.200 0.021 0.024 0.013 0.009 0.013 0.140 0.018 0.412 0.360 0.038 0.042 0.023 0.016 0.023 0.240 0.033 0.452 0.520 0.057 0.063 0.034 0.024 0.034 0.350 0.049 0.496 0.730 0.081 0.090 0.049 0.035 0.049 0.500 0.070 0.545 0.900 0.100 0.110 0.061 0.044 0.061 0.630 0.087 0.598 1.040 0.120 0.130 0.072 0.052 0.072 0.740 0.100 0.656 1.150 0.140 0.150 0.082 0.059 0.083 0.840 0.120 0.721 1.250 0.150 0.170 0.092 0.066 0.093 0.940 0.130 0.791 1.320 0.170 0.180 0.100 0.073 0.100 1.020 0.140 0.868 1.350 0.180 0.190 0.110 0.078 0.110 1.090 0.150 0.953 1.370 0.180 0.200 0.110 0.082 0.110 1.150 0.160 1.047 1.370 0.190 0.210 0.120 0.085 0.120 1.210 0.170 1.149 1.360 0.190 0.210 0.120 0.088 0.120 1.270 0.170 1.261 1.350 0.190 0.210 0.130 0.089 0.130 1.320 0.180 1.384 1.340 0.190 0.210 0.130 0.090 0.130 1.370 0.180 1.52 1.320 0.190 0.210 0.130 0.091 0.130 1.420 0.180 1.668 1.320 0.190 0.210 0.130 0.091 0.130 1.470 0.180 1.832 1.330 0.180 0.200 0.130 0.091 0.130 1.530 0.180 2.011 1.350 0.180 0.200 0.130 0.091 0.130 1.590 0.190 2.207 1.370 0.170 0.190 0.140 0.091 0.130 1.650 0.190 2.423 1.390 0.160 0.190 0.140 0.091 0.130 1.720 0.190 2.66 1.430 0.160 0.190 0.140 0.093 0.130 1.790 0.200 2.92 1.470 0.160 0.200 0.150 0.095 0.130 1.860 0.200 3.205 1.530 0.160 0.210 0.150 0.098 0.140 1.930 0.210 3.519 1.600 0.160 0.220 0.160 0.100 0.140 2.010 0.220 3.863 1.680 0.170 0.240 0.170 0.110 0.150 2.080 0.230 4.24 1.760 0.180 0.260 0.180 0.120 0.150 2.160 0.250 4.655 1.850 0.190 0.290 0.190 0.120 0.160 2.230 0.270 5.11 1.950 0.210 0.330 0.210 0.140 0.170 2.300 0.290 5.61 2.030 0.240 0.370 0.220 0.150 0.180 2.360 0.320 6.158 2.120 0.270 0.430 0.240 0.160 0.200 2.420 0.350 6.76 2.210 0.300 0.490 0.250 0.180 0.210 2.470 0.380 7.421 2.290 0.340 0.560 0.270 0.200 0.230 2.520 0.420 8.147 2.390 0.390 0.640 0.290 0.220 0.250 2.570 0.460 8.943 2.500 0.450 0.740 0.320 0.240 0.270 2.620 0.500 9.818 2.610 0.520 0.850 0.340 0.260 0.300 2.680 0.550 10.78 2.700 0.610 0.980 0.370 0.290 0.330 2.730 0.610 11.83 2.760 0.720 1.130 0.400 0.330 0.360 2.760 0.670 12.99 2.760 0.840 1.300 0.440 0.360 0.400 2.760 0.740 14.26 2.700 0.990 1.500 0.480 0.410 0.440 2.730 0.810 15.65 2.620 1.180 1.730 0.530 0.450 0.490 2.680 0.900 17.18 2.560 1.410 2.000 0.590 0.510 0.540 2.620 1.000 18.86 2.530 1.690 2.310 0.660 0.580 0.610 2.580 1.110 20.71 2.540 2.020 2.660 0.750 0.650 0.700 2.570 1.250 22.73 2.540 2.420 3.060 0.860 0.750 0.800 2.570 1.420

181

KUS329 Grain size (um) / Depth (cm) 9 14 28 50 76 95 113 150 24.95 2.500 2.870 3.480 1.000 0.860 0.930 2.550 1.610 27.39 2.390 3.390 3.920 1.170 0.980 1.090 2.490 1.840 30.07 2.220 3.940 4.350 1.380 1.140 1.280 2.360 2.110 33.01 2.030 4.500 4.740 1.650 1.320 1.510 2.160 2.410 36.24 1.840 5.030 5.050 1.970 1.540 1.810 1.920 2.740 39.78 1.690 5.490 5.250 2.360 1.820 2.160 1.660 3.110 43.67 1.570 5.830 5.310 2.810 2.150 2.570 1.390 3.490 47.94 1.470 6.010 5.220 3.340 2.540 3.030 1.140 3.900 52.62 1.340 6.010 4.960 3.900 3.000 3.530 0.890 4.310 57.77 1.190 5.800 4.570 4.490 3.520 4.040 0.680 4.720 63.41 1.010 5.430 4.090 5.060 4.090 4.530 0.510 5.100 69.61 0.830 4.920 3.580 5.550 4.670 4.980 0.400 5.430 76.42 0.690 4.320 3.080 5.910 5.230 5.330 0.340 5.660 83.89 0.600 3.690 2.640 6.090 5.700 5.550 0.320 5.750 92.09 0.530 3.060 2.260 6.060 6.040 5.600 0.320 5.650 101.1 0.470 2.460 1.930 5.800 6.200 5.490 0.300 5.320 111 0.380 1.900 1.630 5.340 6.150 5.190 0.220 4.770 121.8 0.260 1.400 1.360 4.720 5.880 4.760 0.110 4.040 133.7 0.130 1.000 1.120 4.010 5.430 4.220 0.034 3.240 146.8 0.037 0.710 0.910 3.310 4.850 3.660 0.005 2.490 161.2 0.005 0.540 0.740 2.670 4.210 3.130 0.000 1.880 176.9 0.000 0.460 0.600 2.150 3.560 2.680 0.000 1.420 194.2 0.000 0.430 0.490 1.730 2.940 2.300 0.000 1.070 213.2 0.000 0.420 0.390 1.400 2.350 1.980 0.000 0.780 234 0.000 0.370 0.300 1.130 1.790 1.680 0.000 0.510 256.9 0.000 0.290 0.210 0.890 1.280 1.370 0.000 0.270 282.1 0.000 0.180 0.150 0.690 0.820 1.080 0.000 0.094 309.6 0.000 0.091 0.120 0.540 0.470 0.820 0.000 0.017 339.9 0.000 0.047 0.130 0.440 0.250 0.630 0.000 0.001 373.1 0.000 0.040 0.150 0.390 0.150 0.530 0.000 0.000 409.6 0.000 0.057 0.190 0.370 0.120 0.490 0.000 0.000 449.7 0.000 0.082 0.210 0.350 0.130 0.480 0.000 0.000 493.6 0.000 0.087 0.190 0.300 0.140 0.450 0.000 0.000 541.9 0.000 0.065 0.140 0.230 0.130 0.400 0.000 0.000 594.8 0.000 0.035 0.090 0.150 0.100 0.320 0.000 0.000 653 0.000 0.018 0.059 0.092 0.081 0.250 0.000 0.000 716.8 0.000 0.016 0.048 0.059 0.067 0.200 0.000 0.000 786.9 0.000 0.026 0.055 0.043 0.061 0.160 0.000 0.000 863.9 0.000 0.042 0.072 0.029 0.054 0.130 0.000 0.000 948.3 0.000 0.042 0.068 0.014 0.045 0.096 0.000 0.000 1041 0.000 0.025 0.043 0.003 0.036 0.061 0.000 0.000 1143 0.000 0.006 0.011 0.000 0.030 0.029 0.000 0.000 1255 0.000 0.001 0.001 0.000 0.022 0.010 0.000 0.000 182

KUS329 Grain size (um) / Depth (cm) 164 190 230 250 315 335 363 383 396 0.375 0.150 0.031 0.022 0.230 0.018 0.220 0.150 0.260 0.025 0.412 0.270 0.055 0.039 0.400 0.032 0.380 0.270 0.450 0.045 0.452 0.390 0.082 0.058 0.580 0.048 0.560 0.400 0.660 0.067 0.496 0.560 0.120 0.083 0.810 0.068 0.790 0.570 0.920 0.096 0.545 0.690 0.150 0.100 0.980 0.085 0.970 0.720 1.130 0.120 0.598 0.790 0.170 0.120 1.120 0.100 1.110 0.850 1.290 0.140 0.656 0.890 0.200 0.140 1.220 0.110 1.230 0.960 1.420 0.160 0.721 0.970 0.220 0.150 1.310 0.130 1.330 1.080 1.530 0.180 0.791 1.030 0.240 0.170 1.370 0.140 1.400 1.190 1.600 0.200 0.868 1.070 0.250 0.180 1.410 0.150 1.430 1.280 1.630 0.210 0.953 1.090 0.260 0.190 1.420 0.150 1.430 1.360 1.630 0.220 1.047 1.100 0.270 0.190 1.440 0.160 1.410 1.440 1.600 0.230 1.149 1.100 0.270 0.190 1.470 0.160 1.390 1.510 1.570 0.230 1.261 1.090 0.270 0.190 1.510 0.160 1.350 1.570 1.530 0.230 1.384 1.080 0.270 0.190 1.570 0.160 1.310 1.630 1.490 0.230 1.52 1.060 0.260 0.190 1.650 0.160 1.270 1.680 1.450 0.230 1.668 1.050 0.250 0.190 1.750 0.150 1.240 1.730 1.430 0.230 1.832 1.050 0.240 0.180 1.880 0.150 1.220 1.780 1.430 0.230 2.011 1.050 0.230 0.180 2.020 0.150 1.210 1.830 1.430 0.220 2.207 1.050 0.220 0.180 2.160 0.150 1.210 1.870 1.450 0.220 2.423 1.060 0.210 0.180 2.300 0.150 1.220 1.920 1.470 0.220 2.66 1.080 0.210 0.180 2.420 0.150 1.240 1.960 1.490 0.220 2.92 1.110 0.210 0.180 2.540 0.160 1.270 2.020 1.530 0.220 3.205 1.140 0.210 0.190 2.650 0.170 1.310 2.080 1.570 0.230 3.519 1.190 0.220 0.200 2.750 0.180 1.350 2.160 1.620 0.240 3.863 1.240 0.240 0.220 2.830 0.190 1.410 2.250 1.680 0.260 4.24 1.290 0.260 0.240 2.870 0.210 1.470 2.350 1.730 0.280 4.655 1.360 0.300 0.270 2.880 0.230 1.540 2.460 1.790 0.310 5.11 1.420 0.340 0.300 2.850 0.250 1.600 2.580 1.840 0.350 5.61 1.480 0.400 0.340 2.770 0.280 1.660 2.700 1.880 0.390 6.158 1.550 0.470 0.390 2.640 0.310 1.720 2.830 1.910 0.450 6.76 1.620 0.550 0.440 2.480 0.350 1.780 2.950 1.940 0.510 7.421 1.690 0.640 0.500 2.310 0.380 1.850 3.060 1.970 0.580 8.147 1.760 0.750 0.570 2.160 0.420 1.920 3.170 2.010 0.660 8.943 1.840 0.880 0.650 2.030 0.470 1.990 3.250 2.050 0.750 9.818 1.930 1.030 0.740 1.930 0.520 2.070 3.310 2.100 0.860 10.78 2.010 1.210 0.840 1.850 0.570 2.140 3.310 2.130 0.980 11.83 2.080 1.410 0.950 1.770 0.630 2.180 3.240 2.120 1.130 12.99 2.120 1.640 1.080 1.670 0.690 2.170 3.080 2.070 1.290 14.26 2.140 1.910 1.220 1.580 0.760 2.120 2.830 1.980 1.480 15.65 2.150 2.200 1.390 1.500 0.840 2.060 2.550 1.870 1.690 17.18 2.170 2.520 1.570 1.480 0.930 2.000 2.290 1.790 1.930 18.86 2.210 2.870 1.780 1.510 1.050 1.990 2.080 1.740 2.190 20.71 2.280 3.230 2.020 1.590 1.190 2.010 1.930 1.730 2.480 183

KUS329 Grain size (um) / Depth (cm) 164 190 230 250 315 335 363 383 396 24.95 2.450 3.960 2.590 1.760 1.580 2.100 1.690 1.760 3.140 27.39 2.520 4.290 2.930 1.790 1.850 2.100 1.520 1.770 3.480 30.07 2.550 4.570 3.280 1.780 2.170 2.060 1.320 1.770 3.820 33.01 2.560 4.780 3.640 1.730 2.550 2.000 1.120 1.770 4.150 36.24 2.560 4.920 3.990 1.660 3.000 1.950 0.940 1.760 4.440 39.78 2.560 4.970 4.320 1.570 3.510 1.950 0.810 1.750 4.680 43.67 2.550 4.940 4.590 1.470 4.060 1.980 0.730 1.730 4.840 47.94 2.520 4.800 4.780 1.340 4.620 2.050 0.680 1.670 4.910 52.62 2.460 4.550 4.860 1.180 5.160 2.110 0.630 1.560 4.880 57.77 2.370 4.210 4.830 0.980 5.620 2.130 0.550 1.430 4.730 63.41 2.260 3.780 4.680 0.770 5.970 2.100 0.450 1.280 4.490 69.61 2.140 3.310 4.440 0.580 6.160 2.020 0.350 1.140 4.170 76.42 2.030 2.830 4.140 0.430 6.150 1.910 0.260 1.030 3.800 83.89 1.940 2.380 3.800 0.350 5.920 1.780 0.210 0.970 3.400 92.09 1.840 1.970 3.440 0.310 5.490 1.630 0.190 0.920 2.980 101.1 1.670 1.610 3.070 0.290 4.860 1.420 0.170 0.870 2.550 111 1.400 1.270 2.690 0.270 4.100 1.110 0.150 0.780 2.120 121.8 1.010 0.970 2.300 0.220 3.270 0.680 0.100 0.650 1.680 133.7 0.550 0.710 1.930 0.140 2.460 0.280 0.046 0.510 1.280 146.8 0.200 0.500 1.590 0.058 1.770 0.057 0.010 0.390 0.940 161.2 0.036 0.360 1.280 0.012 1.220 0.005 0.001 0.340 0.680 176.9 0.002 0.280 1.010 0.001 0.850 0.000 0.000 0.350 0.510 194.2 0.000 0.260 0.770 0.000 0.600 0.000 0.000 0.410 0.400 213.2 0.000 0.260 0.580 0.000 0.430 0.000 0.000 0.470 0.330 234 0.000 0.260 0.410 0.000 0.300 0.000 0.000 0.480 0.260 256.9 0.000 0.250 0.300 0.000 0.190 0.000 0.000 0.400 0.200 282.1 0.000 0.240 0.230 0.000 0.110 0.000 0.000 0.250 0.150 309.6 0.000 0.220 0.210 0.000 0.073 0.000 0.000 0.100 0.110 339.9 0.000 0.210 0.240 0.000 0.076 0.000 0.000 0.021 0.100 373.1 0.000 0.200 0.280 0.000 0.110 0.000 0.000 0.002 0.120 409.6 0.000 0.200 0.310 0.000 0.170 0.000 0.000 0.000 0.150 449.7 0.000 0.170 0.310 0.000 0.220 0.000 0.000 0.000 0.160 493.6 0.000 0.130 0.260 0.000 0.220 0.000 0.000 0.000 0.150 541.9 0.000 0.068 0.180 0.000 0.180 0.000 0.000 0.000 0.098 594.8 0.000 0.024 0.089 0.000 0.100 0.000 0.000 0.000 0.042 653 0.000 0.004 0.029 0.000 0.038 0.000 0.000 0.000 0.009 716.8 0.000 0.000 0.005 0.000 0.007 0.000 0.000 0.000 0.001 786.9 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 863.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 948.3 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1041 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1143 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1255 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1377 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 184

KUS329 Grain size (um) / Depth (cm) 419 435 453 481 502 521 536 0.375 0.320 0.420 0.055 0.290 0.072 0.110 0.014 0.412 0.560 0.740 0.097 0.520 0.130 0.200 0.026 0.452 0.810 1.070 0.140 0.760 0.190 0.300 0.038 0.496 1.130 1.500 0.210 1.060 0.270 0.420 0.055 0.545 1.380 1.830 0.260 1.300 0.330 0.530 0.068 0.598 1.570 2.100 0.300 1.480 0.380 0.620 0.081 0.656 1.730 2.310 0.340 1.630 0.430 0.710 0.092 0.721 1.850 2.500 0.390 1.750 0.470 0.790 0.100 0.791 1.940 2.660 0.420 1.840 0.500 0.870 0.110 0.868 1.970 2.770 0.440 1.880 0.520 0.930 0.120 0.953 1.970 2.850 0.460 1.890 0.520 0.990 0.120 1.047 1.950 2.930 0.480 1.880 0.530 1.050 0.130 1.149 1.930 3.020 0.480 1.880 0.520 1.100 0.130 1.261 1.910 3.140 0.480 1.870 0.520 1.160 0.130 1.384 1.890 3.260 0.480 1.860 0.500 1.210 0.130 1.52 1.880 3.380 0.470 1.870 0.490 1.270 0.130 1.668 1.890 3.500 0.460 1.900 0.480 1.340 0.130 1.832 1.910 3.590 0.450 1.940 0.470 1.410 0.120 2.011 1.940 3.640 0.440 1.990 0.460 1.490 0.120 2.207 1.980 3.620 0.430 2.050 0.460 1.580 0.120 2.423 2.010 3.530 0.420 2.110 0.460 1.670 0.110 2.66 2.040 3.360 0.420 2.170 0.460 1.780 0.110 2.92 2.070 3.150 0.430 2.230 0.470 1.890 0.110 3.205 2.100 2.930 0.450 2.300 0.490 2.020 0.120 3.519 2.140 2.710 0.490 2.370 0.500 2.150 0.120 3.863 2.190 2.510 0.540 2.450 0.530 2.290 0.130 4.24 2.230 2.340 0.600 2.520 0.550 2.440 0.130 4.655 2.270 2.180 0.690 2.590 0.580 2.590 0.150 5.11 2.290 2.010 0.790 2.650 0.610 2.740 0.160 5.61 2.290 1.830 0.910 2.680 0.630 2.890 0.180 6.158 2.270 1.630 1.060 2.690 0.660 3.030 0.200 6.76 2.240 1.430 1.220 2.680 0.690 3.170 0.220 7.421 2.200 1.290 1.410 2.670 0.730 3.310 0.250 8.147 2.170 1.200 1.610 2.650 0.760 3.450 0.280 8.943 2.150 1.190 1.850 2.640 0.790 3.570 0.320 9.818 2.140 1.210 2.100 2.620 0.820 3.670 0.360 10.78 2.110 1.240 2.380 2.580 0.860 3.750 0.410 11.83 2.030 1.220 2.670 2.470 0.890 3.790 0.470 12.99 1.900 1.150 2.960 2.300 0.910 3.750 0.530 14.26 1.750 1.050 3.260 2.080 0.920 3.620 0.610 15.65 1.600 0.960 3.530 1.870 0.920 3.410 0.700 17.18 1.490 0.900 3.780 1.710 0.930 3.150 0.810 18.86 1.440 0.870 4.000 1.620 0.950 2.920 0.950 20.71 1.440 0.860 4.180 1.590 1.000 2.750 1.110 185

KUS329 Grain size (um) / Depth (cm) 419 435 453 481 502 521 536 24.95 1.430 0.830 4.370 1.520 1.160 2.490 1.530 27.39 1.370 0.800 4.360 1.400 1.260 2.260 1.800 30.07 1.280 0.780 4.250 1.230 1.380 1.890 2.120 33.01 1.190 0.740 4.070 1.040 1.520 1.400 2.490 36.24 1.120 0.700 3.820 0.870 1.680 0.870 2.920 39.78 1.090 0.620 3.540 0.740 1.870 0.420 3.410 43.67 1.090 0.500 3.230 0.660 2.090 0.140 3.940 47.94 1.070 0.360 2.910 0.610 2.330 0.023 4.500 52.62 1.030 0.200 2.570 0.570 2.590 0.002 5.050 57.77 0.960 0.076 2.210 0.510 2.860 0.000 5.540 63.41 0.860 0.015 1.860 0.430 3.150 0.000 5.940 69.61 0.770 0.001 1.540 0.350 3.430 0.000 6.200 76.42 0.710 0.000 1.260 0.260 3.710 0.000 6.270 83.89 0.690 0.000 1.050 0.180 3.950 0.000 6.120 92.09 0.700 0.000 0.890 0.110 4.120 0.000 5.760 101.1 0.690 0.000 0.760 0.055 4.180 0.000 5.180 111 0.620 0.000 0.630 0.017 4.110 0.000 4.450 121.8 0.470 0.000 0.510 0.003 3.910 0.000 3.630 133.7 0.260 0.000 0.390 0.000 3.630 0.000 2.810 146.8 0.094 0.000 0.280 0.000 3.320 0.000 2.090 161.2 0.016 0.000 0.200 0.000 3.020 0.000 1.540 176.9 0.001 0.000 0.140 0.000 2.740 0.000 1.180 194.2 0.000 0.000 0.099 0.000 2.460 0.000 0.970 213.2 0.000 0.000 0.073 0.000 2.140 0.000 0.840 234 0.000 0.000 0.062 0.000 1.730 0.000 0.730 256.9 0.000 0.000 0.067 0.000 1.290 0.000 0.580 282.1 0.000 0.000 0.095 0.000 0.880 0.000 0.380 309.6 0.000 0.000 0.150 0.000 0.590 0.000 0.190 339.9 0.000 0.000 0.210 0.000 0.440 0.000 0.059 373.1 0.000 0.000 0.260 0.000 0.410 0.000 0.010 409.6 0.000 0.000 0.280 0.000 0.440 0.000 0.001 449.7 0.000 0.000 0.250 0.000 0.450 0.000 0.000 493.6 0.000 0.000 0.160 0.000 0.400 0.000 0.000 541.9 0.000 0.000 0.076 0.000 0.250 0.000 0.000 594.8 0.000 0.000 0.018 0.000 0.100 0.000 0.000 653 0.000 0.000 0.002 0.000 0.022 0.000 0.000 716.8 0.000 0.000 0.000 0.000 0.000 0.000 0.000 786.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 863.9 0.000 0.000 0.000 0.000 0.000 0.000 0.000 948.3 0.000 0.000 0.000 0.000 0.000 0.000 0.000

186

Appendix D

Mean Loss on Ignition Results

Core Mean % Error +/- # OM S.D. S.D 324 3.365 1.416 0.708 322 2.301 0.465 0.2325 325 2.4797 2.479 1.2395 326 2.4958 1.232 0.616 319 3.2766 1.368 0.684 327 3.709 1.674 0.837 328 2.883 1.225 0.6125 318 2.791 1.434 0.717 330 6.805 5.274 2.637 331 2.879 1.452 0.726 329 2.122 1.029 0.5145

Table D.1 Loss on Ignition results referring to Figure 5.24

187

Loss on Ignition results

324 322 325 326 Depth % Depth % Depth Depth % (cm) OM (cm) OM (cm) %OM (cm) OM 0 2.50 0 2.16 0 2.88 0 4.00 4 2.85 10 1.98 5 2.31 11 4.20 26 2.23 20 2.03 8 2.72 29 3.69 38 3.18 30 3.08 12 2.52 37 4.42 50 6.65 40 2.56 19 3.22 48 4.25 59 3.52 50 2.46 25 2.68 54 3.97 64 4.98 60 2.34 31 3.41 66 3.32 70 3.43 70 3.02 36 2.44 73 3.89 85 3.12 80 2.24 39 2.69 84 3.80 89 4.17 90 1.93 45 2.36 94 3.03 100 2.74 100 1.52 51 2.40 99 1.56 109 5.37 Mean 2.30 58 2.31 105 3.32 115 4.67 S.D. 0.47 62 2.42 111 1.18 135 5.68 73 1.22 121 3.00 147 3.09 78 3.00 131 1.42 137 4.34 81 2.15 136 1.82 151 1.91 89 2.64 151 1.58 160 5.00 93 1.76 161 1.31 176 2.24 97 4.40 168 0.89 189 3.49 104 2.20 178 1.79 200 3.16 111 2.76 185 1.19 215 1.66 120 2.52 198 2.53 235 3.43 128 3.30 200 2.00 248 1.47 136 2.70 206 1.11 261 1.46 140 2.60 216 1.86 272 1.15 148 2.03 226 1.75 Mean 3.37 153 2.45 236 0.50 S.D. 1.42 161 2.24 Mean 2.50 170 2.94 S.D. 1.23 179 2.40 183 3.13 190 2.16 198 2.42 206 2.08 218 2.12 226 2.03 235 2.15 247 0.94 254 2.73 268 1.87 275 2.36 Mean 2.48 S.D. 0.58

Table D.2 Loss on Ignition results referring to Figures 5.24 and 5.25a-d 188

319 327 328 318 Depth Depth Depth Depth (cm) %OM (cm) %OM (cm) %OM (cm) %OM 0 5.00 0 5.48 0 3.37 0 3.87 8 6.53 5 5.48 5 3.37 4 3.87 20 5.12 12 5.61 6 4.73 8 3.72 32 4.89 23 5.17 14 3.41 12 4.97 42 4.54 28 6.45 28 2.85 18 3.47 50 3.25 32 5.17 35 4.62 23 3.33 62 2.64 42 5.37 40 5.57 28 2.33 72 3.88 49 4.82 53 3.01 33 8.19 90 2.80 56 3.71 61 2.62 36 1.33 94 2.39 68 4.37 66 2.00 41 0.83 106 2.91 74 4.00 75 3.83 47 1.36 119 1.79 91 3.24 77 1.21 53 3.02 127 3.50 108.5 2.62 94 3.31 56 1.61 137 2.58 113 2.85 99 1.70 61 2.26 148 3.88 127 2.81 110 1.10 66 2.49 158 3.21 137 2.82 121 3.45 80 2.36 164 2.98 154 2.10 133 1.15 90 2.30 175 1.03 156 3.04 149 3.60 100 2.64 184 4.86 181 0.73 151 3.16 107 1.51 194 2.03 187 5.86 165 1.49 117 2.70 200 3.00 197 1.71 172 1.89 138 1.21 202 3.42 205 3.69 177 1.96 144 3.36 211 1.13 212 1.01 Mean 2.88 147 1.65 221 3.49 215 4.02 S.D. 1.22 158 2.13 227 1.08 232 0.63 165 3.14 Mean 3.28 Mean 3.71 175 1.39 S.D. 1.37 S.D. 1.67 176 1.60 180 4.54 186 2.81 192 2.67 197 1.98 Mean 2.73 S.D. 1.43

Table D.2 Loss on Ignition results referring to Figures 5.24 and 5.25a-d

189

330 331 331 329 Depth Depth Depth Depth (cm) %OM (cm) %OM (cm) %OM (cm) %OM 0 7.53 0 4.00 200 1.65 238 1.60 4 7.53 4 4.15 204 2.41 257 2.37 8 5.51 8 8.83 208 1.12 273 2.08 14 4.39 12 1.72 216 3.42 295 3.13 20 4.33 20 2.82 222 3.87 310 1.55 25 3.59 25 3.54 225 1.54 326 2.42 30 9.97 31 4.97 230 1.80 352 2.27 35 11.07 36 3.41 235 2.94 367 2.72 40 24.73 38 3.20 240 3.26 387 1.03 45 6.55 40 2.37 245 0.75 397 0.91 48 10.46 45 4.34 251 2.60 400 1.18 53 5.06 50 4.86 262 1.82 407 1.45 57 7.76 60 2.18 265 1.26 418 4.36 62 2.22 69 4.48 275 3.03 433 3.92 66 2.81 75 3.68 290 0.78 443 2.19 70 2.69 80 3.65 Mean 3.13 451 1.18 74 3.04 82 3.19 S.D. 1.51 461 1.45 79 3.23 86 3.08 329 473 2.72 Depth Mean 6.80 91 3.80 (cm) %OM 487 2.46 S.D. 5.27 95 3.60 0 3.00 498 0.83 99 2.51 5 3.27 507 0.53 105 1.54 9 2.10 515 2.81 110 1.64 14 5.13 523 0.51 115 3.09 29 3.32 533 1.27 120 2.82 36 2.45 Mean 2.05 125 1.34 45 3.03 S.D. 0.99 130 1.98 50 2.50 135 1.68 57 2.09 140 1.60 66 1.01 141 3.74 70 3.44 145 3.04 76 2.83 149 5.76 90 1.66 151 4.63 110 3.84 157 3.29 125 0.94 164 4.07 130 2.42 173 1.01 143 1.07 177 2.59 154 1.09 181 1.16 164 2.33 183 2.93 174 0.78 185 5.11 190 1.70 188 2.35 200 1.60 190 1.15 210 1.56 193 1.84 216 2.01 198 0.88 230 1.89

Table D.2 Loss on Ignition results referring to Figures 5.24 and 5.25a-d

190

Appendix E

X-Ray Fluorescence results

KUS Sum of code Fe2O3 MnO Cr2O3 V2O5 TiO2 CaO K2O P2O5 SiO2 Al2O3 MgO Na2O F La2O3 conc. Fe3 Mn Cr V Ti Ca K P Si Al Mg Na F La # % % % % % % % % % % % % % kcps % 324-10 4.859 0.094 0.118 0.024 0.706 5.235 2.639 0.259 64.376 15.271 3.647 2.706 0.059 0.059 100.051 324-52 13.586 0.384 0.101 0.030 1.384 2.212 4.103 0.313 54.949 16.141 4.384 1.848 0.111 0.000 99.547 324-268 6.446 0.120 0.109 0.033 0.848 4.391 2.430 0.315 62.261 15.663 4.076 2.554 0.033 0.054 99.333 324-269 7.650 0.150 0.100 0.020 0.930 2.830 3.949 0.170 61.620 16.420 2.990 3.080 0.070 0.000 99.979 326-9 9.240 0.220 0.100 0.030 0.780 2.350 3.972 0.170 57.760 18.140 4.000 2.510 0.040 0.000 99.218 326-295 5.500 0.098 0.122 0.012 0.866 4.146 2.787 0.329 63.354 16.244 3.232 2.878 0.061 0.061 99.689 326-297 12.710 0.240 0.100 0.040 1.650 2.900 3.930 0.240 51.690 15.330 5.250 1.890 0.070 0.000 99.950 329-38 9.167 0.146 0.104 0.021 1.188 4.167 3.288 0.250 58.490 16.083 4.292 2.542 0.063 0.000 99.798 329-42 8.310 0.218 0.115 0.034 1.172 4.023 3.020 0.391 59.023 16.736 4.506 2.000 0.103 0.057 99.709 329-417 6.970 0.130 0.100 0.020 0.900 3.290 2.927 0.260 61.550 15.860 3.340 2.400 0.070 0.000 99.733 329-520 4.904 0.096 0.120 0.024 0.723 5.410 2.567 0.337 64.422 15.072 3.277 2.783 0.072 0.000 99.808

Table E.1 Major element geochemical composition of Kusawa Lake, H2O calibrated, referring to figure 5.26

191

Appendix F

Lead 210 and Caesium 137

Cum. Accum median Thickness Thickness Dry Wt # years year of Cs-137 Error 2 (cm) (cm) (g/cm2) per slice deposition (Bq/g) s.d 1.26 2.46 0.14 5.98 1989.01 0.07340 0.00257 1.20 3.66 0.30 7.34 1982.35 0.09510 0.00276 1.39 5.05 0.52 9.53 1973.91 0.17700 0.00355 1.56 6.61 0.79 11.77 1963.26 0.23200 0.00511 1.38 7.99 1.05 11.74 1951.51 0.01450 0.00181 1.77 9.76 1.41 15.58 1937.85 0.00000 0.00000 2.17 11.93 1.81 17.72 1921.20 0.00000 0.00000 2.47 14.40 2.29 20.83 1901.92 0.00000 0.00000 1.61 16.01 2.60 13.79 1884.60 1.28 17.29 2.88 12.22 1871.60 2.06 19.35 3.30 18.35 1856.31 1.29 20.64 3.57 11.91 1841.18 1.85 22.49 3.95 16.69 1826.88 1.85 24.34 4.34 17.44 1809.82

Table F.1 Kusawa Lake down-core profiles of lead-210 and caesium-137 , referring to figure 5.27

192

Microprobe tephra glass results

KUS322-8 KUS324-20 Duke River Fan

(Lab code: UT2256) (Lab code: UT2257) (Froese & Jensen 2005)

SiO 2 74.98 (1.00) 74.83 (0.54) 74.97 (0.70)

TiO 2 0.18 (0.10) 0.19 (0.05) 0.19 (0.06)

Al 2O3 13.93 (0.54) 13.95 (0.26) 13.76 (0.37)

FeO 1.26 (0.16) 1.24 (0.16) 1.31 (0.16) MnO 0.06 (0.04) 0.04 (0.03) 0.05 (0.03) CaO 1.55 (0.35) 1.51 (0.14) 1.58 (0.13) MgO 0.23 (0.05) 0.24 (0.07) 0.39 (0.12)

Na 2O 3.95 (0.24) 4.14 (0.14) 3.94 (0.22)

K2O 3.54 (0.23) 3.53 (0.20) 3.46 (0.16) Cl 0.31 (0.05) 0.32 (0.04) 0.34 (0.04)

H2O diff. 1.92 (0.94) 2.86 (1.73) 2.5 (1.49) n 11 12 63

Table F.2 Average percentage major element composition of glass shards from two Kusawa Lake cores. Notes: n =

number of analysis; H 2O diff = water by difference. Standardization by mineral and glass standard

193

Fig. F.1 Major element geochemistry on Kusawa Lake and Duke River (Jensen & Froese, 2005)

White River Ash layers referring to figure 5.28

Magnetite (wt.%) Ilmenite (wt.%) KUS322-8 KUS324-20 KUS322-8 KUS324-20

SiO 2 0.08 0.10 0.04 0.04

TiO 2 4.49 4.43 28.30 29.23

Al 2O3 1.97 1.98 0.35 0.37

Cr 2O3 0.03 0.10 0.05 0.07

V2O3 0.31 0.36 0.34 0.38

Fe 2O3 58.05 57.44 46.53 44.60

FeO 33.63 33.30 23.58 24.25 MgO 0.99 1.08 0.87 1.01 MnO 0.43 0.36 0.19 0.23 CaO 0.03 0.03 0.10 0.02 NiO 0.02 0.02 0.04 0.02

H2O diff. 0 0.82 0 0

FeO t 85.87 84.99 65.45 64.39 n 2 2 4 4

Table F.3Average percentage magnetite and ilmenite composition of glass shards from two Kusawa Lake cores

Notes: n = number of analysis; FeO t = total Fe as FeO; H 2O diff = water by difference. Standardization by mineral

and glass standards, referring to figure 5.26

194