LICENCE ID McMASTER UNIVERSITY
This Thesis has been written [Thesis, Project Report, etc.] by ______B~r~en~d~a~A~n=n~~S~t~ep~h~a~n~~------for [Full Name(s)] Undergraduate course number Geog 4C6 at McMaster University under the supervision/ direction of ------Dr. Derek C. Ford •
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(This Licence to be bound with the work) THE LITTORAL KARREN OF N EROUTSOS INLET NORTHERN VANCOUVER ISLAND
McMaster University
Brenda Stephan THE LITTORAL KARREN
OF NEROUTSOS INLET NORTHERN VANCOUVER ISLAND
BY
BRENDA ANN STEPHAN
A Research Paper Submitted to the Department of Geography in Fulfillment of the Requirements of Geography 4C6
McMaster University April 1987 ABSTRACT
Limestones exposed in the intertidal zone display numerous pits and basins which form where bodies of water are i so 1 a ted during t ida 1 retreat. These harbour both macro- and microscopic organisms whose metabolites enhance aggressivity and cause solution; grazing and boring activities further aid rock removal. In this area the basins are similar in shape throughout the littoral zone but they vary in size, the maximum relief being at mid tfde level. Unlike the exposed west coast of Ireland, zonation is not well defined: the clearly identifiable morphologies associated with the biological zones in Ireland are not displayed here. Instead it resemb 1 es the karren of the more she 1tered Br i sto 1 channe 1 area but with less mechanical erosion. In both of these areas variations in lithology affect the details of the geomorphology, some beds being significantly more fractured and less pitted than others.
i i ACKNOWLEDGE"ENTS
My stncerest thanks are given to Dr. Derek C. Ford for his support, encouragement and constructive criticism throughout this thesis. Also thank you for affording me the opportunity to experience the west and life in the field. Special thanks to Joyce Lundberg for her guidance and expertise in the topic; to Mary-Louise Byrne for her knowledge on coasts and her friendship; to Ric Hamilton for his advice, patience and talents on the cartographic work; to Steven Siblock for his God like work on the computer to Darlene Watson for her time and skillful typing; finally to Kathleen Harding and Kathleen Gladysz: thanks for all your help and companionship fn the field and at home. It was a great and memorable summer out west and at home.
i i i TABLE OF CONTENTS Page
Title Page ...... Abstract i i Acknow 1 edgements •..•••....•.•...•••.•••.•••••....• i i i Table of Contents .•.••...... •...... ••..••• i v Lfst of Figures ...... vi List of Tables ...... vi i Cover Photo: Study Area ...•....•..••••..••...... X Chapter 1: Introduction and Literature Review 1.1 I nt roduct ion ...... 1 1.2 Zones and processes •....•..•.••••.. 2 1 • 2 • 1 I nt roduct ion ...... •...... 2 1. 2. 2 Literature Review ..•.•••..•.••••.•• 3 1. 2. 3 Zonal Classification ....•..•..•••.. 4 1. 2. 4 Coasta 1 Erosion Processes .•.••••..• 8 1.2.4.1 Bfoerosion ...... •... 8 1.2.4.2 Intertidal Erosion •...•.....•••..• 9 1.2.4.3 Lithological Erosion .....•••••..... 9 1.3 General Models •..•.•.•.••..•.•.••. 1 0 1.4 Conclusions 1 1 Chapter 2: Study Area and Methodology 2. 1 I nt roduct ion ...... 1 2 2.2 Study Area ...... 12 2.3 Geology .•••..•.•..•..••••...•.••.• 14 2.4 C 1 i rna t e •••••••••.••..••••••••••••• 14 2.5 Waves ••••••••••••••••••••••••••••• 16 2.6 Tidal Currents .•..••..•..•...•.••. 16 2.7 Energy Leve 1 s •••..•.•••••••.••.••• 1 7 2.8 Methode 1ogy ...... •....•..•••••• 1 7 2. 8. 1 Field Work ...•..•....•...... ••••. 1 7 2.8.2 Laboratory Work ...... •.....•...... 22 2.8.3 Computing ...•...... •...... 22 Chapter 3: Analysis and Discussion 3 • 1 I nt roduct ion ...... 23 3 • 1 Fabric and Bulk Chemical Composition 23 3.3 Micro-Fracture Density ••..••••••.. 25 3.4 Zona 1 Patterns ...... ••...• 25 3. 4. 1 Effect of Tide Levels ••..••.••..•• 25 3.4.2 Morphometry of Pits ..•.•.•••••••.. 32 3.4.3 Relative Relief .•••.....•.••.•••.• 35 3.4.4 Biological Zonation ..••••.•••••..• 36 3.4.5 The Rillenstefn Zone •.•..•.••••••• 39
tv Page Chapter 4: Conclusions and Future Research 4. 1 Conclusions ..•...... •...... 4 1 4.2 Future Research ...... •.•... 42 References 44 Appendix A 47
v LIST OF FIGURES Page
1 • 1 Temperate Coast Profile •.•.•...•.••.•.•• 6
2. 1 a Study Area: Northern Vancouver Island 48
2. 1 b Study Area: Near Jeune Landing on the Eastern Shore of Neroutsos Inlet •••••.•• 13 2.2 The Geology of Northern Vancouver Island ...... • . . . . . • • . • ...... 49 2.3 Total Monthly Precipitation and Mean Temperature for Port Alice 500 23'N 1270 27'W •••..•..••.••..•••... 50 2.4 Total Monthly Snow and Rain Accumulation for Port Alice 500 23'N 1270 27'W ••••••. 52
2. 5 Precipitation Zones of Northern Vancouver Is 1and ..•••.••.••....••..•••.. 53
2.6 Mean Wind Velocity (kmh-1) and Frequency for Port Hardy sao 41'N 1270 30'W •...••. 54 2.7 Tidal Regime of Tofino ...•..•••.•.•..... 57
2.8 Tidal Currents of Vancouver Island 59
2.9 Individual Limestone Beds of Study Area • 18
2. 1 0 Individual Bed Profiles Indicating the Height Above Low Low Tide of the Sampling Quadrats .•.•.•.••..••.•..••.••• 20
2. 1 1 Examples of Sample Quadrats for Bed 61
2. 12 Examples of Sample Quadrats for Bed 2 2 1
2. 1 3 Examples of Sample Quadrats for Bed 4 62 3 • 1 Height Above Low Low Tide (LLT) vs Width Above LLT for Beds 1 ' 2, 4, A11 Beds ...... 26 3.2 Height Above Low Low Tide (LLT) vs Depth Above LLT for Beds 1 ' 2' 4, All Beds...... 63
vi Page
3.3 Height Above Low Low Tide (LLT) vs W/D Above LLT for Beds 1, 2, 4, All Beds...... 64 3.4 Typical Low Tide Scene: Many Small Pits and Large Quantities of A 1gae ...... 27
3. 5 Typical High Tide Scene: Dominated by Large Pits and Fractures 29 3.6 Height Above LLT vs Logarithmic Width Above LLT for Beds 1,2, 4 ••••••••..•..•• 30 3.7 Height Above LLT vs Logarithmic Depth Above LLT for Beds 1,2, 4 ...... 65
3.8 Height Above LLT vs Logarithmic W/D Above LLT for Beds 1,2, 4 ...... 66 3.9 Smoothness of Pit Bottoms vs Height Above LL T for Beds 1, 2, 4 and A11 Beds •..•.• 31
3. 1 0 Secondary Pit Formation vs Height Above LLT For Beds 1, 2, 4 and All Beds ••••.• 67
3. 11 a Width vs W/D Ratios For All Beds 33 b Depth vs W/D Ratios For Al 1 Beds 33
3. 12a Width vs W/D Ratios for Bed 1 34 b Depth vs W/D Ratios for Bed 1 34
3. 13a Width vs W/D Ratios for Bed 2 68 b Depth vs W/D Ratios for Bed 2 68
3. 14a Width vs W/D Ratios for Bed 4 69 b Depth vs W/D Ratios for Bed 4 69
3. 1 5 An Example of Pit form and Biota Present 35
3. 16 Biological Zonation 38
3. 1 7 Rillenstein of the High Tide Zone 40
vi i LIST OF TABLE Page
2. 1 Total monthly Precipitation and Mean Temperature for Port Alice 500 23'N 1270 27, w ...... 51
2.2 Mean Wind Speed (kmh-1) and Prevailing Direction for Port Hardy 500 4l'N 1270 30'W ••••••••••••••••••.•••••••.•• 55
2.3 Frequency and Mean Wind Velocity for Port Hardy 500 4l'N 1270 30'W •••.••..••. 56
2.4 Tidal Data 58
2.5 Height, Slope and Length of Sampling Quadrats ...... 60
3 • 1 Purity of the Coastal Limestone 24
3. 2 Relative Relief of Sampling Quadrats 70
vi i i " STUDY CHAPTER ONE
INTRODUCTION AND LITERATURE REVIEW
1 • 1 INTRODUCTION Littoral karren are solutional features produced on 1 imestone as a result of the action of seawater and of marine organisms. These produce fretted and roughened depressions. There is a sequence in forms produced from low water mark to high water mark (Sweeting, 1973). The sequence or zones are major horizontal regions on the coast which are differentiated by differing flora and fauna numbers and species (Dale, 1982), and differing karren forms. There are many hypotheses concerning the exact processes responsible for littoral zonation patterns. Many researchers believe that the biota present in an area is the dominant factor beh f nd formation of the zona 1 patterns. B i o 1 og i ca 1 abrasion and corrosion resu 1ts in a very rough surface known as biokarst (Golubic, 1979). Others believe that the zonation is a result of physical processes: tidal action, wave action, and currents are the dominant forces behind the patterns of zonation. The air/water interface also affects the formation of zonal patterns (Dale, 1982). These two views are 1 inked in that the tidal regime controls the distribution of the flora and fauna (Dale, 1982). Many organisms are unable to withstand long perfods of exposure to the air and are therefore restricted to areas 2 with a constant supp 1 y of water. Other organisms are ab 1 e to withstand a I fmited amount of exposure and can exist at a higher tide level. Therefore, the tidal regime is the primary factor controlling the biological zonation patterns (Dale, 1982). Erosion by both tidal action and marine organisms produces a rock surface which retains at low tide, a small amount of water in the pits and depressions (Ginsburg, 1953). These isolated bodies of water become aggressive at night during low tide. Differential solution can then occur where the wet parts of the rock are dissolved but the dry parts remain intact (lundberg, 1986). The aim of this study was to determine (i) if a distinct zonation pattern existed in the small scale geomorphology of the limestone exposed in the littoral of northern Vancouver Is 1and, ( i i) if the geomorpho 1ogy varied significantly with lithology.
1.2 ZONES AND PROCESSES 1 . 2. I INTRODUCTION No previous work has been reported on 1 i ttora 1 karren within Canada, and little in temperate regions. This chapter reviews similar research carried out in temperate regions and focuses on zonation patterns which have been described and the possible processes responsible for these zona 1 patterns. F ina 11 y a comparison between trop i ca 1 and 3 temperate forms wil 1 be discussed.
1.2.2 LITERATURE REVIEW Limestone which outcrops on the sea coast inevitably
undergoes erosion (Trudgill, 1976). There are numerous
processes by which the rock may be eroded such as,
b i o 1 og i ca 1 grazing/boring, wave action, hydration (wetting
and drying), spray impact, salt weathering, abrasion by
sand, chemical solution and salt and/or fresh water mixing
(Trudgi 11, 1976; 1985) The result of all these various
processes is a very distinctive coastline.
The limestone exhibits a variety of forms from the
pavements and en 1arged joints of terrestr i a 1 karren to the
notches, pits, pans and pinnacles of littoral karren (Ley
1979; Lundberg, 1977; Jennings, 1985). L i ttora 1 karren are
micro-rei ief forms found on coastal 1 imestone within the
1 ittoral zone and below low water mark (ley 1977).
Studies of 1 ittoral karren appear frequently in the
1 iterature, but very few refer to temperate coasts. Most of
the reporting is centred around tropical coastlines as
1 imestone coast are more frequent in the tropics because
both foss i 1 cora 1 reefs and a eo 1 ian i te ca 1 car en i tes are
common (lundberg, 1986) For example, Spencer (1985)
describes the lowering of the 1 imestone surface on the Grand
Cayman Island. Ginsburg (1953) studied the erosion of
calcareous rocks in the Florida Keys and Emery (1946) 4 studied rock basins at La Jolla, California. The few temperate studies which appear fn the 1 fterature are centred on the Brftish Isles (Bristol Channel, Co. Clare, Ley 1979;
Lundberg 1976, 1977). From them, it would appear that the karren forms found in temperature regions are distinct from those in tropical regions (Lundberg 1977; Trudgi 11, 1976).
Within the littoral, several karst zones can be
identified upon l i mestones. Many authors be 1 f eve that the zonation is a result of biological erosion which fs modified by mechanical erosion (Lundberg 1977; Schneider and
Torunski, 1983; Trudgi 11, 1983). The tidal regime along the coast affects the distribution of marine organisms. The ecological niches of different organisms across the shore zones are determined by: ( i) the percentage exposure
(exposure refers to the period of time an area f n the
intertidal zone is exposed to aerial elements); (if) the percentage of f nundat ion due to t ida 1 effects and wave
splash (Dale, 1982); (iii) energy levels and; (iv) abrasive material and others.
1.2.3 ZONAL CLASSIFICATION
Karren zones are related to the biological zones which
grade into one another where a sequence occurs down a single face (Lundberg, 1977; Schneider and Torunski, 1982).
Lundberg (1977) Identified four distinct biological zones on
the temperate coast of Ireland. Moving from high water mark 5 to low water mark they are: 1. the Verrucaria zone, 2. the Littorina zone, 3. the Barnacle zone, and 4. the Mussel- Echinoid zone. Each is characterized by differing morphology in the karren forms. Each is located within the littoral zone (Fig. 1.1). The verrucarfa zone is dominated by shallow, circular basins with rilled or pitted walls. The floors of these basins are smooth and flat, and there exists a sharp break in slope between the wall and floor. The 1 i ttor ina zone consists of deeper, more complex and more closely packed pits. The floors are relatively flat-bottomed and have rounded edges. Limpet home scars (depressions on the rock surface created by organisms which rasp out a cavity for shelter during dessication or exposure stress) are dominant at the water level within these pits. In the barnacle zone the wa 11 s of the basins become more undercut wh i 1 e intervening plateau surfaces become smoother. The latter is a result of barnacles covering and protecting the rock. Finally the mussel-echinoid zone has the maximum relief and is dominated by large deep basins which are inter-connected. The surface free of water is dominated by musse 1 s, whereas that which is always below the water is dominated by Paracentrotus lividus (sea urchins} (Lundberg 1977, 1986}. Wi 11 iams' ( 1973) classification scheme included five biological zones. The difference between Wfllfams' and
Lundberg's classifications are in zones four and five. 6
A SEMI·EXPOSEO SHORE
Alg;ae Zone
B
Ftgure 11
Figure 1.1 Temperate Coast Profiles taken from Williams (1970) A, and Lundberge (1977) B. 7 A c c o· r d i n g t o Wi 1 1 i a m s ( 1 9 7 3 ) z o n e f o u r i s t h e Mussel/pinnacle zone and zone five is the Echinoid pit zone. Lundberg (1977) suggests that this Echinoid pit zone is merely the final stage to the mussel/Echinoid zone and that it occurs below low water mark. Ley's (1979) classification scheme differs from both Lundberg's (1977) and Williams' (1971) in that Ley does not incorporate biology into his zones. Ley's twelve zones are related to elevation with respect to the low tide mark and tidal range. The twelve zones moving from high water mark to low water mark are: 1. above high tide- smooth flat sloping surface 2. partially opened joints and pitting 3. small shallow and irregular pools develop 4. pools wfth flat floors and concordant dfvfdes 5. deeper incised pools and passages 6. general rounding of pools as they become more massive 7. just below mean tide level - deeply incised and co a 1 esc ed poo 1 s. Second generation of poo 1 s form f ng within the older pools 8. pool floors become flat and dominate the karren type 9. d i v i des decrease i n s i z e as the p o o 1 s c oa 1 esc e. Shallow pools cover the whole surface. 10. shallow pools become less numerous 11. a pitted but flat surface exists
12. a smooth, rounded sur·face f s f nterrupted by the over deepening and widening of joints. 8 There exists considerable variation within each zone (ley 1977, 1979}. Maximum internal relief occurs just below mid-tide with decreasing complexity of the karren towards the tidal extremities (ley, 1979}.
1.2.4 COASTAL EROSION PROCESSES 1.2.4.1 BIOEROSION Bioerosion is a complex of processes which result in denudation of the rock surface and the development of biokarst (Schneider and Torunski, 1983}. Different processes are associated with the behaviour of different species. There are grazing organisms which, while eating the epil ithic (surface} algae from the rock surface, inadvertently chew off part of the rock as well. This grazing produces grooves and channels on the rock surface called epirelief. There are also organisms which bore into the rock for protection from dessication or grazing organisms. Such boring organisms or Endolithic organisms are (i} boring Cyanophytes and Algae which create small cavities, (ii) boring Sponges, (iii) some species of Bivalves and Barnacles which make long tubular burrows and, (iv} Echinoderms making small spherical pits. Finally there are protectors (eg. some species of barnacles and mussels} that create a protective covering over the rock (lundberg 1986; Trudgill, 1976}. 9 1.2.4.2 INTERTIDAL EROSION
The formation of 1 ittoral karren depends upon the isolation of small bodies of water, which harbour various flora and fauna. These bodies of water occupy primary depressions in the rock surface and are then quickly colonised since they are able to retain moisture for a
1onger period of time then their higher surroundings. The grazing and boring organisms then increase the biological corrosion and abrasion. As a resu 1 t the depressions begin to enlarge laterally and coalesce into one another. Relief is intensified as the wet areas are preferentially bioeroded as fresh seawater is brought in with high tide (Lundberg
1977; Trudgil 1, 1985).
1.2.4.3 LITHOLOGICAL EROSION
Limestones are difficult to classify. By definition, any rock which contains more than fifty percent (50~) by volume of carbonate (calcium, calcium-magnesium, magnesium) is termed 1 imestone or dolomite. The most important characteristics for karren studies are the texture and composition of the rock (Ley, 1977). Ley be 1 i eves in the case of Bristol channel that karren are solely solutional features as opposed to biologically modified ones. It is the susceptibility of the limestone to solution which is the dominant factor in their format ton (Ley, 1977). Solubf 1 tty of the rock fs affected by the porosity, permeability and 1 0 purity of the rock (Ley 1977; Trudgill, 1972}. The impurities in the rock decrease the amount of solution that can occur, thereby decreasing the number of micro-relief forms (Ford, 1986; Ley, 1977}. Impure limestones behave
1 Ike non-carbonate rocks within the intertidal zone.
Therefore, the best marine karren forms require a pure rock
(Ley, 1979}. However, limestone which is dominantly composed of magnesium calcite and aragonite calcarenites may erode by solution and disintegration at a substantially faster rate than porcellanous, well cemented algal limestone
(Ley, 1977, Trudgill, 1972}. Limestone with high porosity
(pore space within the rock) and permeability (inter connectivity of the spaces) va 1 ues w i 1 1 have a greater complexity of micro-relief features (Ford, 1986, Ley, 1977).
The grain size of the 1 i me stone can a 1 so affect the micro-relief features. As grain size increases, so too does the porosity and permeability of rock. Therefore, the micro-rei ief features become more complex with increased grain size (Ley, 1977}.
1.3 GENERAL "ODELS
There are two general models describing 1 ittoral karren; (i) the tropical model and (ii) the temperate model. Within the tropical regions the typical form is an undercut notch. A notch develops in sheltered areas as a result of offshore reefs protecting the shore. In exposed 1 1 areas the notch will disappear giving way to a surf platform and pitted ramp. The typical form in temperate regions is a platform dissected by rock pools. These pools develop due to the fact that the limestone is in exposed environments in most temperate regions (Lundberg, 1986). The differing karren forms found in both regions may result from the fact that the limestone coasts in the tropics are younger than the temperate limestone coasts. The younger rocks are less well cemented and metamorphosed therefore, they are heterogeneous and preserve the relationship between clasts and cements. This relationship then encourages differential erosion (Trudgill, 1985).
1.4 CONCLUSIONS Intertidal erosion of limestone on sea coasts may occur as a result of many physical and biological processes. The cumulative effect of tidal changes and bioerosion leads to the destruction of the coastline (Schneider and Torunskf, 1983). 12 CHAPTER 2
STUDY AREA AND "ETHODOLOGY
1.1 INTRODUCTION
The study area wi 11 be described in terms of its climate, geology, tidal regime, waves and energy levels.
This will then be followed by a description of the methodology used fn acquiring the data.
2.2 STUDY SITE
Canada's Pacific coast is a leading edge continental margin which has been modified by Pleistocene glaciers. The coast 1 i ne is characterized by count 1 ess in 1 ets, fjords and islands (Clague and Bornhold, 1980). It is one such fjord which provided the study area for this report. The study site, illustrated in Figure 2.1a,b (Fig. 2a in Appendix A)
was along the eastern shore of Neroutsos Inlet. The area is situated near the town of Port Alice on northern Vancouver
Island. The area cons f sts of severa 1 -1 f me stone beds which are exposed to both biological and mechanical erosion.
Geology, climate, wind, waves, tidal currents and energy levels al 1 contribute to the morphology of the shore (Clague and Bornhold, 1980). 13
Figure 2.lb Study Area: Near Jeune Landing on the Eastern Shore of Neroutsos Inlet 14 2.3 GEOLOGY
The exposed beds are part of the Quastsfno Formation which is the principle carbonate unit of the island, datingfrom the late Triassic (225-180 my ago) (Howes, 1981;
Mi 1 ls, 1981). The Quatsino Formation extends dominantly NW
SE in three 1 inear belts and the outcrops cover approximately 1000 km2 (Fig. 2.2 in Appendix A) (Mills,
1980). The Quatsino Fm. is a thickly bedded to massive
1 fmestone. The upper part consists of medium to thin bedded
1 imestone interlaminated with black calcareous siltstone.
The lower portions of the formation rests upon the Karmutsen volcanics and consists of thick bedded to massive, fine to microcrystal line, but locally coarsely crystalline, commonly
stylolitic limestone which weathers to brown-grey to black,
I ight grey to white I imestone (Mul Jer, Northcote and
Carl isle, 1974). In general, the formation consists of biomicrite 1 imestone which exhibits a bimodal size distribution, being composed of cora I and pe 1 ecypod debris
in a matrix of fine carbonate muds. There is upwards grading
into calcareous clastic sediments (Mi 11 s, 1981).
2.4 CLIMATE
The climate of northern Vancouver Island is dominated by dry warm summers and coo 1 wet winters. Ra i nfa 11 is the dominant form of precipitation on the island (Fig. 2.3 in
Appendix A). The mean annual precipitation ranges from 1400 1 5 mm to 4600 mm with 70-80% falling between October and March
(Fig. 2.4, Table 2.1 in Appendix A). Snowfall is confined to the mountain regions of the island and is short lived at
sea level (Howes, 1981).
There are three precipitation zones on the is 1and, 1.
The Western Zone; 2. The Southwestern Zones; and 3. The
Northwestern Zone (Fig. 2.5 in Appendix A). Neroutsos Inlet
1 ies within the boundaries of the Western Zone. Within this
zone, the mean annual precipitation increases from 2000 mm
along the west coast to 4600 mm along its eastern boundary.
This increase is a resu 1 t of changes in topography as one
moves westward. There is a convergence of air masses
resulting from the uplift created by the high altitude of
the Insular Mountains and the fjord inlets (Howes, 1981).
Along the coast, the prevailing winds are from the
northwest in summer and the southeast in winter (Tab I e 2. 2
in Appendix A). The greatest wind ve 1 oc it i es occur during
the winter months as a result of the frequent occurrence of
low pressure systems. These low pressure system are
controlled by the offshore Aleutian Low (Clague and
Bornho 1d, 1980). The wind regime within the study area has
a bimodal distribution. The strongest winds come from the
ESE and NNW Winds from the ESE would create the strongest
waves within Neurotsos Inlet as these winds have the
greatest mean velocity and occur most frequently (Fig. 2.6,
Tab 1 e 2. 3 in Appendix A). Wf nds from the WNW to NNW a 1 so 16 have large mean velocities but their frequency of occurrence is 1ower. Therefore these winds are associated with storm conditions and would create large waves within Neurotsos In 1 et as we 1 1 .
2.5 WAVES Waves within the study area are generated by two dominant pressure systems, the Aleutian Low and the North Pacific High. The intensity and direction with which the waves hit the shore are also controlled by the wind regime. Within the protected fjord, Neurotsos In 1 et has 1ower wave heights and energy than on the open ocean coasts (Clague and Bornhold, 1980).
2.6 TIDAL CURRENTS Along the coast of British Columbia the mean tidal range decreases from 5 m in the northern areas to approximately 2 m near Victoria. The mean tidal range at Neroutsos Inlet is approximately 2.7 m (Table 2.4 in Appendix A). Neroutsos Inlet falls within the boundaries of the Tofino tidal zone. The study area is dominated by mixed semi-diurnal tides (Fig. 2.7 in Appendix A) and (Clague and Bornhold, 1980). The currents in this are weak and vary in direction as a result of the Subarctic current which divides into two at about 46o- 500 N, 1300- 1380 W. One current moves south 1 7 to California while the other moves north to Alaska. The currents are towards the north-northwest during winter and autumn and the south during the summer {Fig. 2.8 in Appendix A} {Clague and Bornhold, 1980}.
2.1 ENERGY LEVELS Energy levels are controlled through the interactions of all the above mentioned factors {winds, waves, currents}. Within the protected inlets of the fjords the energy levels are their lowest because the fjords are oriented parallel to the open ocean so that the fetch is short and therefore the waves are small {Clague and Bornhold, 1980}.
2.8 "ETHODOLOGY 2.8.1 FIELD WORK The shore along the eastern coast of Neroutsos Inlet was divided into eight {8} individual beds {Fig. 2.9}. The beds areal 1 of similar thickness with a dip of 32. Most of the beds extend continuously from high water to low water mark with the exception of Bed 3. From the eight beds identified, three beds 5, 6 and 7 were inaccessible during the study period {June 22-24, 1986} as they were constantly inundated with water {Fig. 2.9}. Beds 1, 2, 3 and 4 were all well pitted beds and bed 0 was dominated by microfractures and contained no pitting. 18
~
-~·
!Qf't -~·
·...._,. Js ... ' __, 0 6 12
lotETAES
Figure 2.9 Individual Limestone Beds of Study Area 19 These eight beds where then examined for any karren forms from below low water mark up to high water mark. The karren forms were described and measured in terms of: 1. width in centimeters; 2. depth in centimeters; 3. adescription of the rock surface {eg. rilled, smooth); 4. a description of the wall character (eg. concave, convex) and, 5. a description of the pit floor (eg. smooth, pitted). On each individual bed, 1 m quadrats were laid out at 2 m intervals along the transect. Starting at the high water mark, and ending at low water mark (Fig.2.10) each pits height above low low tide and position on the transect was calculated using basic trigonometry (Table 2.5 in Appendix A). The number of quadrats squares on each transect ranged from 16 on bed 1 to 17 on bed 2 and 15 on bed 4. Within each square metre, the karren forms were described and measured; any fractures present were examined in terms of their length and orientation; the relative relief of the whole quadrate was estimated; any vegetation present was noted a 1 ong with, the type and percentage cover of other marine organisms present; finally a smal diagram accompanied each quadrate. Sma 11 rock samp 1 es were taken from each individual bed for later analysis in the laboratory in order to determine the purity of the
1 i me stone. Sketches of the samp 1 e squares are f 11 ustrated
fn Ffgures 2.11 2.13 (Figures 2.11 and 2.13 are in Appendix A). 20
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=
JJ '"' "" ~ "' ...... I Q ; "' "' .a "" " ., "' .:; ...... ,.. '"' :-. • • "" ...... "C • • • "' :a "' "" :-. • "" .. • "' '"' ~ ; Q ... • "' G .. "' f • r • T • I I I T " ...... I • • • • 1 "' • I • l 1 . • .. .. 'of; Q • Q :a "' ...... • .. • Q...- .. • • • •
Figure 2.10 Individual Bed Profiles Indicating the Height Above Low Low Tide of the Sampling Quadrats .. ~ r a: .. ! ... u :J 1 li~ l l ~ ~ J H • ~ N ~l:J I :u ..... ,. .. I , P...... 1 (1~ .... "U .. n z.. " .. a.. N cu !::. ·- ...... 11! .. 11!1 ...... ' ... ., •• _ & c ~ m :S - ,,. ~ "' r, I ... • , • ., - lt., I .,:::s ! 1: ol:.. il : L •• .. .., ...... , ...,...... j -- 0 LL 8 Jt !' • I ~ " fs fu: Jt " ~ ~ l n fi l ;o n! I l 'i ! ~ -~!! -~ ! 1 •. ,.... l:t• .:;r;. u .. ~.l t;:!-.:; "i ., •"" !t .... • il!r. -- .... • - •• 'fl ...... "I> .!... .. I I> ..H ...... :II • .. • ~ ~ ~~ • "!f .... J:!.. r" ~.!':;.. .,!' .... w.:rJ.. ' L "U"' ~~•• ~ ~~.:=__ , '• ~~~•i ..• N~~'"'HO ~i'WD -' ~~·..... ' -fU ., ~,-J' ~,,:s: :t.!· 5r.;; :; • .;; J :;,~:.;; Ql ~ ;:J • ,,. '0 "' "• 'tt a- ..... :l w..,. -L •-'5 ft .,_ .,....• -e • .,.,...., -•· - • - c"' ; .. :. .. - .. r .... r ..... r :w •• r J~ r ., s: u 1 1 ft [ • r ; ....·- • ...... f .. ~ r... - .,. m cu ];§, liAI!!I lzr il> ll1t lll i liJ;I n c ~ t) -g. VI"' N ~ ..... " ~ ~ ~ ~ ~ 0 • t • • ' ' ~ ...... ·~ ., .. cu ..- ~ )( w"' .. N r-4. N GJ L ;:J OJ ~ w g 'L v ~ .... ~ LL l: ~ ...J 22 2.8.2 LABORATORY WORK The rock samples were analyzed in the laboratory to determine their purity. A smal 1 sample (less than 50 g) was dissolved in 9N (molar) hydrochloric acid (HCl). After the sample had been completely dissolved, the solution was filtered to capture the insoluble residue; the filter paper was dried and weighed. Percentage i nso 1 ub 1 e and then the purity of the limestone were calculated using this data. The results wi 11 be shown and discussed in the analysis section of this chapter.
2.8.3 COHPUTING The raw fie 1 d data was entered into the VAX 8600 computer. Simple two dimensional plots were computed in order to determine if any zonation patterns or relationships existed upon the limestone beds using the statistical package, MINITAB. (i) Width was plotted against depth, (ii) width/depth (W/D) ratios against width and/or depth, (iii) width and depth against height above low water mark and pit wal I character, ( i v) floor and surface against height above low water mark. All of the plots and results are discussed in the analysis section of this chapter 3. 23 CHAPTER THREE
ANALYSIS AND DISCUSSION
3. 1 INTRODUCTION The many various plots which were created from the data wi 11 be analysed for any significant trends. These trends will then be discussed in terms of coastal and geomorphological processes which act upon the shore.
3.2 FABRIC AND BULK CHE"ICAL CO"POSITION All eight beds are of fine grained micrite and appear to be 1 ithologically identical. The five samples were chosen from beds with a great variety of surface features: Bed 0 displayed dense micro fractures but absolutely no pitting. Bed 2 and 3 were highly pitted. Beds 5 and 7 were rarely exposed to the air and have therefore little pitting on their surfaces. The limestone from all of the beds is greater than 92~ pure (Table 3.1). Therefore chemically the beds are similar. This probably explains why the pits are the same size and shape in a 11 the beds but does not explain the presence or absence of pitting. BED SAMPLE FILTER FILTER PAPER INSOLllBLE PERCENT PERCENT WEIGHT PAPER AND RESIDUE INSOLllBLE SOLUBLE (g) (g) RESIDUE (g) (g)
0 42.07 4.00 6.21 2.21 5.25 94.8
2 24.35 3.91 5.26 1. 35 5.54 94.5 1\) 3 31.17 4.14 5.92 1. 78 5.71 94.3 """
5 35.99 3.95 6.18 2.23 6.20 93.8
7 46.94 3.92 7.70 3.78 8.05 92.0
Table 3.1 Purity of Coastal Limestone 25
3.3 "ICRO-FRACTURE DENSITY Micro-fracture density does not determine whether a bed wi 11 develop pits except in the case of Bed 0. Bed 0 ishighly fractured so that the limestone is dissected into such small sections that it is impossible for a pit to develop and grow before ft comes into contact with a fracture and its growth is halted. Beds 1, 2 and 4 al 1 have fractures present at high water mark, yet pit development is possible. The density of fracturing is not as high as on Bed 0 but fractures are present as are pits. Therefore it would appear that pit development is unaffected by the presence of fractures except in the case of Bed 0 and it is a unique bed in that none of the other beds exhibit quite as high a density of fractures as Bed 0. It fs not known why Bed 0 behaves this way. Its and bulk chemical composition is similar to the other beds in the area. Persumably it must be some other factor of the lithology which controls fracturing and pitting.
3.4 ZONAL PATTERNS 3.4.1 EFFECT OF TIDE LEVELS A zona 1 pattern was 1 ooked for in re 1 at ion to tide levels. From Figures 3.1 - 3.3 (Figs. 3.2, 3.3 in Appendix A), it can be seen that only small pits develop at the low low tide (LLT) level (Fig. 3.4). Near high tide (HT), 3.6 m higher, smal 1 pits are also dominant, but larger pits can be 26 • ,.. • • • z... • Bed 1 • • • •l. • 1.l• 2 • l • • • z • - • .. 7 • z .. . • • .;; - • •l l • -·- 6, "~ ..... z J• l .a ------~··1 a.eo·------·------·------·------·------t.7t l·•G %.10 l. •• o J,SO..
...... : .;. • • " lw• • • • Bed 2 •;. • 1>• ~ • • • • •. • * • •z • • • i i; ~; 1 .. 1 7 i]: • + o + + 1 II 7 + •6 0 6 ~ > ... 6 1 o z z • o5 7 • a ------·------·------·------.------·------~-~~o.•o ~.oo z.•o !.40 •.uo B
111-.11"3 ,..,. • • Bed 4 4ij+ • • • z... 3 z• • 3 3 • • 1 • • • 3 3 • 6 Za ~ 3 3 4 !"!). ~ •• 5 25. 3 ~ • • • • 3 7 6 • • • • O• •II S 6 •S • Z6 Z ------·------·------·------·------·------·~··1 c ~.,o z.•l 1.00 l.oG ... ~0 •• tO
• • • • • -. All • •• • ... •z • • • Beds z.-• z 3• • • .. • •• ~ z 3 a O! ~ 3 a Z 0 0 *Z l " *l*7* 5• S " ~ 3 a * Z•Z 2 2 - 5 51~~'* S1 •• ~· •' i ~ ~>a•35 Za o'•" 3 • •~ ~! 3•6•1 •• • ~j•• .;~. ••7~~·; •Z•! +J • ~· 1 • 1 ]o .. ' • • 3• ! • ·~ 3• s~a· zz •------•------•------•------•------.------~•~•L~ 0 0.0 1.0 %.0 ].0 4.0 5.0
Figure 3.1 Height Above Low Low Tide vs Width Above Low Low For Beds 1, 2, 4, and all beds - -
1\) -....j
Figure 3.4 Typical Low Tide Scene: Many Small Pits and Large Quantities of Algae 28 found (Fig. 3.5). The range in pit size increases away from low low tide, and the greatest range is found near the mean tfdal (MT) mark, at a height of approximately 2 m. This appears to be a resu 1 t of the eye 1 i c changes in tides. The pits in the MT area are frequently wetted and dried throughout each semidiurnal tidal cycle. At high water mark there may be prolonged periods of dryness without any wetting, while at low tide mark the opposite is true; pits are constantly wet for long periods. The greatest differential erosion occurs at mid tide level where there is the greatest range of conditions. The trends remain when the data are logged and plotted against height above' low water mark. Conversion to logarithmic scale emphasizes the smaller pits more efficiently (of which there are more present on the beds), the greatest range of pit size was found near the mean tide level (Figures 3.6 - 3.8; Figs. 3.7, 3.8 in Appendix A). The smoothness of pit floors was also plotted against height above low water mark to determine if any pattern exists. From Figure 3.9, it can be seen that there is 1 ittle change in the floor characteristics. At low and high water mark the floors are predominantly smooth. A small change does occur at mean tide 1 eve 1 ( MTL). Just be 1ow MTL floors become rougher or randomly fluctuate between smooth and rough classes. These trends hold true for all three of the beds that were intensely studied. 1\) c.o
Figure 3.5 Typical High Tide Scene: Dominated by Large Pits and Fractures 30
C:oOO • • l • 4 • •J •~ • ··~· J s 3 • • ; • • • • • - 3 .. i • ~ ~ • • • • , 3 • ] - j .. 1 • • ". ~· z ~ l • • z Bed 1 - • ~ • • .•, • -1.)• • •
: •Ol • • • • • l. ~· z • • ~ z 4 • • . .. ; • • 2 • ~ :; i. l • :!.,. J "~ 3 • • z ~ 7 ; • ~ a • .>• 5 z, 3 4 0 ; i . . .. • i II • 5 • ~ 3 • J a .. ~ 7 'i! 5 . . Bed 2 • .. • • .. • .) . 0 ~ 3 • . 3 • ~ s 6 • • • • .. • • z 0 a J -1·~· .. t • • • - • 'tl. .. ~------·------l-.-.:------i::;------;:z;------::oo------,; .i ~ 'J ~
J .... • Ccl02 • • • • z 1 .. z z l. ~· ~ 1 • • • • • 6 • • z z .. .. • 5 ! • ] 4 ~ 1 • • • z ;. • • z .. • J 6 J 3 4 • • ! 5 Bed • 6 7 3 • • z .. i. 6 ~.,)+ J• 3 • • 7 z 5 5 .. ! • 2 ! 1 .. • J • 3 • • • .) • l 3 J • i. z 5 J z • • ! z .,• z . , • 4 3 4 ... i. ~ • • z i 2 • • ------•------•--·------•------•------•------·--•"L~•l4.oo J..•l J.;;o J.ol) ... .;o •• eo
Figure 3.6 Height Above Low Low Tide vs Logarithmic Width Above Low Low Tide For Beds 1, 2, and 4 31
..... ···--~ t 1 - • • • • • • • J. ,. • Bed 1 ~ ...
' ...- . • J . ~ • •
..,_.,.,- ·------·------·------~--·------~ .,.;1 ~-··1 .... 1 ---·------·------c•~-·j , J.sa
a • .,.
Bed 2 • l • •
J •
~. i• • • • • • • • • l
------·------·------·------·------·------1L·•!~.a1 1.a1 z •• a J.~Q •• JO
... J• z • • • • • • ...... t l - J. J• Bed 4
z .J•
'.J• • • • • 1 • z • • • • • • ------·------·------.______.______·------·~··) 1o.a0 .L. ·' J.JO J.el ... 40 .... o
Figure 3.9 Smoothness of Pit Bottoms vs Height Above Low Low Tide For Beds 1, 2, 4 32 The same trends occur with respect to secondary pit development on the floors of the maJor pits (Fig. 3.10 in Appendix A). On beds 1 and 4 secondary pit formation occurs at 1ow tide 1eve 1 , whereas on bed 2 these secondary pits can form anywhere from low to high water mark.
3.4.2 HORPHOHETRY OF PITS To determine if a littoral zonation pattern existed in the geomorphology, the general shape (form) of the pits was examined by plotting width/depth (W/0) ratios against the width and depth for all the beds (Figure 3.11). If a distinct change in form occurs, then perhaps a zonation pattern may be identifiable. From Figures 3.11a and b, it can be seen that the points are all clustered, thereby indicating that the pits are neither wide nor deep. It becomes apparent from looking at the graphs that there is no clear change in shape with size. All the points fall within the same W/0 ratio range of 1-6, regardless of their dimension. Therefore, the general shape of the pit remains constant, although the width and depth may increase. The beds were then examined individually to determine if there was any type of shape change between them. Again W/0 ratio were plotted against width and depth for the individual beds (Figures 3.12- 3.14; Figs. 3.13, 3.14 in
Appendix A). Points were once again clustered, indicating the smal !ness in pitform range. The pits were found within 33
A ......
1.. • .... • .. . 0 .... 7 .... ':: ...... • ...... • •• • 0 ..... 0 12 z• J6 WIDTH em
8 ..• :?' .. ...
1.. .. 0 ...... ~ .... ~ ...... ••• .•• ••• ...... a...... ~ ...... •...... • .. • .. • c ...... • • • 0 8 12 16 20 DEPTH em
Figure 3.11 A, B Width and Depth vs W/D Ratios For All Beds 33
A
2• •
,. 0 .. • -~ .. ~ ...... •...... & ...... • ...... • . • 0 . J ·o
WtQTH em
B ..
• •• ·-·•...... ••• ...... -• .•...... • ...... • . • OL------~----~------~----~~----~~--0 H 5 75 10 1~5 DEPTH em
Figure 3. 12 A, B Width and Depth vs W/D Ratios For Bed 1 34 the range of 1-6. Therefore the similarity between width and depth ratios indicates that there is no change in shape from bed to bed. The pits along each individual bed have the same genera 1 shape. Pit shape is essent i a 11 y constant throughout the entire study area if pits are present at all. Therefore no zonal patterns can be distinguished on the basis of change in pit form. The actual form of the pits is shown by a comparison of their width and depth (Fig. 3.11). Width of a pit is on average three times greater than the depth (Fig. 3.15) but, has concave walls giving the pits a rounded bowl shape. The range of widths and depths increases from Bed 1 to Bed 3. The widths lie between 1-8 em for Bed 1, 1-10 em for Bed 2; and 1-12 em for Bed 3. The depths ranged from 2.5 em for Bed 1 to 4.0 em for Bed 3.
3.4.3 RELATIVE RELIEF When examining the relative relief of the quadrats with respect to height above low water mark there are no distinct trends present (Table 3.2 in Appendix A) but, there Is some indication that the area of greatest relative relief varies from Bed to Bed 4: on Bed 1, it is around mean tide level (1.2-2.0 m), but at high tide level (3.4-4.4 m) on Bed 4. Finally, on Bed 2 there is no dominant zone which exhibits the greatest relief. The fact that the relative relief is w 01
Figure 3.15 An Example of Pit Form and Biota Present 36 greatest at mean tide level for Bed 1 can be explained by the cyclfc changee fn tfdee ae explained above. Bed 4 undergoes these same processes but receives the direct energy of the waves whereas those reaching Bed 1 have been s 1 f ght 1 y refracted. Thus the rate of so 1 uti on is probab 1 y greatest at mid tide 1 eve 1 but with greater me chanica 1 energy. Therefore, the zone of greatest relief is closer to high water mark on Bed 4. The effect of these sma 11 differences in energy 1eve 1 are apparent when examing the three beds with respect to one another. The relative relief increases as one moves from Bed 1 to Bed 4. The average relative relief on Bed is 23.6 em, 24.3 em on Bed 2 and 29.2 em on Bed 4.
3.4.4 BIOLOGICAL ZONATION Examination of the biota present reveals an imbalance between the pit formations found and the biota. For ex amp 1 e, 1 i mpet home scars were found which had barnac 1 es living in them instead of limpets. In reality this would never happen unless some other factor influenced the removal of the 1 impets. Another example of a biotic imbalance is the density of barnacles found on the rock surface. On most rock coasts the barnacles are so closely packed together that there exists no space between them through which bare rock can be seen. This is however not the case on Neroutsos
Inlet. Great quantities of rock are visible through the 37 sparse barnacle cover. It is be 1 i eved that the po 11 utants produced from the pulp mil 1, located a few kilometres south, are killing or driving away the biota which would normally be found on a rock coast such .as this. There are some minor trends present in the marine organisms with respect to height above low water mark. In genera 1 , there are three zones present: i) a zone of no biology (high water line), fi) animals and plants and iii) large plants (low water line). All three beds exhibit these zones with variations in length of each zone (Fig. 3.16). The zone of no marine biota decreases dramatically from Bed 1 to Bed 4 (from 16m-4 m). Bed 1 is the farthest away from the water, thereby making it a harsh environment for marine organisms. There are prolonged periods of dryness during low tide through which the organfsma are unable to survive. Bed 4 is much closer to a source of water thereby enabling marine organisms to survive through the shorter periods of dryness. Therefore, marine organisms are able to colonize beds 2 and 4 sooner and at a hfgher level than bed 1 as a result of the lack of water for life. There are distinct areas within and around the pits where certain marine animals exist. Mussels are found along and in fractures or around and under broken pieces of rock. Barnacles dominate the entire study area but are concentrated around the exposed surfaces of the pits. Sea snails are found inside water filled pfts on the floors, 38
TBEF J..LNE _1
1---
~TL
7 6 5 ~-~ 1- 3 0 ~ 1- '_--==i
I I
J
' I I I ' '
I I I I I I ' ' ~ ' ~ ~
~ ~~ LTL 1:;';'. ~-·"· P.anro - 0 6 12 ...... ,. "'ETRE1 t•rqe ot•nta ~ ~01' studted
Figure 3.16 Biological Zonation 39 whfle limpets are located on all surfaces especially the walls and floors of the pits.
3 ••• 5 THE RILLENSTEIN ZONE
Ril lenstein are rocks with microscaled solution
features (Fig. 3. 17). These mi cror i 11 s were found on Beds
1, 2 and 4. On Bed rillenstein was found for 16m
extendIng from high water mark to tree 1 I ne, 4 m on Bed 2 and 6 m on Bed 4. Rillenstein zones have not been described
on other 1 imestone coasts either in Ireland or in the
tropics. Even in the interior the exposed limestone has no
ri llenstein formation on it. This results from the fact
that the liemstone had a vegetation cover and has only been
recently exposed (1970) as a result of deforestation and
soil erosion on the Island. Rillenstein is able to develop
on the exposed limestone of Neroutsos Inlet due to the
fabric of the rock. The every fine grained homogeneity of
the rock makes it well suited to the formation of
rillenstein if the rock can be kept bare. Storm wash keeps
the rock surface bare, but there is 1 Itt 1 e abrasion to
mechanically erode the rills away. Therefore, r i 11 enste in
can be formed on this bare surface by rain or spray or rain
onto a salty surface. 40
ll)c 0 N
ll) '"Cl.,.., E--- ..c ....OJ) :r: ll) ..c..... 41 CHAPTER FOUR
CONCLUSIONS AND FUTURE RESEARCH
4.1 CONCLUSION
After carefu 1 inspection of the pit morphometry in the littoral zone we can conclude that there is little clear zonation in the pitting. A clear and sharp change in pit form is absent as one moves from low low tide to high tide as we 11 as from bed to bed. The width of a pit is approximately three times greater than the depth throughout the entire study area. This contrasts with the findings of
Williams (1971) and Lundberg (1977) in Ireland on horizontally beded shores. Both Williams (1971) and
Lundberg (1977) identified distinct changes in pit form from high to low water mark (Fig. ). The pits become deeper and begin to undercut their walls towards low tide with the deepest dissection occurring in the echinoid (sea urchin) zone (Lundberg, 1977).
This area, however, does resemble the karren of the more sheltered Bristol Channel area described by Ley (1977;
1979). The greatest diversity in pit size occurs at mean tide level.
Zonation is evident in the biology but not in the pitting. Where beds will support pits, there is little or no correlation between pit size, frequency and morphrometry on the one hand and the marine biotic zonation present. 42 There is strong 1 ithological control with no pits developing on dense 1 y fractured beds. As we 11, the rock wi 11 support the finest scale of karren-rillenstein. The general size and shape of the forms is quite 1 imited and constant throughout the entire area. Therefore, at this site, the eastern shore of Neroutsos Inlet, there is little marine karst zonation. There is a narrow rillenstein zone with few pits, then a wide pit zone with no rillenstein. The pit zone shows that the most varied pits occur at the mean tide line, but this is not a strong trend. The pit form remains constant throughout the entire study area which results from the limemstone being of a 11 the same bu 1 k chemica 1 composition and texture and undergoing the same physical processes.
4.2 FUTURE RESEARCH Further research could be done on Northern Vancouver Island with respect to the 1 ittoral karren. Other limestone
outcrops could be examined in order to determine if what was found at Neroutsos Inlet is the norm for the Island. A site which is affected by the same environmental and physical processes but where a pulp mi 11 is absent would be ideal. This would allow one to determine if the mill has any affect upon the exposed strata. Chern i ca 1 ana 1 yses of the water should also be carried out during both day and night on any future research in this area. This will allow one to 43 determine how aggressive the water is and therefore perhaps provided a device with which erosion rates could be predicted. There are numerous aspects of 1 ittoral karren which could be studied within this area which could not be covered within this thesis 44 REFERENCES
Atmospheric Environment Service. Canada Climate Normals. Temperature and Precipitation British Columbia 1951- 1980. Environment Canada.
Atmospheric Environment Service. Canada Climate Normals. Vol. 5, Wind 1951-1980. Environment Canada.
Clague, J.J. and B.D. Bornhold, 1980. Morphology and Littoral Processes of the Pacific Coast of Canada. In: The Coastline of Canada, S.B. McCann Editor.
Dale, J.E., 1982. Physical and Biological Zonation of Subarctic Tidal Flats at Frobisher Bay, Southeast Baffin Island. Unpublished Masters Thesis. McMaster University.
Emery, K.O., 1946. Marine Solution Basins. Journal of Geology, Vol. LIV, No. 4, 209-228.
Fisheries and Oceans. Canadian Tide and current Tables. 1987. Vo 1 • 6. Bark 1 ey Sound and Discovery. Canadian Hydrographic Service Pacific Coast.
Ford, D.C., 1987. Unpublished Manuscript.
Gladysz, K., 1987. A Report on Karren on Dip Slopes Recently Exposed by Deforestation, N. Vancouver Island. Hons. B.Sc. Thesis.
Golubic, S., 1979. Carbonate Dissolution in Biogeochemical Cycling of Mineral-Forming Elements. Edited by P.A. Trudinger and D.J. Swaine pp. 107-129.
Guinsburg, R.N., 1953. Intertidal Erosion of the Florida Keys. Bul 1. of Marine Science of the Gulf and Caribbean. Vol. 3, No. 1, 55-69.
Howes, D.C., 1981. Terrain Inventory and Geological Hazards, Northern Vancouver Island, British Columbia. Ministry of the Environment, APD, Bul 1. 5.
Jennings, J. N., 1985. Karst Geomorpho 1ogy. Basi 1 B 1 ackwe 11 Inc., New York.
Ley, R.G., 1977. The Influence of Lithology on Marine Karren. Abhandlungen zur karst-und Hohlenkunde, Refhe A-Spelaologie, pp. 81-100.
Ley, R.G., 1979. The development of marine karren along the 45
Bristol Channel coastline. Z. Geomorph. N. F. Supp 1 • Bd. 32, pp. 75-89.
Lundberg, J., 1977. Karren of the Littoral Zone, Burren District, Co. Clare, Ireland. Proceeding 7th Int. Cong. Spel. Sheffield.
Lundberg, J., 1987. Limestone Coasts. Unpublished Manuscript.
Marsh, W.M., and Dozierr, 1981. Landscape. An Introduction to Phys i ca 1 Geography. Addition-Wesley Publishing Company Inc. Philippines.
Mi I Is, P., 1981. Karst Deve I opment and Groundwater f I ow in the Quatsino Formation, Northern Vancouver Island. Unpublished Masters Thesis, McMaster University.
Muller, J.E., Northcote, K.E., and Carlisle, D., 1974. Geology and Mineral Deposits of Alert-Cape Scott Map Area. Vancouver Island, British Columbia. Geological Survey of Canada. Dept. of Energy, Mines and Resources. Paper 74-8, 77 pp.
Pethick, J., 1984. A Introduction to Coastal Geomorphology. Edward Arnold Ltd. Great Britain.
Schneider, J., and Torunski, H., 1983. Biokarst on Limestone Coasts, Morphogenesis and Sediment Production. Marine Ecology. Vol. 4, No. 1, pp. 45-63.
Spencer, T., 1985. Marine Erosion Rates and Coastal Morphology of Reef Limestones on Grand Cayman Island, West Indies. Coral Reefs. Vol. 4, pp. 59-70.
Trudgill, S.T., 1972. Quantification of Limestone Erosion in I ntert ida I Subaeria I and Sub so i 1 Environments, with special reference to Alodabra Atoll, Indian Ocean Trans. Cave Research Group of Great Britain, Vo I • 14, No. 2, pp. 176-179.
Trudg i 1 I , S. T., 1976. The Marine Erosion of Lime stones on Aldabra, Indian Ocean. Z. Geomorph. N.F. Suppl. Bd. 26. pp. 164-200.
Trudgill, S.T., 1983. Preliminary Estimates of Intertidal Limestone Erosion on tree Island, Southern Great Barrier Reef, Australia. Earth Surface Processes and Landforms. Vo 1 • 8, pp. 189-193.
Trudgill, S.T., 1985. Limestone Geomorphology. Longman Group Limited. London and New York. 46
Wi 11 iams, P.W., 1971. Excursion Guide for Fieldwork, Commission on Karst Erosion International Speleological Union. 47
APPENDIX A 48
Figure 2.1a ~tudy ftrea: Northern Vancouver Island 49
PACIFIC OCEAN
~ KARMUTSEN FORMATION TRIASSIC
fj:] BONANZA GROUP (early Jurassic). TERTIARY VOLCANICS and SICKER GROUP late PaleozoK:
~ QUATSINO and PARSON BAY FORMATIOJII: (late Triassic)
[E) LATE MESOZOIC SEDIMENTS and TERTIARY SEDIMENTS
EJ ISLAND INTRUSIVES: JURASSIC
II WEST COAST COMPLEX
FiQure 2.2 The Geolo[!y of ~!orthern Vancouver Isl~nd 50
-1 20 m ~ m"0 10 :D -1> c :0m ;""\ 0 () u
J F M AMJ JASON 0
Figure 2.3: Total Monthly Precipitation and ~ean Temperature For Port Alice 50 23'N 127 27'~ TABLE 2.1
TOTAL MONTHLY PRECIPITATION AND MEAN TEMPERATURE FOR PORT ALICE 50° 23'N 127° 27'W
JAN FEB l-1AR APR MAY JUN JUL AUG SEP OCT NOV DEC
DAILY TEMP 3.1 4.9 5.5 7.8 10.9 13.5 15.9 15.9 13.7 10.0 6 .1 4.6 COC)
TOTAL PPT. 405.4 340.2 310.5 221.6 114.4 76.9 63.8 81.3 196.9 417.4 474.9 532.5 (nun) \Jl
RAIN (nun) 381.1 330.6 302.4 221.3 114. 3 76.9 63.8 82.4 196.9 417.4 4 72.4 521.5
SNOW (mm) 27.9 9.3 7.8 0.4 TRACE 0.0 o.o 0.0 o.o TRACE 2.5 10.5 52
0 Rainfall c;3 Snowfall .--- 50I(
1""\ r--- E E r--- ...... 400 z I-- 0 1- I-- ~ 30c r- a.. (.) r-- a:w 20 0 a.. .---
10 0 - I-- ....-- 1-- w J FM AM J JASON 0
Figure 2.4: Total ~onthlv ~nO\'' and Pain accumulation For Port Alice 50 23'N 127 27'W 53
Str~·Q'/f
Figure 2.5 Precipitation Zones of Northern Vancouver Island 54
N
, ... -.... , , -- , , 1<1' ... '
I ' ' ' ' ' .. ... _ \ ...... \ -...... \ .... ' ......
\ \ ' \ \ \ ' \ ' \ \ \ ' \ ... ._. ______... _ . ' ... ------...... _... ..-'
mean velocity---· frequency -
s Calm 15.6%
-1 Figure 2.6: MEAN WIND VELOCITY ( kmh ) AND FREQUENCY FOR PORT HARDY 50 41'N, 127 30' W TARLE 2,2
-1 MEAN WINil SPEED (Kmh ) AND PREVAILING ))]RECTION FOR PllfrJ' IIARHY 50° 41 'N 127 ° )O'W
\Jl JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC \Jl
SPEEf!1 (Kmh ) 16.6 15.4 14.2 12.2 10.8 10.5 9.5 7.8 8.0 11.7 15.6 17.0
DIRECTION ESE ESE ESE ESE NW NW NNW NW ESE ESE ESE ESE TABLE 2.~
FREQUENCY AND MEAN WIND VELOCITY FOR PORT HARDY 50° 41'N 127° 30 1 W
N NNE NE ENE E SES SE SSE s ssw sw WSW w WNW NW NNW \Jl a' FREQUENCY 3.3 1.8 3.3 1.9 7. 0 14.4 8.3 3.6 7.5 3.7 6.6 4.3 6.9 2.9 5.0 3.9
MEAN VELO~ITY 9.5 7.9 10.2 17.9 24.2 14.0 9.7 8.3 10.0 9.0 9.3 9.9 13.9 15.5 16.0 11.0 (.km- )
CALM 15.6% OF THE TIME 57
CAMPBELL RIVER
3.0 f/) Q) -a;'- 1.5 E 0 DAYS
TO FINO
3.0 f/) Q) -a;'- 1.5 E
DAYS
Figure 2.7 Tidal Re9ime of Tofino and rampbell Piver TABLE 2.4
TIDAL DATA
LOCATION MEAN TIDAL I.ARGE TIDAL TYPE OF TIDE RANGE (m) RANGE (m)
Prince Rupert 54°19'N 130°20'W 4.9 7.6 Mixed Semidiurnal
Bella Bella 52°IO'N 128°08'W 3.4 5.3 Mixed Semidiurnal
Alert Bay 50°35'N 126°56'W 3.5 5.3 Mixed Semidiurnal \J1 Vancouver 49°17'N 123°07'W 3.3 4.9 Mixed Diurnal (}.)
To fino 40°09'N 125°55'W 2.7 3.9 Mixed Semidiurnal
Victoria 48°25'N 123°22'W 1.8 3 .1 Mixed Diurnal
Sooke 48°22'N 123°44'W 2.0 3.2 Mixed Diurnal 59
Residual and Dominant t Currents
• • Direction of Littoral Drift at Spits ~ ()., -()
0 () m 1> z
I
0 50 KM
Fipure 2.8 Tidal Currents of Vancouver Island 60
T,tBLE 2 .5 HEIGHT, SLOPE AND LENGTH OF SAMPLING OUAORATS
BED QUADRATE SLOPE LENGTH HEir.HT AB,VE ~LOW LOW LOW TIDE (•) (•) 1 1 6 35.7 3.7 2 33.3 3.5 3 30.9 3.2 4 28.5 3.0 5 26.1 2.8 6 23.7 2.5 7 21.3 2.2 8 18.!) 2.0 9 16.5 1.7 10 14.1 1.5 11 11.7 1.2 12 (),J 1.0 13 6.9 (1.7 14 4.5 n.5 15 2.1 0.2 16 0.0 0.0 z 1 6.5 40.0 4.5 2 37.5 4.2 3 35.n 4.0 4 32.5 3.7 5 30.0 3.4 6 27 .s 3.1 7 25.0 2.8 8 22.5 2.6 9 20.0 2.3 10 17.5 2.0 11 15.0 1.7 12 12.5 1.4 13 10.0 1.1 14 7.5 0.9 15 5.0 0.6 16 2.5 0.3 17 0.0 n.o
1 7 3~.5 4.8 2 36.3 4.4 3 34.1 4.2 4 31.9 3.~ 5 29.7 3.6 6 27.5 3.4 7 25.3 3.1 8 23.1 2.8 9 20.9 2.5 10 18.7 2.3 11 1F.S 2.0 12 14.3 1.7 13 12.1 1.5 14 ~-~ 1.? 61
HWM ... 111dtll •• ,.. Alot of tnn .,.. lwoUII ....ct AGoruf•t~tlr .a "'• l"'et• (..-.to) .. lathe ..11ef Z7c:a IU le~~steill 1s ,_,,....t
1M lf1dtll 1.1711 1-7 .. lathe "e11ef lDat .. '"" .,..,.t 201 ••t Chef' 11 tle~~stefll is tt"OSOftt
a.4 V1dtll l.S. ltelathe ltel1ef lDat 1-t All Jft 1~ ..~ '111e4 Marino l1ou: 11-.u ~ t..~cln 51 11tt&W1~M lOS •ssals ZS
led V1 dtJI l. JOa 1-11 .. lati¥0 ltel1ef l2c:a 411 pits ·~ Qtar f111ed llld contai• bi"'OIIII lliJ•• all ~ !lot:a. -.,.~,. l1ou: e..,.cln ~s aloa• lS Aooroat•tely lOS I"WOle
led V14tll 3. 6711 lte1ati¥O ~11ef ~7c:a "-d1 ~ p 1 ts liU1 1 erocleel, 1\a rd to •asu~ ,..,.,,. I iota: e..,.c1n 50-601 •ssln lSI alo.. !151
1-ta a.4 Vfdt!l 6.& "-lat1¥0 ltel ief2~ ,..,.,,. 11ou: ,,... 911 e..,.cln 71 bt1~ •~• is dDWI~~o~ted 1tJ -.11 oits
LWM
o0 P•ts high retattve rei ief
~ fractures
Figure 2.11: Examples of Sa~le Ouadrats For Bed 1 62
HWIVI ~ 1M Wf ftfl l. 2all 4-l ..1at1ve .. Hof UCII 1111.-sc.eta ts...., ~ l'1le la,.st Dft ts ~'111M wttll •tar 1114 CDftU11t1 11"*1 al ... Ia ft
1M Wf41tfl z. •s. 4-l .. 1tt1ve ..lief llCII 1111•sc.eta '' lou ,,..-~,.... c ,_ ,.,... Jitl .,.. ..c.e .. 1'1114141 w1ta
·-llllrl,.. •'llll•l1ou: ., ... )S bln~acln ts
1M 11141tll z. ~ 4-5 .. litho -.Jto1' lb LA.-,e IN ,_.,_.~tits .,.. •c.e,. f1llo41 wttll alqu- 1'11,.1,.. ltou: alua 101 E bln~acln ~ \0 l11111ats ~ l(j •ss•ls 5I ~ 1M 1114ltfl z. lOll 4-7 '-lat1ve RaHat' ~ ,._,,. la,.,. 111U -111ad w;tfl ..u.- llld biP'ftlcln, Httor;,.., 'llllssah Mid sea weN ,..,.;,.. ltota: alau ns ~~a,.c 1" n -.ssals lOS ltttor1,.. ~ 4-10 s.a w;cau l.:n. .. ltt•~~e .. l1af :Sci All 'its are ..taP' ftllod and contain sea we.c~ ,..,.,,.. ltou: ., ... !SS bln~aclas 801 11-ts 5S 1ftto,.,,.. ~ IIIISSals :m 4-12 1M W1dtll l.lOII '/~ Relative Re1to1' :l5al llllrine ltou: ., ... 60S MP'ftiC los lOS -.ssols m I /~ s.n Dttl .,.. :.rloctt, I"'Und MCI 111 tata tile P'Odl Clll .. aMlo LWIVI
htgh relative ~'-""~ reltef
Figure 2.13: Examples of Sample Quadrats For Bed 4 63
•
l~. ~· •
4 • Bed 1 1-.J• • • • • • •4 z J.j• j z • -· ~ s , •• • -z s .. z 4 l • -_,,- 1 J 6 iJ • l • z • .1.11• ~ • • • ·------·------·------4------·------.------~-~1 ~.to Q. 10 lo•O 1.10 l.IO 1.50
1•-~· •
Bed 2 u -~· • • • .. • • ... J• .. • , • z • r • z ~ ~· z) ! ! f.,~!~ i ;! 53; i i Q • J+ 5 Z J l ~ Z * 5 S T !o • • • ------·------·------·------·------·------~··4: •• ~ •··~ .;. •• o ~.6-o ... Jo
li .J+ • • • • Bed 4 z z • • • o.l.t• ~ •••• i* iii • ,, • • !• ••• 3 l ~: ~ f i ~~: ~;: ~ •Z.. "'+9 1 *' S 2 ------+------·------·------·------·------·~-~11.10 l •• a J.oo J •• o ... zo ... ao
:lc•r-.. L .. - • u.a• • • • • All U.il+ • • • • Beds 2 l • • l •z • • • • • • • • • • o.J• 3 •• 6Z •• •• • • z 4 j~ •• ,; 7: ~; ;; ~ ~ 3 ! i : ::i; 2 ; - 3 7• ~3 •7•73 S •* •• S 6 + i 53 Z i~oo4 + • - 9 •• I 2•6•• •• • •• • ••• ••Zdl~•l •Z•• •• • ~-~• Z• Z *4 • 5 3 •• ~l•• • 71 •1 56o* Ze Z o.o•------•------•------•------•------_.------~.~-L. 1.0 z.o 3.0 4.0 5.0
Figure 3.2 Height Above Low Low Tide vs Depth Above Low Low Tide For Beds 1, 2, 4, and all beds 64
Zl. a• •
Bed 1 • • , • J• • ~ - ~ ~ l • ~ • . $ . z - i ) • l 2 l • • . • • 1 •l ] • z • Q .II• ' a.,)O·------·------·------·------·------.------~··1 ol.10 1.•0 1.10 4.~0 loSO
a • • Bed 2 1 ... ,)+ • • • z 1 • ... • • • . . . ~ . ' ' 4 ; ! ~: ~ ; .! ; :; ~ j ~ • • • 3 1 l • <>S S l 4 •
------·!------·------.------·------·------~··z;..oo 1.o0 .t.•O ~-~It •·00
• u ..... •
Bed 4 • • • • • • •
• j. ;)• • • • • • • • ~51· j ' • :~ • ~ • •• • ; • .; .;:• - • • •• • 3 •••·- • •5 • ·~·z "• 2 • • :J• ' l1•.o~ ~ ~ • ~ .. z -·~~ 3.> 7• ~- I! •!'•! ...." HB , I 'i•~6aH ! : . .;: 3•3•' 6o •• •• •• !>5 " - ·~ a All - • ]a -~ •o•1:! 9• •• ...... ~ I>· ~·7! • , - ) 4 - 3 1, • .. 34 ...... o.Z•~ .. s : ~- ~ ? ". Beds - .. ·~ -· z.. " .. • • ...... • •• .. • ~-~~· 3 ~ • ~ 5 • -!' • • • . "• • •
Figure 3.3 Height Above Low Low Tide vs W/D Ratios Above Low Low Tide For Beds 1, 2, 4, and all beds 65
l. ,.. • 4.• • • • •4. • • ~ z..-.. J • • ~ • • • - • • ) i • l .. • l • !» .. l Bed 1 - z "• • • • • • l·Z• • 4 .. • • • • ... z • • • - • • • - ) I).J• 3 .. •
CoOS •.. • • .. J .U• • • • • 4 3 i • .. • z • • • 4 3 .. • l • • • ~ 2 1 6 .. 1. .' s . z 2 l 1· S• z ~ ;. 1 . ;: j 0 s 0 :; .) 2 .. 4 • ~ s z z • Bed 2 z • • ! J • .. ;: j z 7 z .. • • • 0 .. l 1 • z • • 7 7 .. ..• .:. :. • .. .. s o.;o• 4 5 .. • 5 ...... • •
• • S+ • :ao• z • • • • l· ~· 5 1 • 3 .. • • 5 • • • • 4 4 7 s • z ) l ~ Bed 4 ~ .. l ..; • .3 4' l •5 • •6 .; •5 i • c lo 2+ .. 3 .; 4 a z 7 5 • • ) ;) ~ .. z 3 .. ..• • •~ •3 l .. 7 7 .. 5 4 • .. .. • • • 4 .. .. 3 ~ i ! .. ! • Q. ------•------•------•------•------•------•~L••l 1• 11 a ~ •• 3 l.OG ~·•" •• ~o •• ao Figure 3.7 Height Above Low Low Tide vs Logarithmic Depth Above Low Low Tide For Beds 1, 2, and 4 66 C401i J .o• • • • z.. J• • • - • .. • • • • l • • • • Bed 1 - • 7 z j • • I. • • - • • J • .. • • • • • • 1 .IJ• .• J .. • J • - • • • .. • ; • - 3 • .. 0 3 • 2 - • • .i •l ;; • a• ~.a;------o:;;------1::o-l • ------•------·------z.1o z.s? J.~o ------~tt.••l CoOi • • • • • l • ... • z • * • • • • ~ .: • ~ . • .. z J z • • 1 J •;:. J J • ' . • ;; * • • ...... z .. J 5 •z 3 J .. i • • 0 . 1 6 3 •;; z 0 z ~ l a Bed 2 • z c .. • • : • • 0 • • z 5 !> z 4 • .. .. 5 J z s • . j • 6 6 • J •' " .. ~ ! "J .. u ·'-'· • ;:. • '.3• • • Co to z * ~ z •.. •j • •~ 2 • •j 4 • • l·i• l .. • 5 • 5 i. i 1 .. ! I z z 5 l 5 '5 j • Bed 4 J 6 • • • l 1 l 4 • • • !i • 3 4 .. 3 • 4 .. z J 4 • 3 •3 z z z ' 3 • .1• ) 3 ' • • z • 4 • -1 .j. ------·------·------·------·------·------·~l-~3 1.oO z... l 3.30 J.oo 4._ft •·•a Figure 3.8 Height Above Low Low Tide vs W/D Ratio Above Low Low Tide For Beds 1, 2, and 4 67 •• J• • J , j • •~-t-t 1 - J.J• Bed 1 z •.... 1. ~· . .. • • • J .. .. . • l z : • J.~o·------·------·------·------·------_.------;·~ ~.to ••• o z.13 ~ •• o ~-so e:.1::~et: - • .. ;. 7 • J • • .a ' Bed 2 • t • • • ------·------·------·------·------·------"~···;.eo 4a$3 ~-·~ J.~~ -.~a ...... • • • • • :zu ' .a.J• Bed 4 z • .,. 1· J• • • • I .~ • • • • • • • ------·------·------·------·------·------•1L•·J 1 • • o ···' J.;o J •• o ••• o ... ., Figure 3.10 Secondary Pit Formation ; vs Height Above Low Low Tide For Beds 1, 2, and 4 68 z· • • ... • • :l • -~ ..• • •• • • • ...... • .....6 ...... • .. ••.. 0 10 za .lC •c !rC WIDTH em 8 18 i:i 12 -~ .. .. w 0 .. .. 8 •• ••••• .. ~...... • 0 ...... •• . .. 0 20 W/0 Figure 3.13 A, B For Bed 2 69 A so- E u • ... ~ . .. Q i :c- ...... ,.,.. •••• .a ...... • • ...... A 6 .... • c ...... • 0 ·o .:c W/0 8 • •a .. • c .. • ~ t2 ... •• 0.. .. w • Q 8 ...... •• ...... • ...... • &A&• .a•• .....• 0 ...... •• •• • •••• 5 TO 20 W/D Figure 3.14 A, B Width and Depth vs W/D Ratios For Bed 4 70 TABLE 3.2 RELATIVE RELIEF OF S~HPLINr. N•A~RATS BED SAK'LE P£LATIYF QUAD~T£ RELIEF ( Clll) 1 1 27 2 27 3 15 4 17 5 18 6 26 7 30 8 23 9 30 10 32 11 32 12 2~ 13 21 14 17 15 27 16 24 2 1 21 2 27 3 27 4 14 5 27 6 13 7 29 8 29 0 15 10 19 11 27 12 40 13 22 14 25 15 29 1 31 2 17 3 31 4 36 s 43 6 32 7 2~ 8 24 ~ 23 10 26 11 35 12 26 13 27