University of Alberta

Extending the applications of tephrochronology in Northwestern North America

by

HayleyAnn Dunning

A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science

Department of Earth and Atmospheric Sciences

©HayleyAnn Dunning Fall 2011 Edmonton, Alberta

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1+1 Canada ABSTRACT

Major-element geochemistry, stratigraphy and Bayesian statistical age modeling are combined with the aim of integrating paleoclimate records. The goal is to create a tephrochronological framework for northwestern North America. The coastal region of southeastern Alaska is explored through a terrestrial peat core and a marine core. The widespread Mount Edgecumbe dacite (MEd) is identified in both cores. The age of the

MEd is modeled between 13,270 -13,050 cal yrs BP. This date is used to estimate the marine reservoir for this area; approximately 320 - 810 years. Four sulphate peaks from the PR Col ice core from Mt Logan are investigated for associated cryptotephras. The expected tephras are found for White River East and Aniakchak events, and possible correlations are found for White River North and Hayes Tephra Set H events. The PR Col age model for these tephras is tested against terrestrial age estimations, and shows good agreement. TABLE OF CONTENTS

CHAPTER 1 - INTRODUCTION

1.1 Introduction 1

1.2 References 6

CHAPTER 2 - METHODOLOGY

2.1 Introduction 11 2.2 Preparation techniques 12 2.2.1 Macrotephra 12 2.2.2 Cryptotephra 13 2.3 Electron microprobe analysis 15 2.3.1 Calibration 15 2.3.2 Conditions for analysis 17 2.4 Data analysis 18 2.4.1 Correcting for offset and drift 18 2.4.2 Normalization 19 2.4.3 Identifying contaminants 20 2.5 Correlations 20 2.6 Bayesian age modeling 22 2.7 Sediment cores 24 2.7.1 PSequencing 24 2.7.2 Bacon 25 2.7.3 Comparison 25 2.8 Single tephra ages 26 2.8.1 Phase model 26 2.8.2 Equals model 27 2.9 Outlier analysis 28 2.10 Conclusions 29 2.11 References 43

CHAPTER 3 - CORRELATING THE TERRESTRIAL AND MARINE RECORD OF THE MOUNT EDGECUMBE VOLCANIC FIELD

3.1 Introduction 48 3.2 Regional setting 50 3.3 Methods 51 3.3.1 Column Point 51 3.3.2 Lower Sitka Sound 52 3.3.3 Microprobe analysis 53 3.3.4 Age determination 53 3.4 Tephra characterization 54 3.5 Correlations 56 3.6 Core ages 58 3.7 MEd age 61 3.8 Marine reservoir estimation 62 3.9 Discussion and conclusions 64 3.10 References 73

CHAPTER 4 - TEPHROCHRONOLOGY OF THE PROSPECTOR RUSSELL COL ICE CORE, MOUNTT LOGAN

4.1 Introduction 78 4.2 PR Col sampling and geochemical analysis 81 4.2.1 White River Ash 83 4.2.2 Aniakchak 85 4.2.3 Hayes Tephra Set H 86 4.3 Bayesian statistical age modeling 87 4.3.1 White River Ash 89 4.3.2 Aniakchak 90 4.3.3 Hayes Tephra Set H 91 4.4 Discussion 91 4.4.1 White River Ash 92 4.4.2 Aniakchak 93 4.4.3 Hayes Tephra Set H 94 4.5 Conclusions 95 4.6 References 115

CHAPTER 5 - CONCLUSIONS

5.1 Conclusions 124 5.2 Further study 125 5.3 References 126

APPENDIX

6.1 Glass data 127 6.2 OxCal codes 168 LIST OF TABLES

Table 2.1 Paradox Lake core chronology 36

Table 2.2 PSequencing and Bacon results 39

Table 2.3 Dates for the Fisher-Funk Phase model 39

Table 2.4 Cores for the Kaguyak Equals model 41

Table 3.1 Geochemistry of investigated tephras 69

Table 3.2 Preliminary Similarity Coefficient matches 70

Table 3.3 Radiocarbon dates for Column Point core 72

Table 3.4 Modeled tephra dates 72

Table 3.5 Dates for MEd Phase model 73

Table 4.1 PR Col target depths and ages 100

Table 4.2 Dates for all Phase models 107

Table 4.3 Core dates for Hayes Tephra Set H Equals model 108 LIST OF FIGURES

Fig 1.1 Locations of tephra deposits 5

Fig 2.1 Mounting procedure for macrotephra 31

Fig 2.2 Mounting procedure for cryptotephra 32

Fig 2.3 Example of improvement by polishing 33

Fig 2.4 Example of normalization of tephra data 33

Fig 2.5 Example of geochemical difference in similar Similarity Coefficients 34

Fig 2.6 Radiocarbon calibration curve issues 35

Fig 2.7 Paradox Lake P_Sequencing output 37

Fig 2.8 Paradox Lake Bacon output 38

Fig 2.9 Fisher-Funk Phase model output 40

Fig 2.10 Kaguyak Equals model output 42

Fig 3.1 Locations map of MEVF and study sites 66

Fig 3.2 Column Point core 66

Fig 3.3 Lower Sitka Sound core 67

Fig 3.4 TAS plot of tephra data 68

Fig 3.5 Tephra data against Type I and II fields 68

Fig 3.6 Comparison of tephra data to MEd reference 71

Fig 4.1 Location map of target tephra deposits 97

Fig 4.2 PR Col core chemical data 98

Fig 4.3 ECM and sulphate plots for target events 99

Fig 4.4 Mounting procedure for cryptotephra 101

Fig 4.5 Geochemical bivariate plots of suspected WRE sections 102

Fig 4.6 Geochemical bivariate plots of suspected WRN sections 103

Fig 4.7 Geochemical bivariate plots of suspected Anaikchak sections 104

Fig 4.8 Geochemical bivariate plots of suspected Hayes Tephra Set H sections 105 Fig 4.9 Location map for Hayes sites visited 106

Fig 4.10 Nenana site photograph 106

Fig 4.11 Wiggle-match output for WRE tree stump 109

Fig 4.12 OxCal output for WRE Phase model 110

Fig 4.13 OxCal output for WRN Phase model Ill

Fig 4.14 OxCal output for final Anaikchak Phase model 112

Fig 4.15 OxCal output for final Hayes Tephra Set H Equals model 113 CHAPTER 1 - INTRODUCTION

1.1 Introduction

Each explosive volcanic eruption creates a unique ash layer, or tephra, which can

be fingerprinted based on its distinctive mineralogy, geochemistry and stratigraphic

properties. Where a tephra occurs as a consistent stratigraphic layer (i.e. not

reworked), it can be considered as marking a single point in time, or isochron.

Tephrostratigraphy can then connect sedimentary sequences in different places based

on the presence of the tephra. Associated age data, whether relative or absolute (e.g.

radiocarbon, lake varves), can then be applied to all locations where the tephra is

present. Records that have been linked in this way may be diverse, ranging from

paleoenvironmental and archaeological reconstructions, to records of eruptive history

for improved hazard assessment.

The combination of geochemical and chronological data can form interlinked

tephrochronological frameworks across environmentally distinct regions, and such

networks have been created, for example, in western Europe (e.g. Davies et al., 2002;

Boygle, 2004; Mortensen et al., 2005); Japan, (e.g. Suzuki, 1996; Machida, 1999); and

New Zealand (e.g. Shane et al., 1995; Shane, 2000; Carter et al., 2004; Alloway et al.,

2007).

The unglaciated area of Yukon and Alaska, collectively termed eastern Beringia, has

undergone many climatological, ecological and archaeological changes in the past

20,000 years, and developing a robust tephrochronological framework for the area

1 would help to accurately date some of the changes. For example, knowing the exact timing of human migration into the New World can help determine the migration route, whether through an ice-free corridor or along a coastal route (Dixon, 2001; Yesner,

2001; Mandryk et al., 2001). The viability of a coastal route relies on the geologic conditions of the coastal area along the Alaska panhandle and British Columbia, and the associated chronology of ice sheet retreat and sea level history (Mann and Streveler,

2008). To meet this need, tephras can provide an integration of the marine and terrestrial records.

Tephras have already been used to constrain the ages of vertebrate fossils, forest beds and pollen records across the Klondike area, central Yukon, and Fairbanks area of

Alaska (e.g. Westgate et al., 1990; Preece at al., 1999, 2000; Froese et al., 2002, 2005).

However, the use has largely been restricted to extremely explosive and widespread eruption products, such as the Old Crow and Dawson tephras (Westgate et al., 1983,

2000). Characterising smaller and more local events will solve specific problems as well as build a large database for the region with potential to form an interconnected lattice of regional tephrostratigraphies between areas.

Tephrochronological studies were at first restricted to volcanologically active countries, where visibly thick layers of ash could be found near to the source. However, since the development of cryptotephra studies ("hidden" tephra; Dugmore, 1989;

Dugmore et al., 1995; Lowe and Turney, 1997), the distance over which volcanic eruptions can be tracked has grown to more than 2000 km from the sources (Hunt,

1999; Alloway et al., 2006). This has expanded the use of tephrochronology not only geographically, but also into new types of records, such as ice cores (e.g. Wastegard and

2 Davies 2009). Ice cores provide some of the best sources for dating tephras, since in many cases they are annually- to decadally- resolved and provide continuous records.

Despite the many new developments occurring in tephrochronology, much work needs to be done to ensure the growing bulk of data is precise and useful for large-scale correlation studies. This requires combining expertise from a range of allied disciplines including geochemistry, Bayesian statistics and modelling.

Many of the early tephro- and cryptotephro- chronological frameworks were developed in Northern Europe, especially with the discovery of tephras associated with acid peaks in the GRIP and GISP2 ice cores from Summit, Greenland (Zielinski, 1997). The opportunity now exists to apply the same methods to the northeast Pacific region with the drilling of a 188 m long core (stretching over 20,000 years into the past) from the

Prospector Russell Col (PR Col) on Mt Logan (Fisher et al., 2004), the highest peak in

Canada located near the border of Yukon Territory and Alaska (Fig 1.1).

This thesis is organized into five chapters, two of which will become manuscripts.

Chapter 2: This project builds on the established tephrochonology lab at the

University of Alberta, set up to rapidly process and analyse tephra geochemistry with the use of the electron microprobe (Jensen, 2007). A new methodology was developed to process and analyse cryptotephras, specifically from ice cores, requiring more careful

consideration of issues such as contamination and conditions needed to probe such

small particles. This project also applies Bayesian statistical tools to tephrochronology,

specifically to radiocarbon dates associated with terrestrial and marine cores, and

comparisons to ice core age estimates. Some of the different methods are compared in

this chapter, as well as determining best practices for the consideration of outliers.

3 Chapter 3: This chapter is being prepared as a manuscript and attempts to tie together the terrestrial and marine records of tephra falls from the Mount Edgecumbe

Volcanic Field (MEVF) around the Pleistocene-Holocene boundary. A major tephra deposit, termed the Mount Edgecumbe dacite (MEd), was first recognized by Riehle et al. (1992) in several terrestrial sequences in southeast Alaska associated with a number of other, smaller tephras (Fig 1.1). A peat core from Column Point, Chichagof Island, was collected in the summer of 2009 by Daniel Mann and Gregory Streveler, and forms the basis of the terrestrial portion of this paper. A marine core, collected by Jason Addison in 2004, forms the marine portion (Addison et al., 2010). Tephras from the Column Point core were extracted and processed by me at the University of Alberta; tephras from the marine core were extracted by Jason Addison, and samples of each were sent to me for analysis. Bayesian statistical tools for tephrochronology were developed from methods presented by Buck et al. (2003) and with the guidance of Christopher Bronk Ramsey for

OxCal, and of Maarten Blaauw and Andres Christen for Bacon.

Chapter 4: This chapter is being prepared as a manuscript, and presents the first results of cryptotephra studies from the PR Col ice core, as well as a comparison of the

PR Col age-depth model to terrestrial dates for four key tephra beds (White River East and North, Aniakchak, and Hayes Tephra Set H; (Fig 1.1). The core was drilled to bedrock by the Geological Survey of Canada (GSC) during the summers of 2001 and 2002, and stored at the GSC office in Ottawa. Sections of the core were sampled by Steve Kuehn and brought back to the University of Alberta. Kuehn prepared and analysed cyptotephras from sections representing the years 1947, 1906-1913, 1894, 1809 and

1783, as well as from the White River East and North events, used in this chapter. Some further analyses of the White River North interval were undertaken by Chris Atkins, as

4 was the analysis of the Aniakchak section. Hayes Tephra Set H cryptotephras were

prepared by Steve Kuehn and analysed by me. I travelled to the Fairbanks area of Alaska

in the summer of 2010 to visit the Jarvis Creek type site and to collect further Hayes

Tephra Set H samples, as well as associated material suitable for radiocarbon dating.

Chapter 5: This chapter summarizes the conclusions from the linking of terrestrial

and marine records using tephrochronology in southeast Alaska, and from the testing of the PR Col age model. The potential for further research in Bayesian statistical modeling

in tephrochronology, and of further work in the PR Col ice core are also explored.

Fig 1.1: Locations of tephra deposits used in this study; and of Mt Logan, the origin of the PR Col ice core. Mt Churchill is the origin of the White River East and North lobes. Tephra distributions from: WRN: Lerbekmo, 2008; WRE: Lakeman et al., 2008; Aniakchak: Beget et al., 1992; Hayes: Riehle et al., 1990; MEd: Riehle et al., 1992.

5 1.2. References

Addison, J.A., Beget, J.E., Ager, T.A., Finney, B.P., 2010. Marine tephrochronology of the Mt. Edgecumbe Volcanic Field, Southeast Alaska, USA. Quaternary Research 73, 277-

292.

Alloway, B.V., Larsen, G., Lowe, D.J., Shane, P.A.R., Westgate, J.A., 2006.

Tephrochronology. In: Elias, S.A. (Ed.), Encyclopaedia of Quaternary Science.

Elsevier, London, pp. 2869-2898.

Alloway B.V., Lowe, D.J., Barrell, D.J.A., Newnham, R.M., Almond, P.C.,

Augustinus, P.C., Bertler, N.A.N., Carter, L, Litchfield, N.J., McGlone, M.S.,

Shulmeister, J., Vandergoes, M.J., Williams, P.W., NZ-INTIMATE members, 2007.

Towards a climate event stratigraphy for New Zealand over the past 30 000 years.

Journal of Quaternary Science 20, 9-35.

Beget, J. E., Mason, O., and Anderson P., 1992. Age, extent and climatic

significance of the c. 3400 BP Aniakchak tephra, western Alaska, USA. Holocene 2,

51-56.

Boygle, J., 2004. Towards a Holocene tephrochronology for Sweden:

geochemistry and correlation with the North Atlantic tephra stratigraphy. Journal of

Quaternary Science 19,103-109.

Buck, C.E., Higham, T.F.G., Lowe, D.J., 2003. Bayesian tools for

tephrochronology. The Holocene 13, 639-647.

6 Carter, C, Alloway, B., Shane, P., Westgate, J., 2004. Deep ocean record of major late Cenozoic rhyolitic eruptions from New Zealand. New Zealand Journal of

Geology and Geophysics 47, 481-500.

Davies, S.M., Branch, N.P., Lowe, J.J., Turney, C.S.M. 2002. Towards a European tephrochronological framework for Termination 1 and the Early Holocene. Philosophical

Transactions of the Royal Society London A360, 767-802.

Dixon, E.J., 2001. Human colonization of the Americas: timing, technology and process. Quaternary Science Reviews 20, 277-299.

Dugmore, A. J. 1989. Icelandic volcanic ash in Scotland. Scottish Geographical

Magazine, 105,168-172

Dugmore, A.J., Larsen, G., Newton A.J., 1995. Seven tephra isochrones in

Scotland. The Holocene 5, 257-266.

Fisher, D.A., Wake, C, Kreutz, K., Yalcin, K., Steig, E., Mayewski, P., Anderson, L.,

Zheng, J., Rupper, S., Zdanowicz, C, Demuth, M., Waszkiewicz, M., Dahl-Jensen, D.,

Goto-Azuma, K., Bourgeois, J.B., Koerner, R.M., Sekerka, J., Osterberg, E., Abbott, M.B.,

Finney, B.P. and Burns, S.J. 2004: Stable isotope records from Mount Logan and Eclipse ice cores and nearby Jellybean Lake; water cycle of the North Pacific over 2 000 years and over 5 vertical kilometres; sudden shifts and tropical connections. Geographie physique et Quaternaire 58, 337-52.

Froese, D., Westgate, J., Preece, S., Storer, J. 2002. Age and significance of the

Late Pleistocene Dawson tephra in eastern Beringia. Quaternary Science Reviews 21,

2137-2142.

7 Froese, D.G., Westgate, J.A., Alloway, B.V., 2005. Field Trip Guide for the

International Conference and Workshop of Tephrochronology and Volcanism: Dawson

City, July 31st - 8th, 2005. Institute of Geological and Nuclear Sciences Limited, Lower

Hutt, New Zealand, p. 132.

Hunt, J.B., 1999. Special issue - Distal tephrochronology, tephrology and volcano- related atmospheric effects - Foreword. Global and Planetary Change 21, VII-VIII.

Jensen, B.J., 2007, 'Tephrochronology of middle to late Pleistocene loess in east- central Alaska', MSc thesis, University of Alberta.

Lakeman, T.R., Clague, J.J., Menounos, B., Osborn, G.D., Jensen, B.J.L., Froese,

D.G., 2008. Holocene tephras in lake cores from northern British Columbia, Canada.

Canadian Journal of Earth Sciences 45, 935-947.

Lerbekmo, J.F., 2008. The White River Ash: largest Holocene Plinian tephra.

Canadian Journal of Earth Sciences 45, 693-700.

Lowe, J. J. and Turney, C. S. M. 1997. Vedde Ash layer discovered in a small lake basin on the Scottish mainland. Journal of the Geological Society, London 154, 605-612.

Machida, H., 1999. The stratigraphy, chronology and distribution of distal marker- tephras in and around Japan. Global and Planetary Change 21, 71-94.

Mandryk, C.A.S., Josenhans, H., Fedje, D.W., Mathewews, R.W., 2001. Late

Quaternary paleoenvironments of Northwestern North America: implications for inland versus coastal migration routes. Quaternary Science Reviews 20, 301-314.

8 Mann, D.H., Streveler, G.P., 2008. Post-glacial relative sea level, isostasy, and glacial history in Icy Strait, Southeast Alaska, USA. Quaternary Research 69, 201-216.

Mortensen, A.K., Bigler, M., Gronvold, K., Steffensen, J.P., Johnsen, S.J., 2005.

Volcanic ash layers from the Last Glacial Termination in the NGRIP ice core. Journal of Quaternary Science 20, 209-219.

Preece, S.J., Westgate, J.A., Stemper, B.S., Pewe, T.L, 1999. Tephrochronology of late Cenozoic loess at Fairbanks, central Alaska. Geological Society of America

Bulletin 111, 71-90.

Preece, S.J., Westgate, J.A., Alloway, B.V., Milner, M.W., 2000. Characterization, identity, distribution, and source of late Cenozoic tephra beds in the Klondike district of the Yukon, Canada. Canadian Journal of Earth Sciences 37, 983-996.

Riehle, J.R., Bowers, P.M., Ager, T.A., 1990. The Hayes tephra deposits, an upper

Holocene marker horizon in south-central Alaska. Quaternary Research 33, 276-290.

Riehle, J. R., Mann, D. H., Peteet, D. M., Engstrom, D. R., Brew, D. A., and Meyer,

C. E., 1992. The Mount Edgecumbe tephra deposits, a marker horizon in southeastern Alaska near the Pleistocene-Holocene boundary. Quaternary Research

37,183-202.

Shane, P., Froggatt, P., Black, T., Westgate, J., 1995. Chronology of Pliocene and

Quaternary bioevents and climatic events from fission-track ages on tephra beds,

Wairarapa, New Zealand. Earth and Planetary Science Letters 130,141-154.

9 Shane, P., 2000. Tephrochronology: a New Zealand case study. Earth Science

Reviews 49: 223-259

Suzuki, T., 1996. Chemical analysis of volcanic glass by energy dispersive x-ray spectrometry with JEOL JED-2001 and JSM-5200: analytical procedures and application. Geographical Reports of Tokyo Metropolitan University 31, 27-36.

Wastegard, S., Davies, S.M., 2009. An overview of distal tephrochronology in northern Europe during the last 1000 years. Journal of Quaternary Science 24, 500-

512.

Westgate, J.A., Hamilton, T.D., Gorton, M.P., 1983. Old Crow tephra: A new

Pleistocene stratigraphic marker across north-central Alaska and Western Yukon

Territory. Quaternary Research 19, 38-54.

Westgate, J.A., Stemper, B.A., Pewe, T.L., 1990. A 3 m.y. record of Pliocene-

Pleistocene loess in interior Alaska. Geology 18, 858-861.

Westgate, J.A., Preece, S.J., Kotler, E., Hall, S., 2000. Dawson tephra: a prominent stratigraphic marker of Late Wisconsinan age in west-central Yukon.

Canadian Journal of Earth Sciences 37, 621-627.

Yesner, D.R., 2001. Human dispersal into interior Alaska: antecedent conditions, mode of colonization, and adaptations. Quaternary Science Reviews 20, 315-327.

Zielinski, G.A., Mayewski, P.A., Meeker, L.D., Gronvold, K., Germani, M.S., Whitlow,

S., Twickler, M.S. and Taylor, K., 1997. Volcanic aerosol records and tephrochronology of the Summit, Greenland, ice cores. Journal of Geophysical Research 102, 625-640.

10 CHAPTER 2 - METHODOLOGY

2.1 Introduction

Confidence in tephra correlations across hundreds to thousands of kilometers relies on accurate data acquisition and geochemical fingerprinting as well as fair representations of uncertainty in age models. Correlations should be based on a sufficiently complete database of local eruptions and use several lines of evidence.

Alongside geochemical data, mineralogical data should be obtained, as well as information on the archaeological, palaeo-environmental or geological context of the tephra. After analysis, correlations should be based on a combination of statistical similarity methods, bivariate plots and further geochemical analysis.

When correlating tephras across different types of records, different dating

methods are often employed, requiring careful consideration of uncertainties. Precise

and accurate dating forms another line of evidence for correlations. This study aims to

correlate tephras between marine and terrestrial cores, and ice and terrestrial cores,

using high-quality geochemical data and Bayesian statistical age models, incorporating

prior knowledge, and providing an objective way of identifying outliers.

Tephra correlations can be rejected if any one line of evidence fails, so the best

analytical methods should be employed at each stage to reduce the possibility of false

positives or negatives.

11 The objectives of this chapter are to lay out the details of the methods used in the following papers and some of the rationale of those methods, with the overall aim of improving robust correlations of tephras across any distance any record.

2.2 Preparation techniques

2.2.1 Macrotephra

Visible tephra layers are typically identified and sampled from sedimentary environments, where they may be mixed with other particles, and so require purification in order to concentrate the shards of volcanic glass. Tephra may be separated from minerals, biogenic components or other masking grains by a range of magnetic and /or density techniques. For the macrotephras used in this project, a combination of grain size and density were employed. Tephra samples were sieved into

60 (250 urn), no. 100 (149 u.m), no. 200 (74 u.m) and no. 325 (44 u.m) size fractions. The mode of eruption and the distance from the source determine which size fraction contains the greatest concentration of shards, so each fraction was inspected visually under a stereoscopic microscope. Shards are inherently unstable, especially small glass shards with a high surface to volume ratio, and will degrade over time (Dugmore et al.

1992 and Blockley et al. 2005). In order to avoid damage that may be caused in acid or alkali washing processes a heavy-liquid separation was thus used. Tetrabromoethane

(TBE) was diluted to a solution of ~2.4 g/ml density measured with a glass float and samples of obsidian and feldspar (rising and sinking, respectively).

12 Once the light density fraction was isolated by flotation, the concentration of glass was mounted for geochemical analysis. The process for mounting in hard-setting epoxy within drilled acrylic pucks is summarized in Fig 2.1. While it generally follows the technique laid out in Lowe (2011), only four holes are drilled per puck, instead of seven, so a greater abundance of shards and room to inscribe the puck was possible.

. . Cryptotephra

For the purposes of this study, only cryptotephra from ice is considered. The method essentially follows that of Kuehn and Froese (2010). Once the desired sections of ice were sampled and melted inside high-density polyethylene bottles, they were dried and placed in a High-Efficiency Particulate Air -filtered drying oven at ~90°C in a clean laboratory to reduce the water volume to 10-15 mL. Each sample is then placed briefly in an ultrasonic bath to suspend particles before concentrating them in a centrifuge. Samples were centrifuged and water was pipette off twice, until only 0.5 mL of water and sample was allowed to remain in the bottom of the tube.

Samples are mounted in a similar acrylic puck as macrotephra, but with only three holes per puck to allow greater surface area for sample distribution, since glass in cryptotephra samples can be sparse. However, instead of laying the pucks on sticky tape, a graphite block coated with adhesive is used to ensure that tephra shards are on a single low-relief surface prior to polishing. Square graphite blocks a little larger than the acrylic pucks are polished on a 2000 grit (about 10 u.) sandpaper on a flat lap wheel to obtain a flat surface. A layer of low-viscosity epoxy is then spread onto the smooth graphite surface to fill in any pore spaces. Once dried, the block is polished again to a

13 flat surface with few or no pores, so that no sample is lost once it is applied to the surface of the block. An adhesive made of Avery Spot-O-Glue™ tabs dissolved in chloroform (trichloromethane) is then applied in a thin, even, coat to the graphite block and the polished side of an acrylic puck is attached. Small blobs of epoxy were placed in the corner of each hole to seal any pore spaces between holes and prevent samples from merging. After the epoxy has cured, the sample is added to its respective hole with a pipette and allowed to evaporate in a laminar flow hood until only the particles remain at the base of the hole. This step is repeated until the entire sample from each centrifuge tube is used. The rest of the hole is filled with epoxy, covered, and left to cure in the laminar flow hood to prevent contamination.

Once completely dry, the puck is separated from the graphite block using a razorblade. Excess epoxy is removed with a grinding wheel before the puck is gently polished to expose the shards. Finally, as with macrotephra pucks, reference marks are added and the puck is coated with carbon ready for EPMA analysis. The mounting procedure is summarized in Fig 2.2.

If polishing of the puck is not done or is insufficient to expose the majority of each grain, analytical totals can be low and results poor. In such cases, pucks can be re- polished and analysed again with the help of the co-ordinate reference system. This is especially useful with cryptotephras as the grains are sparse and difficult to locate. For example, sample L251-7 was repolished after initial EPMA analysis. The second dataset showed a marked reduction of the standard deviation of Al concentrations (Fig 2.3).

14 2.3 Electron microprobe analysis

Electron probe micro-analysis (EPMA) is the standard for geochemical analysis of tephra, since it allows single-shard analysis and is non-destructive, allowing the same mounts to be used again, and the same shards to be analysed by other techniques

(Lowe, 2011; Smith and Westgate, 1969). Bulk analysis of tephra can reduce the quality of results when the chemistry of in-shard phenocryts is measured or when the sample is not sufficiently pure and other minerals are present. The electron microprobe uses wavelength-dispersive analysis (WDS) by directing a focused beam of electrons onto a sample, generating X-rays of particular energies and wavelengths relating directly to individual elements (Reed, 2005). Characteristic X-ray spectra are produced by electrons transitioning between energy levels specific to each element. The use of backscatter electron imaging optical microscopy can image the puck and avoid analysis of phenocrysts or grains that are not glass shards.

2.3.1 Calibration

WDS makes use of crystals that refract the x-rays produced by samples according to their wavelength, and direct them towards a detector. Each crystal is orientated specifically to refract elements predetermined by the user. The machine requires calibration to ensure the analyzing crystals are positioned properly for each element.

Standardisation should be done on a material that has a composition similar to that being analysed, to minimize the need for matrix corrections later on (discrepancies due to the atomic make-up) (Frogatt, 1992; Kuehn et al., in press). The most

15 abundant volcanic glass elements, Na, K, Al, and Si, are calibrated using UA5831, a widely-used Lipari rhyolitic obsidian (Froggatt, 1983; Hunt and Hill, 1996; Kuehn et al., in press). Elements of lower abundance are calibrated using additional standards with greater concentration of the target element. An array of mineral standards was used; diopside for Ca; pyrope for Fe and Mg; Willemite for Mn; tugtupite for CI; and ilmenite forTi. All elements except CI were standardised as oxides to eliminate peak shifts caused by variations in chemical bonding between the sample and standard.

During analysis, instrumental drift may occur and affect the results of elemental analyses. The use of secondary standards, periodically analysed with the unknown samples, allows for potential correction of the analyses afterwards (although it is not recommended for errors >1 wt% for the most abundant elements, or of more than one standard deviation for less abundant elements). Analysing a secondary standard can also highlight poor primary calibration of the electron microprobe.

UA5831 was analysed at several points to evaluate the calibration before any unknowns were run. Throughout this study, the non-hydrated Lipari obsidian (either

UA5831 or ID3506) and a well-characterized secondarily hydrated tephra, Old Crow, were used as secondary standards. Old Crow is a Pleistocene tephra widely- dispersed across northwest North America (Preece et al., 2011; Kuehn et al., in press). The Old Crow tephra is useful in this study since it has a composition more similar to most tephra beds investigated than the Lipari obsidian. 10 points on each of UA5831 and Old Crow were analysed for approximately every 100 unknown shard analyses of macrotephra and around every 30 shards analyses of cryptotephra.

16 2.3.2 Conditions for analysis

Following calibration, the conditions for analysis need to be set up by determining the beam size, beam current, voltage, analysis order and counting times. The set-up of these parameters is especially important in glass analyses, since it is inherently unstable under the electron beam (Kuehn et al., in press). Alkali element migration is a particular problem, strongly affecting Na and occasionally K.

When these elements are lost during analysis, the wt % of the two most abundant elements, Si and Al, is artificially increased. The effect is strongest in rhyolitic samples that contain more Na, especially those that are secondarily hydrated.

Kuehn et al. (in press) demonstrated that a loss of 50% Na can cause an increase in

Al and Si count rates of up to 5% and 4%, respectively for the phonolitic Edziza glass and of less than 2% for Old Crow. Na physically migrates out of the range of the

electron beam during long exposure, with the decrease in X-ray count rates being

approximately exponential (Humphreys et al., 2006; Kuehn et al., in press).

Prevention of migration has largely been achieved through trial and error with

analytical conditions, such as lower beam currents and larger beam diameters

creating lower current densities, or shorter analysis times to reduce the amount

lost. Avoiding Na loss requires analyzing for alkali elements first, lowering counting

times (~30 s total/element), using a defocused beam diameter of at least 10u.m, a

lower voltage (~15KeV) and amperage (~6nA). This system seems to work well for

macrotephra, but cryptotephra particles are commonly less than 10u.m. A more

focused beam is necessary, but in order to minimise the impact of Na loss, trial and

error has given an optimum beam size of ~5u.m (Kuehn, pers. comm. 2011).

17 Two microprobes are in operation at the University of Alberta; a JEOL 8900 and a Cameca SX100. The JEOL has the advantage of clearer backscatter imaging, and so is used for avoiding phenocrysts in macrotephra. However, the Cameca is used for cryptotephra analysis due to its greater sensitivity since it hosts a large thallium acid phthalate (LTAP) crystal that the JEOL does not. The same standards and same analytical conditions (other than beam size) are used on both instruments.

An attempt was made to analyse 15-20 points on individual shards for each tephra sample, which allows for an assessment of each tephra's homogeneity, and whether there is a geochemical trend of magmatic gradients or a bimodal population from magma mixing or post-depositional mixing. It can also help to reduce the impact of reduced precision when methods to reduce Na loss are undertaken. However, this many analyses on each sample was not always possible for distal and cryptotephra samples, even on repeat analytical runs.

2.4 Data analysis

2.4.1 Correcting for offset and drift

Secondary standard values were compared to standard values following analysis and some differences could be corrected for. Corrections were only applied to elements of greater abundance or known problems (i.e. Si, Al, K, Na, Fe and Ca). Lower abundance elements (i.e. CI, Mn, Mg, and Ti) were not corrected for since they have a minute effect on the outcome. If the discrepancy in a certain element is consistent, i.e. always off by the same amount, and above 1 standard deviation, then the accepted value for the

18 element is divided by the average value of the standards analysed in that probe run. The resultant value is the correction factor applied to all shard analyses for that specific element. In some cases, the offset of an element will increase or decrease steadily throughout the analysis run. Correction factors are then calculated for each set of standard analyses and graphed overtime. The correction factor for any one analysis can then be interpolated if the drift is linear - if the offset is non-linear no correction can be applied and the analysis must be repeated.

2.4.2 Normalization

Analytical totals of glasses are rarely 100 wt%, due primarily to secondary hydration by meteoric water that forms as rinds around degrading tephra shards (Froggatt 1983).

The need for normalisation of oxide values to 100% has been debated in tephrochronology, since the deficit can be due to drift or element mobilization

(Hunt and Hill, 1993; Pollard et al., 2003). However, it has been shown that normalisation produces consistent elemental abundances and that finite element analysis shows normalised analyses produce statistically valid results (Shane, 2000;

Stokes et al., 1992). Normalisation eliminates the variation in secondary hydration amount between individual shards and results in a tighter dataset, with less artificial dispersion (Fig 2.4). This is especially important when comparing similar tephras, so

normalization is applied to all datasets in this study.

Recommendations for normalisation suggest analytical totals should be > 95

wt% (Hunt and Hill, 1993). Total for some tephras can be as low as >. 90 wt%, and for

19 cryptotephra shards may be less. However, Pearce et al., (2007) show that totals as low as ~90% can be accepted for certain glasses that can be shown to have undergone no chemical or physical change. For cryptotephra in this study, individual shards with totals above 85 wt% were considered when evaluating correlations. The

% loss due to water loss is reported each time and referred to as H20 diff.

2.4.3 Identifying contaminants

Samples mounted for EPMA analysis rarely consist only of pure glass, especially in cryptotephra mounts, and non-glass grains are often analysed. These can usually be

easily identified by oxide abundances inconsistent with glass (e.g. Al203 > 20 wt%). The same is true when phenocrysts within glass shards are analysed, instead of only glass.

Picking out points that fall off geochemical trends consisting of the majority of the data

often removes analyses of mixed glass and microcryst data, where the electron beam covered both in analysis. Care must be taken to avoid eliminating secondary populations

or shortening the ranges of tephras that may have long geochemical trends.

2.5 Correlations

Correlations of tephras should be based on multiple lines of evidence. The

processed geochemical data from unknown samples can be compared to a database of

characterized tephras in a number of ways. The averages of each tephra (and each

population, if relevant) can be compared statistically to a database by similarity co­

efficients (SCs). The SC of Borchardt et al. (1971) and Borchardt et al. (1972) is based on

20 ratios of oxides, where the concentration of each oxide in one sample is divided by the concentration of the same oxide in another sample, with the greater concentration always placed in the denominator:

HA,B) - —-

,s tne Where drAiB^ similarity coefficient for comparison between sample A and B; / is

the element number; n is the number of elements in a calculation; /?, is X|A / XlB (if X|B>X|A)

or X|B / X|A (if XlA>XlB); XIA is the concentration of element / in sample A; and X|B is the concentration of element / in sample B. The more similar the two values, the larger the ratio. The ratio is equal to 1.00 if the two concentrations are identical, and all ratios are averaged for each pair of samples to produce an overall SC. However, the threshold for statistically significant ratios varies, with an SC of 0.92 typically considered the lowest acceptable value for correlation (Froggatt, 1992). SCs of 0.97 are considered very good, but there is evidence that suspected correlations within and beyond this range of acceptable SCs can be false (Fig 2.5). It is therefore important to take further steps if a correlation from SC analysis is suspected, and SCs are only used as preliminary indicators of correlations in this study. High average SC can be calculated even when one element has a significant offset, so multiple bivariate plots should be constructed to identify major discrepancies in oxide trends. To strengthen the confidence in correlations, the final step is re-probing unknowns at the same time as reference samples of suspected correlatives to ensure they are analysed under the same analytical conditions.

21 2.6 Bayesian age modelling

For tephrochronology to be a useful tool, precise and accurate dating needs to be employed. A single radiocarbon date above or below a tephra can be unrepresentative of the true eruption age in a number of ways. For example there may be a hiatus is sedimentation either before or after the eruption that causes the date to be not directly related; the dated material may be subject to environmental contamination; or the material may encounter problems in the dating procedure causing the date to be erroneous. Without the inclusion of other dates and other information about the environment, the suggested age of a tephra can be inaccurate. Imposing this erroneous date across all occurrences of the tephra can cause many environments to be inappropriately dated.

Carbon 14 (14C) production in the upper atmosphere has varied through time, such that raw radiocarbon dates based on carbon isotope ratios require calibration (Reimer and Reimer, 2007). Calibration curves, based originally on absolute dating of tree rings and the associated carbon isotope concentrations, are inherently "wiggly", and so produce a non-normal probability distribution of possible ages (Reimer and Reimer,

2007) (Fig 2.6). Curves also have regions of near constant ratios across a number of years, termed plateaus, which can generate a wide age range from a single radiocarbon date (Fig 2.6). Where many closely-spaced spikes occur on a calibration curve, one date can produce multiple age ranges, sometimes significantly separated from each other

(Fig 2.6).

In some cases however, it is possible to refine the age range beyond the simple calibration curve by using prior information, such as the position of a date relative to

22 other dates. For example, a sequence of dates within one sediment core could be assumed to get progressively younger towards the top, if there is no evidence of disturbance. The order of the dates imposes a certain constraint on the age range of each date. The principle of using prior information to constrain age ranges is known as

Bayesian statistics (Buck et al., 2003). The range of each date in the sequence has many possible distributions, so the modelling process we employ is a Markov Chain Monte

Carlo (MCMC) simulation. Many iterations of a model are run, and each produces a result that fits within the prior set parameters, and each with its own probability. These are combined to produce a probability density function which represents the probable age range of the date in the sequence.

For this project, most Bayesian statistical models were constructed and run in

OxCal 4.1 (Bronk Ramsey, 2009a). When constructing a Bayesian statistical model, the raw 14C dates and any stratigraphic information form the Priori. Prior information is used to create a Posterior distribution for each date. In OxCal, this distribution is compared to the distribution that would be given if the date had been calibrated separately, and not within a model. Depending on the amount of overlap (reported as a percentage termed the Agreement Index, Al), an individual date may be improved by the Bayesian constraints (Al > 100%), or may be considered an outlier (arbitrarily as an

Al < 60%). Too many outliers will force the entire model below the accepted threshold ofca60%AI.

23 2.7 Sediment cores

The first of two ways in which tephra ages are modelled using Bayesian statistics in this study is by estimating the ages of multiple tephras within one sedimentary sequence. Where tephras are found in stratigraphic sequence with associated dated radiocarbon materials, there are a variety of methods for creating age-depth models for interpolating the age of the tephras. For each of the methods below, a core from

Paradox Lake, Kenai Peninsula, Alaska, was used to construct the models (de Fontaine et al., 2007). Although the core contains numerous tephras, the ages only of five were estimated from these models, to simplify the process. The five tephras are those assumed to be correlative between the cores in the study (Table 2.2, de Fontaine et al.,

2007). The depths of radiocarbon dating points and the tephras are given in Table 2.1.

2.7.1 P_sequencing

A stratigraphic sequence of dates within a sediment core can be modelled in a

Bayesian framework by placing the dates at their appropriate depth. However, dates can be inaccurately modelled if the sediment deposition rate is not constant, which it rarely is in nature. This is especially important when trying to determine the ages of undated materials and known depths between dated materials; i.e. finding the age of tephras between radiocarbon dates. The P_sequence function in OxCal treats the deposition process as random, and includes a prior parameter of increments of change in rate that can be set by the user (Bronk Ramsey, 2008). The increment size is defined by the parameter k, which gives the number of accumulation events per unit depth, and the smaller the value of k, the closer to uniform deposition. The appropriate value of k

24 can be estimated by inspection of the sediment core, or by trial and error, noting the Al for each model run. The resultant model for the Paradox Lake core is given in Fig 2.7.

2.7.2 Bacon

The only Bayesian analytical framework used in the study not constructed with

OxCal is Bacon - a new software package run within the program R that attempts to incorporate more of the uncertainty associated with each radiocarbon date (Blaauw and

Christen, 2011). The entire histogram of each calibrated date is used, and thousands of models are run, choosing a point on the histogram of each date each time. Rather than a consistent age-depth model, the sedimentation rate is estimated between each date, and a prior parameter includes the degree of coherence between the deposition rates of succeeding sections. This parameter, W, can also be set at certain points to represent suspected events, such as a hiatus in deposition where sediment type abruptly changes.

The output includes every model as a single line, so that where many models converge to represent the most likely model, the area is darker. The resultant model for the

Paradox Lake core is given in Fig 2.8.

2.7.3 Comparison

The age range results of the tephras for both models are given in Table 2.2. For each tephra, the age range modelled from Bacon is much tighter; with smaller ranges.

This can also be seen in the histograms in the OxCal P_sequencing plot (Bacon does not plot ranges, producing the age range for each cm of core in a text output). While each

25 date seems to be calibrated with precision, there is still significant length between most of the tephras and any radiocarbon, so that modelled ages rely heavily on the deposition model. While it is tempting to take the Bacon modelled ages as more accurate because they are more precise, the large gaps in dated depths could mean the

uncertainty on each date could truly be as large as the P_sequencing suggests.

2.8 Single tephra ages

The second case of tephra age modelling considered in this study occurs when the

same tephra occurs in many different records. An age range assigned to the tephra in

one location will likely not perfectly match the age range given in another location, due

to uncertainties in radiocarbon dating and differences in stratigraphic relationship to the

tephra. In order to statistically model the likely age range of the tephra based on the

convergence of the dates, two of methods can be employed in OxCal - either a Phase

model or an Equals model.

2.8.1 Phase model

The basic method used throughout this paper is a Phase model, constructed in

OxCal where the dates are placed either in a pre-eruption or post-eruption phase. The

dates are unordered within the phase, but the phases are in chronological order

compared to each other, from oldest to youngest. The phases are separated by

Boundaries, which are calculated by the model. The boundary between the pre- and

post-eruption phases thus defines the modelled age distribution of the eruption.

26 The simplest Phase models contain only raw 14C dates that can be calibrated as part of the Bayesian Phase model (e.g., Blockley et al., 2008 Kuehn et al., 2009). In the northeast Pacific region, the Funk tephra deposit from Fisher volcano has many minimum and maximum dates that can be combined in this way. All dates used in the model are given in Table 2.3. The model was run initially with an outlier analysis. The output of this run is seen in Fig 2.9. For each radiocarbon date, the Prior distribution is in light grey and the Posterior in dark grey. In square brackets after each date code is the

Al value: four dates are identified as potential outliers with Al <60%, forcing the entire model to have an Al of only 26%. Two of these dates were from the early 1970s (Funk,

1973), and would likely be removed in a critical assessment of dates. All four outliers were removed and the model was run again, at which point no additional outliers were identified and the model had an overall Al of 141%. The age of the Funk tephra at the 2- sigma range resulting from this model is 10,540-10,215 BP. In this case, the Phase model has greatly improved the precision of the age estimation for the Funk tephra deposit.

2.8.2 Equals model

The Phase model works for single dates or pairs of dates associated with one tephra, but longer cores with more date information can also be combined. The dates of each core are input in their correct sequence and separate from each other, but within the same statistical model. In the first core the tephra in question is given a name with a

Date query input, and in each subsequent core the position of the tephra is marked with the same Date query function and the same name after an "=" sign. This forces the model to recognise that the tephra is the same event in each core and model the dates

27 appropriately. The Kaguyak tephra has been found across several sediment cores in the

Katmai peninsula (Fierstein 2007). Three of those cores are used to make an equals model of the Kaguyak tephra deposit and calculate its age. The details of the three cores are given in Table 2.4, and the output model is shown in Fig 2.10. The model had good agreement and gave a modelled age of 6450 - 6140 cal yrs BP for the eruption. This is significantly younger than the age determination of the ash by Fierstien (2007), who calibrated a single maximum date to 6730 - 6490 cal yrs BP.

2.9 Outlier analysis

Outliers can be determined either based on uncertainties in the calibration curve, or by context. For example in a Phase model, a certain date may not actually related to the same thing (tephra) as the other dates in the phase, and so be an outlier by context.

Therefore, in order to improve outlier analysis, we use a simple outlier model within all

OxCal models (Bronk Ramsey 2009b; Bacon has an outlier analysis algorithm built into each model - Blaauw and Christen, 2011). We set the parameters of the outlier model so that the dates are defined as a Student's t distribution with 5 degrees of freedom, and gives the scale of dates within a range of 1-10,000 years, where the analysis determines the appropriate scale. Finally, the type of outliers is defined as in the time variable, as opposed to outliers in 14C ratio or concentration. Once the model is defined in this way, each date is given the probability of being an outlier; typically 1 in 20 chance.

The results of the outlier analysis on the first run of the Fisher-Funk phase model can be seen in Fig 2.9. Where the A value next to each date falls below 60%, the date is considered an outlier, and is removed from the next run. In some instances, removing

28 certain outliers and running the model again will make some previously identified outliers rise above the threshold and be accepted. This is typically for dates in sequence or dates that are near the threshold in the first run; however it is advisable to exercise caution when chopping outliers and test several alternatives. In each case, the Al of the entire model will change (in Fig 2.9, the Al of the whole model is shown at the top).

2.10 Conclusions

Methods have been presented to improve geochemical analysis and dating of tephras in order to work towards robust correlations. Below I summarize the main points discussed in the text that work towards this aim.

Geochemical analysis:

• Macrotephra fractions are separated with heavy liquids to avoid glass shard

degradation

• Cryptotephras are set in acrylic pucks set onto graphite blocks to produce a

smooth surface and maximum exposure of shards

• Tephras are prepared separately from other samples in a laminar flow hood to

avoid contamination

• The electron microprobe is calibrated using a set of standards and calibrations is

periodically tested during analysis using a set of secondary standard tephras of

known composition

29 • Beam size, voltage and current of the electron microprobe are set to reduce Na

loss

• Data are corrected for offset and drift by comparison to the secondary

standards

• All data sets are normalized to reduce scatter

• Contaminant points (non-glass and phenocrysts) are removed from all data sets

• Similarity Coefficients are used as a first pass for correlations, but are used

cautiously

Dating:

• Bayesian statistics are used to eliminate some of the inherent uncertainty in

radiocarbon calibration by formally including prior information

• Multiple tephras within one sedimentary sequence are modelled with

consideration of their depth relative to radiocarbon dates

• A single tephras across multiple records is given a date estimation based on an

objective analysis of pre- and post- eruption dates, or by using all core date

information from each site (Phase model and Equals model, respectively)

• Formal outlier analysis is included in every model to highlight statistical outliers

for possible ejection from the model

30 Fig 2.1: Mounting procedure for macrotephra: a) puck attached to sticky tape, sample placed in each hole and topped up with epoxy; b) once dry, sticky tape removed and excess epoxy polished from the bottom to obtain a level surface; c) puck inscribed with identifying mark; d) puck coated with carbon and ready for EPMA analysis.

\

31 -i—r—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—r A L251-7

D 1251-7 re-polishe

CaO 2 - D A

1 - A

I • J l_ J I 1_ _l L. 60 65 70 75 60 St02

Fig 2.3: A comparison of cryptotephra sample geochemistry before and after re-polishing. The data becomes much tighter on the second run.

14 1 , 1 —I— r 1 Old Crow tephra: A Raw

SSDHP D Normalized 4 Accepted average value 13 - A

AJA A 4^v$£ A A

12 - A -

11 i i i ' 1 70 71 72 73 74 75 76 77 SfOj

Fig 2.4: Normalizing a set of analyses of the well-characterized Old Crow tephra makes it tighter and brings it closer to the accepted average value.

33 - A UA1674 D Ksudach reference

Fig 2.5: An unknown sample (UA 1674) returned a similarity co-efficient of 95 to the eruption of Ksudach of 1907. However, this is a false positive as the unknown is over 10,000 years old. This is further demonstrated with bivariate plots, where the two ranges clearly separate.

34 i in—din miiMiwimiMin R_Dato(24S0.40) 99.4% prabttaftfty 2706(231%) 38 33oieP M1I(72.*K)2

MOO 1400 2200 C«Sb™ttd **(»«>)

1*00

1800

1700

isoor

1700 CiltmM<**

Fig 2.6: Radiocarbon calibration curve issues, (a) Non-normal distribution resulting from a normally-distributed raw date, (b) A plateau in the calibration curve causing a wide calibrated age range, (c) A wiggle in the calibration curve causing two peaks in probable age range. All diagrams created in OxCal 4.1 and calibrated using lntCal09.

35 Lab code Depth (cm) Age(14CyrBP) AA-45098 81.5 1375 ± 45 AA-45099 97.5 1225 ± 45 AA-45100 165 2605 ± 40 AA-45101 193 2970 ± 50 Tephra la 225.4 Tephra lb 229.8 Tephra lc 230.8 AA-45102 289 4055 ± 45 AA-45103 311 4565 ± 45 AA-38445 344.5 4920 ± 90 AA-38446 399.5 5600 ± 80 Tephra 2 420.6 AA-38447 552.5 7100 ± 60 Tephra 3 558.4 Tephra 4 616.8 AA-45104 799 9970 ± 70 Beta-177159 873 10,970 ± 70

Table 2.1: Paradox Lake core chronology, from de Fontaine et al., 2007.

36 M4«l}amk**,™fl<>mri*mMk™:*,,(m • ^ Top —— AA45099fA100/ Jl

AA45100IA:101] L

AA45101{A:W1J Ttphn 1a -^ T»phr»1b -£- Ttphn 1c £* AA45102fA96j

AA45103fA:101} m AAX445IA:101] JL AA3844* fA.102] J.

Ttptn!

AA33447 fA:101] -J. Uphrt3 ~~^1 __ T»phr*4

AA45104[A:99j Ml Bf-177159(4 103/ A.

SfOtWfrt PtraawUtefAnxxttlOl)

J J J J J J J A J J Aj A.. ^„^ J. «. v i. A... ^ ,..,.,•..,. ft f ^^i.,L..Ji.iiiii, ^1 -•••• •••••'- i- -rt -f* ^irti/i f t Tifn" lit ------'•'••• ^-^ -f i'f *f i-iitiirtiiiifufliiti 35000 30000 25000 20000 15000 10000 5000 0 -5000 -TOOOO Modlfd da* (BP)

Fig 2.7: OxCal output for Paradox Lake core P_Sequencing. Distributions show the likely age ranges, and the bars beneath each give the 95.4% confidence ranges. Agreement indices for individual radiocarbon determinations are shown following the lab numbers. In each case, the Prior and Posterior are near-perfect matches, so the two sets of distributions cannot be distinguished (in less well-fitting models the Prior distribution is a lighter shade). The Agreement Index of the overall model is 101%.

37 Paradox

1 ftk *B I 1-1

—T- 200 CXptl

Fig 2.8: Bacon output age-depth model for the Paradox Lake core. Darker shaded regions represent more confidence in the model for that section. Individual age distributions are generated separately, and are given in text form in an output file.

38 Tephra P_Sequencing age Bacon age (cal yr BP) (cal yr BP) Tephra la 4110 - 3029 3932 - 3413 Tephra lb 4479 - 3231 4008 - 3466 Tephra lc 4771 - 3626 4047 - 3474 Tephra 2 7907 - 6407 6769 - 6418 Tephra 3 10749 - 7874 8236 - 7907 Tephra 4 11597-8598 9209 - 8576

Table 2.2: 95% confidence age ranges for the six tephras in the Paradox Lake core, from the P_sequencing and Bacon tests.

Code / Description Age Uncertainty Source ref Beta / Under P.F 1 9430 240 Stelling et al. (2005) Beta / Under P.F 2 9300 340 Stelling et al. (2005) Beta/Within P.F 1 9330 160 Stelling et al. (2005) Beta /Within P.F 2 9400 160 Stelling et al. (2005) Beta/South P.F. 9090 50 Stelling et al. (2005) BETA-96824 9130 140 Dochat(1997) BETA-96830 9630 140 Dochat(1997) BETA-96825 7910 160 Dochat(1997) W-3424 9120 250 Miller and Smith (1987) GX-2789 10625 550 Funk (1973) GX-2744 9660 615 Funk (1973) GX-2790 8425 350 Funk (1973) K-2500C-S 9250 140 Fierstein (2007) K-2221-s 8730 230 Fierstein (2007) K-2584G-S 8865 135 Fierstein (2007)

Table 2.3: Dates used to construct the Fisher-Funk tephra Phase model.

39 )»S* rt 1 7BmrttBaTmByff010E r5^mQ»hene

Boundary R_Da* B£TA96825/A:83} R_Dat» GX-2790 [A 103} R_Dat» South PJ*. &•$»/ Pfeat* Pott-#Mp4iOfl Boundary eruption R_Oa*K-2384G*(A26f •-.Mr^- R_Dat» K-2221-S IA:28} R_Da* K-2$0QC*(A:114J R_Oa* GX-2789 (ATrf -^ R_Dat» BS7A-96830/A53/ R_Da* W-3424/A 123} ^*V R_DaatB£TA-96824IA:111J ——£^

R_Dat» GX-2744[A 116} , „—- jfc_

R_0a* Within P.F. 1fA11$J R_Oa* Und*rP.F.2fA:134} R_Oat» UndarP.P1/4:11C9 Pfeaw Pta-anjpfton Boundary Saquanca FWiar#ur* iAmodel^S] 1111• 111111»11 it 11111111111 ii 11 20000 18000 10000 14000 12000 10000 8000 6000 4000 ModaHaddata(BP)

Fig 2.9: First run of the Fisher-Funk phase model. Four dates are identified as outliers, being significantly below the Agreement Index threshold of 60%; K-2584G-S, K-2221-s, GX-2789 and BETA-96830. These force the overall model below the threshold at only 25% agreement.

40 Lab code Age (14C yr BP) Uncertainty (2o) Windy Ck K-2221-s 8730 230 K-2349-s 8600 120 K-2351-s 6995 105 K-2581D 6520 180 K-2544 6420 240 K-2222-s 5545 165 Kaguyaktephra K-2348-s 5220 90 K-2181-s 5130 360 K-2780-s 4800 60 K-2059-s 4260 120 K-2591-s 4230 140 K-2347-s 4185 85 K-2223-s 4080 140 K-2179-s 3260 220 K-2543-s 575 105

Moraine Ck K-2668 10180 130 K-2584G-S 8865 135 K-2584F-S 8500 120 K-2585-s 7440 120 K-2584E-S 5575 95 K-2314-s 5535 215 Kaguyaktephra K-2584D-S 3700 85 K-2583-s 660 70 K-2583-sx 120 40

Busk Ck K-2675H-S 8970 220 K-2675E-S 5700 90 Kaguyaktephra K-2675D-W 5500 60 K-2702C-X 4480 40 K-2702C 4450 80 K-2675C-S 3650 70 K-2675A-S 3450 70

Table 2.4: Dates for each core used in the Equals model. Dates are ordered from bottom to top, with the position of the Kaguyak tephra noted in each. After Fierstein 2007.

41 1 "

aoumtary lop Buih C* fLO**K-267&4^fA.10t) /i_DateKX7SCSfl 102} R_DM*K-2K2C[A 100] FCDateK-mX-tfA 10$ A fi_Dat*K-2675t>-WiAti! -£ •Kaguyak ± Q_DMeK-X?S£-if*.t02J -*• ft_DatfK-X7SHS(H99] •••£- aoundaiy betcm atati Ck • yf^j^ffPfwy--*^ tourdary tip Uomme C* , ^ _ _ ftt>UeK-26t3-lx/A99] * X H_D»t»K-2SKt-tfA 100] m ttBm»K-2SMOt jA 100] JL =Ksgu/e* JL /LD*»K-2314-t{A «0 T ILO**K-28M&* IAT9] A- /LOateK-2it6*M.t00) JL llDX*K-2i*4F-s(A103l -ir H.D#eK-&a4Q* p. 101) -Or HDfK^eeap»T] •A- B^ayammttmm.m-:, ^*Tnca V^L^T f^^****1 '^ toirxtarytopWiMfyCk R_DaU>K-2MT-»lA 101) H.Oa»K-26t1-tfA 120] ftDal*K-2069-tlA*»] lLD**K-2rW*(A.»9f /tDateK-21t1-i(A 12»] H_D*»K-2M*[A 102] Ksgu/tk li_O*»K-2222-lfA105J ttDa»K-2fHpi02) ftOm*K-26*WlA 10$ H.OfK*mi*fA too) ftDl»K^M9-i(A110] (LDM»K-2221-t(A116) aoumtary baton Wmdy t

25000 20000 15000 10000 SOOO 0 -5000 -10000 UodtStddattfaP)

Fig 2.10: Output of the Kaguyak tephra Equals model

42 2.11 References

Blaauw, M., Christen, J.A., 2011. Flexible Paleoclimate Age-Depth Models Using an

Autoregressive Gamma Process. Bayesian Analysis 6,457-474.

Blockley, S.P.E., Pyne-O'Donnell, S.D.F., Lowe, J.J., Mathews, LP., Stone, A.,

Pollard, A.M., Turney, C. S. M., Molyneux, E. G., 2005. A new and less destructive

laboratory procedure for the physical separation of distal tephra glass shards from sediments. Quaternary Science Reviews 24,1952-1960.

Blockley, S.P.E., Bronk Ramsey, C, Pyle, D.M., 2008. Improved age modelling

and high-precision age estimates of late Quaternary tephras, for accurate

palaeoclimate reconstruction. Journal of Volcanology and Geothermal Research 177,

251-262.

Borchardt, G.A., Harward, M.E., Schmitt, R.A., 1971. Correlation of volcanic ash

deposits by activation analysis of glass separates. Quaternary Research 1, 247-260.

Borchardt, G.A., Aruscavage, P.J., and Millard, H.T., Jr., 1972. Correlation of the

Bishop Ash, a Pleistocene marker bed, using instrumental neutron activation analysis.

Journal of Sedimentary Petrology 42,301-306.

Bronk Ramsey, C, 2008. Deposition models for chronological records. Quaternary

Science Reviews 27,42-60.

Bronk Ramsey, C, 2009a. Bayesian analysis of radiocarbon dates. Radiocarbon 51,

337-360.

Bronk Ramsey, C, 2009b. Dealing with outliers and offsets in radiocarbon dating.

Radiocarbon 51,1023-1045.

43 Buck, C.E., Higham, T.F.G., Lowe, D.J., 2003. Bayesian tools for tephrochronology. The Holocene 13, 639-647.

Dochat, T.M., 1997. Quaternary stratigraphy and geomorphology of the Cold

Bay region of the Alaska Peninsula; a basis for paleoenvironmental reconstruction.

PhD thesis, University of Wisconsin-Madison, Madison, 330 pp.

Dugmore, A.J., Larsen, G., Newton A.J., Sugden D.E., 1992. Geochemical stability of fine-grained silicic Holocene tephras in Iceland and Scotland. Journal of

Quaternary Science 7,173-183.

Fierstein, J., 2007. Explosive eruptive record in the Katmai region, Alaska

Peninsula: an overview. Bulletin of Volcanology 69, 469-509.

de Fontaine, C.S., Kaufman, D.S., Anderson, R.S., Werner, A., Waythomas, C.F.,

Brown, T.A., 2007. Late Quaternary distal tephra-fall deposits in lacustrine sediments, Kenai Peninsula, Alaska. Quaternary Research 68, 64-78.

Froggatt, P.C., 1983. Toward a comprehensive Upper Quaternary tephra and ignimbrite stratigraphy in New Zealand using electron microprobe analysis of glass shards. Quaternary Research 19,188-200.

Froggatt, P.C., 1992. Standardization of the chemical analysis of tephra deposits. Report of the ICCT working group. Quaternary International 13-14, 93-96.

Funk, J.M., 1973. Late Quaternary geology of ColdBay, Alaska, and vicinity. M.S.

Thesis, University of Connecticut, 44pp.

44 Humphreys, M.C.S., Kearns, S.L., and Blundy, J.D., 2006. SIMS investigation of electron-beam damage to hydrous, rhyolitic glasses: Implications for melt inclusion analysis. American Mineralogist 91, 667-679.

Hunt, J.B., Hill, P. G., 1993. Tephra geochemistry: a discussion of some persistent analytical problems. The Holocene 3, 271-278.

Hunt, J.B., Hill, P.G., 1996. An inter-laboratory comparison of the electron probe microanalysis of glass geochemistry. Quaternary International 34-36, 229-241.

Kuehn, S.C., Froese, D.G., Carrara, P.E., Foit, F.F., Pearce, N.J.G., Rotheisler, P.,

2009. Major- and trace-element characterization, expanded distribution, and a new chronology for the latest Pleistocene Glacier Peak tephras in western North

America. Quaternary Research 71, 201-216.

Kuehn, S.C., Froese, D.G., 2010. Tephra from ice - a simple method to routinely mount, polish, and quantitatively analyze sparse fine particles. Microscopy and

Microanalysis 16, 218-225.

Kuehn, S.C., Froese, D.G., and Shane, P.A.R., in press. The INTAV intercomparison of electron-beam microanalysis 1 of glass by tephrochronology laboratories, results and recommendations.

Lowe, D.J., 2011. Tephrochronology and its application: a review. Quaternary

Geochronology 6,107-153.

Miller, T. and Smith, R. 1987. Late Quaternary caldera-forming eruptions in the eastern Aleutian arc, Alaska. Geology 15, 431-438.

45 Pollard, A.M., Blockley, S.P.E., Ward, K.R., 2003. Chemical alteration of tephra in the depositional environment: theoretical stability modelling. Journal of Quaternary

Science 18, 385-394.

Pearce, N.J.G., Denton, J.S., Perkins, W.T., Westgate, J.A., Alloway, B.V., 2007.

Correlation and characterisation of individual glass shards from tephra deposits using trace element laser ablation ICP-MS analyses: current status and future potential. Journal of Quaternary Science 22, 721-736.

Preece, S.J., Pearce, N.J.G., Westgate, J.A., Froese, D.G., Jensen, B.J.L., Perkins,

W.T., 2011. Old Crow tephra across eastern Beringia: a single cataclysmic eruption at the close of Marine Isotope Stage 6. Quaternary Science Reviews 30, 2069-2090.

Reed, S.J.B., 2005. Electron microprobe analysis and scanning electron microscopy in geology. Cambridge University Press.

Reimer, P.J., and R.W. Reimer. 2007. Radiocarbon dating: Calibration. In:

Encyclopedia of Quaternary Science. S.A. Elias (ed). 2941-2950.

Shane, P.A.R., 2000. Tephrochronology: a New Zealand case study. Earth- science Reviews 49, 223-259.

Smith, D.G., Westgate, J.A., 1969. Electron probe technique for characterizing

pyroclastic deposits. Earth and Planetary Sciences Letters, 5, 313-319.

Stelling, P., Gardner, J.E., Beget, J., 2005. Eruptive history of Fisher Caldera,

Alaska, USA. Journal of Volcanology and Geothermal Research 139,163-183.

46 Stokes, S., Lowe, D.J., Froggatt, P.C, 1992. Discriminant function analysis and correlation of late Quaternary rhyolitic tephra deposits from Taupo and Okataina volcanoes, New Zealand, using glass shard major element composition. Quaternary

International 13-14,103-117.

47 CHAPTER 3 - CORRELATING THE TERRESTRIAL AND MARINE

RECORD OF THE MOUNT EDGECUMBE VOLCANIC FIELD

3.1 Introduction

The coastal area of northwest North America figures prominently in models of the first migration of humans into the new world (Yesner, 2001), however its viability as a route has been questioned, many researchers instead favouring an ice-free corridor between the Laurentide and Cordilleran ice sheets as the ice age drew to a close. The coastal route has been re-evaluated based on paleo-environmental and geological data suggesting the area was viable and biologically productive between 14,000 and 12,000

BP (Josenhans et al., 1997; Mandryk et al., 2001).

The aim of this study is to investigate late Pleistocene sediments in the panhandle region of South East Alaska in the hopes of finding the Mount Edgecumbe dacite (MEd), which was erupted within the suggested time window of a biologically productive coastal migration route. This widespread tephra layer could serve as an instantaneous time marker in diverse sedimentary archives across the region, allowing environmental conditions, and potentially archaeological records to be linked. As well, if this bed can be

48 found in both the terrestrial and marine record of this region, then the opportunity also

exists to estimate the local marine reservoir near this critical time at the Pleistocene-

Holocene transition. The marine reservoir is a phenomenon where marine organisms

take up carbon that is not in equilibrium with the atmosphere during their growth

stages. This can lead to dates in marine records that are several hundred to more than a

thousand years older than terrestrial organic material of the same age. The marine

reservoir effect may also vary locally, as fjords and basins may include waters that are

incompletely mixed with the open ocean. Hutchinson et al. (2004) studied an area

around the British Columbia - Washington border and found a mean marine reservoir

correction during the late-Pleistocene of 950±50 yr; however for sites in sheltered

locations they determined a higher mean marine reservoir correction of 12001130 yr. It

is therefore important to know the marine reservoir for the immediate area when trying

to tie together the record of marine and terrestrial environments, and changes in local

sea level (Mann and Streveler, 2008).

In this paper, we focus on the MEd and associated tephras in southeastern Alaska,

and the potential to develop tephra isochrons to link sedimentary records in the region.

A series of tephras from a terrestrial site at Column Point, Chichagof Island and a marine

sediment sequence from Lower Sitka Sound (Fig 3.1), are investigated. Specifically, the

objectives of this paper are to:

1. Geochemically characterize the MEd and associated tephras;

2. Determine a robust age for the MEd and associated tephras through

radiocarbon dating of associated organic material;

49 3. Use Bayesian tools to statistically model the most likely age for MEd and any

associated tephras; and

4. Estimate the marine reservoir at the time of MEd deposition through

comparison of age determinations for the marine and terrestrial cores.

3.2 Regional setting

Mt Edgecumbe is a major central peak in the Mount Edgecumbe Volcanic Field

(MEVF) located on southern Kruzof Island in southeast Alaska (Fig 1). Activity began

600,000 years ago as basaltic fissure eruptions, concentrating into a southwest- northeast trending zone by 400,000 years ago, after which Mt Edgecumbe itself began to form (Riehle, 1996). Early eruptive products were dominated by basalt, basaltic andesite, and andesite. As late Pleistocene ice retreated from the island around 14,000 years ago, explosive and more silicic volcanic activity began in the south, leading to the eruption of the MEd tephra ~11,30014C yr BP (Beget and Motyka, 1998). The last activity from the MEVF was 4260 - 4820 cal yrs BP (Riehle and Brew, 1984). ). An additional extensive submarine volcanic field on the Kruzof Island shelf was likely exposed during the sea level lowstand associated with the last glacial maximum (LGM) (Greene et al.,2007).

The MEVF presents a volcanological anomaly in that it occurs close to the Queen

Charlotte-Fairweather transform fault, 10 miles offshore to the west of Mt Edgecumbe

(Riehle, 1996). Basalts erupted from the MEVF reflect both Pacific oceanic and North

American continental plate compositions, likely as a result of the Queen Charlotte-

Fairweather transform fault dipping eastwards beneath Kruzof Island. The magma

50 supplying the MEVF is considered to be in a stratified chamber straddling the fault, producing basaltic lavas at the southwest and northeast ends of the zone, with andesitic and dacitic lavas at Mt Edgecumbe, and rhyolitic lavas at the Crater Ridge volcano to the northeast, also within the centre of the MEVF (Riehle et al., 1992a). It is for this reason that, despite the major eruption from Mt Edgecumbe being referred to as the Mt

Edgecumbe dacite, it is often found with a strong rhyolitic component, reflecting a proposed simultaneous eruption of the two magmatic centres. Little mixing of the two compositions occurs close to the vents, but bimodal deposits have been found in deposits away from Kruzof Island. Prior to this, the only deposits found at a distance from the MEVF were rhyolitic tephras from a violent phase of Crater Ridge activity, so the bimodalism is considered diagnostic of the MEd event, and of the last phase of activity at the Pleistocene-Holocene boundary, ending around 12,000 years ago.

3.3 Methods

3.3.1 Column Point

A 40 cm long monolith was collected from a nearly flat expanse of peat near the level of mean low water on an exposed beach facing the open Gulf of Alaska at Column

Point, Chichagof Island. The peat was strong enough to resist strong wave action in the area, but much has likely been eroded from the top. The peat represents a typical, forested peatland. Numerous small tree stumps and a hummocky nature suggest a pine muskeg forest.

51 The resulting monolith (Fig 3.2), approximately 400 x 150 x 150 mm, is bounded at the top by a thick tephra bed and at the base by a thin gravel layer. Five macro tephra layers were identified by visual inspection of lighter-coloured beds and numbered

UA1674 - 1678 from base to top. Small subsamples of each bed were mixed on a microscope slide with glycerol and confirmed as volcanic glass using transmitted light microscopy. Larger samples of each bed were then extracted, wet sieved and had most of their organic material removed by repeated washes and treatment with hydrogen peroxide. Heavy liquid separation was performed on the remaining fraction (using a mixture of acetone and tetrabromoethane, with a density of ~2.4 g/ml). The resulting concentration of volcanic glass was mounted within an acrylic puck filled with epoxy.

Finally, samples were polished and carbon coated before undergoing wavelength- dispersive electron microprobe analysis (EMPA) to determine glass shard major element geochemistry.

3.3.2 Lower Sitka Sound

A suite of marine cores were taken off the islands of the Alaskan Panhandle from the R/V Maurice Ewing, and of these, the core named EW0408-40JC from Lower Sitka

Sound was determined by Addison et al. (2010) to contain the MEd tephra, as well as several others likely from the MEVF. Eight tephra samples from this core were acquired for analysis. Tephras at 9.08, 9.80, 10.00, 10.29, 10.49, 10.82, 11.08 and 11.10 metres below sea level referred to here by UA numbers 1797-1804, respectively.

52 3.3.3 Mircoprobe analysis

The Column Point and Lower Sitka sound samples were analysed on the University of Alberta's JEOL 8900 electron microprobe using a 15-kV accelerating voltage, a 6-nA

beam current and a 10u.m beam diameter. As well as an obsidian standard, both runs were accompanied by a secondary standard of the well-characterised Old Crow tephra

(Beget and Keskinen, 2003; Preece et al., 2011; Kuehn et al., in press) to assess

instrumental drift during each run, as well as consistency between the two sessions. To obtain a true average of the geochemistry of each sample and to reduce the possibility of contamination affecting our conclusions, effort was made to collect at least 15 analyses of individual shards per sample, although this was not always possible.

After analysis, individual analyses that had totals above 93 wt % were reported as average oxide values normalised to 100% after being corrected for any discrepancy from the values obtained for the standards. Analyses with reported totals of less than 93%

(due primarily to water loss from glass hydration rinds) were excluded from the final dataset, as were analyses with obvious inclusions of phenocrysts.

3.3.4 Age determination

For radiocarbon dating, six segments of the Column Point core were sampled, sieved and examined under a microscope to pick out plant macrofossils and woody fragments for radiocarbon dating. Acid-Base-Acid pre-treatment was carried out at the

University of Alberta. Samples were first heated in HCI at 70°C for 30 minutes. HCI was then pipetted out and replaced by NaOH, and heated again at 70°C for 1 hour. This step

53 was repeated until the liquid in each sample tube was clear. Final washes of HCI were then applied until the sample had a neutral pH. Finally, ultra-pure Milli-Q water was added to submerge the sample which was then heated for 5 minutes. Samples were freeze dried and sent to the Keck-CCAMS facility at University of California, Irvine for

AMS dating. Three standards of known age were prepared at the same time. Samples were chosen primarily to bound the tephras UA1678 and UA1677, although tephras

UA1674, UA1675 and UA1676 were so closely spaced that the possibility of contamination meant that dating materials were only extracted above UA1676 and below UA1674 (Fig 3.2).

Addison et al. (2010) sampled marine bivalves for 14C dating from the Lower Sitka

Sound core. Radiocarbon sampling points however, are all above the tephras; the closest being 47 cm above the first tephra (UA1797) (see paper for details). A marine reservoir correction of 732 years had been applied to the 14C dates, but for the purposes of Bayesian age modelling and new marine reservoir estimation, the raw, un-corrected

14C dates are used here.

3.4 Tephra characterization

Average oxide values for each sample are presented in Table 3.1. All of the tephra beds were light brown in appearance, but displayed a range of glass shard morphologies. UA1674 was largely chunky pumice, with thick walls and some bubble wall shards. Petrology was dominated by amphibole, with some plagioclase and orthopyroxene. It plots firmly within the dacite field on a total alkali silica plot (Fig 3.4).

54 UA1674 plotted in the mid-range of the tephras for most major elements, but with

comparatively high FeOt and MgO.

UA1675 and UA1676 had low shard abundance, and available shards were often very broken up and degraded. UA1676 contained some amphibole and rare clinopyroxene, and had a similar major element composition to one population of

UA1678 (described below). The results for UA1675 plot within the rhyolite field,

although the points are quite scattered. UA1675 had the highest Si02 and K20, and the

lowest Al203 and MgO. UA1676 plots on the border between the dacite and rhyolite fields, and overlaps with a population of UA1678. UA1677 was more shard-rich, but also included an abundance of phenocryst-rich glass. Shard morphology was mostly pumice with thin walls, further hindering analysis.

The shards plot within the dacite field, although with sufficiently low Si02 and high total alkalis for many points to lie on the border of the andesite field (Fig 3.3). UA1677 plotted similar to UA1674 in all major elements, commonly overlapping. However, in the mineral phase it contained a comparable proportion of plagioclase and amphibole.

UA1678 was the most abundant in shards and had a range of morphologies, including chunky pumice and tricuspate and needle-like glasses. Plagioclase again dominated, with some orthopyroxene. Two populations were identified, with sufficient

points in each to indicate a bimodal population. There is a high and low Si02 population,

although they are close together, with the lower Si02 population plotting on the border of rhyolite and dacite. This is termed UA1678 (I), and the other population, plotting tightly within the rhyolite field, denoted UA1678 (II). The MEVF eruptive products have been shown to be both rhyolitic and dacitic in nature (Riehle, 1992b), so that when

55 comparing our data to others', each population of bimodal beds was considered separately. Both beds UA1678 (I) and UA1678 (II) plot in the mid-range for all major

element oxides, with UA1678 (I) being higher in FeOt, Al203, MgO and CaO and lower in

K20.

Tephras from the Lower Sitka Sound marine core were more homogeneous, with all samples plotting in the rhyolite field (Fig 3.3).

Tephras in the northeast Pacific commonly fall into two categories (Type I and Type

II) based on their mineralogy and major- and trace-element glass geochemistry (Preece et al., 1992). The two types do not appear to be constrained to any particular volcanic region; however volcanoes producing Type II are considerably rarer, found only at Hayes volcano in the Aleutian Peninsula and at three volcanoes in the Wrangell Volcanic Field.

Type II tephras occur across the Aleutian-Arc-Alaskan-Peninsula and the Wrangell

Volcanic Field. Some proximal deposits of both types have been found at some volcanoes, such as Mt Wrangell. A plot of all samples analysed in this study against average fields of Type I and II tephras show almost all of them falling in a narrow section where the two types overlap (Fig 3.5).

3.5 Correlations

While the ~11,300 14C yr BP eruption, termed MEd, from Mt Edgecumbe is undoubtedly the largest in the recent history of the MEVF (Beget and Motyka, 1992), other, closely spaced eruptions have left records in the surrounding area. Riehle et al.

56 (1992b) report MEVF tephras from lakes and bogs across southeast Alaska of compositions ranging from rhyolitic to dacitic. More recently, Addison et al. (2010) report MEVF tephras in marine core sequences from localities adjacent to Kruzoff Island.

Of these cores, EW0408-40JC fell within a comparable date range to the Column Point core (all tephras lie below an age determination of ~11,400 14C BP; see Age section for our core). EPMA glass shard analyses from these various sources were selected for comparison to our data. As a first pass for possible correlations, each tephra's geochemistry was compared to the University of Alberta's tephra database, as well as to each other, using similarity co-efficients (SCs). The SC of Borchardt et al. (1971) and

Borchardt et al. (1972) is based on ratios of oxides, where the concentration of each oxide in one sample is divided by the concentration of the same oxide in another sample, with the greater concentration always placed in the denominator:

, _ J^iRi diA,B) ~ ——

Where d^^ is the similarity coefficient for comparison between sample A and B; /' is

the element number; n is the number of elements in a calculation; /?, is X|A / X|B (if X|B>X|A)

or X|B / X|A (if X,A>X|B); XIA is the concentration of element / in sample A; and XlB is the concentration of element / in sample B.

The more similar the two values, the larger the ratio. The ratio is equal to 1.00 if the two concentrations are identical, and all ratios are averaged for each pair of samples to produce an overall SC. However, the threshold for acceptable SCs varies by eruption and by researcher. Riehle et al. (1992b) used several separate analyses of the same bed in the area to determine the influence of composition on acceptable limits of SC in the

MEVF. They found rhyolitic beds were generally more homogeneous, and only SC values

57 above 95 could be considered correlative; from the same ashfall event. Dacitic beds however showed greater heterogeneity, and the same beds analysed in succession may only have a 0.90 - 0.95 SC. The same principles were applied to our SC comparison, so that for the rhyolitic populations, SCs below 0.95 were rejected, and for dacitic populations, SCs below 0.90 were rejected. The results of the preliminary SC examination that match MEVF sources are shown in Table 3.2, and summarised in Fig

3.6.

Since the Lower Sitka Sound core tephras are all highly clustered, only the SC values for the Column Point core are shown in Table 3.2. UA 1676 and UA 1678 (I) both show strong correlations to terrestrial MEVF tephras, and the MEd specifically, but only UA

1678 (II) has high SCs with the Lower Sitka Sound core tephras. UA 1678 is also much thicker in the core, and is dated appropriately for the MEd (see Age section for determination of the Column Point core tephras). For a final assessment of this potential correlation, Fig 3.6 plots suspected MEd tephras from this study against published data.

Addison et al. (2010) identified 9.08 m depth as the MEd tephra, so this is the depth presented here, as well as our own analyses of that tephra (UA 1797). Only UA 1678, from Column Point, captures the full range of the reference data, but the analyses from

Lower Sitka Sound cluster within the high-Si range.

3.6 Core ages

The reported 14C ages for our samples for Column Point and the three standards are given in Table 3.3. The accepted radiocarbon age for the standard IAEA-C5 is 11,800 yrs

BP, exactly as reported in this run (Rozanski et al., 1992). This is especially useful in

58 determining the accuracy of our own ages, since this date fits within our sequence. Firi-

D has an accepted age of 4510 yrs BP; also close to that reported in this run (Boaretto et al., 2002). Simple calibration was first performed using OxCal 4.1 (Bronk Ramsey,

2009a) with the IntCal 09 calibration data of Reimer et al. (2009) (Table 3.3). Since the core appears intact with no evidence of extensive reworking, we can assume the dates should be sequenced with depth, and this prior knowledge can be used in the calibration process. This Bayesian method uses prior knowledge of stratigraphic position and produces a more precise posterior distribution of the likely date of each sample, and allows the detection of outliers. This process was carried out using a 'sequence' function within OxCal 4.1 (Bronk Ramsey 2008). Since there is an apparent age reversal at 12.5 cm depth, a simple outlier model was applied within the sequence model to test the likelihood of any date being an outlier (Bronk Ramsey 2009b). Outliers are distributed using the input of a Student's T-test with five degrees of freedom, and the scaling of the outliers is defined as a distribution anywhere between 1-10,000 years. The outlier model defines the outliers as in the time variable, and each date was given the same prior probability of 1 in 20 of being an outlier. The model identified 12.5 cm as being the outlier, with an agreement value of less than 60%.

To determine probable ages for the tephras, two age-depth models were created for the core. Rejecting 12.5 cm depth radiocarbon age as an outlier, a relatively simple linear age-depth model could be constructed for the core. However, since there are so few points, there is a strong likelihood that too much emphasis is placed on individual dates using this method. It also only gives a single date for any depth, without consideration of error.

59 The P-Sequence function in OxCal 4.1 (Bronk Ramsey, 2008) treats the deposition process as inherently random, in increments defined by the user. The finer the increments, the closer the model is to a uniform deposition. The increment size is defined by the parameter k, which gives the number of accumulation events per unit depth. The best value for k can be determined in part by visual inspection of the grain size of a sediment core (the larger the grain size, the fewer accumulation events per unit depth). While this gives an idea of the scale of k required, it can be refined by testing the model with several closely-spaced values and determining the best fit by noting the agreement value in each run, although this can lead to some circular reasoning. For the

Column Point core, in order to define the depths of each tephra as a single point, the thickness of each tephra must be removed from the total thickness of the core. The outlier defined earlier at 12.5cm depth was also not used in the construction of the model. Trial-and-error showed little change in the model outcome with changing k, suggesting the deposition is near uniform, but a factor of 10 cm-1 seems appropriate (10 deposition events per unit depth). The results for the ages of each tephra using this method are presented in Table 3.4.

Bacon (Blaauw and Christen 2011) constructs age-depth models that take into consideration the associated errors and entire distribution of probabilities for each calibrated date point. To do this, Bacon models thousands of versions of age-depth models for each set of dates. Each time, it chooses one year from the distribution of each date and creates a linear interpolation between each date. The higher the probability of each year within a single date's distribution, the more times it is selected for in the model. After all iterations of the model have been run, a graphic is produced that displays the likelihood of each age-depth model as a shade of grey - the darker the

60 area, the more likely the model. In this way, a distribution of probable ages is given for each depth in the model.

Addison et al. (2010) used a linear age-depth model to interpolate the ages of the tephras in the Lower Sitka Sound core. All dated points are stratigraphically above the tephras. The Lower Sitka Sound core is thus subjected here to the same age-depth models as the Column Point core (Table 3.4), except Bacon, for which a model could not be constructed due to the limited age data related to the tephras. The data for Lower

Sitka Sound is also presented without a marine reservoir correction (see Marine

Reservoir Estimation for a discussion of this).

3.7 MEd age

Accepting that tephra layer 'UA 1678' represents the large dacitic eruption of Mt

Edgecumbe, 'MEd', our radiocarbon age below the ash can be combined with those of other workers to refine the exact date of the eruption. As with sequencing the dates of the core according to stratigraphic position, prior knowledge of the position of the radiocarbon date relative to the ash layer can be combined to constrain the timing of the eruption. We employ a two-phase model consisting of maximum and minimum ages, each defining a phase relating to deposition of the tephra. The ages in each phase are unordered; that is, we assume no knowledge of how these relate to one another.

This is similar to the approach taken by Blockley et al. (2008) and Kuehn et al. (2009) to constrain tephra deposition ages, and allows a more objective approach to age outlier detection through consideration of agreement values. For MEd, there are many well- defined maximum ages, including that from this study. However, there is only one

61 minimum age taken above the tephra layer, from a peat core at Montana Creek (<50km

east of Column Point), southeast Alaska (Riehle et al., 1992b). The age was from a bulk

sample, radiometrically dated, and as such has large error: 11,230 ± 400 14C yrs BP. No

dates from the Lower Sitka Sound core were used, since the closest date is nearly 50 cm

above the suspected MEd tephras (UA 1797), and the marine reservoir has not been

included. All dates used in the analysis are given in Table 3.5.

Using OxCal 4.1, the initial run of the model returned an agreement value of 92%,

but identified BB-77051 as an outlier, with an individual agreement value of less than

50%. Run 2 removed this outlier, and returned an agreement value of 162% with a

modelled MEd eruption age of 13,267 -13,048 cal yr BP. Considering the large errors on the single minimum age, we also tested the model using no defined minimum ages, but

leaving in a boundary, so that the distribution would not be infinite. This third run

returned an agreement value of 135% with a modelled eruption age of 13,270 -13,035 cal yr BP. This is essentially the same as the result with the Montana Creek date

included, suggesting that this layer is too uncertain in itself to strongly affect the

resulting age constraints on the MEd deposition.

3.8 Marine reservoir estimation

One other minimum age exists for the MEd deposition, from the marine core

EW0408-40JC described in Addison et al. (2010). The MEd tephra was identified at 9.08 m depth by Addison et al., and confirmed by a sub-sample analysed for this study at the

University of Alberta (UA 1979).

62 However, as a marine core, the radiocarbon dates above the MEd layer are subject

to a marine reservoir correction. Estimates for the reservoir age in the northeast Pacific

range from 650 - 1300 years (Kovanen and Easterbrook, 2002), and Addison et al.

estimate it as approx. 732 years for this region based on the mean 14C date discrepancy

between paired marine bivalve and terrestrial wood samples from three coastal marine

sediment cores. However, linking MEd on land and in the marine core can provide an

alternative marine reservoir estimation technique that is based on the conclusion that

the material you date on land and in the ocean is known to be the same age; eliminating

much of the uncertainty inherent in pairing bivalve and wood samples.

To estimate the marine reservoir in this region, a different Bayesian method was

used in OxCal 4.1. All dates from the cores of Column Point and Lower Sitka Sound were

included, and other maximum and minimum dates were treated as cores with one date

each. MEd is cross referenced between these cores so that the age in each core is forced to be the same age, once all prior information considering stratigraphic position is taken

into account. To estimate the marine reservoir the command 'Delta_R' was used. When

placed before a marine sequence, it applies a shift in time. If the shift, the marine

reservoir in this case, is known it can be applied here with its error, in the format:

"R_Delta (700, 50), for a shift of 700 years and an error of 50 years. Where the shift is unknown, it can be calculated during calibration using the input: "R_Delta (0,500)", where 500 is an example prior estimate of the shift. Changing the prior estimate of

Delta_R changes the outcome of the marine reservoir estimation, as well as the estimate for MEd deposition. Too low a prior creates a poor 'A' between the prior and posterior marine reservoir, and after some point increasing the prior no longer influences the estimate.

63 Prior R_delta values between 400 - 700 years were tested for this model. In this case, a prior estimate of 500 years gives the best result; any less and the 'A' is pushed close to the threshold, any more and the reservoir estimate changes very little. The reservoir estimate is thus calculated as 320 - 809 years at the 2 sigma range. However, the reservoir is still poorly constrained, at a range of nearly 500 years. This large span is likely due to all marine dates for MEd are above the tephra layer and start relatively far above it, and the one other minimum age (Montana Creek) is also poorly constrained.

3.9 Discussion and conclusions

The Mount Edgecumbe dacite (MEd) has been identified in a coastal peat core

(Column Point) and offshore marine core (Lower Sitka Sound) that correlates with occurrences of the tephra in nearby lake sediment cores (Riehle, 1992b; Beget and

Motyka, 1998). Alongside this, several previously unidentified tephras have been recovered. The MEd tephra is at the top of both the Column Point and Lower Sitka

Sound cores, but the tephras below them are distinctly different. Other than MEd (UA

1678), only UA 1676 from the Column Point core plots alongside the tightly-clustered

Lower Sitka Sound tephras, the others being distinctly more rhyolitic (UA 1674) or dacitic (UA 1675 and UA 1677). This could be a result of preservation potential, or preferred plume direction of rhyolitic tephras towards the west of Mt. Edgecumbe, as opposed to the north (Lower Sitka Sound and Column point respectively). The unmatched component of the Column Point core lies on a geochemical trend with the

MEVF products, and so likely represents previously unidentified eruptions from the field, or may be eruptions from other sources (Fig 3.6).

64 The age of the MEd has been previously reported as ~11,300 C yr BP (Beget and

Motyka, 1998). Here, we used a Bayesian statistical phase model to incorporate all terrestrial ages and make a new estimate of the eruption age. The calculated age 13,270

- 13,050 cal yrs BP, but this could be further improved with improved minimum age estimates for the tephra.

Having the MEd tephra in both the terrestrial and marine record allows a new estimation of the marine reservoir effect in this particular region. However, the lack of precise minimum dates precludes an accurate estimation, and the resulting marine reservoir estimation from Bayesian modelling is 320 - 809 years. The radiocarbon dating points of the Lower Sitka Sound core being far above the MEd also limit the precision of the MEd marine date, and so the accuracy of the marine reservoir estimate. However, we are confident that with new marine core dates and terrestrial minimum ages, the marine reservoir for this region could be greatly improved given the methods presented in this study. Once this has been achieved, there is great potential for deciphering the precise timing of rapid sea-level changes in this area, how they coincide with retreating ice and changing environment, and how these combine to present or preclude the possibility of a coastal migration route into North America.

65 Fig 3.1: Location map with approximate distribution of MEd tephra Riehle et al., 1992b)

Fig 3.2: Column Point peat core. UA numbers accompany tephras. #7080X numbers represent radiocarbon sampling points; numbers are University of California Irvine Accelerator Mass Spectrometry (UCIAMS) lab codes. EEEJ

W.1MI EXD7J Simplified Lithology

Fig 3.3: Lower Sitka Sound EW0408- 40JC marine core. High-resolution linescan imagery, simplified lithology and tephra sample positionsare shown. After Addison et al., 2010.

X" •JI O O O

, O <=> «> _ Cs <

i e> t o Co

n

Massive Mhogenc mud 5 e*-3?—K3-T5-; E3 Laminated diatomaceous mud <=> o ^ <* o [ Coarse to medium sand T »n. [3 Poorly sorted lithogertic mud & gravel N Massive votcanldastic mud

A i. y A (_ V A T Tephra sample -1 T ft-1 •> ftJ 1'" i « -j 'i i i 1 i . . i , Column Point AUAW4 A Trachydacite »UA1675 8 Rhyolite * °UA 1676 • UA1677 A* A • UA«78 A * *A 3 Lower Sitka Sound -n***^^ B B B *tfV° • y • • UA1797 ! 0 \ o UA1798

Fig 3.4: Total alkali silica plot containing all data points from the Column Point and Lower Sitka Sound. After Le Bas et al., 1986.

t9 T—i—i—i—r—i—i—i—i—i—i—i—r—i—i—»—i—i—r Column Point

Lower Sitka Sound Nflt

Fig 3.5: Plot of all analyses with fields that broadly define Type I and Type II tephras. After Preece et al., 1992.

68 Sample Si02 Ti02 AI203 FeOt MnO MgO CaO Na2Q K2Q CI H20d n Column Point UA1674 65.16 (0.63) 0.80 (0.06) 15.76 (0.28) 6.07 (0.30) 0.10(0.03) 1.66 (0.10) 4.89 (0.30) 4.40 (0.23) 1.05 (0.10) 0.09 (0.05) 2.15 (1.38) 48 UA1675 75.57 (0.82) 0.15 (0.06) 13.64 (0.44) 1.62 (0.22) 0.04 (0.03) 0.12 (0.04) 1.17(0.16) 4.35 (0.32) 3.25 (0.13) 0.08 (0.03) 3.01 (1.96) 15 UA1676 70.55 (0.54) 0.43 (0.03) 15.35 (0.27) 3.51 (0.13) 0.07 (0.04) 0.61 (0.03) 2.62 (0.11) 4.78 (0.23) 2.00 (0.04) 0.09 (0.02) 2.97 (2.05) 6 UA1677 64.19 (0.56) 0.98 (0.10) 16.56 (0.74) 5.63 (0.53) 0.11 (0.04) 1.44 (0.21) 4.43 (0.36) 5.18 (0.25) 1.40 (0.14) 0.08 (0.06) 1.73 (1.56) 41 UA1678 (1) 69.80 (0.38) 0.46 (0.05) 15.64 (0.25) 3.58(0.13) 0.07 (0.03) 0.69 (0.07) 2.76 (0.18) 4.96 (0.15) 1.93 (0.07) 0.10 (0.03) 1.90 (0.92) 15 UA1678 (II) 73.05 (0.46) 0.27 (0.03) 14.49 (0.26) 2.64(0.16) 0.04 (0.03) 0.27 (0.06) 1.78 (0.14) 4.92 (0.15) 2.41(0.11) 0.12 (0.06) 3.65 (1.68) 28 ID3506 73.47 (0.67) 0.07 (0.02) 13.16 (0.11) 1.65 (0.08) 0.06 (0.04) 0.05 (0.01) 0.76 (0.06) 3.97 (0.10) 5.05 (0.06) 0.34 (0.02) 1.43 (0.74) 31 Old Crow 75.33 (0.34) 0.30 (0.02) 13.06 (0.21) 1.76 (0.06) 0.06 (0.04) 0.29 (0.02) 1.51 (0.06) 3.74 (0.11) 3.66 (0.06) 0.28 (0.03) 4.18(1.03) 32 Lower Sitka Sound UA1797 73.51 (0.71) 0.27 (0.04) 14.32 (0.38) 2.60(0.13) 0.05 (0.04) 0.26 (0.04) 1.60 (0.18) 4.81 (0.18) 2.46(0.12) 0.14 (0.03) 3.50(1.32) 18 UA1798 73.28 (0.75) 0.28 (0.02) 14.45 (0.22) 2.69 (0.21) 0.05 (0.02) 0.28 (0.06) 1.73 (0.12) 4.77 (0.55) 2.35 (0.10) 0.15 (0.02) 3.50(1.32) 12 UA1799 72.77 (0.27) 0.28 (0.04) 14.52 (0.15) 2.73 (0.10) 0.07 (0.02) 0.30 (0.03) 1.82 (0.09) 5.06 (0.20) 2.35(0.11) 0.12 (0.02) 1.65 (1.61) 12 UA1800 73.09 (0.33) 0.27 (0.05) 14.41 (0.17) 2.74 (0.13) 0.06 (0.03) 0.29 (0.04) 1.72 (0.09) 4.92 (0.10) 2.37 (0.06) 0.14 (0.04) 2.95 (1.15) 16 UA1801 72.92 (0.51) 0.27 (0.04) 14.54 (0.31) 2.70 (0.10) 0.06 (0.03) 0.28 (0.04) 1.75 (0.13) 4.99 (0.31) 2.38 (0.10) 0.13 (0.03) 2.39 (1.10) 28 UA1802 73.20 (0.58) 0.29 (0.05) 14.34 (0.35) 2.66(0.10) 0.05 (0.03) 0.26 (0.05) 1.69 (0.14) 4.97 (0.28) 2.42 (0.11) 0.14 (0.03) 2.77(1.63) 23 UA1803 73.15 (0.54) 0.26 (0.03) 14.35 (0.33) 2.67(0.11) 0.06 (0.03) 0.28 (0.04) 1.72(0.16) 4.99 (0.31) 2.39 (0.10) 0.16 (0.03) 2.43 (1.22) 24 UA1804 73.15 (0.68) 0.27 (0.05) 14.47 (0.45) 2.70 (0.25) 0.06 (0.03) 0.27 (0.06) 1.66(0.21) 4.81 (0.29) 2.45 (0.19) 0.16 (0.06) 5.24 (5.77) 20 ID3506 72.43 (0.75) 0.08 (0.01) 13.25 (0.12) 1.62 (0.07) 0.07 (0.04) 0.05 (0.01) 0.73 (0.04) 4.13 (0.09) 5.05 (0.09) 0.33 (0.02) 2.27 (0.84) 39 Old Crow 74.99 (0.31) 0.31 (0.02) 13.38 (0.12) 1.79 (0.07) 0.06 (0.03) 0.28 (0.02) 1.46 (0.05) 3.70(0.16) 3.73 (0.10) 0.29 (0.02) 6.98 (1.82) 34

Table 3.1: Normalized mean major-element compositions of tephra glasses. Standard deviations of the normalized values are given in parentheses; FeOt is total iron oxide as FeO; n=number of analyses; H20d is estimated water by difference.

69 Sample SC Lab number Location Notes Reference UA 1676 0.97 ACT 2022b Kruzof Island MEd proximal Beget and Motyka, 1998 0.96 19-A2 Kruzof Island Distal rhyolite Riehle etal., 1992b 0.95 2R112b Kruzof Island Pyroclastics Riehle et al., 1992b 0.95 2R136y Kruzof Island Rhyolitic fallout Riehle etal., 1992b 0.95 ACT 2073 Juneau MEd distal Beget and Motyka, 1998 UA 1678 (1) 0.97 ACT 2022 b Kruzof Island MEd proximal Beget and Motyka, 1998 0.95 2R112b Kruzof Island Pyroclastics Riehle etal., 1992b 0.94 19-A2 Kruzof Island Distal rhyolite Riehle etal., 1992b 0.94 IR75b Kruzof Island Proximal dacite Riehle etal., 1992b 0.93 ACT 2073 Juneau MEd distal Beget and Motyka, 1998 UA 1678 (II) 0.99 UA 1802 Lower Sitka Sound MEVF This study 0.98 UA 1804 Lower Sitka Sound MEVF This study 0.98 UA 1798 Lower Sitka Sound MEVF This study 0.98 UA 1803 Lower Sitka Sound MEVF This study 0.98 UA 1801 Lower Sitka Sound MEVF This study 0.97 UA 1800 Lower Sitka Sound MEVF This study 0.97 UA 1799 Lower Sitka Sound MEVF This study 0.97 UA 1797 Lower Sitka Sound MEVF This study 0.96 EW0408-40JC 10.29 Lower Sitka Sound MEVF Addison etal., 2010 0.95 EW0408-40JC -11.10 Lower Sitka Sound MEVF Addison et al., 2010

Table 3.2: Preliminary SC matches to MEVF tephras. (I) and (II) represent dacitic and rhyolitic populations respectively.

70 MEd: Fig 3.6: Tephras from this A UA1678 study plotted against a field • UA1797 0 40JC-9.08m data representing MEd, compiled O 40JC-9.06m from all MEd data from Riehle et al., 1992b, and Beget and Reference data ^> Motyka, 1998. *=Refers to data from Addison et al., 2010; the diamonds are raw data points normalized here, and the circles are the published

1 —I—I— T—r—-j— T—i—r 1 1 -1—i—i—i—

- - — f ^

CaO 2

- =?Bn 1 -- - O O __l JL. 1_ i i 1 J_.._i_.,...l. .,_L.„„_L. 80 65 70 75 80 Lab Radiocarbon Simple calibrated Depth sequenced Description Dated material number age(14CyrsBP) age (cal yr BP) age (cal yr BP)

Standards 70795 49,850 ± 210 Queets A-l FIRI-D-1 70818 4540 ± 70 .040mgC 70819 4510 ± 20 FIRI-D-2 70820 11,800 ± 35 IAEA-C5 Core depth (cm) 70800 11,340 + 40 13,319-13,119 13,258-13,107 4 Woody fragments 70801 11,210 + 45 13,264 -12,921 13,292-13,134 12.5 Grassy fragments 70802 11,985 ± 35 13,966-13,734 13,942 -13,734 21 Twig 70803 12,120 ± 35 14,118-13,820 14,054 -13,839 22.5 Woody fragments 70804 12,220 ± 35 14,464-13,878 14,164-13,947 25.5 Woody fragments 70805 12,280 ± 35 14,820 -13,964 14,453 -14,001 30 Woody fragments

Table 3.3: Radiocarbon determination for the core. Lab numbers are UCIAMS-XXXXX.

Tephra unit Depth sequenced age P-Sequenced age Bacon age (cal yr BP) (cal yr BP) (cal yr BP) UA 1678 > 13,260 13,310 -13,090 13,890-13,195 UA 1677 14,055 -13,735 13,980 -13,845 14,035 -13,830 UA 1676 14,165 -13,945 14,135-13,970 14,080-13,915 UA 1675 14,455 -13,945 14,155-13,990 14,090 -13,920 UA 1674 < 14,455 14,180-14,005 14,100 -13,930 UA 1797 13,480 -13,405 13,495 -13,240 N.D. UA 1798 13,550 -13,475 13,570 -13,280 N.D. UA 1799 13,570 -13,495 13,590 -13,295 N.D. UA 1800 13,600 -13,525 13,620-13,310 N.D. UA 1801 13,260 -13,545 13,640 -13,235 N.D. UA 1802 13.655 -13,580 13,675 -13,435 N.D. UA 1803 13,680 -13,605 13,705 -13.360 N.D. UA 1804 13,680 -13,605 13,075 -13.358 N.D.

Table 3.4: Calibrated age estimates for the tephra units in Column Point and Lower Sitka Sound cores. N.D.= Not Determined.

72 Lab Age (14C Error Location Material Reference Maximum ages B-77056 11230 70 Greentop Peat Beget and Motyka B-77054 11350 70 Greentop Peat Beget and Motyka B-82660 11310 60 Kruzoff Alder Beget and Motyka B-77053 11340 170 Kruzoff Alder Beget and Motyka B-77051 11040 80 Kruzoff Charcoal Beget and Motyka UCIAMS- 11340 40 Column Wood This study Minimum ages Montana 11230 400 Montana Bulk peat Riehle etal.,

Table 3.5: Radiocarbon dates used for Bayesian analysis of MEd deposition.

3.10 References

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Bishop Ash, a Pleistocene marker bed, using instrumental neutron activation analysis.

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Greene, H.G., O'Connell, V.M., Wakefield, W.W., Brylinsky, C.K., 2007. The Offshore

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75 Mandryk, C.A.S., Josenhans, H., Fedje, D.W., Mathewews, R.W., 2001. Late

Quaternary paleoenvironments of Northwestern North America: implications for inland versus coastal migration routes. Quaternary Science Reviews 20, 301-314.

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77 CHAPTER 4 -TEPHROCHRONOLOGY OF THE PROSPECTOR RUSSELL

COL ICE CORE, MOUNT LOGAN

4.1 Introduction

Ice cores provide some of the highest resolution archives of past climate available.

They can provide records of past temperatures, trace gas compositions and atmospheric pollution, among things (e.g., Fischer et al., 1999; Petit et al., 1999; Bender et al., 1997;

Vallelonga et al., 2002; Isaksson et al., 2003). The value of these records, however, is only realized when an accurate and robust age model for the core is available. For many polar ice cores (e.g. Dye 3, GRIP/GISP and NGRIP for Greenland; Vostok for Antarctica), annual resolution is available through differences in seasonal snowfall and resulting density of ice (e.g. Vinther et al., 2006; Ruddiman et al., 2003). In many areas outside of

Greenland and Antarctica, however, ice cores lack annual resolution or may be affected by melt events precluding annual chronologies. Core chronologies therefore rely on dating methods that create tie-points to constrain ice-flow model ages (Fisher et al.,

2004).

78 Mt Logan is the highest mountain in Canada, lying at the border between the Yukon and Alaska in the St. Elias Range (Fig 4.1). Near the top of the Mount Logan massif is a 5

400 m asl plateau with several peaks, the tallest of which is Mount Logan. Low annual temperatures reduce the possibility for melt events and the flat plateau surrounded by peaks restricts the impact of wind on accumulation. These factors suggest the area has probably been stable throughout the Holocene and creates an ideal target location for high-quality ice cores. Three short cores have been taken in the area (NW Col, Eclipse and King Col - Holdsworth et al., 1992; Yalcin and Wake, 2001; Yalcin et al., 2006) reaching between 300 - 1000 years before present (yrs BP). A 188 m long core, referred to as the Prospector Russell Col (PR Col) ice core, was drilled to bedrock by the

Geological Survey of Canada during the summers of 2001 and 2002, that extends to approximately 30,000 yrs BP (Fisher et al., 2004). The drill site was chosen to approximate a flow centre, and it is estimated that only the bottom ~5% is affected by flow discontinuities (Fisher et al., 2004).

The PR Col core is annually resolved for only the first 300 years. A detailed account of the age modeling can be found in Fisher et al. (2008). Layer counting was used until

~110 m depth, marking the first ca. 300 years. The resulting timescale was tested against the earlier timescale of another ice core from Mt Logan, the NW Col ice core

(Holdsworth et al. 1992), and against the known dates of large eruptions such as Katmai in 1912. The deepest tie-point is the transition into late Pleistocene ice marked by the strong shift in oxygen isotopes referenced to the age marked in the Greenland ice cores at 11,703 cal yrs BP (GICC05 integrated Greenland timescale: Johnsen et al., 1997;

Vinther et al., 2006). Between the annually-counted layers and the transition, sulfate peaks are used. Volcanic sulfate peaks are distinguished from sulfate peaks from ocean

79 salt or continental mineral dust by the absence of associated calcium peaks. The peaks were then attributed to large North Pacific eruptions and given ages according to the

Smithsonian online database (Smithsonian, 2007). In particular, the Eastern lobe of the

White River Ash was used as a major tie-point due to its prevalence in the Yukon, given the precise date of 803 AD (Clague et al., 1995). Volcanic eruptions match the theoretical timescale relatively well until a period of poor core quality between ca. 7500

- 9500 years BP (Fisher et al., 2008). The entire core was analysed for delta 180,

electrical conductivity (ECM; 5 mm resolution), calcium and sulfate (S04; annual resolution for the first 300 years; 25-year resolution thereafter) (Fig 4.2).

Volcanic eruptions are often used as tie-points to constrain ice core age-depth models. However, as in the PR Col age model, these are usually correlated by matching sulfate peaks to records of large local or global eruptions. Searching for glass shards within the ice core where sulfate peaks occur can provide confirmation of these correlations if the glass geochemistry can be matched to the appropriate eruption. This study aims to identify the glass chemistry of shards of cryptotephra (invisible to the naked eye) from four sections of the PR Col core that have been correlated to eruptions from southern Alaska based on sulfate and ECM data. The sections investigated span approximately 1100 - 4800 yrs BP. The youngest section of this span was chosen to include the suspected White River Ash eastern lobe eruption (WRE) that formed an important tie-point in the original age-depth model. Beyond this, the record of large

Holocene eruptions was used exclusively to match sulfate peaks to events, until the oxygen isotope transition. However, three other large local eruptions are suspected in the target age range: the northern lobe of the White River Ash (WRN, ca 1700-1900 yrs

BP), the caldera-forming eruption of Aniakchak (ca. 3600 yrs BP), and the closely-spaced

80 series of tephras from Hayes volcano (termed Hayes Tephra Set H; Riehle, 1994) (Fig

4.1). Given that a tephra is identified in the core, the age predicted by the current PR Col

age-depth model for that eruption is then compared to terrestrial radiocarbon dates.

Existing radiocarbon dates are combined into a Bayesian statistical model for each

eruption in order to determine the most likely age range of the tephra independent of the ice core age. In this way, we aim to either confirm the age-depth model, or determine where differences exist and the model may need to be adjusted. Through this

process, we hope to increase the confidence of the PR Col ice core age model and its

inferences about changing atmospheric conditions during the Holocene.

4.2 PR Col sampling and geochemical analysis

The depth - sulphate and electro-conductivity measurement (ECM) plots and sections sampled for each target event are given in Fig 4.3 and Table 4.1. For each plot, the ECM is at 5 mm resolution and the sulphate is at 25-year resolution. Sulphate peaks are thus less well-defined. The suspected WRE interval (around 158 m depth) has a clearly defined ECM peak and corresponding sulphate peak, separating it from the surrounding record. The area of the suspected WRN peak in both records is less pronounced, so a larger section of the core was sampled for analysis (around 165-168 m depth). The Aniakchak tephra and Hayes Tephra Set H are closely spaced in time. The suspected Aniakchak event is younger, and has a more pronounced spike in both ECM and sulphate; the probable Hayes tephra set has several closely-spaced sulphate peaks, but no corresponding pattern is seen in the ECM record. At this depth in the core

(around 176 - 178 m) the resolution is coarser than at the White River interval depths;

81 ~30 years per sample compared to ~3 years per sample, respectively. Fewer samples were thus taken for Aniakchak and Hayes Tephra Set H to cover the ECM and sulphate

peaks.

The target regions in the PR Col ice core were sampled by Steve Kuehn at the

Geological Survey of Canada office in Ottawa. They were then evaporated in a High-

Efficiency Particulate Air (HEPA)-filtered oven to reduce the water volume to 10-15 mL

before being centrifuged at the University of Alberta to remove excess water and concentrate particles. Core section particulates were prepared for analysis by electron

microprobe (EPMA) following the method of Kuehn and Froese (2010), designed to concentrate tephra particles on a low-relief surface for optimal microprobe analyses (Fig

4.4). In this technique, samples are pipetted into acrylic pucks mounted onto smooth graphite blocks, and evaporated within a laminar flow hood. Once the water has been evaporated, pucks were topped with epoxy and removed from the graphite block for polishing. Reference marks are then scored into the puck, so that shards can be re­ located later for additional analyses.

Earlier tests, such as when searching for the 1947 Hekla eruption and the 1912

Katmai eruption, revealed that the mounting epoxy has been contaminated from two tephras also being prepared in the University of Alberta tephrochronology lab (Kuehn, pers. comm., 2010; Appendix I). These were Glacier Peak (Kuehn et al., 2009) and Old

Crow (Preece et al., 2011) tephras. The WRE and WRN samples were prepared for this study at this time and may be affected by the contamination. However, these contaminating shards can be identified by their distinctive geochemistry, and all samples that have been analysed in the University of Alberta tephra lab were queried against the

82 results of this study; only points that are clearly distinct are considered here. The

Aniakchak and Hayes samples were prepared in a clean lab at the University of Alberta with a laminar flow hood, separately from other tephra preparations.

Since many of the shards are exceptionally small, a 5 u,m beam was used on the

University of Alberta's Cameca SX100 electron microprobe, with a 15-kV accelerating voltage and a 3-nA beam current. Standardization of the microprobe was achieved with glass and mineral standards, and instrument operation was checked periodically during analyses with use of well-characterized secondary standards; Lipari obsidian and Old

Crow tephras (Beget and Keskinen, 2003; Kuehn et al., in press). Individual analyses that had totals above 85 wt % are reported as average oxide values normalised to 100%.

Analyses with reported totals of less than 85% (due primarily to water loss from glass hydration rinds, or in which the beam was not centred on the shard) were excluded from the final dataset, as were analyses with obvious inclusions of phenocrysts.

Thirty-seven samples were analysed, and of these, 20 contained volcanic glass shards (Table 4.1). The suspected WRE and WRN intervals had clusters of samples with high numbers of shards, whereas the shards in the Aniakchak and Hayes intervals were more dispersed.

4.2.1 White River Ash

The White River Ash is the result of two separate eruptions (Volcanic Explosivity

Index of 6) of Mt Churchill (Richter et al., 1995; Fig 4.1). The smaller, northern lobe was erupted around 1700 14C years BP, straddling the border between Alaska and the Yukon

83 Territory (Lerbekmo and Campbell, 1969). The larger eastern lobe, with an estimated volume of 47 km3 (Lerbekmo 2008), was erupted around 1250 14C years BP and extends across Yukon Territory, into the Northwest Territories and northern British Columbia

(Lakeman et al., 2008).

Reference samples of White River East (WRE) show a relatively large compositional range (Clague et al., 1995; Lerbekmo 2008). In the target PR Col depths, 32 glass shards were recovered across two sections (L240-7 and L240-9). Two populations of glass shard geochemistry were identified, however the low-Si population had only 6 shards, and does not plot within the compositional range of any known eruptions, and likely represents an unknown eruption. The higher-Si shards plot alongside Glacier Peak reference samples (red symbols in Fig 4.5) and are considered contamination. The remaining 17 shards are plotted against the reference samples in Fig 4.5, and appear to be a good match. L240-9 contains only 3 shards within the range of the WRE reference data, and all of them lie at the lower-Si range. L240-7 contains 15 shards spread throughout the range of reference data, and marks the WRE eruption.

The White River North (WRN) tephra has a wider compositional range than WRE.

Although many core sections in the sulphate peak area (Fig 4.3) yielded glass shards, only L251-7, with 28 shards, plots closely with the reference data (Fig 4.6). Most of the shards obtained for all samples plot on trend with WRN in a Si-Al bivariate plot (Fig

4.6a), but there is a clear separation between samples in Si-Ca and Si-Na bivariate plots

(Fig 4.6b and 4.6d). In these, all but L251-7 fall off the trend and plot distinct profiles from the reference data. L251-7 shards have a relatively flat K profile with increasing Si, whereas the reference data increase in K with increasing Si. The two fields overlap at the

84 low-Si range, and the lesser K at the high-Si end of the range in L251-7 may be due to small K loss during analysis. L251-7 shards plot closest with WRN reference material and do not overlap with any possible lab contaminants, and so it is likely derived from Mt

Churchill and may well represent the WRN eruption.

4.2.2 Aniakchak

The Aniakchak volcano is a 10 km-wide caldera that formed approximately 3400 cal yrs BP (Beget et al., 1992). This eruption expelled more than 5 x 1010 m3 of material in a northerly direction (Fig 4.1). Aniakchak has a characteristic bimodal composition, with low- and high- Si populations (58-60 and 70-73 wt % respectively). Despite the strong northerly distribution of the visible tephra fallout, cryptotephra particles have been found in the GRIP ice core (Pearce et al., 2004), dated at 1645 ± 4 AD (3591 - 3599 cal yrs BP)

The bimodal nature of the distal tephra is a key feature in identifying the

Aniakchak tephra. Only 3 samples contained glass shards, and of these, only L267-1 has both populations (Fig 4.7). L267-1 has 4 shards that plot with the low-Si population and one that plots with the high-Si population. L266-3 and L266-1 each have 4 shards that plot with the high-Si population. No samples below L267-1 contain glass shards. It is unlikely material would be dispersed downwards in the snow pack from a high elevation site like PR Col, so we consider L267-1 to mark the first arrival of the Aniakchak tephra and the best approximation of the eruption event.

85 4.2.3 Hayes Tephra Set H

The Hayes volcano produced at least seven or eight closely-spaced eruptions

between 3800 - 3500yrs BP (Riehle 1994). Two main lobes exist, to the south and to the

northeast of the volcano (Fig 4.1). In the northeast lobe, three different tephra beds

have been identified and named the Jarvis Creek Ash, the Cantwell Ash and the Tangle

Lakes Ash (Pewe 1975, Bowers 1979, Beget et al., 1991). However, these beds are

compositionally similar compared to the large compositional range in the proximal

deposits (Riehle 1994). Riehle (1994) suggested a correlation between the northeast

lobe tephras and the oldest of the proximal deposits and in lieu of separate names

proposed that the series of tephras be termed Tephra Set H.

A wide compositional range is observed in the PR Col core glass shards across a long

section of ice ( ~1 m), possibly representing the entire span of the tephra set. For this

study, a sample of tephra from the Jarvis Creek type site was collected (UA 1811 in Fig

4.8, from the Jarvis Creek location in Fig 4.9) for direct comparison to the PR Col cryptotephra. This sample plots closely with the Hayes Tephra Set H reference data, overlapping with the northeast lobe tephras at the higher Si-range (Fig 4.8). The PR Col cyptotephras also span a lower Si - higher Al range that is consistent with some of the younger Hayes proximal deposits. Another site visited for this study (Nenana location in

Fig 4.9) found one high-Si and one low-Si tephra in a stratigraphic sequence (Fig 4.10), also plotted in Fig 4.8 (UA 1815 and UA 1814 respectively). The sequence supports a trend in the Hayes tephra set of decreasing Si and increasing Al through the eruption set. The PR Col tephras also span this trend, but do not represent any coherent

86 sequence. More work needs to be done on these beds to make the connection between

Hayes Tephra Set H and the PR Col record clear.

4.3 Bayesian statistical age modeling

Radiocarbon dates are rarely used individually, especially when they are needed to constrain the age of a tephra bed. Traditionally, tephra age models have been based on the close association of radiocarbon dated materials and the tephra (e.g. Clague et al.,

2005; Froese et al., 2002). Another approach is the use of Bayesian statistics, which allows additional information that may be available to be formally included in age models. For example, information about how the dates relate to each other or the physical properties of the sediment can be included. In this way prior information can help constrain dates that may otherwise have large and uncertain ranges. For example if dates are above or below a tephra, they bound the possible tephra deposition as minimum or maximum dates respectively.

When constructing a Bayesian statistical model, raw 14C dates and any stratigraphic or physical information form the Priori. The basic model used throughout this paper is a

Phase model, constructed in OxCal 4.1 (Bronk Ramsey 2009a) where dates from many locations are placed either in a pre-emption or post-eruption phase. The dates are unordered within the phase, but the phases are in chronological order compared to each other, from oldest to youngest. The groups are separated by Boundaries, which are calculated by the model. The boundary between the pre- and post-eruption phases thus defines the modelled age distribution of the eruption. Priori information is used to produce a Posterior distribution for each date. In OxCal, this distribution is compared to

87 the distribution that would result if the date had been calibrated individually, and not within a model. Depending on the amount of overlap (reported as a percentage termed the Agreement Index, Al), an individual date may be improved by the Bayesian constraints (Al > 100%), or may be considered an outlier (Al < 60%). Too many outliers will force the entire model below the accepted threshold of 60%. The 60% threshold is somewhat arbitrary, and approximately one in twenty dates are likely to fall below this threshold, so that other criteria should be considered when rejecting a date from a model (Bronk Ramsey 2009b).

Outliers can be determined either based on uncertainties in the calibration curve, or by context, i.e. whether that date is actually related to the same thing as the other dates in the phase. Therefore, in order to improve outlier analysis, we use a simple outlier model within the phase model (Bronk Ramsey 2008). The model defines the dates as a Student's t distribution with 5 degrees of freedom (longer tails than a normal distribution), and gives the scale of dates within a range of 1-10,000 years, where the analysis determines the appropriate scale. Finally, the type of outliers is defined as in the time variable, as opposed to outliers in 14C ratio or concentration; i.e. that the outlier is out of sequence rather than a poor analytical result. Once the model is defined in this way, each date is given the probability of being an outlier; typically 1 chance in

20.

This basic model is used for each of the tephras in question in this study, except for the Hayes tephra set H. In this case, many interpolated dates exist within sediment cores, but very few dates exist close enough to the tephra to be considered reliable maximum or minimum ages. In this case, a different model was used, an Equals model

88 that includes all dates for each core. The tephra is given a name within a date query that is repeated in each core after an "=" sign. This forces the tephra to be modelled as the same age, while considering all the surrounding sediment core age data. All dates used in the phase models are presented in Table 4.2, while the data from the sediment cores used for Hayes tephra set H are presented in Table 4.3.

4.3.1 White River Ash

The age of the WRE eruption is often reported as 803 AD (Clague et al., 1995), however this represents an intercept age of the mode of the age distribution, and ignores the inherent uncertainties of 14C dating and calibration. Several maximum 14C dates exist for the WRE eruption, but few minimum dates have been determined.

Clague et al. (1995) collected a tree stump buried by the ash and presumably killed by the eruption. By dating two sections of tree rings, the possibility exists for wiggle-match dating, a calibration method that attempts to match the varying 14C concentrations in consecutive years recorded in tree rings to variations in the calibration curve. With only two sections of the stump dated, and with a reasonably large gap in age between the two, the modelled date of the eruption is not perfectly constrained. However, the modelled age of the tree's death, and hence the inferred eruption age is 1238-1096 cal years BP (Fig 4.11).

We still cannot be certain that the tree was killed at the time of the eruption, so other terrestrial dates are incorporated into a phase model. The tree date is included as a calendar date not to be further calibrated, placed alongside the eruption boundary as an estimate of its timing. The outlier analysis returned no probable outliers, so the first

89 result was accepted. This model gives an eruption date in the range 1240 - 1040 cal

years BP, or approximately 810 AD ± 100 (Fig 4.12). This is consistent with the PR Col age

of 787 AD ± 12.

Many of the 14C dates available for WRN were determined before the revolution in

AMS dating that has led to more precise ages. However, several previously unpublished

dates on tree stumps in association with the tephra were used in constructing the phase

model (Froese unpub; Reyes and Froese unpub). Initial outlier analysis flagged two of the dates published in the 1960s: 1-275 and 1-6466. A second run flagged WK-8888 and

Y-2303; a third flagged 1-7572 and GSC-400; and a final run returned an eruption age of

1705 -1610 cal yrs BP (Fig 4.13). All but one of these dates were analysed before 1980, and the other (WK-8888; Froese unpub.) was rejected by the authors while modelling the WRN eruption. All of these flagged dates were thus consequently removed before the subsequent model run. This is consistent with the range that WRN shards were found in the PR Col core (sample L251-7; 1640 -1665 cal yrs BP).

4.3.2 Aniakchak

Many 14C ages for the Aniakchak caldera-forming eruption exist, but they vary widely (Table 4.2). Outlier analysis determined five dates as likely outliers. These were removed before a second run of the model with outlier analysis was run. From this second run, three dates were still deemed to be outliers. In this last run, the dates remaining to make the model with were 1-14236, B-19643 and NSRL-12336 for the pre­ emption phase, and W-3125, 1-14221, 1-14226, W-3466, W-4052 and 1-14228 for the post-eruption phase, providing an eruption date range of 3945 - 3690 cal yrs BP (Fig

90 4.14). This is considerably older than the age determined in the GRIP core of approximately 3595 cal yrs BP. The estimated age of the tephra from the PR Col core model is 3830 - 3515 cal yrs BP, which overlaps with the terrestrial age determination.

4.3.3 Hayes tephra set H

Tephras with characteristics similar to the Jarvis Creek Ash, either in geochemistry or mineralogy, have been identified at several sites in Alaska. Radiocarbon dates taken from these sites generally are not close enough to the tephra itself to be useful as true maximum or minimum dates, so the equals models was used instead. Where individual dates do exist, they are placed in short "cores" made up of the unknown tephra and the date(s) of that site (Table 4.3). The result of the core matching is shown in Fig 4.15. The core describing the Cantwell Ash (Beget et al., 1991) has most of its dates out of order and is inconsistent with most of the other cores. The dates identified as outliers in this core were removed and left a wide possible range for the eruption. However, when combined with all the other cores, an age with very few outliers in single cores was established of 4065 - 3810 cal yrs BP. This is at the older end of the published age range for the tephra set (of ~3800 yrs BP; Riehle et al., 1990), but is at the younger end of the range determined from the PR Col model (4050 - 4830 yrs BP).

4.4 Discussion

All target sections analysed contained at least two samples that produced volcanic glass. Within these, one or more samples contained glass that can be considered

91 correlative with the eruption in question: 15 shards in L240-7 for WRE; 28 shards in

L251-7 for the probable WRN; L267-1 for Aniakchak contained 5 shards covering both populations; and 12 shards over 5 samples for Hayes (L269-1, L269-3, L269-6, L270-3,

L270-4).

4.4.1 White River Ash

Glass shards with a major element geochemistry matching WRE reference samples have been identified at the target depth (~158m depth) in the PR Col core. This is consistent with the preliminary sulphate peak match based on large Pacific eruption records alone. The terrestrial dates agree well with the suggested age in the PR Col core, so this correlation is consistent with the existing ice core age model. The identification and dating of WRE makes the tephra a good tie-point for records across northwestern

North America. The possibility exists even to extend the use of WRE across northeastern

North America with cryptotephra, and a preliminary study has already shown promising results for eastern North America (Pyne O'Donnell, 2011).

Shards with a major element geochemistry similar to other Mount Churchill sourced ashes were found in just one sample associated with the suspected WRN sulphate peak, and the date is within the younger range of the terrestrial dates (L251-7 at 1640 - 1665 yrs BP). Less reference geochemical data exist for WRN than WRE, and the data are quite dispersed, but these preliminary data suggests a possible match geochemically and chronologically. Each date in the phase model has two peaks in the probable date range due to multiple peaks in the calibration curve, leaving the eruption also with two peaks (Fig 4.13). In this case, if the geochemistry can be more confidently

92 correlated to WRN, and the PR Col age model is further confirmed, the opportunity

exists to use the ice core model to calibrate the terrestrial radiocarbon dates more

precisely.

4.4.2 Aniakchak

The ages from terrestrial dates alone suggest that it is significantly older than the age that proposed on the basis of the GRIP ice core (3945 - 3690 and 3595 ± 4 cal yrs BP

respectively). The terrestrial age model agrees with the PR Col model (3830 - 3515 cal yrs BP, or 3765 - 3795 cal yrs BP if sample L267-1 is taken as the first arrival of the ash).

However the PR Col core is less well resolved than the GRIP ice core, so there remains a

possible discrepancy with the independent ages. The geochemistry of the Aniakchak glass in GRIP is determined from analytical scanning electron microscope (ASEM) analyses (Hammer et al., 2003). This technique produces a more scattered dataset, but does seem to correlate with reference samples analysed with EMPA (Denton and

Pearce, 2008). Eight single-shard trace element analyses were performed using secondary ion mass spectrometry (SIMS) and compare favourably to Aniakchak reference data (Hammer et al., 2003; Pearce et al., 2004).The identification of the

Aniakchak tephra in GRIP is relatively robust, so it is likely that the problem lies somewhere in the age determinations. The terrestrial ages vary across a wide age range, and it may be that not enough high-quality radiocarbon ages exist. The GRIP core chronology has been integrated with the Dye-3 and NGRIP Greenland cores (Vinther et al., 2006) and the age-depth model has been confirmed across several proxy records

(e.g. Muscheler et al., 2004; Bohncke and Hoek, 2007; Vinther et al., 2008). The most

93 recent calibration method, to 6 -Centurty tree rings, proposed a change to the

chronology of only seven years; too little to account for the discrepancy (Baillie, 2008).

A new age estimate based on sedimentation models for several lake cores in the

Ahkulan Mountains, southwestern Alaska, places the Aniakchak eruption at 3685 ± 100

cal yrs BP (Kaufman et al., in press); older than the GRIP age, at the young end of the terrestrial age model estimate, and older than the PR Col age of sample L267-1. More work clearly needs to be done to obtain high-precision terrestrial dates that bound the

Aniakchak tephra and resolve the age discrepancies. At this time, the identification of

Aniakchak tephra in PR Col cannot confirm the age model.

4.4.3 Hayes Tephra Set H

From proximal deposits and geochemical data from a site visited for this study, there seems to be a trend of decreasing Si and increasing Al as the deposits get younger.

The site has two laterally consistent tephras in stratigraphic sequence (Fig 4.10).

Although several radiocarbon samples were prepared from this site, they were unfortunately ruined in transit and no reliable age determination could be constructed for the sequence. Although we cannot place absolute dates on these tephras, the sequence shows the same pattern of geochemical trend over the two tephras: the bottom UA 1815 has higher SI and lower Al, where the top UA 1814 has the opposite profile (Fig 4.8).The PR Col tephras include both populations of glass, but do not seem to show a consistent trend over time, the populations scattered over the extent of the core sections sampled. Additional probing of the PR Col samples may produce more glass shards with a stronger pattern, or alternatively the populations could be teased apart

94 using trace-element analysis to provide further lines of evidence for a trend through

time. The core was not sampled for 3 cm below L240-7, the lowest Hayes sample that

contained glass, and sampling the core at this depth may produce more Hayes shards

and pinpoint the first arrival of the tephra set to Mt Logan.

Despite the proximal Hayes deposits showing seven distinct eruptions, the terrestrial age model of Hayes-like tephras is remarkably tight (4065 - 3810). However,

all the cores used in the model were northeast from the volcano, and therefore likely

only capture the oldest phase of the tephra set. Even so, the modelled age of this lobe

of the set is older than published ranges, and further work should investigate if the same can be said of the younger, more southerly tephras in the set.

4.5 Conclusions

Four regions of the PR Col ice core with large sulphate peaks have been investigated for tephras with geochemistries matching those of their suspected causative eruptions. All regions have produced volcanic glass, but we are only confident in two matches; those of the White River Ash eastern lobe and the Aniakchak caldera- forming eruption. Comparison of the modelled ice-core ages to estimates of the terrestrial ages in a Bayesian statistical framework is consistent for WRE, but has significant discrepancies for Aniakchak. These discrepancies are reinforced when the estimated age of the Aniakchak eruption in the GRIP ice core is considered.

The suspected White River Ash northern lobe sulphate peak produced tephra with a geochemistry likely from Mt Churchill, the source of the White River Ash, but we

95 cannot say for certain whether it is from the northern lobe eruption. The PR Col age model and terrestrial determination overlap, although over a relatively wide range of terrestrial dates, with two distinct peaks.

The Hayes Tephra Set H poses a challenge for precise age determination, since there are several closely-spaced eruptions. There appears to be a geochemical trend as the eruptions progress, and although the variation is expressed in the PR Col record, the pattern is not consistent. Further groundwork and ice-core investigation is needed to tease out the eruption sequence, but we can be quite certain that some portion of the set is represented in the ice core, at a comparable age to the terrestrial tephras.

The positive correlation and age match for WRE confirms the PR Col age model for that depth; around 1150 cal yrs BP. However, this is the only section at present that we can provide independent confirmation of, since the other sections face questions either of their geochemistry (for WRN), their age determination compared to other records

(for Aniakchak) or both (for Hayes Tephra Set H).

96 Fig 4.1: Location map of the volcanoes and associated tephra deposit distributions used in this study. Mt Logan is also shown, the origin of the PR Col ice core. Tephra ranges: WRN: Lerbekmo, 2008; WRE: Lakeman et al., 2008; Aniakchak: Beget et al., 1992; Hayes: Riehle et al., 1990 (limit is 1 cm isopach).

97 2 4 6 8 10 12 14 16 i I i i i I i I i 1 i I • I i • _og

a

b

c

d

^-30 "O o c 600 - <, CD n 0 Q- 400 c o t 5 200 f E | VMJWJM^ CO 0 ""' Y1 4 ' 6^1 10 12 14 Thousands of real years BP («rt *o sown

Fig 4.2: The Holocene of PRCol, Mt Logan using the timescale described in the text, (a) The oxygen isotope (d 180) profile, (b) the S04 and Ca++ concentrations in ppb (parts per billion by mass), (c) Large volcanic eruptions in Alaska, Aleutian Islands and Kamchatka Peninisula, taken from the Smithsonian Volcanic Explosivity Index listing, (d) Shows 25-yr averages of the GISP2 volcanic sulfate record (Zielinski et al., 1997). (e) GISP2 d 180 record (Stuiver er al., 1997) and (f) the GISP2 total sulfate record (Zielinski et o/.,1997). The grey bar in (b) indicates where core quality was poor. After Fisher et al., 2008.

98 75.00 10 WRE ^ 70.00 9 •"*• 8 65.00 • • • 7 a. 60.00 • _a • • • • 6 « 55.00 • • • 5 j|U[k;j.i •ECM ifli Ik tii 2 45.00 fe.1'Aj'uJi Lrim'jflL 1 I' 40.00 I JUE1IL 0 35.00155.0 0 156.00 157.00 158.00 159.00 160.00 Depth (cm)

85.00 WRN 10 80.00 9 75.00 8 2- 70.00 7 £ 65.00 6 aj 60.00 5 I 55.00 4 Sulfate % 50.00 3 •ECM 45.00 SSI 2 40.00 LViTi'M^I^UiVMVIiil 1 »M »• i ,f 35.00 %± r i • 0 165.00 165.50 166.00 166.50 167.00 167.50 168.00 Depth (cm)

250.00 Aniakchak Hayes tephra set H 200.00 31 a 150.00 at J2 100.00 Sulfate 3 •ECM 50.00

0.00 175.00 175.50 176.00 176.50 177.00 177.50 178.00 Depth (cm)

Fig 4.3: ECM and sulphate plots for target intervals; a) White River East; b) White River North; c) Aniakchak and Hayes Tephra Set H. Event Sample No. Depth to top Depth to bottom Age (yrs BP) (m) (m) White River East L240-5 157.93 158.00 1152 -1153 No shards L240-6 158.00 158.06 1153 -1155 No shards L240-7 158.06 158.12 1155 -1158 19 L240-8 158.12 158.18 1158-1161 No shards L240-9 158.18 158.24 1161 -1163 12 L240-10 158.24 158.30 1163 -1166 No shards L240-11 158.30 158.36 1166 -1169 No shards White River North L249-7/250-1 165.54 165.67 1590 -1594 8 L250-2 165.67 165.80 1594 -1599 3 L251-1 165.80 165.91 1599 -1603 Not analysed L251-2 165.91 166.02 1603 -1607 Not analysed L251-3 166.02 166.14 1607 -1616 Not analysed L251-4 166.14 166.25 1616 -1624 Not analysed L251-5 166.25 166.36 1624 -1632 8 L251-6 166.36 166.47 1632 -1640 10 L251-7 / 252-1 166.47 166.61 1640 -1665 28 L252-2 166.61 166.75 1665 -1670 21 L252-3 166.75 166.89 1670 -1675 15 basaltic L252-4 166.89 167.04 1675 -1683 No shards L252-5 167.04 167.18 1683 -1693 3 L252-6 167.18 167.32 1693 -1704 3 L252-7/253-1 167.32 167.45 1704 -1714 No shards Aniakchak L265/266-1 175.24 175.41 3513 - 3432 4 L266-2 175.41 175.58 3432 - 3716 No shards L266-3 175.58 175.75 3716 - 3763 4 L266-4/267-1 175.75 175.87 3763 - 3796 5 L267-2 175.87 175.94 3796 - 3815 No shards L267-3 175.94 176.00 3815-3831 No shards No sampling done between these intervals Hayes Set H L268-1/269-1 176.35 176.53 4052 - 4338 4 L269-2 176.53 176.61 4338 - 4367 No shards L269-3 176.61 176.69 4367 - 4396 2 L269-4 176.69 176.76 4396 - 4422 No shards L269-5 176.76 176.84 4422-4451 No shards L269-6/270-1 176.84 176.96 4451-4494 2 L270-2 176.96 177.09 4494 - 4585 No shards L270-3 177.09 177.22 4585 - 4695 2 L270-4 177.22 177.38 4695 - 4830 2

Table 4.1: Target intervals and associated sulphate peaks in the PR Col core. The age of each section is based on the model by Fisher et al. (2008). The ages are in yrs BP rather than the conventional yrs before 2000, so that ages could be more easily compared to radiocarbon ages, n is the number of glass shards probed per sample.

100 1 - Application of adhesive 2 - Application of sample to polished block by pipette

3 - Cured epoxy ready to 4 - Polished, inscribed be separated from and coated mount mount and polished

Fig 4.4: Mounting procedure for cryptotephra. After Kuehn a Froese, 2010. 17 A White River East • L-240-7 16 - • 0 L-240-9

15 B <>• DA AljO, CaO 2 14 -

D 13 - °D oD0n

12 • i i 69 71 73 75 77 79 SlOa 3 I • i i III I 1 - i "" T ' t I t 1 i i I 1 D D n 0 0 n 2 - 0 D A • °O D* 0 FeOt Kj0 3 fc OS A 0 1 m nrtn • -

C d

n I I .1 1 ,,1. 1 ,-JL-—_.1 1 I I 1 1 71 73 75 77 79 71 73 75 77 79 SiOj,

Fig 4.5: Geochemical bivariate plots of suspected WRE sections. Symbols that have been turned red are suspected contaminants; most likely Glacier Peak material.

102 20 T—T T—T -r—r—r 6 IT T T 1' I T "T "1 T I I—I T I I I T !

• ;. WWfc reference 5 • . O * D LJW-7/2S0-1 0 L250-2 4 15 O L251-S Aip, •B» L251-6 F«Ot 3 » L2S1-7 • J O L252-2 2 10 — V L252-5 - a - O L2S2-6 1 o -J • i i i i -I l_ t i I i i .1 I k I 63 68 73 78 60 80 SiOj

r i " r i |~~*r__,—p—J—J—^...^—,___, — 6 r—i—r—T—i—T—i—r—i—i—I—i—i—i—r

m. • 5 • a • D 4 n D CaO 3 NajO 5 v ^ \

2 4

1 3 o o° d * t i i.„. i -L i 1 .1 , 1 1 1 l__i.....i 65 80 65 70 75

SK)2

Fig 4.6: Geochemical bivariate plots of suspected WRN sections. A • I 20 U Aniakchak reference : A 1265/266-1 O L266-3 18 - 0 L266-4/L267-1 AIA Ca0 4 16 Ot>t 0 V — 14 - - a 'A - n 10 I

KjO 2 -

SJO, SKDj

Fig 4.7: Geochemical bivariate plots of suspected Anaikchak sections.

104 16 T r 7\ Jmw Cwtmfftntfit uMMrCsfltwM 1 - —r- T__.._.r,.„.—>T r t r—— L_I Hsjm pMBhnrt dtpotfts 15 -<9 6 UA1811 O UA1814 - •*o * [Qi UAU15 o 14 *$ PRCdflaMML-) AIA X - 0 s * * 13 - l#> ?. * - «» * 12 - 8 * » * b , 11 „i i„ i ,. t 1 A...... L.. 1 L. i.. ., 70 72 74 7i 78 70 72 74 76 71 sto2 S1O2 —r I I I r I1 I ""t ) 11" r • ' r ~" 1 ~

4 -

3 - o * *§ *J Naj0 4 K*0 n * 5b o»^fe<^•Sw , * *K " % xm ,A * *D * D D

J_ ' ' ' I, I t I J_ I , 1, 70 72 74 76 78 70 72 74 76 78 SiOj SKDj

Fig 4.8: Geochemical bivariate plots of suspected Hayes Tephra Set H sections.

105 NenanaI I Jarvis Creek

:>

•p -^-gs. **

V i

^

Fig 4.9: Location map for Hayes volcano and the two sites visited for this study. Hayes Tephra Set H distribution after Riehle et al., 1990 (limit is 1 cm isopach).

Fig 4.10: Nenana site Hayes Tephra Set H tephras. UA 1815 and 1814 are high and low-Si populations respectively (see Fig 4.8). TeDhra Code / DescriDtion 14C Ase Uncertainty (2a) Source reference White River East Maximum dates GSC-4012 1210 60 Blake (1987) GSC-748 1210 130 Lowdon and Blake (1970a) GSC-408 1200 140 Lowdon and Blake (1968) GSC-956 1190 130 Lowdon and Blake (1970b) GSC-934 1280 130 Lowdon and Blake (1970a) GSC-1568 1280 130 Lowdon and Blake (1973) GSC-1000 1300 130 Lowdon and Blake (1970a) AA-B3252A 1552 45 Livingston (2009) Minimum dates GSC-343 1240 130 Lowdon and Blake (1968) AA-B3251A 1116 60 Livingston (2009) Other GSC-5619/Tree rings 1260 50 Clague etal. (1995) GSC-5617/Tree rings 1430 70 Clague etal. (1995) White River North Maximum dates 1-276 1750 110 Fernald (1962) Y-2303 1990 80 Lowdon and Blake (1968) 1-6094 1785 90 Lowdon and Blake (1968) 1-6464 1825 90 Lowdon and Blake (1968) 1-7506 1850 85 Lowdon and Blake (1968) 1-7572 1925 80 Lowdon and Blake (1968) 1-6466 2005 90 Lowdon and Blake (1968) UCIAMS-26763 1775 15 Reyes and Froese(unpub) UCIAMS-26762 1740 15 Reyes and Froese(unpub) GSC-400 1990 130 Lerbekmo et al. (1975) WK-10365 1748 48 Livingston (2009) Beta-164540 1820 50 Livingston (2009) WK-8888 1970 70 Froese(unpub) Fl 1700 48 Froese(unpub) F2 1833 53 Froese(unpub) Minimum dates Beta-164539 1680 60 Livingston (2009) AA-B3259A 1696 47 Livingston (2009) UCIAMS-26763 1775 15 Reyes and Froese(unpub) UCIAMS-26764 1730 15 Reyes and Froese(unpub) 1-275 1520 100 Fernald (1962) 26764 1730 15 Reves and Froese(unpub) Aniakchak Maximum dates 1-14, 236 3570 80 Miller and Smith (1987) B-19643 3570 100 Beget et al. (1992) B-7760 2400 80 Kaufman and Hopkins (1985) W-4929 4830 80 Ager(1982) NSRL12336 3630 85 Kaufman (in press) Minimum dates 1-14, 221 3410 90 Miller and Smith (1987) 1-14, 226 3520 140 Miller and Smith (1987) W-3466 3610 200 Miller and Smith (1987) W-4052 3490 200 Miller and Smith (1987) W-4582 3670 60 Miller and Smith (1987) 1-14, 228 3500 80 Miller and Smith (1987) 1-14, 223 3370 90 Miller and Smith (1987) B-23170 3700 90 Beget et al. (1992) B-33758 3750 80 Beget et al. (1992) W-3125 3350 200 Miller and Smith (1987) B-7761 3340 90 Kaufmann and Hopkins (1985) 1-13, 990 4000 100 Riehle et al. (1987) W-4625 6430 90 Ager(1982) Table 4.2: Age data used in the construction of Phase models Site / Lab code Age(14CyrBP) Uncertainty (2a) Site / Lab code Age(14CyrBP) Uncertainty (2a) Paradox Lake" Jarvis Creekc AA-45098 1375 45 3120 210 AA-45099 1225 45 3360 275 AA-45100 2605 40 Tephra AA-45101 2970 50 3660 275 Tephra 4350 140 AA-45102 4055 45 AA-45103 4565 45 Tangle lakesc AA-38445 4920 90 3140 135 AA-38446 5600 80 3660 140 AA-38447 7100 60 Tephra AA-45104 9970 70 3700 295 Beta-177159 10970 70 Beta-125980 13250 80 Cantwellc Tephra Tustumena Lake a 2630 165 CAMS-90108 41800 2300 3305 105 CAMS-92792 2005 40 5085 180 CAMS-92793 1695 40 6115 100 CAMS-92794 2995 40 6705 280 Tephra CAMS-90109 3580 35 Bear Laked Tephra CAMS-120731 850 35 CAMS-92795 3840 40 CAMS-120732 1705 35 CAMS-92796 4345 40 CAMS-120733 2185 35 CAMS-92797 4265 40 CAMS-120734 2300 40 CAMS-90110 4885 35 CAMS-120735 2890 35 CAMS-95390 6330 45 CAMS-120736 3410 35 CAMS-95391 6530 45 Tephra CAMS-92798 8160 45 CAMS-120737 3835 35 CAMS-95392 19040 50 CAMS-120738 4575 35 CAMS-92799 8325 40 CAMS-120875 5125 35 CAMS-120876 5720 35 Sitel4b CAMS-120877 6025 35 1-13356 3500 90 CAMS-120878 7980 40 1-13357 3520 90 1-13352 3460 110 Jarvis Creeke Tephra Tephra 1-13352 3810 100 96054 3770 20 1-13353 3880 100 Wonder Lake Site30b Tephra 1-12276 3530 100 CAMS-12291 3830 60 Tephra 1-12275 3670 160

Table 4.3: Cores used in the construction of the Hayes Tephra Set H Equals model.a de Fontaine et al., 2007;b Riehle, 1985;c Beget et al., 1991;d Schiff et al., 2008;e This study; f Child etal., 1998.

108 3xCaiy4 17 Brerfc Ramsay (2010); r1 Amtwt*H»»cdaufromRg«raf«Ul(2O03fc

Felling date

Gap 30

GSC-S619 (1260,50)

Gap 149 S

GSC-561'7•(1430,70)-

1800 1600 1400 1200 1000 Modelled date (BP)

Fig 4.11: Wiggle-match output for a tree stump buried by the WRE eruption. Raw dates are from Clague et al., 1995.

109 OtCH it.t.7BtafkKtummao%m tSMKymhettdtlaltamlietmtetmtxlMt

Boundary

R_DateAA-B3251A

R_Date GSC-343

Phase Post-eruption^ C_Date(783J1) Boundary WRE eruption

R_DateAA-B3252A

R_Date GSC-1000

R_Date GSC-934

R_Date GSC-956

R_Oate GSC-408

R_Date GSC-4012

Boundary

• 11 > 111 > i LLU | I I • • • i i > i i i i i i i ) I i i .I..* t t i ) i I..I.L.J , I | 4000 3500 3000 2500 2000 1500 1000 500 0 -500 Modelled date (BP)

Q*C*V4 17Bfor*ft»reoy<2010H-5 WRE eruption 95 4% probability 1240(95 4%)1040BP

0 0061 0 004 0 002 8 a.

J_ 1300 1200 1100 1000 900 Modelled date (BP)

Fig 4.12: OxCal output for WRE Phase model, a) Distributions show the likely age ranges, and the bars beneath each give the 95.4% confidence ranges. The Prior distribution is a lighter shade; the Posterior darker, b) Close-up of the modelled eruption date distribution, with 95.4% confidence range at the top and represented as a bar beneath.

110 ,'"•••"»••' i' i« TT" l^'ITT'iy^T*H'^'^''!,^"'"~™Tni'iY'''iTfiTii'r TT T™"'

B»ta-164$39

AA-B3259A

UCIAMS-26764

Post-eruption

WRNeruptbn

F2

Ft

Beta-164540 Xk.

WK-10365 ••«?•

UCIAMS-26762 _JL-c_

UCIAMS-26763

1-276 rara:

I-7S06 ^-*_

1-6464

1-6094 ^^-—^iSiT^ I""%'*>, J(. ', mwsm*-'¥:

m &>m- 2500 2000 1S00 1000

Modelled date (BP)

o.c:*?*i?a-srfc3at*awastotr$ WRNeruption 95.4% probability 1705 (95.4%) 1609BP

A- 0.02 1 0.01 r

s 0- 0.

1700 1650 1600 1550 Modelled date (BP)

Fig 4.13: OxCal output for WRN Phase model, a) Distributions show the likely age ranges, and the bars beneath each give the 95.4% confidence ranges. The Prior distribution is a lighter shade; the Posterior darker, b) Close-up of the modelled eruption date distribution, with 95.4% confidence range at the top and represented as a bar beneath. There are two clear peaks in date probability, around 1700 and 1625 yrs BP.

Ill &C***t.rairt*mM*m\m.r»1maittWK*ll»imtlMlimt*maX»l.

/-1422S

W-4052

W-3466

t-14226

1-14221 jafjT*-

W-3125

f* *3 .Sflijl • T* IB** i -A* ••• •if* Post-eruption olifir Anakchak Ervp/on

NSRL12336

B-19643

M4236

i.m..M

lf(|f|||f|«?- ft !»;Itf *f

» • * i* 'M' 'nfii' * i* * ' J 'I'H'I^MIHI f* i* ' i 'i *i '.' i1 I'II'IIM'I i' fn t ' r * i r i f i ' ni i ' i 'i i' *li if ' I'I rl fi '. i' 'n r* i M'I fi ^ i ' M * • * I* 4 i* 1 i ' il ' 7000 WOO 5000 4000 3000 2000 1000

Mode/led date (BP)

mmtixmrnHfrmtmnin Aniakchak Eruption 95.4% probability 3946 (95.4%) 3695BP

§ |, 0.005 -

S CL

jJL »-•'•' >ii»*tltiiitJU i tnf * ,1 I,,* .I, * • j " ' * . I , , 4200 4000 3800 3600 Modelled date (BP)

Fig 4.14: OxCal output for the final Aniakchak Phase model, with all outliers removed, a) Distributions show the likely age ranges, and the bars beneath each give the 95.4% confidence ranges. The Prior distribution is a lighter shade; the Posterior darker, b) Close-up of the modelled eruption date distribution, with 95.4% confidence range at the top and represented as a bar beneath.

112 ft» wonder Lake CAW-12291 , , ottom Wonder lake-

=Hams

'Qlc, »*»'»#•» «&*&** f JdBK} m?6*u

*&WA S- *W

=Haves

A» uantweii

jgttgm Cantwell tQP tangle Lakes ^JTayes

jt"i «* J

UMVtS-120733 CAMS-120734 CAMS-120735 CAMS-120736 =Mayes QA/m-i'20737 CAMS-120738 1-120875 1-120876 1-120877 , tt >-120878 bottom.Sear Lake ia jp*v k *» *"* wnskw iayes2 CAMS-90109 ^92795 S-92796

mm?AMS-92799 y •0M w top HaradoxLake "•45099 -45J00 ..M5101 Hayes •mt „. 5104 mw%eta-\117159 5'eta-125980 ^gm^^doxLake- j • ' ' • \ t • ' • ' at tt 1111—u. ' ' T f • ' 40000 30000 20000 10000 -10000 -2000C Model fed date (BP)

113 ac*\*.v7am*nm». antra Hayes 95.4% probability 4065 (95.4%) 3809BP

I 0.006 |. 0.004 | 0.002 o. 0

... I , i i J. 1 .... 1 , , , 1 i i i i , !•.. t t . . . i I . . . 1 , i a 1 • . I , J ! ...I..*..*..*. ! I . , . , i 1 4200 4100 4000 3900 3800 3700 Modeled date (BP)

Fig 4.15: OxCal output for the final Hayes Tephra Set H Equals model, with all outliers removed, a) Distributions show the likely age ranges, and the bars beneath each give the 95.4% confidence ranges. The Prior distribution is a lighter shade; the Posterior darker, b) Close-up of the modelled eruption date distribution, with 95.4% confidence range at the top and represented as a bar beneath. 4.6 References

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Chappellaz, J., Davis, M., Delaygue, M., Delmotte, M., Kotlyakov, V.M., Legrand, M.,

Lipenkov, V.Y., Loruis, C, Pepin, L., Ritz, C, Saltzman, E., Stievenard, M., 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica.

Nature 199,429-436.

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Preece, S.J., Pearce, N.J.G., Westgate, J.A., Froese, D.G., Jensen, B.J.L., Perkins,

W.T., 2011. Old Crow tephra across eastern Beringia: a single cataclysmic eruption at the close of Marine Isotope Stage 6. Quaternary Science Reviews 30, 2069-2090.

Pyne-O'Donnell, S., Hughes, P., Amesbury, M., Booth, B., Charman, D., Daley, Y.,

Loader, N., Mallon, G., Mauquoy, D., Street-Perrott, A., Woodman-Ralph, J., 2011.

Towards a Holocene distal tephrochronology for north-eastern North America. XVIII

INQUA Congress, Bern. Abstract 1894.

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121 Riehle, J. R., Bowers, P. M., and Ager, T. A., 1990. The Hayes tephra deposits, an

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Schiff, C. J., Kaufman, D. S., Wallace, K. L, Werner, A., Kud, T.-L, Brown, T.A., 2008.

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K.K., Dahl-Jensen, D., Rasmussen, S.O., Steffensen, J.P., Svensson, A.M., 2008.

122 Synchronizing ice cores from the Renland and Agassiz ice caps to the Greenland ice core chronology. Journal of Geophysical Research 113, D08115 DOI: 10.1029/2007JD009143.

Yalcin, K., and Wake, C.P., 2001. Anthropogenic signals recorded in an ice core from

Eclipse Icefield, Yukon Territory, Canada. Geophysical Research Letters 28,4487-4490.

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Environment 40, 7152-7163.

123 CHAPTER 5 - CONCLUSIONS

5.1 Conclusions

The coastal region of the Alaskan panhandle contains at least one significant tephra that can be linked across terrestrial and marine records, providing chronological control.

The MEd tephra has been re-dated from terrestrial records using a Bayesian statistical model to 13,270 - 13,050 cal yrs BP, and this in turn helps to constrain the marine reservoir for this area by estimating the difference between the terrestrial and marine age estimates; approximately 320 - 810 years.

The MEVF study also identified four previously unrecognised tephras in the terrestrial record, three of which differ significantly from previously identified MEVF tephras. Aside from MEd, seven other tephras were identified in the marine core, but all had geochemical signatures close to the MEVF reference data.

Four widespread Alaskan tephras have been identified in the PR Col ice core from the St. Elias Range on the border between the Yukon and Alaska; the White River Ash

Eastern and Northern lobes; the Aniakchak caldera-forming eruption; and the Hayes

Tephra Set H. This result confirms the preliminary matches of these sulfate peaks to the large volcanic eruptions used to construct the age model for the ice core. Testing of the accuracy of the age model for the ice core was accomplished through comparison of the modeled age for each eruption and the terrestrial age estimate based on a Bayesian statistical model of all available related dates.

124 Both of these studies have brought together many elements required to create a robust tephrostratigraphical framework for northwestern North America. Diverse records have been integrated, from the marine, terrestrial and glacial domains. An effort has been made to use the best practices for precise geochemical fingerprinting and age modeling.

5.2 Further Study

The terrestrial Phase model for MEd has only one, poorly constrained minimum date and would be improved with better minimum radiocarbon dates. This is generally true for many tephra deposits; good minimum dates rely on sediment deposition resuming immediately after the eruption, and this is often not the case. Further work should concentrate on obtaining more marine dates for MEd, and sampling radiocarbon material for dating closer to the tephra. This would allow better comparison of age from the terrestrial and marine record, and a more precise estimation of the local marine reservoir correction.

The MEVF tephras seem to plot where the Type I and Type II category fields overlap. To further characterize the MEVF tephras and unravel the underpinning of the

MEVF magmatic setting, trace element data should be obtained. Preece et al. (in press) propose a new classification scheme based on trace element data that further separates tephra beds in this region into either adakite, transitional, or typical arc.

More, and more precise terrestrial dates would also be an aim of further study of the PR Col tephras, particularly for the Aniakchak and Hayes Tephra Set H events. For

125 the former, more terrestrial dates could provide insight into the discrepancy between

the terrestrial Phase model and the ice core age from the well-constrained integrated

Greenland ice core age model. For the latter, radiocarbon dates need to be found to

better constrain the individual tephras in the set. Further geochemical, stratigraphical

and chronological study of the individual tephras could uncover a geochemical trend in

the set over time. Probing more sections of the PR Col core above and below those

investigated in this study could also help resolve this trend.

The identification of the White River East tephra over 2000 km from the source

(Pyne O'Donnell, 2011) also gives the possibility that the developing framework could be

applied across the whole of northern North America, and study of terrestrial and ice core records in the eastern Canadian Arctic would help strengthen this possibility.

5.3 References

Preece, S.J., Westgate, J.A., Froese, D.G., Pearce, N.J.G., Perkins, W.T., in press. A catalogue of late Cenozoic tephra beds in the Klondike goldfields and adjacent areas,

Yukon Territory. Canadian Journal of Earth Sciences.

Pyne O'Donnell, S., Hughes, P., Amesbury, M., Booth, B., Charman, D., Daley, Y.,

Loader, N., Mallon, G., Mauquoy, D., Street-Perrott, A., Woodman-Ralph, J., 2011.

Towards a Holocene distal tephrochronology for north-eastern North America. XVIII

INQUA Congress, Bern. Abstract 1894.

126 APPENDIX I - GLASS DATA

Column Point

Reported Sample Si02 Ti02 AI203 FeO MnO MgO CaO Na20 K20 CI total H20dil UA 1674 ColP A-05 64.88 0.79 15.81 6.16 0.22 1.75 4.97 4.33 1.03 0.06 99.48 0.53 ColP A-06 64.06 0.78 15.87 6.61 0.09 1.80 5.02 4.49 1.06 0.21 97.76 2.24 ColPA-07 65.07 0.79 15.90 6.06 0.07 1.59 5.29 4.13 0.98 0.12 97.24 2.76 ColP A-08 64.06 0.78 15.73 6.49 0.13 1.82 5.49 4.38 1.04 0.09 99.71 0.29 ColP A-10 64.25 0.79 16.12 6.18 0.05 1.86 5.30 4.32 1.03 0.10 98.95 1.05 ColPA-11 64.17 0.80 15.87 6.24 0.10 1.68 5.29 4.90 0.88 0.08 98.02 1.98 ColPA-24 63.85 0.81 16.09 6.37 0.08 1.80 5.19 4.53 1.08 0.20 97.31 2.69 ColP A-25 65.11 0.74 15.81 5.98 0.15 1.73 5.34 4.02 1.01 0.11 98.65 1.35 ColP A-27 64.77 0.96 15.58 6.32 0.13 1.70 4.52 4.58 1.36 0.08 96.12 3.88 ColPA-28 63.89 0.81 16.23 6.44 0.12 1.78 5.17 4.41 1.04 0.11 99.88 0.12 ColP A-29 64.60 0.81 15.92 6.46 0.07 1.73 5.23 4.07 1.05 0.07 96.07 3.93 ColA-21 64.64 0.80 15.96 6.42 0.09 1.53 5.27 4.09 1.03 0.16 93.34 6.66 ColA-4 64.83 0.88 15.55 6.25 0.11 1.69 5.27 4.21 1.11 0.10 98.94 1.06 ColA-14 65.07 0.77 15.80 6.13 0.09 1.58 5.07 4.28 1.06 0.15 98.12 1.88 ColA-2 65.12 0.82 15.61 6.49 0.11 1.66 5.19 3.91 1.03 0.07 99.35 0.65 ColA-3 65.18 0.72 15.80 6.23 0.09 1.69 5.15 4.07 0.98 0.10 98.10 1.90 ColA-12 65.23 0.80 15.79 5.97 0.13 1.61 5.24 4.11 1.00 0.12 98.63 1.37 ColA-19 65.28 0.74 15.98 5.80 0.09 1.56 4.94 4.25 1.13 0.23 96.95 3.05 ColA-15 65.31 0.80 15.84 5.67 0.09 1.61 4.93 4.61 1.08 0.07 97.41 2.59 ColA-7 65.36 0.78 16.01 5.80 0.13 1.55 4.84 4.12 1.20 0.20 94.02 5.98 ColA-1 65.55 0.72 15.62 5.74 0.10 1.60 5.11 4.36 1.08 0.13 99.42 0.58 UA 1674-12 65.10 0.78 16.47 5.96 0.05 1.61 5.05 3.90 1.01 0.08 98.19 1.81 UA 1674-14 65.14 0.82 15.66 6.01 0.08 1.77 4.96 4.49 0.98 0.09 97.89 2.11 UA 1674-15 64.55 0.79 16.10 6.15 0.13 1.78 4.87 4.51 1.01 0.10 97.48 2.52

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Reported Sample Si02 Ti02 AI203 FeO MnO MgO CaO Na20 K20 CI total H20diff 40JC - 9.08 UA1797 73.10 0.23 14.83 2.64 0.02 0.28 1.64 4.71 2.38 0.17 94.88 5.12 UA1797 74.26 0.26 14.05 2.43 0.00 0.18 1.38 4.72 2.60 0.13 97.01 2.99 UA1797 72.61 0.26 14.88 2.70 0.10 0.29 1.63 5.00 2.40 0.12 97.73 2.27 UA1797 73.01 0.25 14.63 2.52 0.07 0.26 1.80 4.98 2.35 0.13 96.50 3.50 1797 1 72.93 0.28 14.65 2.68 0.13 0.29 1.76 4.86 2.29 0.13 98.30 1.697 1797 6 73.32 0.25 14.36 2.85 0.03 0.25 1.62 4.85 2.32 0.15 96.87 3.133 1797 8 73.40 0.28 14.34 2.51 0.04 0.28 1.62 4.82 2.59 0.12 95.56 4.443 1797 9 74.32 0.33 13.66 2.59 0.02 0.21 1.36 4.61 2.77 0.12 96.02 3.984 1797 14 74.87 0.33 13.73 2.23 0.04 0.21 1.27 4.69 2.47 0.16 96.19 3.814 1797 16 73.13 0.25 14.22 2.68 0.04 0.31 1.67 5.09 2.49 0.11 99.67 0.333 1797 17 72.62 0.34 14.69 2.67 0.06 0.34 1.88 4.85 2.40 0.14 94.44 5.562 1797 19 73.40 0.30 14.22 2.63 0.03 0.25 1.59 5.01 2.47 0.10 97.64 2.363 1797 22 72.99 0.28 14.48 2.70 0.00 0.30 1.75 4.98 2.42 0.10 96.07 3.926 1797 23 74.28 0.24 13.79 2.56 0.05 0.25 1.49 4.79 2.45 0.11 96.87 3.13 1797 24 72.84 0.29 14.54 2.65 0.07 0.30 1.89 4.82 2.39 0.21 96.99 3.009 1797 25 73.54 0.20 14.53 2.54 0.10 0.27 1.45 4.90 2.35 0.13 96.05 3.948 1797 26 73.74 0.24 14.32 2.64 0.08 0.30 1.56 4.51 2.50 0.12 95.55 4.451 1797 28 74.76 0.25 13.80 2.51 0.00 0.19 1.38 4.38 2.55 0.17 94.63 5.374 Average 73.51 0.27 14.32 2.60 0.05 0.26 1.60 4.81 2.46 0.14 96.50 3.50 SD 0.71 0.04 0.38 0.13 0.04 0.04 0.18 0.18 0.12 0.03 1.32 1.32

40JC-9.80 UA1798 72.47 0.27 14.76 2.68 0.09 0.30 1.90 5.15 2.25 0.13 97.62 2.38 UA1798 72.92 0.25 14.73 2.50 0.07 0.29 1.76 4.97 2.37 0.14 97.61 2.39 UA1798 72.85 0.28 14.59 2.89 0.02 0.28 1.54 5.01 2.41 0.13 97.23 2.77 UA 1798 1 73.52 0.28 14.36 2.37 0.07 0.23 1.61 5.08 2.34 0.18 99.61 0.39 UA 1798 2 73.04 0.31 14.46 2.78 0.06 0.30 1.80 4.87 2.31 0.11 98.57 1.43 UA 1798 3 73.81 0.26 14.11 2.54 0.08 0.22 1.54 4.73 2.57 0.16 95.62 4.38 UA 1798 6 72.09 0.31 14.58 3.15 0.05 0.43 1.85 5.05 2.37 0.16 95.43 4.57

134 UA 179813 73.53 0.27 14.15 2.59 0.03 0.23 1.63 5.03 2.44 0.14 97.36 2.64 UA 179814 74.77 0.32 14.16 2.58 0.04 0.28 1.69 3.57 2.43 0.19 95.00 5.00 UA 1798 21 73.16 0.24 14.45 2.68 0.06 0.29 1.78 5.05 2.17 0.16 97.97 2.04 UA 1798 26 72.92 0.26 14.55 2.64 0.05 0.28 1.77 5.12 2.31 0.15 99.34 0.66 UA 1798 28 74.24 0.30 14.46 2.86 0.05 0.23 1.83 3.67 2.26 0.14 94.96 5.04 Average 73.28 0.28 14.45 2.69 0.05 0.28 1.73 4.77 2.35 0.15 97.19 2.81 SD 0.75 0.02 0.22 0.21 0.02 0.06 0.12 0.55 0.10 0.02 1.62 1.62

40JC-10.00 UA1799 72.98 0.27 14.46 2.59 0.06 0.26 1.64 5.00 2.61 0.14 94.76 5.25 UA1799 72.63 0.28 14.60 2.77 0.06 0.27 1.69 5.12 2.44 0.14 96.14 3.86 UA 1799 3 72.87 0.25 14.36 2.68 0.04 0.28 1.86 5.19 2.36 0.13 100.26 -0.25 UA 1799 6 73.04 0.26 14.56 2.76 0.09 0.30 1.81 4.76 2.33 0.14 99.45 0.55 UA 179910 72.61 0.28 14.49 2.74 0.07 0.29 1.78 5.22 2.41 0.15 98.98 1.02 UA 179914 73.14 0.32 14.44 2.62 0.06 0.31 1.82 4.85 2.33 0.14 99.88 0.12 UA 1799 16 72.17 0.32 14.64 2.93 0.09 0.32 1.97 5.18 2.32 0.07 98.77 1.23 UA 1799 22 72.83 0.30 14.43 2.62 0.05 0.35 1.90 5.15 2.25 0.14 98.77 1.23 UA 1799 23 72.43 0.24 14.72 2.80 0.04 0.31 1.90 5.26 2.24 0.10 99.41 0.59 UA 1799 24 72.84 0.37 14.23 2.73 0.10 0.30 1.79 5.35 2.19 0.13 97.65 2.35 UA 1799 25 72.80 0.26 14.66 2.81 0.09 0.31 1.85 4.78 2.35 0.13 98.79 1.21 UA 1799 26 72.89 0.27 14.68 2.68 0.07 0.29 1.81 4.88 2.37 0.09 97.32 2.68 Average 72.77 0.28 14.52 2.73 0.07 0.30 1.82 5.06 2.35 0.12 98.35 1.65 SD 0.27 0.04 0.15 0.10 0.02 0.03 0.09 0.20 0.11 0.02 1.61 1.61

40JC-10.29 UA1800 72.35 0.24 14.86 2.88 0.06 0.31 1.77 5.14 2.24 0.15 96.36 3.64 1800 2 73.22 0.26 14.41 2.82 0.07 0.24 1.76 4.83 2.24 0.15 96.71 3.29 1800 4 73.04 0.31 14.37 2.71 0.04 0.31 1.91 4.84 2.32 0.14 96.91 3.09 1800 8 73.26 0.22 14.36 2.83 0.10 0.32 1.63 4.86 2.36 0.07 97.82 2.18 1800 12 73.14 0.28 14.26 2.72 0.06 0.30 1.74 4.98 2.35 0.18 96.52 3.48 1800 18 73.61 0.17 14.31 2.43 0.08 0.24 1.68 4.92 2.38 0.17 99.39 0.61 1800 19 73.47 0.31 14.21 2.75 0.03 0.23 1.62 4.82 2.40 0.15 97.08 2.92 1800 21 72.50 0.23 14.58 2.94 0.07 0.33 1.83 4.99 2.34 0.19 96.77 3.24 1800 22 73.18 0.24 14.37 2.72 0.01 0.26 1.71 4.97 2.42 0.12 96.62 3.38 1800 23 73.33 0.26 14.27 2.66 0.05 0.28 1.63 5.02 2.37 0.14 98.55 1.45

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40JC-10.82 UA1802 73.10 0.28 14.61 2.64 0.04 0.23 1.55 4.94 2.47 0.14 95.25 4.75 UA1802 72.31 0.27 14.92 2.60 0.05 0.26 1.84 5.04 2.55 0.17 95.24 4.76 UA1802 74.10 0.30 13.74 2.64 -0.01 0.22 1.55 4.89 2.41 0.15 96.19 3.81 UA1802 72.51 0.37 14.54 2.83 0.03 0.32 1.79 4.98 2.45 0.18 97.89 2.11 UA1802 73.44 0.27 14.25 2.60 -0.01 0.22 1.55 5.00 2.55 0.13 95.99 4.01 UA1802 72.85 0.28 14.56 2.77 0.07 0.23 1.65 4.99 2.44 0.16 96.88 3.12 UA 1802 1 74.43 0.34 13.80 2.50 0.04 0.19 1.39 4.68 2.55 0.11 96.31 3.69 UA 1802 2 72.74 0.21 14.72 2.72 0.06 0.31 1.81 5.13 2.22 0.11 100.61 -0.61 UA 1802 4 74.22 0.34 13.75 2.60 0.08 0.23 1.45 4.74 2.46 0.16 98.04 1.96 UA 1802 8 72.85 0.24 14.39 2.71 0.00 0.26 1.74 5.31 2.38 0.13 98.74 1.26 UA 1802 9 73.43 0.32 14.69 2.89 0.05 0.33 1.84 4.03 2.30 0.16 99.19 0.81 UA 1802 11 72.79 0.26 14.06 2.61 0.09 0.32 1.73 5.35 2.66 0.16 96.70 3.30 UA 1802 13 72.81 0.33 14.59 2.69 0.06 0.31 1.85 5.00 2.29 0.11 97.80 2.20 UA 1802 14 73.96 0.42 13.75 2.53 0.08 0.16 1.48 4.90 2.56 0.21 96.75 3.25 UA 1802 17 73.18 0.24 14.56 2.57 0.05 0.28 1.76 4.86 2.41 0.11 95.22 4.78 UA 1802 19 73.77 0.27 13.94 2.72 0.08 0.25 1.67 4.82 2.38 0.13 98.44 1.57 UA 1802 21 72.78 0.31 14.55 2.75 0.07 0.28 1.69 5.01 2.44 0.15 95.49 4.51 UA 1802 23 73.62 0.22 14.18 2.68 0.04 0.22 1.61 4.93 2.36 0.16 98.15 1.85 UA 1802 24 72.77 0.27 14.45 2.73 0.05 0.29 1.81 5.12 2.42 0.12 97.96 2.04 UA 1802 26 72.84 0.31 14.41 2.70 0.06 0.30 1.93 4.88 2.45 0.15 98.64 1.36 UA 1802 27 73.21 0.30 14.29 2.63 0.06 0.25 1.63 5.11 2.45 0.08 98.94 1.06 UA 1802 29 72.85 0.20 14.59 2.49 0.07 0.27 1.74 5.46 2.26 0.08 93.76 6.24 UA 1802 30 72.94 0.26 14.43 2.68 0.05 0.30 1.82 5.13 2.31 0.11 98.13 1.87 Average 73.20 0.29 14.34 2.66 0.05 0.26 1.69 4.97 2.42 0.14 97.23 2.77 SD 0.58 0.05 0.35 0.10 0.03 0.05 0.14 0.28 0.11 0.03 1.63 1.63

40JC-11.08 UA1803 73.52 0.30 14.34 2.67 0.11 0.18 1.47 4.77 2.50 0.12 98.39 1.61

137 UA1803 73.37 0.25 14.27 2.77 0.07 0.29 1.62 4.99 2.23 0.14 97.46 2.54 UA1803 73.11 0.28 14.51 2.57 0.02 0.24 1.58 5.03 2.53 0.14 95.96 4.04 UA1803 73.03 030 14.49 2.64 0.10 0.36 1.73 4.84 2.38 0.13 96.34 3.66 UA1803 72.49 0.24 14.79 2.85 0.10 0.28 1.75 5.10 2.27 0.14 98.52 1.48 UA 1803 3 73.94 0.27 14.61 2.87 0.04 0.31 1.78 3.73 2.32 0.17 97.40 2.60 UA 1803 4 72.85 0.28 14.40 2.77 0.08 0.27 1.73 4.92 2.58 0.16 96.57 3.43 UA 1803 5 72.61 0.26 14.62 2.73 0.07 0.29 1.90 5.15 2.26 0.14 97.11 2.89 UA 1803 6 72.89 0.24 14.49 2.70 0.03 0.29 1.84 5.02 2.39 0.14 98.94 1.06 UA 1803 7 72.83 0.22 14.53 2.68 0.05 0.29 1.89 5.04 2.40 0.09 98.34 1.66 UA 1803 13 73.76 0.35 13.90 2.46 0.06 0.30 1.46 5.03 2.55 0.17 97.99 2.01 UA 1803 14 73.13 0.23 14.47 2.45 0.06 0.26 1.75 5.12 2.41 0.16 98.85 1.15 UA 1803 15 73.02 0.22 14.30 2.64 0.00 0.29 1.80 5.16 2.41 0.19 98.47 1.53 UA 1803 16 72.61 0.22 14.65 2.66 0.10 0.33 1.91 4.99 2.37 0.22 97.28 2.72 UA 1803 18 73.81 0.28 13.75 2.66 0.09 0.27 1.44 5.05 2.50 0.18 96.75 3.26 UA 1803 19 7438 0.30 13.40 2.60 0.04 0.27 1.37 4.99 2.52 0.18 96.59 3.41 UA 1803 20 72.73 0.30 14.53 2.66 0.09 0.29 1.88 5.01 2.41 0.11 98.69 1.31 UA 1803 21 73.01 0.24 14.33 2.65 0.08 0.34 1.82 5.04 2.38 0.14 98.37 1.63 UA 1803 22 72.65 0.23 14.50 2.74 0.04 0.29 1.81 5.25 2.35 0.18 98.87 1.13 UA 1803 23 73.12 0.27 14.37 2.70 0.05 0.22 1.76 5.02 2.34 0.18 99.00 1.01 UA 1803 24 74.15 0.24 13.80 2.56 0.03 0.26 1.58 4.86 2.43 0.12 94.99 5.02 UA 1803 25 73.21 0.26 14.17 2.63 0.06 0.24 1.67 5.20 2.42 0.16 96.38 3.62 UA 1803 26 72.27 0.23 14.41 2.84 0.05 0.27 1.87 5.51 2.24 0.40 99.04 0.96 UA 1803 30 73.03 0.26 14.66 2.69 0.01 0.31 1.82 4.89 2.20 0.15 95.39 4.61 Average 73.15 0.26 14.35 2.67 0.06 0.28 1.72 4.99 2.39 0.16 97.57 2.43 SD 0.54 0.03 0.33 0.11 0.03 0.04 0.16 0.31 0.10 0.06 1.22 1.22

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(JO ID PR Col

Can. Can. depth depth to Sample to top bottom Reported Target event Numbers (m) (m) Shard Si02 Ti02 AI203 FeO MnO MgO CaO Na20 K20 CI Total H20diff Notes Hekla 1947 133-1 33 60 33 83 L33-1 Sh5 Ptl 65 37 0 84 15 83 4 93 0 04 134 4 22 4 79 2 53 Oil 10017 -0 17 L33-1 Sh4 Ptl 73 90 0 23 14 55 155 0 01 0 45 160 5 03 2 63 0 04 95 03 4 97 L33-1 Sh8 Ptl 73 79 0 28 14 95 182 0 06 0 42 144 4 08 3 00 016 87 10 12 90 L33-1 ShOO Ptl 70 86 0 38 15 72 2 48 0 09 0 58 142 3 99 4 22 0 24 85 82 14 18 133-1 ShlO Ptl 72 96 0 27 14 45 172 0 01 0 41 156 4 19 4 28 0 16 84 02 15 98 L33-1 Sh3 Pt2 7162 0 34 14 56 2 60 0 05 0 42 138 5 02 3 89 0 12 89 85 10 15 L33-1 Shi Ptl 76 19 0 23 12 71 104 0 04 0 19 0 98 3 75 4 76 010 93 82 618 L33-1 Shi Pt2 76 32 0 22 13 02 100 0 01 013 0 91 3 54 4 80 0 05 94 50 5 50 L33-1 Shl3 Ptl 75 83 0 30 13 00 119 0 04 0 21 101 3 70 4 61 Oil 94 38 5 62 L33-1 Shl3 Pt2 76 12 0 21 12 91 111 0 06 0 18 0 94 3 72 4 72 0 04 90 33 9 67 L33-1 Shl7 Ptl 75 40 0 25 13 14 125 0 02 0 26 109 4 00 4 51 0 08 94 91 5 09 L33-1 Shl8 Pt2 64 66 0 84 16 76 3 97 0 06 134 2 87 5 05 4 37 0 07 96 38 3 62 L33-1 Shl8 Ptl 64 32 0 95 16 95 3 72 015 133 2 99 5 06 4 47 0 06 97 75 2 25 L33-1 Sh02 Ptl 75 85 0 25 13 17 136 0 01 0 31 164 3 96 3 24 0 22 94 71 5 29 Old Crow contamination'' L33-1 Sh6 Ptl 75 44 0 33 12 72 173 0 09 0 30 165 3 70 3 72 0 31 93 93 6 07 L33-1 Sh6 Pt2 75 35 0 28 12 78 171 0 03 0 32 153 3 84 3 87 0 29 93 74 6 26 L33-1 ShO Ptl 77 56 0 14 12 77 0 96 0 00 0 22 114 3 65 3 40 0 16 94 28 5 72 Glacier Peak contamination7 L33-1 Shl2 Ptl 77 56 0 23 12 62 109 0 00 0 20 124 3 61 3 36 0 09 93 93 6 07 L33-1 Shl4 Ptl 77 55 0 21 12 99 109 0 00 0 27 122 3 26 3 22 0 19 94 63 5 37 L34-1 A,B 33 83 34 08 L34-1 Sh5 Ptl 75 21 016 14 82 0 83 0 04 0 17 0 96 4 13 3 49 0 18 86 10 13 90 L34-1 Sh7 Ptl 73 17 0 35 14 78 141 0 04 0 42 163 5 31 2 78 0 10 93 97 6 03 L34-1 Sh7 Pt2 73 29 0 27 14 66 154 0 05 0 42 147 5 23 2 89 0 16 94 98 5 02 Mazama contamination'' L34-1 Sh8 Ptl 70 35 0 51 14 58 2 93 0 04 0 58 2 35 4 23 3 91 0 51 95 62 4 38

140 L34-1 Sh8 Pt2 70 34 0 39 14 51 2 94 0 06 0 58 2 44 4 27 4 01 0 46 95 21 4 79 L34-1 Sh2 Ptl 74 91 0 29 13 55 143 0 06 0 26 130 3 74 4 39 0 07 93 78 6 22 L34-1 Sh2 Pt2 74 68 0 29 13 77 136 0 06 0 32 131 3 75 4 41 0 04 92 33 7 67 L34-1 Sh6 Ptl 73 88 0 10 16 59 104 0 04 0 41 146 4 10 2 24 0 12 9172 8 28 L34-1 Sh4 Ptl 75 27 0 28 13 10 166 0J.0 0 30 156 3 82 3 65 0 26 96 62 3 38 Old Crow contamination' L34-1 Sh4 Pt2 75 55 0 24 12 89 180 0 00 0 32 164 3 58 3 70 0 28 94 91 5 09 134-2 34 08 34 32 L34-2 Sh21 Pt3 66 61 0 74 16 06 4 06 0 09 117 3 11 5 79 2 22 0 14 99 49 0 51 L34-2Sh21Pt4 67 10 0 86 16 14 4 15 0 14 107 3 17 5 07 2 17 0 12 99 54 0 46 L34-2 Sh24 Ptl 75 00 0 15 14 95 110 0 03 0 26 123 3 70 3 41 0 17 87 53 12 47 134-2 Shl4 Ptl 73 48 0 25 15 38 134 0 10 0 44 161 4 57 2 68 0 15 86 05 13 95 L34-2 Shl9 Ptl 7169 0 38 15 82 2 16 0 09 0 51 172 4 62 2 59 0 41 79 00 2100 L34-2Shl9Pt2 72 99 0 47 15 62 198 0 08 0 40 173 3 98 2 43 0 31 84 76 15 24 134-2 Sh2 Ptl 73 88 0 22 14 46 166 0 06 0 34 186 4 08 3 12 0 32 94 86 5 14 L34-2 Sh20 Ptl 69 00 0 56 16 76 3 73 0 08 0 72 184 4 69 2 46 0 17 95 37 4 63 134-2 Sh20 Pt2 70 02 0 50 15 43 3 79 0 13 0 62 2 02 4 91 2 41 0 16 95 91 4 09 L34-2 ShlO Ptl 73 03 0 39 14 66 2 22 0 04 0 44 163 4 50 2 88 0 21 90 31 9 69 Mazama contamination' L34-2 Shl3 Ptl 73 32 0 43 14 54 2 01 0 02 0 44 154 4 59 2 92 0 19 96 35 3 65 L34-2 Sh3 Ptl 7159 0 54 14 84 2 69 0 09 0 50 183 4 01 3 68 0 22 83 26 16 74 134-2 Sh4 Ptl 72 08 0 48 14 60 2 62 0 03 0 50 184 4 30 3 46 0 10 95 58 4 42 L34-2 Sh9 Ptl 73 11 0 19 14 46 187 0 04 0 16 0 89 5 21 3 91 0 15 98 12 188 L34-2 Sh8 Ptl 75 87 0 02 13 68 123 0 08 0 06 0 39 3 91 4 63 0 13 94 56 5 44 L34-3 ShlO Ptl 76 01 0 02 14 17 0 66 0 13 0 03 0 48 4 19 4 29 0 01 96 56 3 44 L34-2 Sh8 Ptl 75 87 0 02 13 68 123 0 08 0 06 0 39 3 91 4 63 0 13 94 56 5 44 L34-2 Shl8 Ptl 76 08 0 15 13 39 102 0 09 019 0 87 3 24 4 72 0 26 74 85 25 15 134-2 Shl8 Pt2 75 44 0 19 14 57 0 92 0 06 0 15 0 87 3 06 4 58 0 16 90 20 9 80 L34-2 Sh27 Ptl 75 59 0 26 12 93 172 0 06 0 26 153 3 72 3 67 0 26 95 20 4 80 Old Crow contamination' L34-2 Shll Ptl 77 05 0 19 13 00 121 0 07 0 25 123 3 39 3 44 0 17 84 48 15 52 Glacier Peak contamination' L34-2 Shll Pt2 76 00 0 35 13 28 157 0 04 0 32 129 3 58 3 30 0 27 74 70 25 30 L34-2 Shl2 Ptl 76 85 0 21 13 13 119 0 01 0 23 122 3 46 3 47 0 23 90 07 9 93 L34-2 Shl5 Ptl 76 92 0 14 12 82 109 0 00 0 23 118 3 69 3 80 0 12 89 61 10 39 L34-2 Shl7 Ptl 76 82 0 20 13 03 105 0 07 0 27 129 3 64 3 47 0 16 95 28 4 72

141 L34-2 Shl7 Pt2 76 73 Oil 13 03 102 0 01 0 24 136 3 96 3 39 0 15 95 76 4 24 L34-2 Sh26 Ptl 77 02 0 25 12 78 0 99 0 07 0 23 114 3 75 3 64 0 13 95 80 4 20 L34-2 Sh26 Pt2 77 61 0 17 12 70 0 96 0 01 0 20 113 3 72 3 36 0 16 94 94 5 06 L34 2 Sh6 Ptl 76 46 0 19 13 63 146 0 04 0 32 120 3 29 3 20 0 21 85 38 14 62 L34 2 Sh7 Ptl 77 26 0 19 13 02 108 0 08 0 27 119 3 46 3 35 0 09 93 82 6 18 L34-2 Sh7 Pt2 76 92 0 18 12 93 105 0 03 0 21 119 3 83 3 49 0 16 89 54 10 46 L34-3 34 32 34 57 L34-3 Shi Ptl 7145 0 61 15 15 2 80 0 07 0 54 181 4 66 2 67 0 24 8911 10 89 L34-3 Shl3 Pt2 74 44 0 20 13 95 195 Oil 0 20 124 4 35 3 33 0 22 10142 -142 L34 3 Shll Ptl 73 51 0 43 14 41 195 0 05 0 43 164 4 58 2 83 0 16 95 41 4 59 Mazama contamination' L34-3 Shl3 Ptl 74 40 0 23 13 63 190 0 03 0 25 135 4 54 3 49 0 18 97 27 2 73 L34-3 Sh3 Ptl 73 86 0 20 15 67 138 0 04 0 38 120 3 26 3 60 0 41 68 06 3194 134-3 Sh9 Ptl 73 24 Oil 14 15 2 03 0 02 0 19 0 87 5 16 4 05 0 16 92 91 7 09 L34-3 Sh9 Pt2 73 76 Oil 14 40 2 01 0 06 016 0 86 4 66 3 85 014 97 94 2 06 L34-3 ShlO Ptl 76 01 0 02 14 17 0 66 0 13 0 03 0 48 4 19 4 29 0 01 96 56 3 44 L34-3 ShlO Pt2 76 09 0 03 14 24 0 72 0 15 0 04 0 52 4 20 4 01 0 00 98 44 156 L34-3 Sh5 Ptl 74 55 0 24 10 80 4 07 0 03 0 03 0 31 5 30 4 26 0 41 95 86 414 L34-3 Sh4 Ptl 77 38 0 22 12 61 141 0 01 0 14 0 76 141 5 86 0 19 93 48 6 52 L34-3 Sh2 Ptl 75 37 0 25 13 08 178 0 01 0 29 148 3 65 3 80 0 30 90 27 9 73 Old Crow contamination' 134-3 Sh6 Ptl 77 28 0 25 12 55 114 0 09 0 34 122 3 68 3 28 0 17 94 40 5 60 Glacier Peak contamination' L34-3 Sh7 Ptl 76 56 0 25 14 27 0 99 0 07 0 22 1 19 3 36 2 91 0 19 92 24 7 76 L34-3 Sh7 Pt2 77 11 010 13 46 100 0 02 0 23 124 3 57 3 13 0 14 95 09 4 91 L34 3 Sh8 Ptl 77 13 011 13 07 101 0 07 0 23 124 3 33 3 57 0 26 85 93 14 07 L34-3 Sh8 Pt2 77 15 019 12 84 0 96 0 03 0 23 126 3 80 3 37 016 94 74 5 26 L34-4/35-1 34 57 34 77 L34-4_35-l ShlO Ptl 65 61 0 86 15 91 4 63 0 09 128 3 76 5 23 2 54 Oil 99 21 0 79 L34-4_35-l ShlO Pt2 65 38 0 89 1611 4 50 011 131 3 66 5 21 2 72 011 96 86 3 14 L34-4_35-l Sh5 Ptl 73 23 0 23 14 84 157 0 03 0 53 156 5 05 2 82 015 86 31 13 69 L34-4_35-l Sh5 Pt2 73 61 0 32 14 91 153 0 04 0 40 154 4 64 2 83 0 18 85 47 14 53 134-4_35-l Sh9 Ptl 72 27 0 36 14 94 2 26 0 05 0 47 173 5 12 2 60 019 96 47 3 53 L34-4_35-l Sh3 Ptl 74 97 0 23 13 76 118 0 05 0 26 109 3 88 4 52 0 08 94 63 5 37 L34-4_35-l Sh3 Pt2 75 43 0 24 13 62 1 19 0 02 0 21 104 3 73 4 47 0 04 95 78 4 22 L34-4 35-1 Sh4 Ptl 76 04 0 33 13 09 150 0 04 016 0 94 3 68 4 07 015 95 48 4 52

142 L34-4_35-l Sh8 Ptl 60 87 0 87 17 83 5 46 0 10 188 6 42 4 54 166 0 38 92 58 7 42 L34-4_35-l Sh8 Pt2 6182 102 17 33 5 69 Oil 173 5 44 4 75 172 0 40 93 81 6 19 L34-4_35-l Sh9 Pt3 70 85 0 41 17 14 195 0 04 0 46 163 4 64 2 68 0 21 96 75 3 25 L34-4_35-l Sh7 Ptl 75 23 0 30 13 28 164 0 04 0 28 161 3 82 3 49 0 31 9158 8 42 Old Crow contamination' L34-4_35 1 Sh2 Ptl 77 90 0 40 1194 124 0 03 0 13 0 96 3 57 3 57 0 25 94 27 5 73 Glacier Peak contamination' L34-4 35-1 Sh2 Pt2 77 69 0 28 12 24 126 0 04 Oil 0 98 3 63 3 56 0 21 96 24 3 76 L36-1 34 77 35 04 L36-1 Sh2 Ptl 74 89 0 23 13 82 150 0 05 0 22 109 4 52 3 59 Oil 9179 8 21 L36-1 Sh2 Pt2 75 97 0 18 13 58 152 0 02 0 21 112 4 06 3 20 0 12 95 17 4 83 Glacier Peak contamination' L36-2 35 04 35 30 136-2 Sh6 Pt2 75 16 0 10 13 73 124 0 01 0 25 159 4 08 3 50 0 33 98 41 159 L36-2 Sh5 Pt2 74 87 0 60 13 15 185 0 06 0 35 154 3 67 3 62 0 28 90 65 9 35 136-2 Sh6 Ptl 73 36 Oil 14 85 165 0 03 0 41 173 413 3 39 0 34 96 91 3 09 L36-2 Sh9 Ptl 73 20 0 32 14 32 2 15 0 10 0 30 119 4 71 3 61 Oil 95 38 4 62 136-2 Sh9 Pt2 72 73 0 30 14 13 2 28 0 10 0 31 118 5 02 3 79 0 15 88 95 1105 L36-2 Sh7 Ptl 76 09 0 27 13 37 102 0 00 0 23 0 96 3 54 4 44 0 07 97 39 2 61 136-2 Sh7 Pt2 75 36 0 19 13 66 111 0 04 0 25 104 3 86 4 39 Oil 9132 8 68 L36-2 Sh4 Ptl 67 34 127 13 33 6 23 0 07 110 3 96 5 06 162 0 00 100 92 -0 92 L36-2 Sh4 Pt2 67 50 118 13 80 5 99 0 04 103 3 88 4 85 170 0 02 10152 -152 L36-2 Sh3 Pt2 69 87 Oil 17 91 0 61 0 00 0 14 3 88 5 32 2 08 0 08 94 24 5 76 L36-2 Shi Pt2 69 45 0 49 16 63 177 0 07 0 29 3 79 4 84 2 64 0 04 98 14 186 136-2 Shl3 Pt2 72 58 0 26 17 52 112 0 06 0 31 114 3 51 3 17 0 33 74 69 25 31 136-2 ShlO Pt2 75 47 0 21 13 77 0 89 0 05 0 31 175 5 04 2 43 0 07 96 37 3 63 L36-2 ShlO Ptl 74 51 018 14 39 0 84 0 00 0 16 2 00 5 46 2 44 0 03 95 15 4 85 L36-2 Sh5 Ptl 75 26 0 28 13 15 163 0 06 0 27 145 3 73 3 94 0 22 97 45 2 55 Old Crow contamination' L36-2 Shi Pt3 76 68 0 15 12 97 128 0 04 0 27 131 3 65 3 45 0 20 9114 8 86 Glacier Peak contamination' L36-2 Shl3 Ptl 76 62 0 18 13 50 107 0 06 0 30 118 3 69 3 21 0 19 9135 8 65 L36 2 Sh2 Ptl 76 90 0 25 12 68 103 0 07 0 23 114 4 15 3 43 0 12 93 89 6 11 L36-2 Sh2 Pt2 77 44 0 20 12 67 0 95 0 02 0 22 113 3 76 3 45 0 17 94 22 5 78 L36-2 Sh3 Ptl 76 39 0 14 13 90 0 98 0 03 0 26 164 3 51 3 04 0 10 93 55 6 45 L36 2 Sh8 Ptl 75 95 0 20 13 52 157 0 07 0 32 1 21 3 59 3 30 0 26 79 60 20 40 L36-3 35 30 35 54 L36-3 Sh3 Ptl 66 04 0 79 16 70 3 88 0 07 151 3 76 4 53 2 56 0 15 92 35 7 65 L36-3 Shl5b Pt3 66 23 0 73 16 73 3 63 0 03 139 3 98 4 73 2 38 0 17 96 60 3 40

143 136-3 ShlO Pt2 75 45 0 20 13 95 140 0 06 0 34 127 3 79 3 35 018 87 25 12 75 L36-3 Shl6 Ptl 7146 0 41 15 23 2 48 0 07 0 75 181 4 96 2 66 018 92 96 7 04 L36-3 Shl6 Pt2 7168 0 46 15 51 2 59 0 03 0 52 164 4 70 2 65 0 22 8159 18 41 L36-3 Sh6 Ptl 7199 0 39 15 90 2 01 0 00 0 45 169 4 67 2 70 0 20 87 31 12 69 L36-3 Sh8 Ptl 72 73 0 38 15 03 165 0 06 0 45 165 5 12 2 79 0 15 86 85 13 15 L36-3 Sh8 Pt2 73 29 0 33 15 19 160 0 04 0 44 161 4 68 2 68 0 14 88 59 1141 L36-3 Shi Ptl 73 11 0 45 14 65 2 03 0 01 0 40 155 4 72 2 92 0 14 99 54 0 46 L36-3 Shi Pt2 72 99 0 49 14 59 2 00 0 00 0 45 173 4 56 2 98 0 21 95 34 4 66 L36-3 Shl8 Ptl 72 43 0 37 14 68 2 17 010 0 51 177 4 84 2 88 0 26 8146 18 54 L36-3 Sh2 Ptl 7137 119 13 05 4 05 0 09 0 53 2 11 3 72 3 84 0 05 98 41 159 136-3 Sh2 Pt2 69 70 111 14 29 4 11 0 03 0 56 2 72 411 3 30 0 08 90 61 9 39 136-3 Sh22 Ptl 69 51 130 13 82 3 94 0 05 0 74 2 49 415 3 97 0 01 98 35 165 L36-3 Sh22 Pt2 69 59 125 13 82 4 37 0 08 0 71 2 57 4 26 3 26 0 08 98 65 135 L36-3 Sh30 Pt2 70 09 115 13 51 4 55 0 13 0 87 2 58 3 76 3 35 0 03 10148 -148 L36-3 Sh4 Ptl 69 85 103 14 37 4 32 0 07 0 69 3 00 3 38 3 24 0 04 96 12 3 88 L36-3 Shl5 Ptl 73 83 100 13 39 3 04 0 02 0 23 136 3 00 4 10 0 04 97 69 2 31 L36-3 Sh20 Pt2 73 17 108 13 53 3 24 0 01 0 41 198 2 58 3 88 Oil 87 61 12 39 L36-3 Shl9 Ptl 72 00 0 30 13 85 177 0 06 0 24 147 6 43 3 84 0 05 96 61 3 39 L36-3 Sh21 Ptl 72 52 0 29 14 45 161 0 14 0 27 0 90 4 67 4 87 0 28 73 01 26 99 L36-2 Sh7 Ptl 76 09 0 27 13 37 102 0 00 0 23 0 96 3 54 4 44 0 07 97 39 2 61 L36-2 Sh7 Pt2 75 36 0 19 13 66 111 0 04 0 25 104 3 86 4 39 Oil 9132 8 68 L36-3 Sh29 Pt2 67 88 135 13 29 5 67 0 10 101 3 14 4 31 3 20 0 05 99 32 0 68 L36-3 Sh9 Ptl 66 45 0 95 16 41 3 82 0 05 0 59 4 62 4 48 2 59 0 03 97 17 2 83 L36-3 Sh28 Ptl 65 49 0 83 17 46 4 49 0 04 0 61 5 97 4 21 0 90 0 00 99 19 0 81 L36-3 Shl4 Ptl 77 89 0 24 1197 0 91 0 00 0 16 0 62 3 51 4 60 0 09 97 84 2 16 L36-3 Shl4 Pt2 77 99 0 29 12 15 0 71 0 03 0 15 0 54 3 30 4 79 0 06 9122 8 78 L36-3 Shl2 Ptl 70 47 123 1419 4 01 Oil 0 27 2 37 4 63 2 69 0 04 100 30 -0 30 L36-3 Sh25 Ptl 63 65 114 16 10 4 12 0 09 167 5 81 5 24 2 01 0 17 68 71 3129 L36 3 Shl7 Ptl 75 69 0 17 13 26 143 0 04 0 39 2 08 2 99 3 74 0 21 80 60 19 40 Old Crow contamination' L36 3 ShlO Ptl 77 24 0 20 13 03 105 0 08 0 20 123 3 72 3 09 0 16 96 49 3 51 Glacier Peak contamination' 136 3 Sh27 Ptl 76 64 0 17 13 32 160 0 04 0 29 128 3 19 3 29 0 18 83 27 16 73

144 L36-3 Sh5 Ptl 77 06 0 19 12 78 106 0 03 0 21 1 17 3 86 3 45 0 19 94 68 5 32 136-3 Sh5 Pt2 76 84 0 21 13 28 107 0 00 0 23 120 3 60 3 45 0 12 95 37 4 63 136-3 Sh7 Ptl 76 90 0 13 12 92 106 0 09 0 25 119 3 77 3 55 0 14 94 06 5 94 L36-3 Sh7 Pt2 77 29 0 21 12 74 100 0 04 0 18 1 16 3 57 3 63 0 16 93 97 6 03 1906-1913 L58 5131 5153 L58-1 68 29 104 14 74 4 32 0 13 112 3 08 3 55 3 73 0 01 98 91 109 L58-3 68 20 102 15 05 4 03 012 119 3 77 3 73 2 82 0 07 98 35 165 L58-10 77 10 0 12 12 67 0 64 0 09 Oil 0 62 3 64 4 94 0 08 96 96 3 04 L58-2 76 37 0 06 13 34 0 94 0 03 0 09 0 79 3 69 4 57 0 13 92 43 7 57 L58-4 67 19 0 97 14 68 4 56 0 06 129 3 97 4 79 2 43 0 06 98 88 112 L58-11 78 88 0 10 12 94 0 68 0 06 0 07 0 63 183 4 72 0 08 94 84 5 16 L59-1 5153 5177 L59-123 7190 108 13 79 3 00 0 00 0 28 2 34 3 82 3 72 0 06 96 37 3 63 L59-117 72 72 0 47 14 48 2 17 0 03 0 51 2 01 4 88 2 59 0 13 96 12 3 88 L59-118 73 04 0 39 14 40 2 16 0 04 0 50 2 11 4 53 2 63 0 19 96 42 3 58 L59-11 77 54 0 20 12 57 0 99 0 06 0 23 127 3 69 3 30 0 16 93 16 6 84 L59-113 77 43 0 24 12 61 102 0 04 0 25 125 3 47 3 57 0 12 95 90 4 10 L59-12 77 53 0 19 12 66 0 99 0 00 019 130 3 61 3 41 Oil 93 26 6 74 L59-127 69 56 107 14 46 4 12 0 05 0 77 2 88 4 67 2 36 0 06 96 79 3 21 L59-112 75 41 018 14 53 139 0 02 0 33 187 3 97 2 23 0 07 98 09 191 L59-122 7195 2 11 13 35 2 73 0 05 0 25 199 3 71 3 83 0 04 95 82 4 18 L59-2 5181 52 02 L59-2 29 75 33 0 33 13 15 183 0 07 0 29 147 3 50 3 68 0 33 93 39 6 61 L59-2 12 77 29 0 18 13 14 0 96 0 04 0 19 114 3 43 3 45 017 94 55 5 45 L59-2 18-1 77 68 0 05 13 00 0 78 0 08 0 12 0 94 3 66 3 59 0 10 96 50 3 50 L59-2 18-2 77 73 0 10 12 92 0 76 0 02 Oil 0 89 3 89 3 48 Oil 96 08 3 92 L59-2 18-3 77 43 0 15 13 10 0 79 0 02 012 0 97 3 67 3 66 0 09 97 74 2 26 L59-2 26-1 77 46 0 21 12 98 0 97 0 04 0 23 118 3 33 3 44 016 95 49 4 51 L59-2 26-2 77 55 0 21 12 94 0 96 0 00 0 23 124 3 36 3 34 0 18 95 74 4 26 L59-2 2-1 74 39 014 14 06 169 0 02 017 0 98 4 24 417 013 95 97 4 03 L59-2 23 74 25 0 24 14 23 2 03 0 05 0 13 0 96 3 94 4 04 0 14 95 46 4 54 L59-2 2-2 75 89 015 14 31 185 0 09 0 19 107 2 10 4 25 0 10 93 73 6 27 L59-2 27-2 75 10 0 28 10 64 4 22 0 03 0 02 0 23 4 44 4 57 0 48 95 58 4 42 L59-2 27-3 74 58 018 10 75 4 25 0 05 0 04 0 23 4 78 4 64 0 48 93 99 6 01

145 L59-2 27-1 74.55 0.16 10.62 4.30 0.12 0.02 0.31 4.78 4.77 0.37 96.18 3.82 L59-2 22 70.35 0.50 15.53 2.89 0.07 0.68 2.53 4.84 2.46 0.14 97.66 2.34 L59-2 20 70.77 0.43 14.93 3.84 0.14 0.41 1.92 4.70 2.75 0.12 96.03 3.97 1.59-3,60-1 5-1 75.60 0.37 13.02 1.62 0.04 0.25 1.56 3.30 3.90 0.34 88.22 11.78 L59-3,60-l 5-2 75.77 0.39 13.17 1.68 0.01 0.32 1.54 3.04 3.80 0.29 91.98 8.02 L59-3,60-l 11-1 77.73 0.04 12.95 0.70 0.07 0.14 0.94 3.78 3.53 0.11 94.93 5.07 L59-3,60-l 11-2 78.20 0.07 12.61 0.79 0.07 0.12 0.93 3.60 3.53 0.08 95.57 4.43 L59-3,60-l 12-1 77.59 0.18 12.95 1.01 0.05 0.20 1.26 3.25 3.39 0.12 93.90 6.10 L59-3,60-l 12-2 77.54 0.19 12.87 1.08 0.03 0.21 1.23 3.26 3.43 0.15 91.80 8.20 L59-3,60-l 13-1 77.63 0.19 12.86 1.10 0.00 0.24 1.22 3.26 338 0.13 93.76 6.24 L59-3,60-l 13-2 77.44 0.20 12.78 1.17 0.04 0.19 1.27 3.34 3.39 0.17 93.51 6.49 L59-3,60-l 15-1 77.66 0.20 12.87 1.06 0.07 0.25 1.17 3.01 3.54 0.16 93.19 6.81 L59-3,60-l 15-2 77.74 0.19 12.66 1.00 0.02 0.21 1.17 3.36 3.55 0.10 93.27 6.73 1.59-3,60-115-3 77.78 0.20 12.82 0.94 0.04 0.17 1.17 3.25 3.48 0.14 93.84 6.16 1.59-3,60-1 15-4 76.99 0.19 13.20 1.02 0.03 0.31 1.16 3.37 3.60 0.11 92.84 7.16 L59-3,60-l 16-1 77.73 0.22 12.98 0.97 0.01 0.19 1.21 3.29 3.23 0.16 94.64 5.36 L59-3,60-l 16-2 77.95 0.10 12.85 0.99 0.07 0.21 1.30 3.10 3.29 0.14 96.65 3.35 L59-3,60-l 19-1 77.52 0.15 12.70 1.03 0.06 0.23 1.27 3.49 3.40 0.15 93.19 6.81 L59-3,60-l 19-2 77.69 0.19 12.85 0.95 0.00 0.24 1.29 3.16 3.49 0.13 93.86 6.14 L59-3,60-l 2-1 73.91 0.28 14.05 1.59 0.04 0.37 1.54 3.77 4.39 0.05 91.12 8.88 139-3,60-1 2-2 73.99 0.30 14.02 1.82 0.06 0.29 1.58 3.38 4.47 0.10 90.63 9.37 139-3,60-1 3-2 74.85 0.27 14.03 1.26 0.04 0.25 1.20 3.64 4.36 0.10 94.14 5.86 139-3,60-1 3-3 74.29 0.29 14.12 1.40 0.06 0.29 1.32 3.61 4.54 0.07 92.85 7.15 1.59-3,60-1 3-4 74.84 0.33 13.85 1.33 0.06 0.28 1.27 3.45 4.49 0.10 89.52 10.48 1.59-3,60-110-1 75.75 0.09 13.37 1.05 0.04 0.03 0.88 4.12 4.56 0.09 91.87 8.13 1.59-3,60-110-2 76.23 0.05 13.64 0.97 0.07 0.08 0.81 3.56 4.46 0.14 95.51 4.49 1.59-3,60-110-3 76.05 0.05 13.67 1.04 0.04 0.04 0.86 3.56 4.61 0.10 94.31 5.69 139-3,60-1 21-1 76.02 0.22 13.32 1.09 0.04 0.25 1.09 3.29 4.66 0.03 94.35 5.65 L59-3,60-l 21-2 76.04 0.23 13.23 1.08 0.00 0.18 1.03 3.46 4.65 0.09 95.48 4.52 1.59-3,60-1 9-1 77.06 0.08 13.77 1.02 0.04 0.22 1.61 3.46 2.64 0.10 92.81 7.19 1.59-3,60-1 9-2 77.54 0.05 14.21 0.83 0.00 0.18 1.58 2.74 2.80 0.06 95.70 4.30 139- 3,60-1 9-3 77.09 0.10 13.89 0.78 0.04 0.19 1.64 3.52 2.66 0.10 92.73 7.27 L59- 3,60-114 69.55 0.70 15.10 3.15 0.08 0.76 2.72 4.80 3.00 0.15 97.47 2.53 L59- 3,60-1 1-2 68.48 0.44 14.14 4.72 0.14 0.18 1.12 5.43 5.11 0.22 95.14 4.86 L59-3,60-11-1 70.66 0.27 13.19 4.72 0.10 0.04 0.96 4.81 5.03 0.21 94.66 5.34 L60-2 52.24 52.54 L60-2 Sh4 Ptl 68.87 1.06 14.32 4.14 0.08 0.95 2.84 4.01 3.69 0.03 100.27 -0.27 L60- 2 Sh4 Pt2 69.14 1.04 14.24 4.11 0.07 1.06 2.78 3.87 3.63 0.06 101.00 -1.00 L60- 2 Sh4 Pt3 69.14 1.03 14.19 4.03 0.10 0.99 2.89 3.82 3.77 0.05 99.59 0.41 Leo-•2 Sh4 Pt4 69.50 0.98 14.20 4.12 0.10 1.00 2.85 3.65 3.54 0.06 99.28 0.72 Leo-•2 Sh4 Pt5 69.43 0.96 14.24 4.45 0.01 0.87 2.62 3.85 3.51 0.06 100.28 -0.28 Leo-•2 Shi Ptl 73.56 0.38 14.54 1.95 0.05 0.36 1.75 4.22 3.07 0.14 98.66 1.34 Leo-•2 Shi Pt2 73.81 0.43 14.33 2.02 0.04 0.45 1.71 3.87 3.14 0.19 99.63 0.37 L60- 2 Sh2 Ptl 74.23 0.39 14.60 1.89 0.07 0.44 1.66 4.01 2.60 0.12 97.00 3.00 L60-•2 Sh2 Pt2 73.94 0.45 14.79 1.92 0.01 0.43 1.67 4.09 2.61 0.09 96.72 3.28 L60-•2 Sh3 Ptl 77.61 0.16 13.01 0.97 0.00 0.23 1.21 3.33 3.36 0.11 95.18 4.82 L60-•2 Sh3 Pt2 77.91 0.13 13.17 0.95 0.06 0.18 1.08 2.88 3.47 0.17 95.53 4.47 Leo-•2 Sh3 Pt3 77.94 0.18 12.90 0.99 0.07 0.19 1.14 3.06 3.40 0.14 95.73 4.27 Leo-•2 Sh5 Ptl 77.74 0.20 13.15 0.97 0.03 0.24 1.18 3.04 3.28 0.17 96.41 3.59 L60 •2 Sh5 Pt2 77.73 0.20 12.95 1.00 0.00 0.22 1.18 3.15 3.42 0.14 96.10 3.90 L60 •2 Sh5 Pt3 77.32 0.19 13.17 1.01 0.01 0.26 1.25 3.22 3.39 0.18 89.73 10.27 0.17 Leo-•2 Sh5 Pt4 77.73 0.19 13.09 0.99 0.00 0.25 1.22 2.95 3.41 95.92 4.08 0.15 Leo-•2 Sh5 Pt5 77.74 0.20 12.93 1.03 0.05 0.21 1.20 3.18 3.32 95.85 4.15 L60-3 52.54 52.85 Leo- 3 Shi Ptl 73.23 0.96 13.85 3.62 0.08 0.75 2.09 2.04 3.33 0.06 98.37 1.63 Leo- 3 Shi Pt2 73.32 0.97 13.61 3.53 0.07 0.79 2.10 2.19 3.33 0.08 98.48 1.52 L60- 3 Shi Pt3 73.28 0.89 13.80 3.76 0.02 0.69 2.16 2.05 3.29 0.06 98.17 1.83 L60-•3 Shi Pt4 73.36 0.95 13.72 3.56 0.02 0.73 2.23 2.09 3.29 0.05 99.01 0.99 L60-•3 Sh3 Ptl 70.67 0.54 16.19 1.05 0.05 0.06 3.05 4.91 3.44 0.04 97.57 2.43 Leo- 3 Sh3 Pt2 77.37 0.52 11.95 0.98 0.02 0.05 0.33 3.41 5.35 0.04 98.60 1.40 Leo- 3 Sh3 Pt3 64.12 0.26 20.53 1.00 0.01 0.06 5.34 6.18 2.47 0.03 100.74 -0.74 L60-•3 Sh4 Ptl 60.57 0.25 23.80 0.94 0.01 0.05 8.09 5.38 0.90 0.00 101.12 -1.12 L60-•3 Sh5 Pt2 84.40 0.35 9.28 0.79 0.05 0.30 2.32 2.11 0.41 0.00 99.54 0.46 L60-•3 Sh2 Ptl 88.69 0.36 6.33 0.63 0.02 0.16 0.33 1.09 2.39 0.00 99.10 0.90

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J> 00 L63-2 53.71 53.92 L63- 2 Shi Ptl 77.56 0.19 12.86 1.01 0.04 0.25 1.14 3.43 3.37 0.15 98.07 1.93 L63 •2 Sh3 Ptl 77.70 0.16 13.14 0.84 0.02 0.26 1.17 3.23 3.32 0.16 96.07 3.93 L63 2 Sh5 Ptl 71.81 0.44 15.24 2.22 0.06 0.62 2.08 4.74 2.60 0.18 100.81 -0.81 L63 •2 Sh4 Ptl 75.62 0.19 12.40 1.69 0.11 0.04 0.29 2.94 6.69 0.02 97.43 2.57 L63-3 53.92 54.14 L63- 3 Sh3 Ptl 70.92 1.25 13.79 4.21 0.10 0.66 2.27 3.13 3.62 0.05 98.73 1.27 L63- 3 Sh3 Ptl 77.28 0.20 12.70 0.93 0.02 0.19 1.26 3.59 3.62 0.21 94.14 5.86 L63- 3 Sh4 Ptl 78.11 0.15 12.87 0.92 0.05 0.23 1.15 3.25 3.10 0.16 96.27 3.73 L63- 3 Sh4 Pt2 77.87 0.19 12.85 0.86 0.00 0.28 1.16 3.43 3.22 0.14 93.98 6.02 L63- 3 Shi Ptl 76.03 0.20 14.01 1.48 0.01 0.31 1.51 3.96 2.40 0.10 97.80 2.20 L63-4 54.14 54.35 L63-4 ShlO Ptl 71.37 1.03 13.56 3.95 0.07 0.74 2.37 3.31 3.54 0.04 96.80 3.20 L63-4 ShlO Pt3 71.38 1.02 13.60 3.83 0.07 0.69 2.46 3.29 3.57 0.09 96.61 3.39 L63-4Sh6Ptl 69.92 1.34 14.50 3.58 0.00 0.43 2.39 4.56 3.25 0.02 97.65 2.35 L63- 4 Sh7 Ptl 73.41 0.49 14.78 2.00 0.05 0.46 1.67 4.05 2.94 0.15 94.99 5.01 L63- 4 Sh2 Ptl 75.70 0.31 13.53 1.69 0.04 0.28 1.45 3.09 3.64 0.27 96.73 3.27 L63- 4 Sh3 Ptl 75.50 0.35 13.20 1.72 0.05 0.32 1.41 3.58 3.57 0.30 95.13 4.87 L63- 4 Sh3 Pt2 75.69 0.32 13.20 1.71 0.05 0.32 1.49 3.25 3.66 0.31 94.45 5.55 L63- 4 Sh3 Pt3 75.73 0.29 13.09 1.73 0.10 0.34 1.47 3.28 3.70 0.26 94.75 5.25 L63-4 ShlO Pt2 67.83 0.89 16.10 3.04 0.03 0.60 3.91 4.45 3.10 0.05 97.13 2.87 L63-•4 ShlO Pt4 54.15 0.03 27.99 0.73 0.00 0.09 10.83 5.88 0.30 0.00 100.05 -0.05 L63-•4 Sh4 Ptl 69.32 0.63 16.35 1.87 0.01 0.22 3.37 5.08 3.07 0.08 95.60 4.40 L63-•4 Sh5 Ptl 64.67 0.62 18.66 2.94 0.03 0.50 5.16 4.79 2.56 0.07 98.68 1.32 L63-•4 Sh8 Ptl 74.50 0.46 13.81 2.11 0.04 0.53 1.59 2.95 3.67 0.34 82.67 17.33 L63-4 Sh9 Ptl 72.52 0.67 13.60 2.68 0.07 0.62 1.90 4.01 3.88 0.05 98.79 1.21 L63-4 Sh9 Pt2 70.78 0.71 13.43 3.77 0.10 1.54 2.69 3.65 3.31 0.02 99.86 0.14 LBS-•4 Sh9 Pt3 75.84 0.68 12.25 2.28 0.03 0.24 1.05 3.27 4.35 0.01 97.83 2.17 LBS-•4Sh9Pt4 55.54 0.07 27.54 0.72 0.05 0.05 9.63 5.94 0.45 0.00 101.27 -1.27 L64-1 54.35 54.53 L64- lShl7Ptl 69.33 1.08 14.80 4.59 0.12 1.11 3.04 2.67 3.13 0.13 96.26 3.74 L64- 1 Sh4 Ptl 69.36 1.08 14.20 4.23 0.01 1.15 3.18 3.56 3.13 0.10 95.95 4.05 L64- 1 Shl8 Ptl 73.32 0.31 14.86 2.28 0.09 0.39 1.94 4.12 2.55 0.13 94.66 5.34 L64- 1 Shl8 Pt2 73.27 0.33 14.77 2.35 0.05 0.46 1.95 4.16 2.55 0.10 95.77 4.23 L64- 1 Sh25 Ptl 73.70 0.34 14.81 2.34 0.03 0.45 1.90 3.51 2.77 0.15 91.81 8.19

149 L64-1 Sh20 Ptl 74.37 0.28 14.99 1.59 0.05 0.49 1.66 3.77 2.69 0.11 95.31 4.69 L64-1 Sh26 Ptl 74.10 0.36 14.61 1.90 0.09 0.45 1.62 4.02 2.70 0.16 96.75 3.25 L64-1 Sh9 Ptl 73.95 0.44 14.47 1.90 0.07 0.43 1.59 4.20 2.75 0.19 95.83 4.17 L64-1 Sh24 Ptl 75.93 0.23 13.07 1.68 0.07 0.29 1.38 3.37 3.70 0.27 95.24 4.76 L64-1 cont Shl5 Ptl 77.66 0.22 12.76 0.96 0.01 0.26 1.24 3.48 3.27 0.14 95.52 4.48 L64-1 Shll Pt3 78.07 0.15 12.91 0.99 0.00 0.24 1.27 3.04 3.14 0.18 95.64 4.36 L64-1 Shl2 Ptl 77.55 0.15 12.76 0.97 0.05 0.18 1.22 3.74 3.24 0.15 95.19 4.81 L64-1 Shl3 Ptl 77.90 0.18 12.76 1.02 0.07 0.24 1.17 3.33 3.17 0.17 93.79 6.21 L64-1 Shl9 Ptl 77.47 0.19 13.12 1.01 0.02 0.28 1.28 3.16 3.28 0.18 94.30 5.70 L64-1 Sh2 Pt2 78.32 0.12 12.83 0.93 0.03 0.25 1.15 2.96 3.31 0.12 94.58 5.42 L64-1 Sh22 Ptl 77.13 0.00 12.10 1.37 0.11 0.05 0.27 4.24 4.50 0.24 93.03 6.97 L64-1 Sh22 Pt2 77.64 0.06 12.32 1.23 0.12 0.02 0.28 3.78 4.31 0.24 97.05 2.95 L64-1 Shi Ptl 64.63 0.02 18.76 0.01 0.02 0.00 0.00 0.21 16.34 0.01 98.54 1.46 L64-1 Sh3 Ptl 66.11 0.00 20.01 0.03 0.02 0.01 0.59 13.23 0.00 0.00 100.75 -0.75 L64-1 ShS Ptl 65.40 0.12 19.69 0.64 0.00 0.03 1.10 9.86 3.14 0.02 99.16 0.84 L64-1 Sh8 Ptl 66.76 1.85 13.37 5.43 0.07 0.83 2.86 5.38 3.32 0.14 94.15 5.85 L64-1 Shl4 Pt2 56.67 0.96 17.85 9.03 0.08 4.41 3.69 2.72 4.54 0.05 89.41 10.59 L64-1 Shl4 Pt3 56.73 0.97 18.22 8.80 0.14 4.39 3.46 2.60 4.64 0.05 90.36 9.64 L64-1 Sh21 Ptl 76.88 0.18 13.33 1.21 0.04 0.35 1.26 2.86 3.33 0.56 81.07 18.93 L64-1 Sh23 Ptl 66.64 0.92 15.90 5.09 0.14 1.73 2.93 3.68 2.81 0.15 84.80 15.20 L64-1 ShlO Ptl 77.27 0.12 13.18 0.92 0.07 0.22 0.76 3.84 3.51 0.10 92.97 7.03 L64-1 ShlO Pt2 77.44 0.16 13.29 0.79 0.09 0.16 0.70 3.60 3.62 0.15 93.00 7.00 L64-2 Shi Pt 1 71.24 1.29 13.23 3.99 0.08 0.46 2.02 3.70 3.93 0.06 98.24 1.76 L64-2 Sh5 Ptl 72.96 0.33 14.41 337 0.18 0.29 1.43 4.46 2.42 0.14 95.95 4.05 L64-2 Sh5 Pt2 72.87 0.35 14.79 3.48 0.12 0.31 1.50 4.06 2.37 0.14 96.89 3.11 L64-2 Sh9 Ptl 73.92 0.43 14.49 1.82 0.06 0.43 1.73 4.02 2.93 0.16 96.82 3.18 L64-2 Shll Ptl 76.48 0.32 12.92 1.75 0.05 0.32 1.50 2.79 3.62 0.24 93.12 6.88 L64-2 ShlO Ptl 77.92 0.19 12.68 0.93 0.04 0.27 1.29 3.13 3.33 0.21 93.83 6.17 L64-2 Sh3 Pt2 77.96 0.21 12.76 0.96 0.00 0.23 1.15 3.26 3.35 0.12 93.61 6.39 L64-2 Sh6 Ptl 77.61 0.13 12.74 1.05 0.03 0.22 1.23 3.66 3.18 0.16 95.01 4.99 L64-2 Sh6 Pt2 77.56 0.15 12.89 1.12 0.08 0.26 1.17 3.16 3.45 0.16 93.11 6.89

150 L64- 2 Sh2 Ptl 71.20 0.69 15.25 1.50 0.03 0.12 3.10 4.27 3.77 0.08 97.92 2.08 L64-2 Sh3 Pt3 77.01 0.18 12.98 1.65 0.03 0.30 1.30 2.89 3.40 0.26 84.44 15.56 L64- 2 Sh7 Ptl 82.15 0.03 12.28 0.78 0.00 1.51 2.05 0.22 0.93 0.04 76.46 23.54 L64- 2 Sh8 Ptl 64.74 0.15 27.76 0.83 0.10 0.22 0.96 2.33 2.65 0.26 81.48 18.52 L64- 2 Shl3 Ptl 63.60 0.29 18.04 4.54 0.12 0.14 1.08 6.71 5.28 0.19 99.59 0.41 L64- 2 Sh4 Ptl 52.00 0.27 5.85 15.01 0.48 13.16 12.27 0.85 0.11 0.00 96.91 3.09 L64-•2 ShlO Ptl 75.90 0.20 10.36 4.35 0.08 0.01 0.26 4.22 4.24 0.37 95.14 4.86 L64-3 54.73 54.91 L64-•3 Shi Ptl 74.02 0.44 14.45 1.87 0.02 0.45 1.72 4.01 2.81 0.21 95.77 4.23 L64-•3 Sh3 Pt3 75.04 0.27 14.01 2.00 0.05 0.27 1.53 3.72 3.00 0.11 93.53 6.47 L64-•3 Sh4 Ptl 76.19 0.29 12.97 1.68 0.07 0.28 1.51 3.30 3.37 0.35 94.61 5.39 L64-•3 Sh5 Ptl 77.57 0.15 12.59 1.03 0.08 0.20 1.23 3.75 3.23 0.16 94.11 5.89 L64-•3 Sh5 Pt2 77.26 0.26 12.89 1.01 0.06 0.22 1.16 3.60 3.36 0.17 93.94 6.06 L64-•3 Sh5 Pt3 77.49 0.19 12.79 1.01 0.01 0.24 1.25 3.39 3.43 0.18 93.26 6.74 L64-•3 Sh2 Ptl 76.10 0.13 13.05 1.43 0.07 0.13 0.50 3.96 4.45 0.18 94.77 5.23 L64-•3 Sh2 Pt2 75.82 0.19 13.34 1.59 0.05 0.08 0.53 3.90 4.38 0.13 94.81 5.19 L64-•3 Sh6 Ptl 76.72 0.04 13.12 1.02 0.11 0.11 0.81 3.62 4.31 0.14 95.14 4.86 L64-•3 Sh6 Pt2 76.78 0.12 13.28 0.93 0.05 0.09 0.78 3.64 4.21 0.12 95.12 4.88 L64-•3 Sh7 Ptl 75.80 0.08 13.27 0.95 0.05 0.09 1.53 3.70 4.37 0.17 91.99 8.01 L64-4 54.91 55.10 L64-4 Shll Ptl 70.55 1.18 14.13 4.23 0.03 0.96 2.90 2.62 3.32 0.08 98.08 1.92 L64-4 Sh8 Ptl 70.08 1.28 13.66 4.57 0.08 0.75 2.55 3.48 3.49 0.06 97.86 2.14 L64-4 Sh8 Pt2 71.10 1.20 13.55 4.23 0.01 0.74 2.51 3.21 3.37 0.07 98.66 1.34 L64-4 ShlO Ptl 72.68 0.33 14.51 3.38 0.16 0.14 1.50 4.15 2.96 0.19 97.28 2.72 L64-4 Sh3 Ptl 72.09 0.24 14.56 4.13 0.13 0.27 1.74 3.87 2.85 0.14 95.44 4.56 L64-4 Sh7 Ptl 76.43 0.12 13.60 0.52 0.06 0.03 0.69 3.81 4.70 0.06 99.09 0.91 L64- 4 Shi Ptl 77.68 0.06 12.17 1.21 0.12 0.01 0.25 4.07 4.20 0.23 95.11 4.89 L64-4Sh5Ptl 78.12 0.06 12.08 1.37 0.06 0.05 0.26 3.50 4.22 0.28 95.57 4.43 L64- 4 Sh9 Ptl 78.00 0.00 12.20 1.35 0.18 0.05 0.26 3.62 4.13 0.22 95.44 4.56 L64- 4 Sh4 Pt2 75.04 0.19 14.13 2.06 0.06 0.17 1.06 3.94 3.25 0.10 95.87 4.13 L64-4Sh4Ptl 99.81 0.00 0.07 0.00 0.00 0.00 0.04 0.04 0.04 0.00 98.45 1.55 L64-4 Sh4 Pt3 1.29 1.37 16.88 2.54 1.59 0.99 0.95 0.00 0.15 74.23 1.10 98.90 L64- 4 Sh2 Ptl 76.94 0.27 11.88 1.84 0.01 0.01 0.70 1.61 6.67 0.06 93.52 6.48

151 LO

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DOOtHisrsOrsrorMrM ro in co oo smiscnr^cncntH'tfoq rM rM rM rsi \D \S> ID _ cno^rMrsirsiroroododoooScricr__ __ i o cn ID ID 00 ^j- ID ID ID ID Is CD CD ID CO CD CO ID ID is in ID ID ID rs

Vi D- i-i o_ +J o_ O- iJ 4-i m ro m rsi ro oo °- ^H tH °- cn °- °- CD ro ro tH rsi rsi rsi ro tH «3- rsi rsi cn tH uiwininioininintnino^oninincncoincniniOLOiniotncoini/) 4444444444444 L74-2 Shll Ptl 75.28 0.26 13.40 1.22 0.01 0.31 1.67 3.79 3.75 0.32 89.94 10.06 L74-2 Sh6 Ptl 75.95 0.31 12.94 1.67 0.04 0.26 1.54 3.25 3.74 0.31 94.31 5.69 L74-2 Shl7 Ptl 76.13 0.25 13.05 1.77 0.04 0.32 1.58 2.95 3.65 0.26 95.25 4.75 L74-2 Sh7 Ptl 77.38 0.15 12.81 1.02 0.03 0.27 1.32 3.38 3.48 0.16 94.78 5.22 L74-2 Sh7 Pt2 77.44 0.21 12.62 1.08 0.00 0.24 1.28 3.49 3.44 0.21 94.15 5.85 L74-2 Shl2 Ptl 78.03 0.14 12.88 1.17 0.01 0.23 1.31 3.76 2.32 0.14 91.53 8.47 L74-2 Shl8 Ptl 78.55 0.28 13.58 1.69 0.11 0.32 1.56 0.87 2.78 0.26 93.67 6.33 L74-2 Sh8 Ptl 66.99 1.05 14.91 4.65 0.06 1.46 3.79 3.95 3.08 0.07 98.56 1.44 L74-2 Sh2 Pt2 67.72 1.03 14.48 4.57 0.10 1.26 3.43 4.08 3.27 0.06 97.75 2.25 L74-2 Shl4 Ptl 68.22 1.04 14.52 4.48 0.13 1.25 3.46 3.32 3.47 0.10 97.88 2.12 L74-2 Sh3 Ptl 68.24 1.03 14.75 4.60 0.05 1.31 3.41 3.42 3.08 0.11 99.52 0.48 L74-2 Sh2 Ptl 68.39 0.96 14.50 4.16 0.04 1.17 3.43 4.29 3.01 0.05 99.02 0.98 L74-2 Shl6 Ptl 68.81 1.15 14.59 4.67 0.09 1.15 3.31 2.86 3.29 0.08 98.50 1.50 L74-2 Sh5 Ptl 69.11 1.10 13.86 4.40 0.09 0.90 2.96 3.72 3.83 0.04 98.05 1.95 L74-2 Shi Ptl 71.40 1.22 13.19 4.51 0.05 0.73 2.29 2.57 3.97 0.07 97.75 2.25 L74-2 Shl3 Ptl 64.81 0.73 18.90 2.67 0.02 0.37 5.55 4.63 2.30 0.02 98.54 1.46 L74-2 Sh9 Ptl 70.05 1.24 12.74 3.72 0.05 1.60 2.64 3.28 4.64 0.04 96.81 3.19 L74-3 60.15 60.36 L74-3 Sh3 Ptl 73.55 0.30 14.44 2.12 0.14 0.10 0.93 4.13 4.06 0.23 87.92 12.08 L74-3 Sh5 Ptl 73.72 0.46 15.04 2.19 0.05 0.54 1.63 3.45 2.69 0.23 92.37 7.63 L74-3 Sh8 Pt2 77.93 0.23 12.60 0.98 0.06 0.22 1.26 3.40 3.16 0.15 94.58 5.42 L74-3 Shll Ptl 78.21 0.19 12.58 0.98 0.07 0.22 1.16 3.21 3.26 0.12 93.95 6.05 L74-3Shl2Ptl 70.82 0.98 14.39 3.04 0.02 0.37 2.45 4.03 3.78 0.10 96.96 3.04 L74-3 Sh7 Pt2 73.02 1.18 12.97 3.37 0.06 0.43 1.81 3.04 4.02 0.08 96.54 3.46 L74-3 Sh9 Pt3 68.56 1.01 14.45 4.46 0.03 0.93 3.02 4.02 3.51 0.03 97.79 2.21 L74-3 Shi Ptl 68.71 1.08 14.41 4.20 0.06 1.00 3.05 3.22 4.17 0.09 99.58 0.42 L74-3 Sh9 Pt2 68.77 1.17 14.20 4.27 0.12 0.89 2.85 4.15 3.53 0.03 96.28 3.72 L74-3 Sh9 Ptl 69.06 1.21 14.03 4.01 0.05 1.23 2.67 4.03 3.55 0.16 92.28 7.72 L74-3 Shl4 Ptl 69.43 1.13 14.36 4.41 0.06 1.09 3.04 3.15 3.24 0.08 97.70 2.30 L74-3 Shl3 Pt2 70.40 1.23 13.88 3.65 0.10 0.53 2.75 3.20 4.24 0.01 95.00 5.00 L74-3 Sh2 Ptl 70.39 1.21 15.04 2.48 0.06 0.87 1.60 3.37 4.91 0.08 92.40 7.60 1809 L132-1 90.90 91.08 L132-lShlPt2 75.09 0.32 13.27 1.77 0.03 0.28 1.61 3.68 3.66 0.27 93.89 6.11

153 L132- 1 Shi Ptl 75.16 0.30 13.21 1.71 0.05 0.28 1.63 3.53 3.82 0.32 93.34 6.66 L132- lShlPt3 75.09 0.26 13.33 1.72 0.06 0.32 1.63 3.54 3.80 0.25 92.84 7.16 L132- 1 Sh3 Ptl 49.27 3.03 13.28 14.43 0.19 5.22 10.50 3.49 0.53 0.05 97.18 2.82 L132- 1 Sh3 Pt2 49.19 2.94 13.38 14.66 0.21 5.31 10.58 3.17 0.51 0.05 96.85 3.15 L132- 1 Sh2 Ptl 78.03 0.41 11.36 1.35 0.08 0.18 0.61 2.84 3.85 130 57.92 42.08 L132-2 91.08 91.23 L132- 2 Sh4 Ptl 75.84 0.27 13.47 1.20 0.06 0.25 1.14 3.23 4.48 0.06 92.15 7.85 L132- 2 Sh7 Ptl 75.49 0.22 13.76 1.55 0.01 0.25 1.15 4.22 3.21 0.12 95.87 4.13 L132- 2ShlPt3 77.01 0.13 12.88 1.05 0.03 0.28 1.27 3.86 3.36 0.14 94.15 5.85 L132-•2 Shi Ptl 77.08 0.25 12.69 1.11 0.02 0.26 1.23 3.85 3.38 0.13 92.27 7.73 L133- 2 Sh8 Pt3 77.10 0.23 12.59 1.05 0.06 0.23 1.20 3.53 3.85 0.16 88.05 11.95 L132-2ShlPt2 77.35 0.19 12.83 1.03 0.02 0.19 1.25 3.50 3.48 0.15 93.94 6.06 L132- 2 Sh3 Ptl 77.47 0.19 12.59 0.79 0.05 0.16 0.75 3.40 4.56 0.04 95.21 4.79 L132- 2 Sh8 Ptl 77.85 0.14 13.01 0.64 0.04 0.18 0.95 3.88 3.22 0.10 92.75 7.25 L132- 2 Sh8 Pt2 77.96 0.08 12.91 0.64 0.00 0.13 1.08 3.82 3.28 0.09 94.68 5.32 L132-•2 Sh5 Pt2 73.84 0.34 14.84 1.47 0.09 0.47 1.58 4.53 2.72 0.12 94.55 5.45 L132-•2 Sh9 Ptl 76.18 0.04 14.27 0.63 0.16 0.07 0.48 4.05 4.09 0.03 98.07 1.93 L132-•2 Sh9 Pt2 76.52 0.01 14.25 0.65 0.09 0.07 0.45 3.93 4.00 0.04 95.14 4.86 L132- 2 Sh9 Pt3 76.79 0.03 14.08 0.67 0.15 0.04 0.41 3.74 4.10 0.00 93.80 6.20 L133-•2 Sh6 Pt2 57.69 0.16 25.35 0.89 0.01 0.11 8.28 7.03 0.48 0.00 100.50 -0.50 L132-•2 Sh2 Ptl 70.95 0.50 15.93 3.02 0.09 1.10 1.55 3.58 3.03 0.27 79.74 20.26 3.19 7.27 L132-•2 Sh7 Pt2 77.82 0.24 14.11 1.64 0.05 0.24 1.23 1.34 0.15 92.73 L133-1 91.23 91.40 L133 1 Sh7 Ptl 74.40 0.27 13.75 1.71 0.09 0.18 1.31 3.69 4.48 0.10 98.14 1.86 L133 1 ShlO Ptl 74.32 0.34 13.50 1.94 0.05 0.28 1.48 3.42 4.12 0.56 94.58 5.42 L133- lShl6Ptl 75.85 0.30 12.85 1.71 0.08 0.32 1.50 3.36 3.68 0.34 92.75 7.25 L133- 1 Sh5 Ptl 76.89 0.23 13.17 0.93 0.05 0.19 0.90 3.15 4.41 0.07 94.33 5.67 L133- 1 Sh4 Pt2 76.96 0.18 13.07 1.42 0.08 0.15 0.81 3.82 3.35 0.15 92.86 7.14 L133 •1 Sh4 Ptl 77.03 0.15 12.96 1.35 0.07 0.17 0.83 3.65 3.62 0.17 92.00 8.00 L133 •1 Sh3 Ptl 77.26 0.21 12.96 1.33 0.04 0.20 0.87 3.60 3.42 0.12 93.24 6.76 L133-•lShl9Ptl 78.12 0.16 12.59 0.96 0.02 0.23 1.19 3.22 3.42 0.08 95.24 4.76 L133 1 Shll Ptl 76.75 0.21 13.71 1.35 0.00 0.32 1.70 3.75 2.13 0.08 95.33 4.67 L133 !ShllPt2 76.58 0.29 13.42 1.45 0.01 0.27 1.63 3.89 2.37 0.09 95.87 4.13

154 L133 •lShl2Ptl 72.88 0.40 14.76 3.09 0.03 0.38 1.70 3.84 2.82 0.12 96.19 3.81 L133 •1 Sh20 Ptl 74.75 0.18 14.77 1.65 0.07 0.63 1.51 2.80 3.30 0.34 80.08 19.92 L133 •1 Sh8 Ptl 78.18 0.17 13.33 1.13 0.06 0.22 1.32 2.97 2.35 0.25 88.25 11.75 L133 •1 Sh9 Ptl 74.12 0.32 14.05 2.00 0.05 0.35 1.46 3.38 3.82 0.44 82.06 17.94 L133 •lShl7Ptl 79.01 0.22 13.44 1.03 0.04 0.20 1.39 1.60 2.89 0.19 96.51 3.49 L133 •lShl9Pt2 79.56 0.20 13.17 1.02 0.02 0.26 1.27 1.23 3.14 0.13 93.92 6.08 L133 •1 Shi Ptl 89.40 0.42 4.53 1.53 0.08 0.44 0.86 2.40 0.29 0.05 97.24 2.76 L133-2 91.40 91.54 L133-2 Sh9 Pt4 76.27 0.28 12.95 1.68 0.07 0.28 1.48 3.03 3.65 0.30 95.58 4.42 L132-2 Sh4 Ptl 75.84 0.27 13.47 1.20 0.06 0.25 1.14 3.23 4.48 0.06 92.15 7.85 L133-2 Sh7 Ptl 73.55 0.26 14.39 2.12 0.00 0.17 0.87 4.57 3.90 0.17 97.84 2.16 L133- 2 Sh7 Pt2 73.69 0.31 14.06 2.01 0.06 0.20 0.94 4.54 4.03 0.16 98.75 1.25 L133-•2 Sh2 Ptl 75.31 0.21 13.12 1.77 0.00 0.27 1.56 3.67 3.83 0.27 94.12 5.88 L133-•2 Sh2 Pt2 75.07 0.30 13.18 1.83 0.07 0.29 1.56 3.64 3.76 0.29 94.77 5.23 L133-•2 Sh8 Pt3 77.10 0.23 12.59 1.05 0.06 0.23 1.20 3.53 3.85 0.16 88.05 11.95 L132-•2 Sh8 Pt2 77.96 0.08 12.91 0.64 0.00 0.13 1.08 3.82 3.28 0.09 94.68 5.32 L133-•2 Sh5 Ptl 77.97 0.13 12.79 1.02 0.03 0.28 1.25 3.16 3.22 0.15 94.72 5.28 L133-•2 Shi Ptl 78.65 0.16 12.22 0.63 0.02 0.15 0.79 3.80 3.51 0.07 93.56 6.44 L133 •2 Sh3 Pt3 48.84 3.10 12.97 14.52 0.21 5.61 10.16 4.13 0.46 0.00 99.03 0.97 L133-•2 Sh4 Ptl 88.22 0.23 5.54 1.27 0.02 0.44 1.03 2.82 0.39 0.03 98.55 1.45 L133 •2 Sh6 Pt2 57.69 0.16 25.35 0.89 0.01 0.11 8.28 7.03 0.48 0.00 100.50 -0.50 1783 L147-1 97.61 97.78 L147 1 Sh3 Ptl 67.04 0.75 15.87 4.37 0.05 1.23 3.30 4.70 2.53 0.16 96.14 3.86 L147 1 Sh3 Pt2 67.54 0.81 16.06 4.39 0.11 1.16 3.30 4.06 2.43 0.13 95.83 4.17 L147- lSh22ptl 73.79 0.45 14.15 2.25 0.15 0.47 2.08 4.67 1.87 0.12 96.05 3.95 L147- 1 Sh22 pt2 73.76 0.47 14.07 2.31 0.15 0.54 1.92 4.81 1.91 0.07 97.45 2.55 L147- lShl9 75.93 0.13 13.68 1.72 0.08 0.12 0.78 3.94 3.48 0.14 95.19 4.81 L147 IShll 76.34 0.20 13.41 1.46 0.07 0.21 1.12 3.83 3.21 0.16 94.91 5.09 L147- lShl7 76.13 0.22 13.31 1.70 0.05 0.29 1.46 2.77 3.82 0.24 93.81 6.19 L147 lShl4 74.12 0.21 14.41 2.01 0.08 0.14 0.86 3.86 4.17 0.14 95.73 4.27 L147 IShIO 73.95 0.25 14.29 1.95 0.06 0.15 0.87 4.34 4.02 0.12 99.66 0.34 L147-lShl 8 78.54 0.21 12.87 0.88 0.06 0.29 1.17 2.65 3.20 0.14 95.22 4.78 L147 lSh4 79.25 0.27 12.04 1.13 0.02 0.37 0.77 2.72 3.38 0.05 94.28 5.72

155 L147-1 Sh5 77.22 0.25 13.87 1.31 0.04 0.32 1.57 3.12 2.20 0.09 95.08 4.92 L147-1 Sh6 77.96 0.18 12.73 0.90 0.09 0.25 1.24 3.20 3.27 0.16 95.76 4.24 L147-1 Shl3 73.50 0.32 14.56 2.01 0.03 0.50 1.73 4.32 2.86 0.18 93.39 6.61 L147-1 Shl5 74.22 0.18 14.49 1.54 0.03 0.36 1.92 3.87 3.10 0.28 98.29 1.71 L147-1 Sh20 Ptl 73.49 0.24 15.32 1.56 0.05 0.46 1.65 4.42 2.75 0.06 95.21 4.79 L147-1 Sh20 Pt2 73.87 0.33 15.03 1.45 0.09 0.41 1.70 4.18 2.85 0.08 93.74 6.26 L147-1 Sh9 73.70 0.45 14.46 2.05 0.06 0.45 1.75 4.31 2.60 0.19 94.46 5.54 L147-1 Shi Ptl 44.54 0.46 13.43 17.45 0.27 9.24 12.58 1.82 0.19 0.02 97.42 2.58 L147-1 Shi Pt2 44.42 0.53 13.68 17.76 0.20 9.01 12.44 1.81 0.16 0.00 98.21 1.79 L147-1 Shi Pt3 44.88 0.54 13.83 17.49 0.24 8.96 12.15 1.74 0.15 0.01 98.11 1.89 L147-1 Shl2 76.16 0.25 13.53 1.09 0.00 0.39 1.29 3.30 3.60 0.38 80.09 19.91 L147-1 Sh21 pt 76.20 0.26 13.72 1.05 0.04 0.28 1.24 3.11 3.73 0.38 69.67 30.33 L147-1 Sh21 ptl 77.21 0.10 12.84 1.15 0.01 0.19 1.28 3.15 3.72 0.34 69.57 30.43 L147-1Sh7 46.38 1.09 9.00 21.58 0.53 8.39 10.78 1.54 0.61 0.12 97.83 2.17 L147-1 Sh8 61.47 0.45 19.72 2.56 0.03 3.48 5.01 5.78 1.50 0.00 98.23 1.77 L147-2 97.78 97.94 L147-2 Sh4 Ptl 75.116 0.170 14.157 1.802 0.096 0.207 1.069 3.890 3.360 0.133 95.124 4.876 L147-2ShlPtl 78.499 0.185 13.093 0.950 0.027 0.236 1.213 2.309 3.342 0.145 94.873 5.127 L147-2 Sh2 Ptl 77.887 0.181 12.944 0.943 0.012 0.241 1.318 3.052 3.312 0.110 94.767 5.233 L147-2 Sh3 Ptl 77.382 0.214 13.108 1.042 0.026 0.252 1.212 3.536 3.061 0.167 94.914 5.086 L147-2 Sh3 Pt2 77.513 0.151 12.833 0.988 0.057 0.235 1.338 3.550 3.178 0.157 94.317 5.683 L147-2 Sh6 Ptl 77.907 0.208 12.931 0.993 0.067 0.283 1.251 2.895 3.333 0.132 93.360 6.640 L147-2 Sh8 Ptl 77.463 0.269 13.133 1.010 0.071 0.238 1.292 3.095 3.277 0.152 93.556 6.444 L147-2 Sh8 Pt2 78.146 0.161 12.910 0.947 0.037 0.205 1.233 2.988 3.245 0.128 95.707 4.293 L147-2 Sh6 Pt2 79.980 0.257 13.176 1.008 0.068 0.234 1.244 0.935 2.963 0.135 92.144 7.856 L148 97.94 98.10 L148 Sh20 Pt2 72.08 0.38 15.03 3.61 0.10 0.20 1.49 4.02 2.92 0.18 98.24 1.76 L148 Sh20 Ptl 72.41 0.35 14.12 3.36 0.19 0.20 1.46 4.88 2.90 0.14 96.67 3.33 L148 Sh23 Ptl 73.69 0.30 14.49 2.16 0.11 0.26 1.18 4.05 3.65 0.12 94.90 5.10 L148 Sh2 Pt3 73.69 0.30 14.06 1.67 0.09 0.35 1.57 3.84 4.38 0.04 95.40 4.60 L148 Sh2 Pt2 73.98 0.33 13.81 1.56 0.07 0.34 1.61 3.78 4.45 0.08 94.29 5.71 L148 Sh8 Ptl 76.09 0.22 13.93 1.26 0.05 0.32 1.49 4.12 2.40 0.11 88.93 11.07 L148 Shi Ptl 77.86 0.20 12.89 0.91 0.02 0.24 1.23 3.48 3.05 0.15 96.50 3.50

156 L148Shl3Ptl 77.48 0.13 12.64 1.03 0.07 0.20 1.23 3.67 3.39 0.17 97.22 2.78 L148 Shl4 Ptl 78.01 0.24 12.73 0.93 0.02 0.23 1.18 3.30 3.24 0.13 96.39 3.61 L148Shl5Ptl 77.98 0.19 12.73 0.97 0.05 0.24 1.21 3.16 3.31 0.15 97.61 2.39 L148Shl7Ptl 76.73 0.11 13.63 0.71 0.08 0.07 0.88 3.00 4.75 0.05 96.08 3.92 L148 Shl9 Pt2 77.77 0.25 12.68 0.94 0.04 0.26 1.14 3.33 3.47 0.13 96.04 3.96 L148 Sh4 Ptl 77.93 0.22 12.71 0.96 0.03 0.22 1.23 3.14 3.39 0.17 94.11 5.89 L148 Sh5 Ptl 77.35 0.23 12.84 1.10 0.08 0.27 1.25 3.23 3.48 0.16 93.31 6.69 L148 Sh7 Ptl 77.18 0.13 13.62 1.23 0.01 0.23 1.49 3.90 2.14 0.08 93.42 6.58 L148 Shl6 Ptl 74.09 0.22 14.87 1.37 0.04 0.52 2.03 4.21 2.62 0.04 95.08 4.92 L148Shl8Ptl 73.95 0.29 14.99 1.40 0.05 0.48 1.59 4.39 2.76 0.10 96.13 3.87 L148 Sh21 Ptl 73.91 0.39 14.55 1.94 0.09 0.41 1.56 4.27 2.66 0.20 95.79 4.21 L148 Sh6 Pt3 73.38 0.41 14.59 2.07 0.07 0.46 1.68 4.43 2.77 0.16 94.78 5.22 L148 Sh9 Ptl 74.18 0.36 14.22 1.93 0.05 0.38 1.65 4.32 2.68 0.23 95.03 4.97 L148 Sh6 Pt2 67.15 0.64 19.71 3.59 0.09 0.70 1.70 3.73 2.28 0.42 69.12 30.88 L148Shl2Ptl 58.77 0.04 10.07 12.70 0.15 9.39 1.69 7.16 0.02 0.02 97.60 2.40 L148Shl9Ptl 77.22 0.19 12.66 1.08 0.02 0.21 1.15 3.64 3.47 0.37 73.81 26.19 WRE L240-1 157.69 157.75 L240 1 Shi Ptl 75.22 0.15 13.66 1.29 0.03 0.04 0.91 4.05 4.42 0.24 74.75 25.25 L240 1 Sh4 Ptl 76.45 0.34 13.27 1.30 0.01 0.30 1.30 3.39 3.49 0.14 86.33 13.67 L240 1 Sh6 Ptl 72.82 0.32 14.45 2.46 0.12 0.55 1.89 5.25 1.94 0.20 75.83 24.17 L240-2 157.75 157.81 No shards L240-3 157.81 157.87 No shards L240-4 157.87 157.93 No shards L240-5 157.93 158.00 No shards L240-6 158.00 158.06 No shards L240-7 158.06 158.12 L240 7 Shi Ptl 73.94 0.16 14.56 1.38 0.05 0.29 1.71 4.04 3.47 0.41 83.35 16.65 L240 7 Shi Pt2 73.67 0.16 15.31 1.28 0.10 0.32 1.63 4.08 3.17 0.28 99.04 0.96 L240 7 Shl-1 73.65 0.15 15.71 1.31 0.00 0.25 1.58 3.99 3.04 0.32 100.67 -0.67 L240 7 Shl-2 75.12 0.22 13.85 1.25 0.07 0.30 1.79 3.57 3.50 0.34 90.99 9.01 L240 7Shl-3 75.17 0.24 14.41 1.34 0.02 0.37 1.72 3.22 3.24 0.28 98.89 1.11 L240 7Shl-4 75.42 0.16 14.15 1.28 0.04 0.32 1.65 3.35 3.33 0.29 97.34 2.66 L240 7 Sh4 Ptl 76.51 0.22 12.74 1.01 0.00 0.31 1.25 4.07 3.79 0.11 86.70 13.30

157 L240 7 Sh4 Pt2 76.31 0.20 13.30 1.00 0.03 0.20 1.19 3.97 3.64 0.16 90.71 9.29 L240 7 Sh8 Ptl 73.59 0.18 14.87 1.54 0.04 0.38 1.83 4.10 3.11 0.37 95.30 4.70 L240 7 Sh9 Ptl 72.68 0.34 14.64 2.11 0.01 0.54 1.66 4.69 2.94 0.39 63.42 36.58 L240 7 Sh9-1 73.63 0.40 14.42 2.04 0.07 0.82 1.62 3.92 2.90 0.17 95.77 4.23 L240 7 Sh9-2 73.66 0.42 15.12 1.95 0.05 0.38 1.76 3.63 2.85 0.18 89.20 10.80 L240 7 Sh9-3 73.92 039 14.47 2.01 0.06 0.51 1.66 3.96 2.85 0.17 9330 6.70 L240 7 Sh3 Ptl 75.80 0.19 13.39 1.54 0.03 0.37 1.16 3.72 3.64 0.16 85.63 14.37 L240 7 Sh5 Ptl 75.39 0.28 12.81 1.77 0.01 0.28 1.44 3.89 3.88 0.26 89.40 10.60 L240 7 Sh5-1 75.90 0.31 12.87 1.72 0.11 0.25 1.47 3.38 3.72 0.26 93.36 6.64 L240 7 Sh3 Pt2 77.01 0.23 12.83 1.00 0.05 0.24 1.22 3.56 3.70 0.18 87.30 12.70 L240 7 Sh4-1 77.74 0.25 12.66 0.94 0.00 0.23 1.22 3.45 3.36 0.14 95.60 4.40 L240 7 Sh3-1 77.32 0.26 13.01 1.01 0.01 0.12 1.13 3.43 3.59 0.12 93.07 6.93 L240 7 Sh3-2 78.23 0.18 12.60 0.97 0.05 0.27 1.18 2.96 3.43 0.14 93.72 6.28 L240-8 158.12 158.18 No shards L240-9 158.18 158.24 L240 9 ShlO-1 56.79 1.84 13.87 10.80 0.12 3.91 7.55 3.84 1.17 0.11 97.64 2.36 L240 9 Shll Ptl 57.08 1.57 13.79 11.17 0.15 3.76 7.45 3.58 1.23 0.23 77.21 22.79 L240 9 Sh4 Ptl 54.91 1.91 13.30 12.52 0.13 3.40 7.10 4.68 1.76 0.30 71.47 28.53 L240 9 Sh4-1 55.76 1.77 13.17 12.00 0.15 3.54 7.26 4.52 1.69 0.14 80.62 19.38 L240 9 Sh6 Ptl 57.22 1.67 13.07 11.59 0.19 3.80 7.92 3.13 1.34 0.06 96.66 3.34 L240 9 Sh6-1 56.75 1.92 13.47 11.52 0.23 3.96 7.61 3.16 1.34 0.05 98.22 1.78 L240 9 Sh8 Ptl 57.18 1.66 13.70 11.22 0.20 3.70 7.03 3.34 1.75 0.21 76.30 23.70 L240 9 Sh8-1 57.46 1.64 14.02 10.69 0.16 3.96 7.07 3.18 1.77 0.05 99.82 0.18 L240 9 Sh8-2 57.21 1.75 13.99 10.86 0.13 4.01 7.05 3.06 1.88 0.08 99.59 0.41 L240 9 Sh8-3 57.44 1.57 13.98 11.18 0.14 4.01 7.34 2.61 1.72 0.02 100.07 -0.07 L240 9 Sh5 Ptl 57.28 1.77 14.10 10.99 0.10 3.36 3.51 6.20 2.10 0.60 53.54 46.46 L240 9 Sh5-1 57.84 1.61 14.29 11.07 0.18 3.03 3.55 6.01 2.00 0.42 65.02 34.98 L240 9 Sh3 Ptl 57.52 1.71 14.36 10.86 0.12 2.97 4.17 5.56 2.22 0.50 64.89 35.11 L240 9Shl2-l 72.71 0.26 14.89 1.73 0.04 0.42 2.12 4.48 2.99 0.37 90.94 9.06 L240 9Shl2-2 73.11 0.17 14.88 1.66 0.07 0.38 2.14 4.22 3.06 0.31 89.73 10.27 L240 9 Sh9-1 73.36 0.41 14.45 2.19 0.04 0.27 1.22 4.42 3.54 0.10 94.92 5.08 L240 9 Sh9 Ptl 71.15 0.35 16.23 2.33 0.05 0.24 1.27 4.85 3.36 0.17 78.80 21.20

158 L240 9 Sh9-2 71.05 0.39 15.50 2.24 0.09 0.60 1.96 5.00 3.08 0.09 98.41 1.59 L240 9 Sh9-3 69.77 0.39 16.28 1.99 0.08 0.41 2.88 5.29 2.85 0.07 98.64 1.36 L240 9 Shi Ptl 77.37 0.20 12.70 1.07 0.02 0.27 1.26 3.64 3.28 0.18 88.91 11.09 L240 9 Sh7-1 77.11 0.32 13.43 1.07 0.04 0.17 1.35 1.95 3.34 1.22 36.56 63.44 L240 9 Sh7-2 77.33 0.32 13.66 1.36 0.05 0.21 1.23 2.04 3.30 0.50 55.11 44.89 L240-10 158.24 158.30 No shards L240-11 158.30 158.36 No shards L240-12 158.36 158.42 No shards L240-13 158.42 158.48 No shards L240-14 158.48 158.54 No shards L240-15 158.54 158.61 No shards WRN L248-1/249-1 164.79 164.92 No shards L249-2 164.92 165.04 No shards L249-3 165.04 165.17 No shards L249-4 165.17 165.29 L249-41 71.56 0.62 15.50 2.93 0.08 0.67 1.93 3.21 3.41 0.09 93.91 6.09 L249-4 2 76.39 0.27 13.97 1.43 0.06 0.37 1.55 3.61 2.28 0.09 93.41 6.59 L249-4 3 76.79 0.04 12.81 0.24 0.07 0.06 0.41 3.53 5.72 0.33 69.20 30.80 L249-5 165.29 165.41 No shards L249-6 165.41 165.54 No shards L249-7/250-1 165.54 165.67 L249-7Sh4 67.70 0.69 15.62 3.98 0.13 0.98 2.66 5.42 2.72 0.12 89.26 10.74 L249-7 Sh 10 69.01 1.34 15.80 2.11 0.01 0.12 1.85 5.79 3.94 0.04 97.05 2.95 L249-7 Sh 3 pt 1 69.86 0.56 15.36 2.75 0.17 0.47 1.09 6.60 2.98 0.16 93.03 6.97 L249-7 Sh 9 70.12 0.55 14.82 2.86 0.04 0.69 2.18 4.42 3.48 0.84 64.19 35.81 L249-7 Sh 3 pt 2 70.18 0.46 15.75 2.58 0.15 0.44 1.24 6.17 2.87 0.16 93.55 6.45 L249-7 Sh 2 72.41 0.41 14.78 1.99 0.10 0.48 1.63 5.11 2.94 0.15 90.19 9.81 L249-7Sh7 75.60 0.06 13.92 0.37 0.13 0.05 0.86 3.83 4.46 0.72 49.17 50.83 L249-7 Sh 1 76.79 0.13 13.03 0.71 0.03 0.17 1.01 3.95 4.00 0.18 82.26 17.74 L250-2 165.67 165.80 L250-2Shl6 62.59 1.02 17.06 5.64 0.08 1.79 5.32 4.69 1.61 0.21 83.51 16.49 L250-2 Sh8 74.98 0.12 13.78 1.00 0.05 0.12 0.85 4.25 4.65 0.20 88.68 11.32 L250-2 Sh5 77.17 0.18 13.24 1.10 0.07 0.27 1.61 2.31 3.63 0.42 67.94 32.06 L250-2 Sh2 77.53 0.49 11.12 1.83 0.07 0.29 0.84 4.40 3.19 0.23 94.19 5.81

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o L251-7 repolished (24) 69.97 0.51 15.45 2.78 0.05 0.88 2.85 4.82 2.41 0.28 88.39 11.61 L251-7 repolished (6) 70.14 0.66 15.02 2.70 0.09 0.91 2.79 4.77 2.54 0.38 89.39 10.61 L251-7 repolished (8) 70.17 0.57 15.07 2.57 0.06 0.80 2.53 4.42 3.58 0.22 97.60 2.40 L251-7 repolished (12) 70.54 0.55 15.56 2.57 0.11 0.81 2.61 4.48 2.51 0.26 88.42 11.58 L251-7 repolished (9) 70.99 0.56 14.78 2.46 0.06 0.80 2.35 430 3.53 0.17 102.71 -2.71 L251-7 repolished (19) 70.99 0.50 16.98 2.35 0.06 0.62 1.88 3.66 2.75 0.20 94.13 5.87 L251-7 repolished (11) 71.62 0.50 14.80 2.50 0.08 0.85 2.57 4.42 2.45 0.20 97.89 2.11 L251-7 repolished (2) 71.65 0.46 14.86 2.33 0.08 0.54 2.95 4.55 2.41 0.17 98.49 1.51 L251-7 repolished (27) 71.92 0.51 14.42 2.40 0.09 0.72 2.34 4.79 2.61 0.20 98.82 1.18 L251-7 repolished (1) 72.15 0.63 14.18 2.48 0.05 0.69 2.29 4.43 2.91 0.19 96.66 3.34 L251-7 repolished (23) 72.35 0.36 14.74 2.18 0.06 0.66 2.27 4.47 2.70 0.21 93.13 6.87 L251-7 repolished (18) 72.39 0.49 14.33 2.36 0.07 0.67 2.45 4.43 2.61 0.19 100.71 -0.71 L251-7 repolished (17) 72.50 0.51 14.05 2.52 0.08 0.70 2.23 4.39 2.69 0.32 86.53 13.47 L251-7 repolished (25) 73.06 0.43 13.77 2.10 0.05 0.59 2.14 4.37 3.29 0.21 98.55 1.45 L251-7 repolished (20) 74.05 0.33 13.94 1.77 0.08 0.51 2.22 4.45 2.41 0.26 94.57 5.43 L251-7 repolished (40) 74.28 0.30 13.85 1.68 0.08 0.47 1.93 4.52 2.60 0.29 91.08 8.92 L251-7 repolished (21) 74.33 0.33 13.57 1.97 0.05 0.47 2.24 4.27 2.53 0.24 95.69 4.31 L251-7 repolished (14) 74.35 0.34 14.47 1.63 0.07 0.52 1.99 4.29 2.15 0.20 96.84 3.16 L251-7 repolished (26) 74.72 0.35 13.58 1.75 0.04 0.44 1.95 4.45 2.53 0.19 99.03 0.97 L251-7 repolished (43) 75.09 0.26 13.56 1.66 0.03 0.42 1.75 4.25 2.69 0.29 94.35 5.65 L251-7 repolished (42) 75.51 0.27 13.07 1.69 0.04 0.44 1.97 4.06 2.75 0.20 97.68 2.32 L251-7 repolished (41) 75.63 0.31 12.90 1.75 0.07 0.42 2.08 3.93 2.66 0.26 91.12 8.88 L252-2 166.61 166.75 L252-2(4) 63.78 0.59 18.08 4.09 0.11 0.81 5.47 5.00 1.83 0.23 95.80 4.20 L252-2 (20) 64.23 0.40 17.27 4.96 0.08 2.03 4.58 4.46 1.67 0.31 91.03 8.97 L252-2 (35) 65.34 0.61 17.47 3.47 0.10 0.82 4.68 5.12 2.12 0.27 90.80 9.20 L252-2 (1) 67.70 0.37 1835 1.63 0.06 0.42 4.41 5.03 1.90 0.14 99.51 0.49 L252-2 (22) 69.21 0.59 1538 3.19 0.10 0.95 3.42 4.54 2.35 0.28 87.96 12.04 L252-2(8) 71.60 0.62 14.22 2.77 0.08 0.90 2.97 4.06 2.56 0.22 96.14 3.86 L252-2(7) 72.18 0.57 14.32 2.53 0.08 0.77 2.75 4.03 2.52 0.26 89.08 10.92 L252-2 (34) 73.70 0.33 14.04 1.92 0.04 0.54 2.58 4.19 2.46 0.20 95.78 4.22 L252-2 (21) 74.69 0.30 14.29 1.49 0.04 0.47 1.63 3.92 2.89 0.29 75.52 24.48

161 L252-2 (26) 74.98 0.30 13.26 1.79 0.06 0.32 1.42 3.75 3.84 0.27 93.52 6.48 L252-2 (12) 75.48 0.29 12.62 1.82 0.09 0.29 1.51 3.76 3.82 0.33 88.28 11.72 L252-2 (3) 75.87 0.28 12.12 1.35 0.03 1.33 0.46 7.07 1.41 0.09 99.08 0.92 L252-2 (25) 75.89 0.30 13.02 1.51 0.03 0.40 1.94 4.08 2.63 0.19 98.63 1.37 L252-2 (27) 76.06 0.34 12.86 2.01 0.03 0.33 1.45 2.89 3.71 0.31 88.84 11.16 L252-2(14) 76.34 0.21 13.34 0.86 0.01 0.28 1.25 4.08 3.49 0.14 95.10 4.90 L252-2 (32) 76.38 0.17 13.24 1.36 0.03 0.30 1.34 4.60 2.47 0.10 95.29 4.71 L252-2 (23) 76.79 0.22 13.06 0.98 0.00 0.27 1.12 4.10 3.29 0.17 93.05 6.95 L252-2 (28) 77.15 0.21 12.59 1.42 0.04 0.29 1.27 3.59 3.14 0.30 74.82 25.18 L252-2 (31) 77.21 0.18 12.80 0.91 0.02 0.23 1.21 3.95 3.31 0.17 94.19 5.81 L252-2 (29) 77.46 0.24 12.63 0.99 0.04 0.23 1.25 3.44 3.49 0.23 87.08 12.92 L252-2(19) 78.96 0.42 8.32 2.77 0.02 1.40 0.72 5.65 1.48 0.26 67.74 32.26 L252-3 166.75 166.89 L252-3 (11) 58.48 1.72 14.60 9.58 0.27 4.03 5.86 4.25 1.09 0.13 96.56 3.44 L252-3 (7) 58.54 1.91 15.98 8.38 0.19 2.13 6.14 5.47 1.13 0.15 99.67 0.33 L252-3(8) 58.71 1.72 16.72 8.14 0.22 2.46 6.49 4.36 0.98 0.20 94.39 5.61 L252-3(5) 59.00 1.72 16.49 8.49 0.26 2.11 6.69 4.25 0.87 0.13 100.34 -0.34 L252-3 (17) 59.42 1.60 15.50 7.76 0.25 2.77 5.86 5.46 1.24 0.15 96.93 3.07 L252-3 (12) 59.59 2.01 14.91 9.28 0.28 2.61 5.18 4.51 137 0.27 78.55 21.45 L252-3 (3) 59.47 1.16 18.61 5.73 0.14 1.64 6.43 5.92 0.81 0.09 98.87 1.13 L252-3 (4) 59.70 1.71 16.28 7.60 0.27 2.00 6.23 5.00 1.05 0.15 98.75 1.25 L252-3 (9) 60.11 1.86 14.25 9.58 0.24 2.61 4.98 4.81 1.41 0.16 97.86 2.14 L252-3 (18) 60.35 1.21 16.45 7.45 0.24 2.57 5.46 5.03 1.09 0.15 97.31 2.69 L252-3 (16) 61.03 1.43 15.94 7.21 0.28 2.30 5.45 5.19 1.02 0.16 98.27 1.73 L252-3(15) 61.89 1.23 15.44 7.05 0.26 2.80 4.84 5.41 0.94 0.13 95.35 4.65 L252-3 (6) 62.56 1.05 17.08 6.13 0.22 1.90 4.52 5.17 1.23 0.14 97.91 2.09 L252-3 (1) 63.79 1.04 16.10 5.93 0.19 1.79 437 5.36 1.29 0.15 94.39 5.61 L252-3 (19) 64.70 0.87 16.33 5.40 0.21 1.60 4.02 5.20 1.34 0.33 84.25 15.75 L252-4 166.89 167.04 No shards L252-5 167.04 167.18 L-252-5 Sh8 76.32 0.23 13.62 1.05 0.01 0.23 1.43 4.67 2.32 0.11 89.91 10.09 L-252-5 Shl6 Ptl 72.84 0.36 14.45 1.82 0.00 0.45 1.64 5.31 2.95 0.18 94.92 5.08 L-252-5 Shl6 Pt2 72.02 0.41 14.67 1.96 0.08 0.49 1.68 5.47 2.93 0.29 89.67 10.33

162 L252-6 167.18 167.32 L-252-6Sh6 77.28 0.23 12.86 0.96 0.05 0.21 1.10 3.73 3.46 0.13 94.67 5.33 L-252-6 Shl4 76.53 0.25 13.14 1.19 0.08 0.26 1.24 3.83 3.31 0.16 91.87 8.13 L-252-6Shl6 76.81 0.13 12.77 0.98 0.06 0.26 1.22 4.01 3.59 0.17 93.49 6.51 L252-7/253-1 167.32 167.45 No shards L253-2 167.45 167.57 No shards L253-3 167.57 167.70 No shards L253-4 167.70 167.82 No shards L253-5 167.82 167.95 No shards L253-6 167.95 168.07 No shards Aniakchak L265/266-1 175.24 175.41 5/1. 58.25 1.14 18.19 5.84 0.10 2.46 7.61 5.55 0.80 0.07 98.34 1.66 5/8. 46.74 0.36 10.92 16.90 0.20 10.80 12.50 1.46 0.12 0.01 98.18 1.82 5/10. 72.80 0.38 14.46 1.99 0.05 0.48 1.84 4.99 2.80 0.22 96.69 3.31 5/11. 73.24 0.37 14.50 1.77 -0.02 0.44 1.78 4.89 2.81 0.19 97.43 2.57 5/25. 44.34 0.30 12.99 20.42 0.38 7.88 11.95 1.49 0.26 0.01 98.00 2.00 5/28. 47.04 1.72 46.52 1.35 0.03 0.49 0.30 0.11 2.39 0.05 99.82 0.18 5/42. 77.20 0.19 12.95 1.08 0.06 0.25 1.20 3.55 3.40 0.11 96.17 3.83 5/43. 77.10 0.19 12.92 0.98 0.05 0.22 1.24 3.71 3.42 0.16 96.63 3.37 5/47. 48.11 0.38 36.24 2.84 0.08 0.75 0.05 0.36 11.18 0.01 93.63 6.37 5/48. 62.76 0.20 19.56 2.06 0.06 1.10 0.10 0.30 13.79 0.07 93.28 6.72 5/54. 57.94 0.03 0.79 11.25 0.22 16.80 12.75 0.13 0.03 0.03 101.02 -1.02 5/55. 57.97 -0.03 0.67 10.98 0.20 16.90 13.08 0.15 0.02 0.03 100.24 -0.24 5/56. 51.46 0.56 1.99 9.53 0.23 15.54 20.51 0.16 0.01 0.01 101.01 -1.01 5/59. 45.27 0.52 12.65 18.35 0.33 9.61 11.52 1.45 0.29 0.00 97.78 2.22 5/62. 49.58 0.45 7.60 16.27 0.27 12.33 12.50 0.79 0.21 -0.01 98.68 1.32 5/69. 52.90 0.57 4.25 10.88 0.21 17.13 13.42 0.52 0.04 0.06 95.68 4.32 5/75. 44.04 0.30 13.16 18.94 0.36 9.16 12.70 1.02 0.31 0.01 96.55 3.45 5/77. 48.58 0.35 33.61 4.71 -0.02 1.15 -0.02 0.32 11.27 0.01 93.91 6.09 5/86. 49.20 0.32 7.08 17.85 0.35 11.14 13.10 0.76 0.18 0.02 96.96 3.04 5/87. 51.36 0.21 5.21 17.28 0.42 12.01 12.80 0.56 0.11 0.03 97.03 2.97 L266-2 175.41 175.58 No shards L266-3 175.58 175.75 8/6. 70.71 0.54 15.25 2.79 0.04 0.78 2.60 4.27 2.86 0.16 96.01 3.99

163 8/13. 76.82 0.18 13.10 1.85 0.04 0.30 1.25 2.98 3.23 0.25 94.20 5.80 8/26. 85.91 0.22 5.48 1.56 0.02 1.11 0.38 4.24 1.01 0.06 97.23 2.77 8/34. 48.89 1.90 4.76 7.85 0.16 14.27 21.61 0.53 0.01 0.01 101.71 -1.71 8/37. 77.52 0.26 12.40 1.39 0.02 1.35 0.32 5.35 0.81 0.59 87.39 12.61 8/44. 69.93 0.59 15.44 3.34 0.08 0.73 2.32 4.65 2.85 0.09 97.06 2.94 L266-4/267-1 175.75 175.87 11/9. 58.74 1.68 15.26 9.08 0.19 2.80 5.42 5.46 1.29 0.07 100.11 -0.11 11/17. 60.64 1.41 17.44 6.17 0.21 1.38 5.45 5.93 1.24 0.14 101.24 -1.24 11 / 44. 59.32 1.22 15.89 8.93 0.19 2.47 5.61 4.57 1.66 0.13 98.82 1.18 11/67. 57.54 0.74 20.76 5.52 0.14 1.40 7.56 5.32 0.94 0.09 99.80 0.20 11/68. 52.33 0.20 6.05 9.13 0.22 17.95 13.00 1.04 0.06 0.01 96.59 3.41 11/72. 72.25 0.39 14.98 2.01 0.09 0.49 1.74 5.17 2.72 0.16 94.82 5.18 11/75. 44.26 1.21 12.56 11.21 0.18 15.16 12.48 2.51 0.38 0.06 97.67 2.33 11/78. 46.62 0.47 12.74 12.08 0.22 13.32 13.08 1.37 0.07 0.02 96.91 3.09 11/79. 47.97 0.36 832 20.33 0.45 9.18 12.30 0.70 0.37 0.03 98.25 1.75 L267-2 175.87 175.94 No shards L267-3 175.94 176.00 14/1. 55.87 0.12 2.80 5.72 0.18 20.96 13.71 0.57 0.05 0.02 97.83 2.18 14/9. 41.97 0.06 27.30 6.53 0.09 0.03 23.95 0.03 0.01 0.04 99.27 0.73 14/11. 57.28 0.01 2.26 9.44 0.19 17.33 13.14 0.18 0.06 0.13 97.46 2.54 14/14. 42.66 0.08 26.89 6.69 0.14 0.03 23.46 0.00 -0.01 0.06 93.98 6.02 14/18. 38.26 0.08 32.58 3.21 0.31 0.02 25.53 -0.02 -0.01 0.00 96.78 3.22 Hayes L268-1/ 269-1 179.35 176.53 L-269-11 74.90 0.30 13.96 1.23 0.03 0.24 1.03 3.85 4.36 0.10 94.59 5.41 L-269-1 2 73.19 -0.01 15.47 0.08 0.00 0.01 2.29 8.84 0.03 0.09 100.42 -0.42 L-269-1 3 76.99 0.21 13.07 0.96 -0.01 0.25 1.19 3.66 3.50 0.17 94.37 5.63 L-269-1 4 76.82 0.25 13.59 0.77 0.05 0.09 1.11 4.23 3.06 0.03 94.72 5.28 L269-2 176.53 176.61 No shards L269-3 176.61 176.69 L-269-3 1 73.04 0.33 15.68 1.51 0.06 0.45 1.51 4.63 2.61 0.18 93.14 6.86 L-269-3 2 78.07 0.17 13.31 1.13 0.08 0.23 0.99 3.51 2.42 0.10 94.71 5.29 L269-4 176.69 176.76 No shards L269-5 176.76 176.84 No shards L269-6/ 270-1 176.84 176.96 L-269-61 72.16 0.45 15.31 1.82 0.07 0.54 1.59 5.31 2.52 0.23 99.10 0.90 L-269-6 2 74.99 0.27 13.70 1.75 0.07 0.28 1.52 3.63 3.51 0.28 92.80 7.20

164 L270-2 179.96 177.09 No shards L270-3 177.09 177.22 L-270-31 73.60 0.17 14.72 1.70 0.11 0.11 0.44 4.68 4.37 0.10 9330 6.70 L-270-3 2 76.76 0.27 13.44 0.98 0.05 0.23 1.10 3.69 3.33 0.14 93.21 6.79 L270-4 177.22 177.38 L-270-41 72.63 0.22 15.32 1.59 0.04 0.39 1.78 4.54 3.14 0.34 95.71 4.29 L-270-4 2 72.78 0.24 15.19 1.51 0.02 0.40 1.84 4.31 3.33 0.39 90.06 9.94

165 Hayes sites visited in this study

Comment Si02 Ti02 AI203 FeO MnO MgO CaO Na20 K20 CI total H20 diff UA 1811 72.84 0.22 14.94 1.62 0.08 0.90 2.16 4.20 2.64 0.41 96.89 3.11 UA1811 72.19 0.24 15.48 1.81 0.12 0.98 2.12 4.25 2.38 0.43 96.27 3.73 UA 1811 73.41 0.23 14.80 1.59 0.09 0.78 2.02 4.14 2.59 0.34 95.94 4.06 UA 1811 72.55 0.22 15.08 1.85 0.04 0.92 2.14 4.24 2.55 0.42 96.82 3.18 UA 1811 72.78 0.23 15.14 1.78 0.09 0.92 2.13 3.99 2.50 0.45 97.31 2.69 UA 1811 72.25 0.27 15.04 1.92 0.08 0.91 232 4.23 2.51 0.46 95.67 4.33 UA 1811 73.93 0.22 14.61 1.57 0.09 0.74 1.91 3.83 2.74 0.38 95.77 4.23 UA 1811 72.95 0.23 15.17 1.76 0.13 0.78 1.96 4.13 2.49 0.41 97.09 2.91 UA 1811 73.13 0.24 14.74 1.76 0.04 0.88 2.17 4.15 2.52 0.38 96.59 3.41 UA 1811 72.91 0.22 14.86 1.73 0.04 0.90 2.12 4.19 2.61 0.42 97.32 2.68 UA 1811 71.36 0.27 15.37 2.01 0.15 1.09 2.40 4.33 2.57 0.46 97.01 2.99 UA 1811 72.36 0.25 15.08 1.80 0.12 0.94 2.21 4.13 2.65 0.45 96.82 3.18 UA 1811 73.14 0.21 14.67 1.58 0.10 0.85 2.17 4.18 2.68 0.42 96.45 3.55 Average 72.76 0.23 15.00 1.75 0.09 0.89 2.14 4.15 2.57 0.42 96.61 3.39 SD 0.61 0.02 0.25 0.13 0.03 0.09 0.13 0.12 0.09 0.03 0.54 0.54

UA 1814 72.96 0.23 14.89 1.78 0.00 0.87 2.20 4.05 2.61 0.41 96.93 3.07 UA 1814 73.08 0.24 15.10 1.72 0.03 0.79 2.16 3.78 2.66 0.42 96.64 3.36 UA 1814 68.98 0.22 17.31 1.78 0.08 1.11 3.69 4.43 2.03 0.36 97.35 2.65 UA 1814 69.03 0.52 15.67 2.86 0.08 1.44 2.94 4.55 2.66 0.24 98.99 1.01 UA 1814 68.71 0.54 15.69 3.12 0.11 1.60 2.95 4.46 2.57 0.25 97.45 2.55 UA 1814 69.04 0.58 15.30 3.11 0.10 1.65 2.97 4.58 2.40 0.26 97.47 2.53 1814 3 70.54 0.53 15.15 3.14 0.08 0.75 3.00 3.98 2.55 0.26 93.69 6.31 1814 13 70.47 0.44 15.06 2.99 0.10 0.94 2.88 4.48 2.40 0.25 98.31 1.69 1814 2 71.61 0.40 14.86 2.61 0.13 0.53 1.75 4.99 2.92 0.21 97.88 2.12 1814 6 70.73 0.46 15.76 2.85 0.11 0.83 2.61 3.89 2.49 0.27 98.77 1.23 1814 7 72.20 0.28 15.03 2.07 0.07 0.58 2.60 4.08 2.53 0.56 92.18 7.82 Average 70.67 0.40 15.44 2.55 0.08 1.01 2.71 4.30 2.53 0.32 96.88 3.12 SD 1.62 0.14 0.70 0.59 0.04 0.39 0.53 0.37 0.22 0.11 2.10 2.10

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h-iOOO00UJh-iO J> UJ ;P» h-1 NJ j> in UJ t-i si sj oo ui ISJ in APPENDIX II - OXCAL CODES

All codes are given as in the initial run: all dates are used, including later-identified outliers.

Methodology

Paradox Lake core - P_sequence

PlotQ { Outlier_Model("General",T(5),U(0,4),"t"); SequencefParadox Lake") { Boundary("Bottom") { z=875; }; R_Date("Beta-177159", 10970, 70) { z=873; Outlier(0.05); }; R_Date("AA45104", 9970, 70) { z=799; Outlier(0.05); }; Date("Tephra 4") { z=616.8; }; Date("Tephra 3") { z=558.4; }; R_Date("AA38447", 7100, 60) { z=552.5; Outlier(0.05); }; Date("Tephra 2") { z=420.6; }; R_Date("AA38446", 5600, 80)

168 { z=399.5; Outlier(0.05); }; R_Date("AA38445", 4920, 90) { z=344.5; Outlier(0.05); }; R_Date("AA45103", 4565, 45) { z=311; Outlier(0.05); }; R_Date("AA45102", 4055, 45) { z=289; Outlier(0.05); }; Date("Tephra lc") { z=230.8; }; Date("Tephra lb") { z=229.8; }; Date("Tephra la") { z=225.4; }; R_Date("AA45101", 2970, 50) { z=193; Outlier(0.05); }; R_Date("AA45100", 2605, 40) { z=165; Outlier(0.05); }; R_Date("AA45099", 1225, 45) { z=97.5; Outlier(0.05); }; R_Date("AA45098", 1375, 45) { z=81.5; Outlier(0.05); }; Boundary("Top") { z=0; }; }; };

Fisher-Funk Phase model

Options() { klterations=1000; }; Plot() { Outlier_Model("General",T(5),U(0,4),"t"); Sequence("Fisher-Funk") { BoundaryO; Phase("Pre-eruption") { R_Date("Under P.F.I", 9430, 240) { Outlier(0.05); }; R_Date("Under P.F.2", 9300, 340) { Outlier(0.05); }; R_Date("Within P.F.I", 9330,160) { Outlier(0.05); }; R_Date("GX-2744", 9660, 615) { Outlier(0.05); }; R_Date("BETA-96824", 9130,140) { Outlier(0.05); }; R_Date("W-3424", 9120, 250) { Outlier(0.05); }; R_Date("BETA-96830", 9630,140) { Outlier(0.05); }; R_Date("GX-2789", 10625, 550) { Outlier(0.05); }; R_Date("K-2500C-s", 9250,140) { Outlier(0.05); }; R_Date("K-2221-s", 8730, 230) { Outlier(0.05); }; R_Date("K-2584G-s", 8865,135) { Outlier(0.05); }; }; Boundary("Eruption"); Phase("Post-eruption") { R_Date("South P.F.", 9090, 50) { Outlier(0.05); }; R_Date("GX-2790", 8425, 350) { Outlier(0.05); }; R_Date("BETA-96825", 7910,160) { Outlier(0.05); }; }; Boundary(); }; };

Kaguyak tephra - Equals model

Plot(Kaguyak equals model)

171 { Sequence("Windy Ck") { Boundary("bottom Windy Ck"); R_Date("K-2221-s", 8730, 230); R_Date("K-2349-s", 8600,120); R_Date("K-2351-s", 6995,105); R_Date("K-2581D", 6520,180); R_Date("K-2544", 6420, 240); R_Date("K-2222-s", 5545,165); Datef'Kaguyak"); R_Date("K-2348-s ",5220, 90); R_Date("K-2181-s ",5130, 360); R_Date("K-2780-s ",4800, 60); R_Date("K-2059-s", 4260,120); R_Date("K-2591-s", 4230,140); R_Date("K-2347-s", 4185, 85); Boundary("top Windy Ck"); }; Sequence("Moraine Ck") { Boundary("bottom Moraine Ck"); R_Date("K-2668", 10180,130); R_Date("K-2584G-s", 8865,135); R_Date("K-2584F-s", 8500,120); R_Date("K-2585-s", 7440,120); R_Date("K-2584E-s", 5575, 95); R_Date("K-2314-s", 5535, 215); Date("=Kaguyak"); R_Date("K-2584D-s", 3700, 85); R_Date("K-2583-s", 660, 70); R_Date("K-2583-sx", 120,40); Boundary("top Moraine Ck"); }; Sequence("Bush Ck") { Boundary("bottom Bush Ck"); R_Date("K-2675H-S", 8970, 220); R_Date("K-2675E-s", 5700, 90); Date("=Kaguyak"); R_Date("K-2675D-W", 5500, 60); R_Date("K-2702C-x", 4480, 40); R_Date("K-2702C", 4450, 80); R_Date("K-2675C-S", 3650, 70); R_Date("K-2675A-S", 3450, 70); Boundary("top Bush Ck"); }; }; Correlating the terrestrial and marine record of the Mount Edgecumbe Volcanic Field

Column Point DJSequence

Plot() { D_Sequence( "ColP no thick") { First( ); R_Date( "27 cm", 12280, 35); Gap( 40); Date( "A"); Gap( 20); Date( "B"); Gap( 20); Date( "C"); Gap( 20); R_Date( "24.5 cm", 12220, 35); Gap( 120); R_Date( "21.5 cm", 12120, 35); Date( "D"); Gap( 20); R_Date( "21 cm", 11985, 35); Gap( 680); R_Date( "4 cm", 11340, 40); Gap( 20); Date( "E"); }; };

Lower Sitka Sound D_Sequence

Plot() { D_Sequence( "Lower Sitka Sound") { First( ); Date( "1804"); Gap( 2); Date( "1803"); Gap( 26); Date( "1802"); Gap( 33); Date( "1801"); Gap( 20); Date( "1800");

173 Gap( 29); Date( "1799"); Gap( 20); Date( "1798"); Gap( 72); Date( "1797"); Gap( 47); R_Date( "WW5476", 11522, 58); Gap( 120); R_Date( "WW5475", 11126, 59); Gap( 267); R_Date( "WW5474", 10987, 56); Gap( 219); R_Date( "WW5473", 10952, 55); Gap( 186); R_Date( "WW5472", 10881, 61); }; };

Column Point PJSequence

{ P SequencerColP" , 1) { Boundary("Bottom") { z=29.5; }; R Date("30", 12280, 35) { z=27; }; Date("A") { z=26; }; Date("B") { z=25.5; }; Date("C") { z=25; }; R Date("25.5," , 12220, 35) { z=24.5; }; R_Date("22.5", 12120, 35) { z=21.5; }; Date("D") { z=21.5; }; R_Date("21", 11985, 35) { z=21; }; R_Date("4", 11340,40) { z=4; }; Date("E") { z=3.5; }; Boundary("Top") { z=0; }; }; };

Lower Sitka Sound P_Sequence

Plot() { P_Sequence("Lower Sitka Sound" { BoundaryC'Bottom") { z=1110; }; Date("1804") { z=1110; }; Date("1803") { z=1108; }; Date("1802") { z=1082; }; Date("1801") { z=1049; }; Date("1800") { z=1029; }; Date("1799") { z=1000; }; Date("1798") { z=980; }; Date("1797") { z=908; }; R_Date("WW5476", 11522, 58) { z=861; }; R_Date("WW5475", 11126, 59) { z=594; }; R_Date("WW5474", 10987, 56) { z=375; }; R_Date("WW5473", 10952, 55) { z=189; }; R_Date("WW5472", 10881, 61) { z=96; }; Boundary("Top") { z=0; }; }; };

176 MEd Phase model

SequencefMEd") { BoundaryO; PhasefPre-eruption") { R_Date("B-77056", 11230, 70); R_Date("B-77054", 11350, 70); R_Date("B-82660", 11310, 60); R_Date("B-77053", 11340,170); R_Date("B-77051", 11040, 80); R_Date("CP-70800", 11340, 40); }; Boundary("MEd eruption"); Phase("Post-eruption") { R_Date("Montana Ck", 11230,400); }; BoundaryO; };

MEd marine reservoir model

Plot() { Sequence("ColP") { Boundary("bottom ColP"); R_Date("70805", 12280, 35); R_Date("70804", 12220, 35); R_Date("70803", 12120, 35); R_Date("70802", 11985, 35); R_Date("70801", 11210,45); R_Date("70800 ",11340,40); Date("MEd"); Boundary("top ColP"); }; Sequence("B-77056") { Boundary("bottom 77056"); R_Date("B-77056", 11230, 70); Date("=MEd"); Boundary("top 77056"); }; Sequence("B-77054") { Boundary("bottom 77054"); R_Date("B-77054", 11350, 70); Date("=MEd"); Boundary("top 77054"); }; Sequence("B-82660") { Boundaryf'bottom 82660"); R_Date("B-82660", 11310, 60); Date("=MEd"); Boundary("top 82660"); }; Sequence("B-77053") { Boundary("bottom 77053"); R_Date("B-77053", 11340, 170); Date("=MEd"); Boundary("top 77053"); }; Sequence("B-77051") { Boundary("bottom 77051"); R_Date("B-77051", 11040, 80); Date("=MEd"); Boundary("top 77051"); }; Sequencef'Montana Creek") { Boundary("bottom Montana Creek"); Date("=MEd"); R_Date("Montana Creek", 11230,400); Boundary("top Montana Creek"); }; Delta_R(0,500); Sequence("40JC") { Boundary("bottom 40JC); Boundary("=MEd"); R_Date("WW5476", 11522, 58); R_Date("WW5475", 11126, 59); R_Date("WW5474", 10987, 56); R_Date("WW5473", 10952, 55); R_Date("WW5472", 10881, 61); Boundaryftop 40JC"); }; };

Tephrochronology of the PR Col ice core Wiggle-match WRE stump

OptionsQ { Resolution=l; }; Plot() { D_Sequence( "Wiggle-match WRE") { R_Date( "GSC-5617", 1430, 70); Gap( 149.5); R_Date( "GSC-5619", 1260, 50); Gap( 30); Date("Fellingdate"); }; };

WRE Phase model

OptionsQ { klterations=1000; }; Plot() { Outlier_Model("General",T(5),U(0,4),"t"); Sequence("WRE") { BoundaryO; Phase("Pre-eruption") { R_Date("GSC-4012", 1210, 60) { Outlier(0,05); }; R_Date("GSC-408", 1200,140) { Outlier(0,05); }; R_Date("GSC-956", 1190,130) { Outlier(0,05); }; R_Date("GSC-934", 1280,130) { Outlier(0,05); }; R_Date("GSC-1000", 1300,130) { Outlier(0,05); }; R_Date("AA-B3252A", 1552, 45) { Outlier(0,05); }; }; Boundary("WRE eruption"); C_Date(783, 71); Phase("Post-eruption") { R_Date("GSC-343", 1240,130) { Outlier(0,05); }; R_Date("AA-B3251A", 1116, 60) { Outlier(0,05); }; }; BoundaryO; }; };

WRN Phase model

OptionsO { klterations=1000; }; Plot() { Outlier_Model("General",T(5),U(0,4),"t"); Sequence("WRN") { BoundaryO; Phase("Pre-eruption") { R_Date("l-6094", 1785, 90) { Outlier(0.05); }; R_Date(" 1-6464", 1825, 90) { Outlier(0,05); }; R_Date("l-7506", 1850, 85) { Outlier(0,05); }; R_Date("l-7572", 1925, 80) { Outlier(0,05); }; R_Date("l-6466", 2005, 90) { Outlier(0,05); }; R_Date("l-276", 1750,110) { Outlier(0,05); }; R_Date( "GSC-400", 1990,130) { Outlier(0,05); }; R_Date("UCIAMS-26763", 1775, 15) { Outlier(0,05); }; R_Date("UCIAMS-26762", 1740,15) { Outlier(0,05); }; R_Date("WK-10365", 1748, 48) { Outlier(0,05); }; R_Date("Beta-164540", 1820, 50) { Outlier(0,05); }; R_Date("Fl", 1700,48) { Outlier(0,05); }; R_Date("F2", 1833, 53) { Outlier(0.05); }; R_Date("Y-2303", 1990, 80) { Outlier(0.05); }; R_Date("WK-8888", 1970, 70) { Outlier(0.05); }; }; Boundaryf'WRN eruption"); Phasef'Post-eruption") { R_Date("F62-2", 1520,100) { Outlier(0,05); }; R_Date("26764", 1730,15) { Outlier(0,05); }; R_Date("AA-B3259A", 1696, 47) { Outlier(0,05); }; R_Date("Beta-164539", 1680, 60) { Outlier(0,05); }; }; BoundaryO; }; };

Anaikchak Phase model

Options() { klterations=1000; }; Plot() { Outlier_Model("General",T(5),U(0,4),"t"); Sequence("Aniakchak") { BoundaryO; Phase("Pre-eruption") { R_Date("l-14 236", 3570, 80) { Outlier(0.05); }; R_Date("B-19643", 3570,100) { Outlier(0.05); }; R_Date("B-7760", 2400, 80) { Outlier(0.05); }; R_Date("W-4929", 4830, 80) { Outlier(0.05); }; R_Date("NSRL12336", 3630, 85) { Outlier(0,05); }; }; Boundaryf'Eruption"); Phase("Post-eruption") { R_Date("W-3125", 3350, 200) { Outlier(0.05); }; R_Date("l-14 221", 3410, 90) { Outlier(0.05); }; R_Date("B-23170", 3700, 90) { Outlier(0.05); }; R_Date("B-33758", 3750, 80) { Outlier(0.05); }; R_Date("B-7761", 3340, 90) { Outlier(0.05); }; R_Date("l-13 990", 4000,100) { Outlier(0.05); }; R_Date("l-14 226", 3520,140) { Outlier(0.05); }; R_Date("W-3466", 3610, 200) { Outlier(0.05); }; R_Date("W-4052", 3490, 200) { Outlier(0.05); }; R_Date("W-4582", 3670, 60) { Outlier(0.05); }; R_Date("l-14 228", 3500, 80) { Outlier(0.05); }; R_Date("l-14 223", 3370, 90) { Outlier(0.05); }; }; BoundaryO; }; };

Hayes Tephra Set H Equals model

Plot(Hayes equals model) { SequencefParadox Lake") { Boundary("bottom Paradox Lake") R_Date("Beta-125980", 13250, 80) R_Date("Beta-177159", 10970, 70) R_Date("AA-45104", 9970, 70); R_Date("AA-38447", 7100, 60); R_Date("AA-38446", 5600, 80); R_Date("AA-38445 ",4920, 90); R_Date("AA-45103 ",4565,45); R_Date("AA-45102 ",4055, 45); Date("Hayes"); R_Date("AA-45101 ",2970, 50); R_Date("AA-45100 ",2605, 40); R_Date("AA-45099 ",1225, 45); R_Date("AA-45098 ",1375, 45); Boundary("top Paradox Lake"); }; SequencefTustumena Lake") { Boundaryf'bottom Tustumena Lake"); R_Date("CAMS-92799", 8325,40); R_Date("CAMS-92798", 8160,45); R_Date("CAMS-95391", 6530,45); R_Date("CAMS-95390", 6330,45); R_Date("CAMS-90110", 4885, 35); R_Date("CAMS-92797", 4265,40); R_Date("CAMS-92796", 4345, 40); R_Date("CAMS-92795", 3840,40); Date("=Hayes"); R_Date("CAMS-90109", 3580, 35); Date("Hayes2"); R_Date("CAMS-92794", 2995,40); R_Date("CAMS-92793", 1695,40); R_Date("CAMS-92792", 2005,40); Boundary("top Tustumena Lake"); }; Sequence("Bear Lake") { Boundary("bottom Bear Lake"); R_Date("CAMS-120878", 7980, 40); R_Date("CAMS-120877", 6025, 35); R_Date("CAMS-120876", 5720, 35); R_Date("CAMS-120875", 5125, 35); R_Date("CAMS-120738", 4575, 35); R_Date("CAMS-120737", 3835, 35); Date("=Hayes"); R_Date("CAMS-120736", 3410, 35); R_Date("CAMS-120735", 2890, 35); R_Date("CAMS-120734", 2300,40); R_Date("CAMS-120733", 2185, 35); R_Date("CAMS-120732", 1705, 35); R_Date("CAMS-120731", 850, 35); Boundary("top Bear Lake"); }; Sequence("Jarvis Creek") { Boundaryfbottom Jarvis Creek"); R_Date("JCl", 4350,140); R_Date("JC2", 3660, 275); Date("=Hayes"); R_Date("JC3", 3360, 275); R_Date("JC4", 3120, 210); Boundary("top Jarvis Creek"); }; Sequence("Tangle Lakes") { Boundary( bottom Tangle Lakes"); R_Date("TLl", 3700, 295); Date("=Hayes"); R_Date("TL2", 3660,140); R_Date("TL3", 3140,135); Boundary("top Tangle Lakes"); }; Sequence("Cantwell") { Boundary("bottom Cantwell"); R_Date("CWl", 6705, 280); R_Date("CW2", 6115,100); R_Date("CW3", 5085,180); R_Date("CW4", 3305,105); R_Date("CW5", 2630,165); Date("=Hayes"); Boundary("top Cantwell"); }; SequencefSite 14") { Boundary("bottom Site 14"); R_Date("l-13353", 3880,100); R_Date("l-13352", 3810,100); Date("=Hayes"); R_Date("l-13352b", 3460,110); R_Date("l-13357", 3520, 90); R_Date(" 1-13356", 3500, 90); Boundary("top Site 14"); }; Sequence("Site 30") { Boundary("bottom Site 30"); R_Date("l-12275", 3670,160); Boundary("=Hayes"); R_Date("l-12276", 3530,100); Boundary("top Site 30"); }; Sequence("JClc") { Boundary("bottom JClc"); R_Date("96054", 3770, 20); Boundary("=Hayes"); Boundary("topJClc"); }; Sequence("Wonder Lake") { Boundaryf'bottom Wonder Lake"); R_Date("CAMS-12291", 3830, 60); Boundary("=Hayes"); Boundary("top Wonder Lake"); }; };

187