Geomorphology of
Vancouver Island:
Extended Legends to Nine Thematic Maps
Victoria,
British Columbia
Research Report
No. RR 02
December 2005
by RH Guthrie
Regional Geomorphologist
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
i
© 2005 Province of British Columbia
Library and Archives Canada Cataloguing in Publication Data
Guthrie, R. H. (Richard Hamilton), 1969Geomorphology of Vancouver Island [electronic resource]: extended legends to nine
thematic maps.
Includes bibliographical references: p.
Available on the Internet.
ISBN 0-7726-5469-7
1. Geomorphology - British Columbia – Vancouver Island - Maps. 2. Vancouver
Island (B.C.) – Maps, Physical. 3. Geomorphology – British Columbia – Vancouver
Island. 4. Geomorphology – British Columbia – Vancouver Island – Bibliography. 5.
Geomorphological mapping. I. British Columbia. Ministry of Environment. II. Title.
GB428.5.C3G87 2005
551.41’09711’2
C2005-960253-8
Citation
Guthrie, R.H. 2005. Geomorphology of Vancouver Island [electronic resource]:
extended legends to nine thematic maps.
B.C. Ministry of Environment, Victoria, BC. Research Report No. RR02.
Copies of this report are available online through B.C. Ministry of Environment at
http://wlapwww.gov.bc.ca/wld/pub/pub.htm
Disclaimer: Interpretation of the results and analysis are solely those of the author and
do not represent the opinions of the Ministry of Environment or the Government of
British Columbia.
ii
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
ACKNOWLEDGEMENTS
The excellent work and assistance of Charles Penner on aspects of every map is gratefully
acknowledged. Mapping difficulties were made easier with technical support by Ross
Pettit and Shari Lindsay. Gail Harcombe of the Ministry of Environment provided or
arranged editorial review. Warren Cooper and Pete Law agreed to review the extended
legends.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
iii
ABSTRACT
The Geomorphology of Vancouver Island is a series of nine 1:100 000 based thematic
maps that collectively describe the physical nature of Vancouver Island. The maps are
printed at two convenient scales: 1:400,000 and 1:250,000 that allow the island to be
viewed on one or two E-sized plots (measuring 34 by 44 inches on a plotter). The nine
thematic maps are:
1. Vancouver Island Bedrock Geology Map
2. Vancouver Island Surficial Geology Map
3. Vancouver Island Coastal Geomorphology Map
4. Vancouver Island Fluvial Processes Map
5. Vancouver Island Gullying Map
6. Vancouver Island Snow Avalanche Map
7. Vancouver Island Karst Potential Map
8. Vancouver Island Wetlands and Organic Soils Map
9. Vancouver Island Mass Wasting Map
Different levels of analysis are tied to each theme, from high levels of analysis (Mass
Wasting and Coastal Geomorphology, for example) to no analysis (compilations of the
Bedrock Geology and Wetlands and Organic Soils, for example). The extended legends
in this report give some idea of the level of analysis and the implications, source data,
and references for additional reading. The Mass Wasting Map is the subject of a separate
report.
iv
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
TABLE OF CONTENTS
Introduction and Background ................................................................................... 1
Geomorphology and the Biosphere...................................................................... 1
Geomorphology and Risk .................................................................................... 1
A Rationale for Mapping Geomorphology........................................................... 1
Map Themes and Extended Legends......................................................................... 3
1. Vancouver Island Bedrock Geology Map......................................................... 3
References for the Bedrock Geology Map...................................................... 4
2. Vancouver Island Surficial Geology Map ......................................................... 6
Definitions for the Surficial Geology Map................................................... 10
References for the Surficial Geology Map (see also Table 1) ........................ 10
3. Vancouver Island Coastal Geomorphology Map............................................ 13
Definitions for the Coastal Geomorphology Map ....................................... 13
References for the Coastal Geomorphology Map......................................... 17
4. Vancouver Island Fluvial Processes Map ........................................................ 17
Channel Behaviour ..................................................................................... 17
References for the Fluvial Processes Map..................................................... 19
5. Vancouver Island Gullying Map .................................................................... 19
References for the Gullying Map................................................................. 19
6. Vancouver Island Snow Avalanche Map ........................................................ 21
References for the Snow Avalanche Map ..................................................... 21
7. Vancouver Island Karst Potential Map........................................................... 22
References for the Karst Potential Map ....................................................... 23
8. Vancouver Island Wetlands and Organic Soils Map ...................................... 24
References for the Wetlands and Organic Soils Map ................................... 25
9. Vancouver Island Mass Wasting Map............................................................ 25
Appendix
Geomorphology of Vancouver Island: Nine Thematic Maps ............................. 26
List of Tables
Table 1. Source data and authors for the terrain mapping used in the Vancouver
Island Surficial Geology Map ..................................................................................... 7
Table 2. The Vancouver Island rivers examined on air photographs and plotted
sagainst Church’s (1992) criteria for alluvial rivers (Figure 18) ................................. 19
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
v
List of Figures
Figure 1. Relationships among geology, geomorphology, and the biosphere. The
basic landscape foundation and structure is dictated by bedrock geology, typically
formed millions of years ago, and acted on by geomorphic processes.......................... 2
Figure 2. Vancouver Island Bedrock Geology: Rock formations of the Cenozoic Era
(66 My to present) ..................................................................................................... 3
Figure 3. Vancouver Island Bedrock Geology: Rock formations of the Mesozoic Era
(66 My to 251 My) .................................................................................................... 5
Figure 4. Vancouver Island Bedrock Geology: Rock formations of the Paleozoic Era
(251 My to 542 My) .................................................................................................. 5
Figure 5. An example of a terrain unit symbol (modified from
Howes and Kenk 1988) ............................................................................................. 6
Figure 6. Commonly mapped surficial materials: (A) colluvium, (B) moraine, (C)
colluvium over moraine (separated by yellow line), and (D) bedrock........................ 12
Figure 7. Fluvial deposits are materials transported by rivers .................................... 12
Figure 8. Water-deposited sediments: Glaciofluvial sediments are transported by
glacial outwash and typically contain sands and gravels ............................................ 12
Figure 9. Marine sediments are reworked and deposited in a marine environment ... 13
Figure 10. Less commonly mapped surficial materials include (A)
organics in and around wetlands and bogs, and (B) eolian landforms,
transported or reworked by wind.............................................................................. 13
Figure 11. Detail of the Coastal Geomorphology map ............................................. 14
Figure 12. A sandy beach on the west coast of Vancouver Island .............................. 15
Figure 13. A typical rocky shoreline on Vancouver Island ........................................ 15
Figure 14. Rock stacks (A) and platforms (B) on Vancouver Island’s west coast ....... 15
Figure 15. Fiords are long steep runs into the ocean, with no visible beach; they
are common on the west coast of Vancouver Island.................................................. 16
Figure 16. A tidal flat is a depositional marine environment where fine sands and
organics accumulate ................................................................................................. 16
Figure 17. An estuary on Vancouver Island showing the rich vegetation that
thrives in the brackish depositional environment...................................................... 16
Figure 18. Forty-two Vancouver Island rivers(*) (listed in Table 2) plotted on
Church’s (1992) criteria for single and multi-thread channels .................................. 18
Figure 19. Gullied terrain in Teeta Creek on Vancouver Island................................ 20
Figure 20. Snow avalanche tracks on Mount Colonel Foster on Vancouver Island ... 21
Figure 21. Minor karren development on exposed limestone.................................... 23
Figure 22. A cave (A) where the Artlish River disappears underground, and a karst
canyon (B) known as Devil’s Bath............................................................................ 23
Figure 23. A wetland in a mountain valley on Vancouver Island showing a rich
biological community............................................................................................... 24
Figure 24. Much of the northern tip of Vancouver Island has low relief, which
leads to the development of wetlands and deep organic layers .................................. 25
vi
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
INTRODUCTION AND BACKGROUND
Geomorphology is the study of the physical features of the Earth’s surface, specifically the
landforms and the landform processes, their origins and composition, and predictions
about their future form and behaviour. Applied geomorphology uses the knowledge and
techniques to provide or assist in finding solutions to planning, resource, engineering,
conservation, or environmental problems.
Geomorphology and the Biosphere
Floral and faunal communities are inexorably linked to the physical processes that
establish the landscape. Physical processes include geological controls (e.g., tectonics),
acted upon by modern processes (delta formation, landslides, weathering, surface erosion
and solution of rock, glaciation, creation of sand dunes, wetland formation, and river
erosion, for example). Biotic communities find niches and locations created by these
processes where they are able to survive and propagate. Changes to the system from a
new external force (e.g., land development, flood, earthquake, climate change) can affect
species or even ecosystems in ways that are readily apparent. A particular concern occurs
where a forcing mechanism impacts the geomorphic process or underlying structure and
causes substantial changes to all systems.
Figure 1 shows the linkage between geomorphic and biological systems, the time scales
required to build them, and potential threats to the systems.
Geomorphology and Risk
Geomorphology is important not only to understand the processes at work at a moment
in time, but to understand the magnitude–frequency relationships inherent in the
landscape. How often will this site flood? What is the likelihood of a landslide occurring
after this activity? How long would this beach take to recover from a particular use? How
long before sand dunes take over this portion of the island? Where is it safe to build?
Understanding magnitude and frequency characteristics of the geomorphic processes is
a fundamental part of risk analysis.
A Rationale for Mapping Geomorphology
Few large areas are geomorphically homogenous. Vancouver Island is physically
heterogeneous and defined by, among other things, bedrock and surficial geology,
climate, physiography, glacial history, and land use. Land use and land management
decisions may impact the development of new ecosystems and exacerbate ecosystem
survival. Encroachment of wetlands, shorelines, and deltas, increased landslides and site
alteration, increased sediment delivery to streams, and destruction of erodible channels
are examples of potential side effects of increased land use.
Vancouver Island, however, is not equally vulnerable to development, nor is it equally
vulnerable to types of development. Some regions may be vulnerable to slope instability,
others sensitive to dissolution. Some may be particularly robust to forest development,
but vulnerable to mining or urban development.
In 1981, a first attempt was made at differentiating the processes active on northern
Vancouver Island by the Ministry of Environment (Howes 1981). In Terrain Inventory
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
1
Figure 1. Relationships
among geology,
geomorphology, and the
biosphere. The basic
landscape foundation and
structure is dictated by
bedrock geology, typically
formed millions of years ago,
and acted on by geomorphic
processes. The geomorphic
processes may last only a
few seconds (a landslide, for
example) or a few thousand
years (river valley formation),
but in aggregate, they have
been working for thousands
of years to define the physical
characteristics at a particular
location. Ecosystems and
species are defined by the
locations within whose
physical limits they are able
to thrive. Forcing mechanisms
can affect each system
(depending on sensitivity to
the change), but those forcing
mechanisms that change
structure or geomorphic
response will have impacts
all the way up the system
diagram.
and Geological Hazards: Northern Vancouver Island, Howes described the types of
processes at work, where these processes occurred, and management implications that
might be associated with them. More than anything, however, Howes (1981) advocated
the use of terrain mapping and explained how such mapping could be further developed
to derive hazard maps.
Building on similar principles, nine thematic maps have been developed that collectively
describe Vancouver Island’s dominant geomorphic features and processes. Although not
exhaustive of all processes, the maps, together with the extended legends provided in
this report, are designed to give land managers, scientists, and environmental specialists
fundamental geomorphic information at a usable scale of up to 1:100,000. For practical
purposes, print file maps have been created at 1:400,000 (the entire island on one Esized sheet) and 1:250,000 (the island on two E-sized sheets).
2
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
The level of analysis differs from one map to another and is described in the legend
for each theme, except for the Mass Wasting map, which is documented in a separate
report. References to further research are provided for each theme.
MAP THEMES AND EXTENDED LEGENDS
The nine thematic maps are:
1. Vancouver Island Bedrock Geology Map
2. Vancouver Island Surficial Geology Map
3. Vancouver Island Coastal Geomorphology Map
4. Vancouver Island Fluvial Processes Map
5. Vancouver Island Gullying Map
6. Vancouver Island Snow Avalanche Map
7. Vancouver Island Karst Potential Map
8. Vancouver Island Wetlands and Organic Soils Map
9. Vancouver Island Mass Wasting Map
1. Vancouver Island Bedrock Geology Map
The Bedrock Geology map (see Appendix) is a compilation of two data sets produced by
the British Columbia Ministry of Energy and Mines (Massey et al. 2003a,b). The data
was compiled and a legend generated from the familiar formation names (Figures 2–4).
Some units were checked in the field on an ad hoc basis, including a field trip with Nick
Massey, one of the original mappers. No additional analysis was conducted on this
data.
Figure 2. Vancouver Island
Bedrock Geology: Rock
formations of the Cenozoic Era
(66 My to present; adapted
from Massey et al. 2003a,b).
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
3
References for the Bedrock Geology Map
Gabrielse, H., and C.J. Yorath (eds.). 1991. Geology of the Cordilleran orogen in
Canada. Geol. Surv. Can., Ottawa, ON.
Howes, D.E. 1981. Terrain inventory and geological hazards, Northern Vancouver
Island. B.C. Minist. Environ., Assess. and Plann. Div., Victoria, BC. APD Bull. 5.
Massey, N.W.D., D.G. MacIntyre, and P.J. Desjardins. 2003a. Digital map of British
Columbia: Tile Nm 10, Southwest British Columbia. B.C. Minist. Energy and
Mines, Victoria, BC. Geofile 2003-3.
Massey, N.W.D., D.G. MacIntyre, and P.J. Desjardins. 2003b. Digital map of British
Columbia: Tile Nm 9, Southwest British Columbia. B.C. Minist. Energy and
Mines, Victoria, BC. Geofile 2003-4.
Monger, J.W.H. (ed.). 1994. Geology and geological hazards of the Vancouver
Region, Southwestern British Columbia. Geol. Surv. Can., Ottawa, ON. Bull.
481.
Muller, J.E. 1977. Geology of Vancouver Island. Geol. Sur. Can., Ottawa, ON. Open
file 463.
Muller, J.E., K.E. Northcote, and D. Carlisle. 1974. Geology and mineral deposits of
Alert Bay–Cape Scott map area (92L-1021), Vancouver Island, British Columbia.
Geol. Surv. Can., Ottawa, ON. Paper 74-8.
Muller, J.E., and J.A. Roddick. 1983. Geology, Alert Bay–Cape Scott, British
Columbia. Geol. Surv. Can., Ottawa, ON. Map 1552A.
Roddick, J.A. 1980. Geology of Northeast Alert Bay map area, British Columbia.
Geol. Surv. Can., Ottawa, ON. Open File 722.
Smyth, W.R. 1997. Bedrock geology of Brooks Peninsula. Pages 2.1–2.8 in R.J.
Hebda, and J.C. Haggarty, eds. Brooks Peninsula: An ice age refugium on
Vancouver Island. B.C. Minist. Environ., Lands Parks, Victoria, BC. Occas.
Pap. 5.
Yorath, C.J., and H.W. Nasmith. 1995. The geology of Southern Vancouver Island: A
field guide. Orca, Victoria, BC.
4
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Figure 3. Vancouver Island
Bedrock Geology: Rock
formations of the Mesozoic Era
(66 My to 251 My; adapted
from Massey et al. 2003a,b).
Figure 4. Vancouver Island
Bedrock Geology: Rock
formations of the Paleozoic Era
(251 My to 542 My; adapted
from Massey et al. 2003a,b).
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
5
2. Vancouver Island Surficial Geology Map
The Vancouver Island Surficial Geology Map (see Appendix) divides the island into units
according to the dominant terrain type within a polygon. Terrain types are based on
the Terrain Classification System for British Columbia (Howes and Kenk 1997; see that
report for more information).
Bobrowsky et al. (1992) report that by 1992, more than 2000 surficial geology maps
of various types and scales were publicly available for British Columbia. The number
has undoubtedly grown substantially since then, particularly as terrain mapping became
the standard for the forest industry. On Vancouver Island complete terrain mapping
is available digitally at 1:50 000 through the Ministry of Energy and Mines; see http:
//www.em.gov.bc.ca/Mining/Geolsurv/Terrain&Soils/frbcguid.htm (April 2005). The
maps are digital compilations of maps produced by the Ministry of Environment from
1972 to 1980, the Ministry of Energy, Mines and Petroleum Resources in 1993, and
Environment Canada from 1980 to 1983. Original mapping sources are listed Table
1. For this map, no new information was added in the extraction of dominant terrain
types, but limited field checks were conducted to resolve miscoding or non-standard
coding issues.
Terrain mapping was formally adopted in British Columbia with the publication of the
terrain classification system (Howes and Kenk 1988, 1997). This system was based on
previous research in the province and consisted of a method of codifying the landscape
from aerial photographs into polygons or landscape units that were inwardly similar,
but varied at least slightly from adjacent polygons. The codes synthesize geomorphic
materials and processes into a terrain unit symbol (Figure 5)
Figure 5. An example of a
terrain unit symbol (modified
from Howes and Kenk 1988).
This symbol describes a sandy
gravely (sg) glaciofluvial (FG)
terrace (t) modified by slow
downslope failures (F) that
are no longer active (I). The
glaciofluvial (FG) material type
would be highlighted for the
Vancouver Island Surficial
Geology Map. The codification
is more complicated when two
or more surficial materials
are recognized, but the
leading material is generally
considered dominant. For
example, Mb/Cv represents
morainal blankets (Mb) more
than colluvial veneers (Cv),
and Moraine (in this case
deep) would be shown on the
Vancouver Island Surficial
Geology Map. Terrain mapping
is described in detail in Howes
and Kenk (1997).
6
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Table 1. Source data and authors for the
terrain mapping used in the Vancouver
Island Surficial Geology Map. MOE =
Ministry of Environment, EMPR = Ministry
of Energy, Mines and Petroleum Resources,
ENV CAN = Environment Canada.
Map NTS
Map Name
Author
Map Type
Year
Scale
Agency
102I/15
Scott Islands
A Chatterton
Surficial Geology
1979
1:50 000
MOE
102I/16
Cape Scott
A Chatterton
Surficial Geology
1979
1:50 000
MOE
102I/8E
Cape Parkins
A Chatterton
Surficial Geology
1978
1:50 000
MOE
102I/9
San Josef
A Chatterton
Surficial Geology
1979
1:50 000
MOE
92B/11
Sydney
Surficial Geology
1993
1:50 000
EMPR
92B/12
Shawnigan
HE Blythe &
NW Rutter
J Senyk
1975
1:50 000
MOE
92B/12
Shawnigan
1993
1:50 000
EMPR
92B/12
Shawnigan Lake
HE Blythe,
NW Rutter &
LM Sankeralli
M Dunn
Surficial Geology &
Topography
Surficial Geology
Physiographic Constraints
1980
1:50 000
ENV CAN
92B/13
Duncan
L Lacelle
1975
1:50 000
MOE
92B/13
Duncan
M Dunn
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92B/14
Mayne Island
M Dunn
Physiographic Constraints
1980
1:50 000
ENV CAN
92B/5
Sooke
J Senyk
1975
1:50 000
MOE
92B/5
Sooke
1993
1:50 000
EMPR
92B/6
Victoria
Surficial Geology
1993
1:50 000
EMPR
92C/10
Carmanah
HE Blythe &
NW Rutter
HE Blythe &
NW Rutter
N Alley
Surficial Geology &
Topography
Surficial Geology
Surficial Geology
1975
1:50 000
MOE
92C/13E
Ucluelet
I Cotic
1975
1:50 000
MOE
92C/14
Barkley Sound
J Jungen
1975
1:50 000
MOE
92C/14
Alberni Inlet
1983
1:50 000
ENV CAN
92C/15
Nitinat
M Dunn &
A Jacob
N Alley
Surficial Geology &
Topography
Surficial Geology &
Topography
Physiographic Constraints
Surficial Geology
1975
1:50 000
MOE
92C/15
Alberni Inlet
Physiographic Constraints
1983
1:50 000
ENV CAN
92C/16
Cowichan Lake
M Dunn &
A Jacob
N Alley
Surficial Geology
1977
1:50 000
MOE
92C/8
River Jordan
N Alley
Surficial Geology
1975
1:50 000
MOE
92C/9
San Juan
N Alley
Surficial Geology
1975
1:50 000
MOE
92E/10
Nootka
D Howes
Surficial Geology
1980
1:50 000
MOE
92E/14
Port Eliza
J Senyk
Surficial Geology
1978
1:50 000
MOE
92E/15
Zeballos
J Senyk
Surficial Geology
1980
1:50 000
MOE
92E/16
Gold River
D Howes
Surficial Geology
1980
1:50 000
MOE
92E/1E
Vargas Island
D Howes
Surficial Geology
1978
1:50 000
MOE
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
7
8
Map NTS
Map Name
Author
Map Type
Year
Scale
Agency
92E/7E
Estevan Point
D Howes
Surficial Geology
1979
1:50 000
MOE
92E/8
Hesquiat
D Howes
Surficial Geology
1979
1:50 000
MOE
92E/9
Muchalat Inlet
D Howes
Surficial Geology
1980
1:50 000
MOE
92F/1
Nanaimo Lakes
J Jungen
1975
1:50 000
MOE
92F/1
Nanaimo Lakes
M Dunn
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/10
Comox
M Dunn
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/10NE
Comox
J Jungen
1980
1:50 000
MOE
92F/10SW
Comox
J Jungen
1975
1:50 000
MOE
92F/11
Forbidden Plateau
J Jungen
1975
1:50 000
MOE
92F/11
Forbidden Plateau
M Dunn
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/12
Buttle Lake
J Jungen
1975
1:50 000
MOE
92F/13
Upper Campbell
J Senyk
1975
1:50 000
MOE
92F/14
Oyster River
J Jungen
1975
1:50 000
MOE
92F/14
Oyster River
M Dunn
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/15NE
Powell River
B Thomson
1980
1:50 000
MOE
92F/15SW
Powell River
J Jungen
1975
1:50 000
MOE
92F/16
Haslam Lake
B Thomson
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology
1980
1:50 000
MOE
92F/2
Alberni Inlet
J Senyk
1975
1:50 000
MOE
92F/2
Alberni Inlet
1983
1:50 000
ENV CAN
92F/3
Effingham
M Dunn &
A Jacob
J Jungen
Surficial Geology &
Topography
Physiographic Constraints
1975
1:50 000
MOE
92F/3
Alberni Inlet
1983
1:50 000
ENV CAN
92F/4
Tofino
M Dunn &
A Jacob
J Jungen
Surficial Geology &
Topography
Physiographic Constraints
1975
1:50 000
MOE
92F/5
Bedwell
J Jungen
1975
1:50 000
MOE
92F/6
Great Central
L Lacelle
1975
1:50 000
MOE
92F/7
Horne Lake
L Lacelle
1975
1:50 000
MOE
92F/7
Horne Lake
M Dunn
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/8
Parksville
J Jungen
1975
1:50 000
MOE
92F/8
Parksville
M Dunn
Surficial Geology &
Topography
Physiographic Constraints
1980
1:50 000
ENV CAN
92F/9
Texada Island
B Thomson
Surficial Geology
1980
1:50 000
MOE
92G/11
Squamish
B Thomson
Surficial Geology
1980
1:50 000
MOE
92G/12
Sechelt Inlet
B Thomson
Surficial Geology
1980
1:50 000
MOE
92G/13
Jervis Inlet
B Thomson
Surficial Geology
1980
1:50 000
MOE
92G/14
Cheakamus River
J Ryder
Surficial Geology
1980
1:50 000
MOE
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Map NTS
Map Name
Author
Map Type
Year
Scale
Agency
92G/4
Nanaimo
M Dunn
Physiographic Constraints
1980
1:50 000
ENV CAN
92G/4W
Nanaimo
I Cotic
1975
1:50 000
MOE
92G/5
Sechelt
B Thomson
Surficial Geology &
Topography
Surficial Geology
1980
1:50 000
MOE
92K/1
Powell Lake
K Drabinsky
Surficial Geology
1979
1:50 000
MOE
92K/2
Redonda Island
B Thomson
Surficial Geology
1980
1:50 000
MOE
92K/3NE
Quadra Island
B Thomson
Surficial Geology
1980
1:50 000
MOE
92K/3SW
Quadra Island
J Jungen
1972
1:50 000
MOE
92K/4
Salmon River
J Jungen
1972
1:50 000
MOE
92K/5N
Sayward
B Thomson
Surficial Geology &
Topography
Surficial Geology &
Topography
Surficial Geology
1980
1:50 000
MOE
92K/5S
Sayward
J Jungen
1972
1:50 000
MOE
92K/6
Sonora Island
B Thomson
Surficial Geology &
Topography
Surficial Geology
1980
1:50 000
MOE
92K/6SW
Sonora Island
J Jungen
1972
1:50 000
MOE
92K/7
Toba Inlet
K Drabinsky
Surficial Geology &
Topography
Surficial Geology
1979
1:50 000
MOE
92K/8
Little Toba River
K Drabinsky
Surficial Geology
1979
1:50 000
MOE
92L/1
Schoen Lake
J Jungen
Surficial Geology
1980
1:50 000
MOE
92L/10
Alert Bay
A Pattison
Surficial Geology
1980
1:50 000
MOE
92L/11
Port Mcneill
A Pattison
Surficial Geology
1980
1:50 000
MOE
92L/12
Quatsino
A Chatterton
Surficial Geology
1980
1:50 000
MOE
92L/13
Shushartie
A Chatterton
Surficial Geology
1980
1:50 000
MOE
92L/2
Woss Lake
J Senyk
Surficial Geology
1980
1:50 000
MOE
92L/3
Kyuquot
J Senyk
Surficial Geology
1980
1:50 000
MOE
92L/4
Brooks Peninsula
A Pattison
Surficial Geology
1980
1:50 000
MOE
92L/5
Mahatta Creek
A Pattison
Surficial Geology
1980
1:50 000
MOE
92L/6
Alice Lake
A Pattison
Surficial Geology
1980
1:50 000
MOE
92L/7
Nimpkish
J Senyk
Surficial Geology
1980
1:50 000
MOE
92L/8
Adam River
J Jungen
Surficial Geology
1980
1:50 000
MOE
The Vancouver Island Surficial Geology Map represents the dominant surficial material
type as reported on the 1:50,000 terrain maps. Dominant material type means that
where more than one type was present, following the mapping standard, the material
that occupies the most space in the polygon was selected. Limited surface expression
was incorporated into the map in terms of material depth. “Veneers” were considered to
be less than 1 m deep, “blankets” more than 1 m, and “mixed” a combination of both.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
9
Please see Howes and Kenk (1997) for a detailed discussion of terrain mapping; however,
the general definitions used are supplied below (from Howes and Kenk 1997).
Definitions for the Surficial Geology Map
• Anthropogenic – Artificial material or geological material modified such that the
physical properties have been altered.
• Colluvium (Figure 6) – Sediment that is a product of gravity-induced downslope
movement. Colluvium does not involve other transport agents such as water or ice,
but the material can contain either.
• Moraine (Figure 6) – Sediment deposited by glaciers that has not been modified by
other transport agents.
• Fluvial sediments (Figure 7) – Sediment transported and deposited by riverine
processes. Fluvial sediments are also known as alluvium.
• Glaciofluvial sediments (Figure 8) – Sediment clearly deposited by glacial meltwater
streams.
• Marine and Glaciomarine (Figures 8 and 9) – Sediment laid down in a marine
environment (close to a glacier in the latter) that may include materials settling from
suspension, gravity flows and, in glaciomarine, released from sediment trapped in
melting flows. These deposits may be well sorted and stratified.
• Exposed bedrock (Figure 6) – Bedrock outcrops with little or no sediment cover.
• Lacustrine sediments – Generally silt and fine sand, stratified and well sorted deposits
from old lakes.
• Organic (Figure 10) – Sediments resulting from thick accumulations of vegetation in
wetlands such as peat bogs, fens, and swamps.
• Ice – Areas of permanent snow and ice.
• Eolian (Figure 10) – Wind-transported sediment, generally composed of sand.
• Undifferentiated – A layered sequence of surficial sediments that could not be
separated.
References for the Surficial Geology Map (see also Table 1)
Blyth, H.E. 1996. The Quaternary geology of Southeastern Vancouver Island, B.C.
MSc Thesis, Univ. Alberta, Edmonton, AB.
Bertrand, B. 1989. Clay mineral assemblages from late Quaternary deposits on
Vancouver Island, southwest British Columbia. Quatern. Res. 31:41–56.
Bobrowsky, P.T., T. Giles, and W. Jackaman. 1992. Surficial geology map index of
British Columbia. B.C. Minist. Energy, Mines, Petrol. Resour., Victoria, BC.
Open file 1992-13.
Clague, J.J. 1976. Quadra Sand and its relation to the late Wisconsin glaciation of
southwest British Columbia. Can. J. Earth Sci. 13:803–815.
Clague, J.J. 1977. Quadra Sand: A study of the late Pleistocene geology and
geomorphic evolution of coastal southwest British Columbia. Geol. Surv. Can.,
Ottawa, ON. Pap. 77-17.
10
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Clague, J.J. 1994. Quaternary stratigraphy and history of south-coastal British
Columbia. Pages 181–192 in J.W.H. Monger, ed. Geology and geological hazards
of the Vancouver Region, southwestern British Columbia. Geol. Surv. Can.,
Ottawa, ON. Bull. 481.
Howes, D.E. 1981a. Terrain inventory and geological hazards, Northern Vancouver
Island. B.C. Minist. Environ., Assess. and Plann. Div., Victoria, BC. APD Bull. 5.
Howes, D.E. 1981b. Late Quaternary sediments and geomorphic history of northcentral Vancouver Island. Can. J. Earth Sci. 18:1–12.
Howes, D.E. 1983. Late Quaternary sediments and geomorphic history of northern
Vancouver Island, British Columbia. Can. J. Earth Sci. 20:57–65.
Howes, D.E. 1997. The Quaternary geology of Brooks Peninsula. In R.J. Hebda, and
J.C. Haggarty, eds. Brooks Peninsula: An ice age refugium on Vancouver Island.
B.C. Minist. Environ., Lands, Parks, Victoria, BC. Occas. Pap. 5.
Howes, D.E., and E. Kenk, editors. 1988. Terrain classification system for British
Columbia. B.C. Minist. Environ., and Minist. Crown Lands, Victoria, BC.
Minist. Environ. Man. 10.
Howes, D.E., and E. Kenk, editors. 1997. Terrain classification system for British
Columbia (revised edition). B.C. Minist. Environ. and Minist. Crown Lands,
Victoria, BC. Minist. Environ. Man. 10.
Maxwell, R.E. 1997. Soils of Brooks Peninsula. In R.J. Hebda, and J.C. Haggarty,
eds. Brooks Peninsula: An ice age refugium on Vancouver Island. B.C. Minist.
Environ., Lands and Parks, Victoria, BC. Occas. Pap. 5.
Ryder, J.M., and J.J. Clague. 1989. British Columbia (Quaternary stratigraphy and
history, Cordilleran Ice Sheet). Pages 48–53 in R.J. Fulton, ed. Quaternary
geology of Canada and Greenland. Geol. Surv. Can., Ottawa, ON.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
11
Figure 6. Commonly
mapped surficial materials:
(A) colluvium, (B) moraine,
(C) colluvium over moraine
(separated by yellow line),
and (D) bedrock. Note that
colluvium and moraine can
often be difficult to tell apart
and contextual information
from air photographs is
useful. On Vancouver Island,
most tills are basal tills and
are therefore extremely
dense (occasionally similar
to concrete). This material is
also commonly referred to as
hardpan in the construction
industry.
Figure 7. Fluvial deposits
are materials transported by
rivers. They may include deltaic
deposits (B) in lakes or oceans.
If the sediment is reworked
by lake or ocean water, or
carried farther in that transport
medium, it may become marine
or lacustrine sediment. Marine
and lacustrine sediments are
usually better sorted and often
much finer grained.
Figure 8. Water-deposited
sediments: Glaciofluvial
sediments are transported by
glacial outwash and typically
contain sands and gravels.
They may be mixed with,
or intermixed and confused
with marine sediments,
depending on the nature of the
depositional environment. In
either case, they are usually
well sorted and stratified. (A)
shows glaciofluvial sediments
near Port Hardy, and (B) on
the Cowichan River. Marine and
glaciomarine sediments are
typically finer, often with high
clay content.
12
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Figure 9. Marine sediments
are reworked and deposited
in a marine environment.
Materials range from cobbles
and gravels to clay, but are
typically well sorted.
Figure 10. Less commonly
mapped surficial materials
include (A) organics in and
around wetlands and bogs,
and (B) eolian landforms,
transported or reworked by
wind. In (B), marine sands are
being eroded and reworked by
wind. You can just make out
the remnants of a fence on
the left side of the picture.
3. Vancouver Island Coastal Geomorphology Map
The Coastal Geomorphology Map (see Appendix) divides the coastline into areas of erosion
and areas of deposition. It represents original mapping from 1:20,000 air photographs
onto 1:100,000-scale TRIM based map sheets and digitized into a GIS. The usable
resolution is therefore 1:100,000, but the accuracy will be greater in some instances. The
map was created by drawing a line around the shoreline of Vancouver Island and giving
sections of the line morphological attributes (Figure 11, and definitions below). More
than one line mapped for the same piece of shoreline represents two prominent shoreline
types, and their relative position is indicated by the relative positions of the two lines
(Figure 11).
Definitions for the Coastal Geomorphology Map
• Anthropogenic – Modified shoreline such that the original shoreline is no longer
functional or resolvable, such as fills, jetties, breakwaters, dykes, and other shorelineprotection structures.
• Sand bar, sandy beach, gravely beach – Well sorted, largely depositional beaches. May
include spits, beaches, bars, and sand ridges (Figure 12).
• Rocky beach with gravel, and rocky shoreline – Poorly sorted largely erosional
shoreline. Includes short rock ramps, and may have pockets of gravel and cobbles.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
13
Figure 11. Detail of the
Coastal Geomorphology
map. Colour codes: Yellow =
sand bars, sandy beaches,
gravely beaches. Blue = rocky
beaches with gravel, and rocky
shorelines. Red = rocky cliffs,
stacks, and platforms. Brown
= fiords with little or no beach.
Purple = deltas. Orange =
tidal flats. Green = estuaries.
Double lines indicate more
than one obvious beach type.
The line relative line position
indicates the relative position
on the shore.
• Rocky cliff, stack and platform – Erosional shoreline dominated by resistant bedrock.
May include promontories on either side of a pocket beach.
• Fiord – Long steep uniform slope into the water, with little or no beach. The
environment is typically neutral with low deposition (typically a result of steep,
resistant, bedrock slopes without sediment) and low erosion (largely protected from
erosive forces sufficient to modify the slope) (Figure 15).
• Delta – Sediment deposited from a stream or river into a marine environment (Figure
7B).
• Tidal Flat – Protected marine depositional environments that accumulate fine
sediments, mud, and organic matter (Figure 16).
• Estuary – A depositional feature transitional between deltaic and marine environments.
Estuaries are formed in brackish water reflective of both riverine and marine processes
(Figure 17).
Note: Deltas, estuaries, and tidal flats often grade into one another and may not be well
distinguished across all areas in this study.
14
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Figure 12. A sandy beach on
the west coast of Vancouver
Island.
Figure 13. A typical rocky
shoreline on Vancouver Island.
Figure 14. Rock stacks
(A) and platforms (B) on
Vancouver Island’s west coast.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
15
Figure 15. Fiords are long
steep runs into the ocean,
with no visible beach; they are
common on the west coast of
Vancouver Island.
Figure 16. A tidal flat
is a depositional marine
environment where fine sands
and organics accumulate.
Figure 17. An estuary on
Vancouver Island showing the
rich vegetation that thrives
in the brackish depositional
environment.
16
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
References for the Coastal Geomorphology Map
Carter, L. 1973. Surficial sediments of Barkley Sound and the adjacent continental
shelf, west coast Vancouver Island. Can. J. Earth Sci. 10:441–459.
Clague, J.J., and P.T. Bobrosky. 1994. Tsunami deposits beneath tidal marshes on
Vancouver Island, British Columbia. Geol. Soc. Am. Bull. 106:1293–1303.
Friele, P.A., and I. Hutchinson. 1993. Holocene sea-level change on the central west
coast of Vancouver Island, British Columbia. Can. J. Earth Sci. 30:832–840.
Harper, J.R. 1980. Seasonal changes in beach morphology along the BC coast. Pages
136–150 in Proc. of Canadian Coastal Conference, Burlington, ON.
4. Vancouver Island Fluvial Processes Map
The Vancouver Island Fluvial Processes Map (see Appendix) delineates the spatial extent
of both fluvial and glaciofluvial sediments. More importantly, it distinguishes two very
separate landforms and land management implications consequent of their presence.
Channel Behaviour
A recent report by Burge (2004) examined differences within and between single and
multi-thread river channels. Burge (2004) reports that, at the pattern scale, single
channels and multi-thread channels can be differentiated primarily by discharge and
total stream power. Stream power is the relationship between discharge and gradient;
its relationship to channel form was examined by Church (1992) and others. Church
plotted a general relationship between channel form and stream power (Figure 18).
Experience on Vancouver Island suggests that there is considerable morphological
variation in rivers, and that some are more vulnerable to braiding than others.
Consequently, we plotted the lower alluvial reaches of 42 rivers (Table 2) on Vancouver
Island, with discharges ranging two orders of magnitude, against Church’s (1992)
criteria. The results are also shown in Figure 18.
The 42 Vancouver Island rivers clustered near the upper limit of single thread channels
(the upper line in Figure 18). Experience indicated, however, that this was probably
not true for all rivers on Vancouver Island. Airphoto interpretation with limited field
checking was conducted for each river in an attempt to determine the extent to which
they were actually vulnerable to wandering or braiding. The results were unequivocal:
streams on Vancouver Island are vulnerable to braiding and wandering within their
active floodplain, subject to other geomorphic controls. The three key components
are:
• Geomorphic controls were critical on all streams. From the 42 rivers assessed, on
Vancouver Island we found that streams were commonly constrained by bedrock
and large glaciofluvial deposits that were more compact than the recent alluvium of
the floodplain. Although the bedrock control was expected, the glaciofluvial response
was more surprising. Generally, field experience has shown that glaciofluvial deposits
are often under attack by river channels and represent massive sources of sediment.
However, they also tend to be at higher elevations than the floodplain and resistant
enough to develop steep faces; both characteristics that limit channel movement.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
17
• The active floodplain is intended to represent the non-cohesive, non-compacted
alluvial portion of the floodplain, but may include areas that are currently suspended
or dormant. In essence, it may include anything that has been active floodplain in the
last few thousand years, under climatic conditions similar to today’s. This portion of
floodplain is typically mapped as Fluvial in terrain mapping.
• Vancouver Island streams are not automatically multi-threaded or braided despite
their plotting position, even when not physically constrained by bedrock or
glaciofluvial terraces. The streams appear to be at or near a threshold of stability within
their own banks and, once disrupted, may remain unstable for decades. That stability
is a function of stream inputs, including water, sediment load and, importantly, bank
stability. Millar and Quick (1993) proposed a parameter ’ to quantify the effects of
bank vegetation on stability and, related it to, among other things, stream width and
depth ratios. Eaton et al. (2004), Millar (2000, 2005), and Millar and Quick (1993)
have shown that bank vegetation exerts an important control on alluvial channel river
patterns, including the transition between single and multi-thread types.
An analysis of Figure 18 and examination of air photographs support the conclusion
that riparian vegetation plays a fundamental role in the stability of alluvial parts of
Vancouver Island streams. Further, the loss of that vegetation can change the dynamics
of river channels so that they move into an active multi-channel regime from which they
are slow (taking several decades) to recover. The Eve River confluence with the Adam
River is an excellent example.
Consequently, areas mapped as Fluvial are vulnerable to riparian harvesting, changes
in peak flows, and increased sediment input. Areas mapped as Glaciofluvial may be
ongoing sources of sediment in a watershed.
Figure 18. Forty-two
Vancouver Island rivers(*)
(listed in Table 2) plotted
on Church’s (1992) criteria
for single and multi-thread
channels. River names have
been excluded for readability.
18
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Table 2. The Vancouver
Island rivers examined on
air photographs and plotted
against Church’s (1992)
criteria for alluvial rivers
(Figure 18).
River name
River name
Adam
Benson
Memekay
Nahwitti
Browns
Carmanah
Nimpkish
Oyster
Chemainus
Quatse
Cluxewe
Eve
Salmon
Salmon at Memekay
Fisherman
San Josef
Gold
Goodspeed
San Juan
Shusharite
Gordon
Hathaway
Standby
Tsable
Heber
Tsitika
Tsolum
Keith
Keogh
Tsulton
Klootchlimmis
Kokish
Upana
Wallbran
Koksilah
Wanokana
Mac Jack
Waukwaas
Mahatta
Marble
White
Zeballos
References for the Fluvial Processes Map
Burge, L.M. 2004. Testing links between river patterns and in-channel characteristics
using MRPP and ANOVA. Geomorphology 63:115–130.
Church, M. 1992. Channel morphology and typology. Pages 126-143 in P. Calow
and G.E. Petts, eds. The rivers handbook, vol. 1: Hydrological and ecological
principles. Blackwell Science, Oxford.
Eaton, B.C., M. Church, and R.G. Millar. 2004. Rational regime model of alluvial
channel morphology and response. Earth Surfaces Processes and Landforms 29:
511–529.
Millar, R.G. 2000. Influence of bank vegetation on alluvial channel patterns. Water
Resour. Res. 36:1109–1118.
Millar, R.G. 2005. Theoretical regime equations for mobile gravel-bed rivers with
stable banks. Geomorphology 64:207–220.
Millar, R.G., and M.C. Quick. 1993. Effect of bank stability on geometry of gravel
rivers. J. Hydraulic Eng. 119:1343–363.
5. Vancouver Island Gullying Map
The Vancouver Island Gullying Map (see Appendix) delineates terrain units on Vancouver
Island that have been identified as gullied (see references), or alternatively, terrain that
contains erodible sediments deeper than 1 m, on slopes steeper than 25%, for more than
100 m (terrain with gully potential).
Gullies are steep incised channels that convey water, sediment, and woody debris (Figure
19). In British Columbia, gullies are formally described as having a sidewall higher than
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
19
3 m, overall channel gradient steeper than 25%, and a sidewall slope of more than 50%
(B.C. Ministry of Forests 2001). Gullies may not be active year-round and can be hard
to identify on air photographs in forested terrain.
Gullies are associated with channelized debris flows, colluvial and alluvial fan
destabilization, sediment generation, snow avalanches, and the rapid transport of water.
Crossing gullies and gully systems remains a substantial challenge for land managers.
Figure 19. Gullied terrain
in Teeta Creek on Vancouver
Island. The gullies may be
dry for part of the year, but
their steep, incised nature
translates to substantial power
as a transport mechanism for
the rest of the year.
References for the Gullying Map
Bovis, M.J., T.H. Millard, and M.E. Oden. 1998. Gully processes in coastal British
Columbia: The role of woody debris. Pages 49–75 in Carnation Creek and Queen
Charlotte Islands Fish/Forestry Workshop: Applying 20 Years of Coastal Research
to Management Solutions. B.C. Minist. For., Res. Program, Victoria, BC. Land
Manage. Handb. 41.
B.C. Ministry of Forests. 2001. Gully assessment procedure guidebook, 4th ed. Forest
Practices Code of B.C., B.C. Minist. For., Victoria, BC.
Hogan, D.L., and Millard, T.H. 1998. Gully assessment procedures. Pages 183–188
in Carnation Creek and Queen Charlotte Islands Fish/Forestry Workshop:
Applying 20 Years of Coastal Research to Management Solutions. B.C. Minist.
For., Res. Program, Victoria, B.C. Land Manage. Handb. 41.
Millard, T.H. 1999. Debris flow initiation in coastal British Columbia gullies. B.C.
Minist. For., Vanc. For. Reg., Nanaimo, BC. Tech. Rep. 002.
Millard, T.H., M.P. Wise, T.R. Rollerson, S. Chatwin, and D.L. Hogan. 1998. Gully
system hazards, risks and forestry operations in coastal British Columbia. Pages
20
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
1149–1156 in Proc. of 8th Congr. of the Int. Assoc. Eng. Geol. and Environ.
Balkema, Rotterdam, The Netherlands.
6. Vancouver Island Snow Avalanche Map
The Vancouver Island Snow Avalanche Map (see Appendix) delineates terrain units that
have been identified as modified by snow avalanches (see references) or nivation (frost
action and mast wasting beneath a snow bank), or alternatively, steep terrain above 800
m in elevation (the snow accumulation zone on the coast).
Snow avalanches, the rapid downslope movement of snow and debris (Figure 20),
are a common feature in British Columbia; more than 300 000 are thought to occur
annually, primarily in forested areas (Weir 2002). They initiate in high-elevation areas
(generally above 800 m) where thick snow accumulates seasonally.
Although snow avalanches tend to occur away from population centres on Vancouver
Island, they have potential to affect the lives of backcountry users. More typically, they
can impact linear infrastructure (roads and power lines, for example) and the forestry
resource. They may also increase the flow of sediment to streams, and may be associated
with debris flows.
Figure 20. Snow avalanche
tracks on Mount Colonel Foster
on Vancouver Island.
References for the Snow Avalanche Map
Hungr, O., and D.M. McClung. 1987. An equation for calculating snow avalanche
run-up against barriers. Pages 605-612 in Avalanche formation, motion and
effects. IAHS Publ. 162.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
21
McNay, R.S., L.D. Peterson, and J.B. Nyberg. 1988. The influence of forest stand
characteristics on snow interception in the coastal forests of British Columbia.
Can. J. For. Res. 18:566–573.
Stethem, C. 2003. Snow avalanche risk management in Canada. Pages 51–57 in Proc.
of 3rd Can. Conf. on Geotechnique and Natural Hazards, Edmonton, AB.
Storck, P., Kern, T. and Bolton, S. 1999. Measurement of differences in snow
accumulation, melt and micrometeorology due to forest harvesting. Northwest
Sci. 73:87–101.
Weir, P. 2002. Snow avalanche management in forested terrain. B.C. Minist. For.,
Res. Br., Victoria, BC. Land Manage. Handb. 55. http://www.for.gov.bc.ca/hfd/
pubs/Docs/Lmh/Lmh55.pdf
7. Vancouver Island Karst Potential Map
Karst is a unique landform typified by underground drainage and a ground surface
characterized by hollows, pits, and runnels in bedrock. Karst is generally formed by
the solution of limestone and marble by water. Karst landforms include caves, arches,
canyons, springs, and sinkholes, as well as finer relief patterns such as karren (Figures
21 and 22).
Three major geological units on Vancouver Island are susceptible to karstification: the
Parsons Bay Formation, Quatsino Formation, and Mount Mark Formation (see Figures
3 and 4).
Karst potential has been mapped for British Columbia by Stokes (1999) and a
methodology has been developed for establishing karst inventories that combine the
concept of karst potential (amount and type of soluble bedrock) with vulnerability
(Stokes and Griffiths 2000; B.C. Ministry of Forests 2003; Resource Inventory and
Standards Committee 2001). Karst is well developed on Vancouver Island and the
Vancouver Island Karst Potential Map (see Appendix) provides a simple view of karst
potential that is based largely on bedrock geology and the input of local experts. The
two categories of karst potential, high and moderate, correspond roughly to bedrock
that is more than 50% soluble and 20 to 49% soluble, respectively, and that is intensely
or moderately intensely karstified (Stokes and Griffiths 2000; B.C. Ministry of Forests
2003; Resource Inventory and Standards Committee 2001).
22
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Figure 21. Minor karren
development on exposed
limestone.
Figure 22. A cave (A) where
the Artlish River disappears
underground, and a karst
canyon (B) known as Devil’s
Bath. A closer view of Devil’s
Bath would reveal small-scale
(cm) pitting and ridges that
make the bedrock razor sharp,
and give the feature its name.
References for the Karst Potential Map
British Columbia Ministry of Forests. 2003. Karst management handbook for British
Columbia. B.C. Minist. For., Victoria BC. http://www.for.gov.bc.ca/hfp/fordev/
karst/karstbmp.pdf
Resources Inventory Standards Committee (RISC). 2001. Karst inventory standards
and vulnerability assessment procedures for British Columbia. The Karst Task
Force, Victoria, BC. http://srmwww.gov.bc.ca/risc/pubs/earthsci/karst/index.htm
Stokes, T. 1999. 1:250,000 karst potential maps of British Columbia. B.C. Minist.
For., Res. Br., Victoria, BC. http://www.for.gov.bc.ca/hfp/fordev/karst.htm
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
23
Stokes, T.R., and P. Griffiths. 2000. A preliminary discussion of karst inventory
systems and principles (KISP) for British Columbia. B.C. Minist. For., Victoria,
BC. Work. Pap. 51.
8. Vancouver Island Wetlands and Organic Soils Map
The Wetland and Organic Soils Map (see Appendix) is a compilation of three data sets
that represent depositional environments where soils and vegetation accumulate. The
data sets are from wetlands delineated on the 1:50,000 British Columbia Watershed Atlas
(the digital version of the National Topographic Maps), the British Columbia Sensitive
Ecosystem Inventory (various scales, most at 1:10,000 or 1:15,000) for Vancouver Island,
and Vancouver Island 1:50,000 terrain maps (see references). No additional analysis was
completed for this data.
Wetlands develop where water and land meet in geomorphically stable or depostional
parts of the landscape, such as ponds, marshes, swamps, estuaries, and peatlands (see
Figures 22 and 23).
The relative stability of wetlands and their relationship with water produces a
landscape rich with biological import and diversity. Similarly, the landscape position
is often considered a safely developable area. Wetlands perform the additional role
of water regulator, ameliorating potential impacts to water quality and quantity.
Land management decisions around wetlands have long been focal points for public
discussion.
Figure 23. A wetland in a
mountain valley on Vancouver
Island showing a rich
biological community.
24
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
References for the Wetlands and Organic Soils Map
McPhee, M., P. Ward, J. Kirkby, L. Wolfe, N. Page, K. Dunster, N.K. Dawe, and I.
Nykwist. 2000. Sensitive ecosystems inventory: East Vancouver Island and Gulf
Islands, 1993–1997. Vol. 2: Conservation manual. Can. Wildl. Serv., Pac. and
Yukon Reg. Tech. Rep. Ser. 345.
Ward, P., G. Radcliffe, J. Kirkby, J. Illingworth, and C. Cadrin. 1998. Sensitive
ecosystems inventory: East Vancouver Island and Gulf Islands, 1993–1997. Vol.
1: Methodology, ecological descriptions and results. Can. Wildl. Serv., Pac. and
Yukon Reg. Techn. Rep. Ser. 320.
Websites:
http://srmwww.gov.bc.ca/fish/watershed_atlas_maps/index.html
http://srmwww.gov.bc.ca/ecology/ecoregions/
http://srmwww.gov.bc.ca/sei/van_gulf/ecosystems.html
Figure 24. Much of the
northern tip of Vancouver
Island has low relief, which
leads to the development of
wetlands and deep organic
layers (see also Figure 10a).
Organics are indicated by
the brown vegetation on this
photograph.
9. Vancouver Island Mass Wasting Map
The Vancouver Island Mass Wasting map is the subject of a separate report:
Guthrie, R.H. 2005. Geomorphology of Vancouver Island: Mass Wasting Potential.
Research Report No. RR 01. B.C. Minist. Environ., Nanaimo, B.C.
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
25
APPENDIX 1: Geomorphology Of Vancouver Island: Nine
Thematic Maps
This PDF report contains three maps for each map theme, in the same order as the
expanded legends.
In addition, for practical purposes, print file maps have been created at 1:4000,000 and
1:250,000. Click on the links below for the ‘E-sized’ files.
Vancouver Island Bedrock Geology Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/bedrock.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/bedrockn.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/bedrocks.jpg
Vancouver Island Surficial Geology Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/surfical.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/surficaln.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/surficals.jpg
Vancouver Island Coastal Geomorphology Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/coastal.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/coastaln.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/coastals.jpg
Vancouver Island Fluvial Processes Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/fluvial.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/fluvialn.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/fluvials.jpg
Vancouver Island Gullying Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/gully.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/gullyn.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/gullys.jpg
Vancouver Island Snow Avalanche Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/snow_all.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/snow_n.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/snow_s.jpg
Vancouver Island Karst Potential Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/karst.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/karstn.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/karsts.jpg
26
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
Vancouver Island Wetlands and Organic Soils Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/wetland.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/wetlandn.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/wetlands.jpg
Vancouver Island Mass Wasting Map
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/mass_all_final.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/mass_n.jpg
http://wlapwww.gov.bc.ca/wld/documents/techpub/rr2/maps/mass_s.jpg
Geomorphology of Vancouver Island: Extended Legends to Nine Thematic Maps
27