Geological investigations and logistics in the Ellsworth
900 difference in declination is due to rapid changes in the paleomagnetic field with respect to Antarctica during the Lower Paleozoic cannot be discounted at the present level of coverage. A solid data base from the Paleozoic of the east antarctic craton will be required before the problem is fully resolved. Furthermore, the results for the Ellsworth Mountains presented here represent only 3 sites of the total of 70. At this stage in the investigation, the data are most consistent with a theory proposing a microplate nature of West Antarctica.
50
'JII'M,"
Sr ndon.
C>.
90* W -
EIGHTS COAST
C)
O)
EAST ANTARCT IC CRATON IMInI
Ellsworth •
Minny S tation
I
Mine
-90•E
0
13"0 LAND
Taylor Valley !^Q
ISO.
Figure 2. Map showing major crustal units of Antarctica with mean declinations of paleomagnetic vectors from Upper! Late Cambrian and Early Ordovician rocks. The result from the Ellsworth Mountains is approximately 900 different from those of the east antarctic craton.
This research was supported by the Scott Turner Fund of the University of Michigan and by National Science FounFoundation grant DPP 78-21730. The authors wish to thank Rob Van der Voo for providing facilities at the University of Michigan for the preliminary study of unoriented samples.
Geological investigations and logistics in the Ellsworth Mountains, 1979-80 JOHN F. SPLETrSTOESSER Minnesota Geological Survey University of Minnesota St. Paul, Minnesota 55108 GERALD F. WEBERS Macalester College St. Paul, Minnesota 55105
36
References Alley, R. B., and Watts, D. R. 1979. Paleomagnetic investigation of the northern antarctic peninsula. EQS. Transactions, American Geophysical Union, 60, 240. Dalziel, I. W. D. In press. The pre-Jurassic history of the Scotia Arc: A review and progress report. In C. Craddock (Ed.), Antarctic Geoscience. Madison: The University of Wisconsin Press. deWit, M. J . 1977. The evolution of the Scotia Arc as a key to the reconstruction of southwestern Gondwanaland. Tectonophysics, 37, 53-82. Elliot, D. H., Watts, D. R., Alley, R. B., and Gracanin, T. M. 1978. Geologic studies in the northern antarctic peninsula, R/V Hero cruise 78-lB. February 1978. Antarctic Journal of the U.S., 13(4), 12-13. Elston, D. R., and Purucker, M. E. 1979. Detrital magnetization in red beds of the Moenkopi Formation (Triassic), Gray Mountain, Arizona. Journal of Geophysical Research, 84, 1653- 1666. Graham, J . W. 1949. The stability and significance of magnetism in sedimentary rocks. Journal of Geophysical Research, 59, 131 - 137. Manzoni, M., and Nanni, T. 1977. Paleomagnetism of Ordovician Lamprophyres from Taylor Valley, Victoria Land, Antarctica. Pure and Applied Geophysics, 115, 961-978. McQueen, D. M., Scharnberger, C. K., Scharon, L., and Halpern, M. 1972. Cambro-Ordovician paleomagnetic pole position and rubidium-strontium total rock isochron for charnockitic rocks from Mirnyy Station, East Antarctica. Earth and Planetary Science Letters, 16, 433-438. Schopf, J . M. 1969. Ellsworth Mountains: Position in West Antarctica due to sea floor spreading. Science, 164, 63-66. Stump, E. 1976. On the late Precambrian-early Paleozoic metasediments and metasedimentary rocks of the Queen Maud Mountains, Antarctica, and a comparison with rocks of similar age from southern Africa (Report 62). Columbus: The Ohio State University, Institute of Polar Studies. Watts, D. R. In press. Potassium-argon and paleomagnetic results from King George Island, South Shetland Islands. In C. Craddock (Ed.), Antarctic Geoscience. Madison: The University of Wisconsin Press. Zijderveld, J . D. A. 1968. Natural remanent magnetizations of some intrusive rocks from the Sor Rondane Mountains, Queen Maud Land, Antarctica. Journal of Geophysical Research, 73, 3773-3785.
The most ambitious field project of the 1979-80 austral summer season in Antarctica was conducted in the Ellsworth Mountains between 3 December and 12 January. The area studied included both the Sentinel Range (north) and the Heritage Range (south), from about 77 0 15'S to 80°30'S latitude and 80°W to 87°30'W longitude (see figure 1). The camp, Ellsworth Camp (also known as Camp Macalester), was located adjacent to Minnesota Glacier at 79°05'S 85°58'W, about midway between the northern and southern extremities of the mountains. Camp elevation was about 1,250 meters above sea level. This was the largest field program in the Ellsworth Mountains in the 20-year history of studies there. Participating were 42 scientists and technicians representing eight countries (U.S., 28; West Germany and New Zealand, 4
ANTARCTIC JOURNAL
transportation to outcrop areas that could be reached on 1-day trips. The scientific projects conducted during the field season are summarized in table 1. The largest contingent of scientific personnel, under the direction of C. F. Webers, included numerous senior investigators studying a variety of topics related to a comprehensive analysis of the geology of the
ma
po, M1ULMA -
---
ROW" 71777 \! VINSON MASSIF
•.
/fr
cy I
CAMPM*LES1ER
GLACEP
l4
Af
ELLSWORTH MOUNTAINS
! Qç
/
Figure 1. Location map of the Ellsworth Mountains (modified from Figure 1 in Craddock, Anderson, and Webers 1964).
each; England, 2; Japan, Norway, Switzerland, and the U.S.S.R., 1 each). Scientific priorities were determined by C. F. Webers, and flight schedules for the three UH-1N turbine ("Huey") helicopters (figure 2) were made up daily by J . F. Splettstoesser. A total of 353 helicopter hours were flown during the season in direct support of science projects. The flying operation was under the command of LCDR W. Ferrell from 3 December to 26 December, and under LCDR D. Ellison thereafter. The camp, constructed by personnel employed by Holmes and Narver, Inc., consisted of five Jamesway buildings. The Holmes and Narver camp manager for the season was David Waidrip. Many geologic investigations were conducted using the main camp as a base of operations. For long-term studies in remote areas, tent camps were established. A total of 15 different camp sites were occupied during the period from 11 December to 10 January. Up to 22 people were in a maximum of six camps at one time. Most of the field studies in the areas of tent camps were conducted on foot, but often the local topography and distances prevented this and helicopters transported investigators to critical outcrops. Skidoos were also used in remote field operations for local
1980 REvIEw
-0
Figure 2. UK-IN helicopter at Polarstar Peak (left) and Mt. Ulmer (right) in northern Sentinel Range, about 100 nautical miles from base camp.
Ellsworth Mountains. The goals were: (1) to conduct a detailed study of significant areas that composed parts of the 13,000-meter stratigraphic section of the Ellsworths; (2) to obtain extensive collections of the fossil floras and faunas throughout the stratigraphic section for correlative, environmental, and evolutionary study; (3) to examine the evolution of landforms beginning with a probable Jurassic uplift through continental glaciation and partial recession; (4) to chart the sequence of major structural geologic events in the area; (5) to analyze the tectonic relationship of the Ellsworths to the Antarctic Peninsula and to the East Antarctic Shield; and (6) to obtain information on the nature and composition of a variety of igneous rocks exposed in the Heritage Range. These goals were accomplished. The success of the pro- gram was due largely to the helicopter support, which permitted a large amount of research within a relatively large area. All stratigraphic units exposed in the Ellsworth Mountains were studied in detail for paleoecological, paleontological, sedimentological, and stratigraphic characteristics. The Whiteout Conglomerate was found to contain stratified sediments at two stratigraphic positions and to contain boulder pavements. Crashsite Quartzite stratigraphy will be extended to the Heritage Range and modified. The Heritage Group will be subdivided into a number of new units. The Minaret Group was found to overlie the Heritage Group. No major unconformities (except for boulder pavements) were found anywhere in the stratigraphic column. Table 2 shows a tentative stratigraphic
37
column compared with Craddock's (1969) and Hjelle, Ohta, and Winsnes' (1978). Seven new faunas of Middle and Late Cambrian age, and one of Devonian age, were found. Previously known faunas and the Glossopteris flora were re-collected. A single major deformational phase occurred in the Late Triassic-Early Jurassic, as was previously known. Possible smaller scale deformations and their timing are being evaluated. Preliminary paleomagnetic
data indicate a major rotation of the Ellsworth Mountains block. All known igneous rocks in the Ellsworth Mountains were collected for further study. Landform sequences were examined and paleo-karst features were studied and collected. This project was supported by National Science Foundation grant DPP 78-21720 to Macalester College, St. Paul,
Minnesota.
Table 1. Summary of scientific investigations in the Ellsworth Mountains, 1979-80
Scientific project
Principal investigator
Number in party
Helicopter hours flown in support of project
Dates In field
24'
177.8
Dec. 3-Jan. 17
102.5
Dec. 3-Jan. 11
Comprehensive geologic study
G. F. Webersb
Glacial history
G. Dentond
6
Evolution of West Antarctic-Andean Cordillera
I. Daiziel'
2
Geodetic control
D. Knutzen9
3
48.7
Dec. 3-Jan. 11
Radiometric survey
E. Zeller"
4
11.7
Dec. 12-Dec. 19
Meteorite search
W. Cassidy
3.5
Dec. 20-Dec. 26
Soil development
I. Campbell/G. Claridge
8.8
Dec. 9-Dec. 18
2
Dec. 20-Jan. 17
42 353.0'
Total
Includes foreign exchange scientists. 'Included with Webers' total. 'Test flights and other flying not directly associated with science support raised this total to 364.1 hours. Time periods for individual field personnel varied.
C
b Other personnel were J. Anderson, A. Bramall, W. Buggisch, J. Collinson, C. Craddock, J. Craddock, P. von Gizycki, P. Gould, C.
Hudak, C. Matsch, A. Ojakangas, J. Pojeta, L. Rosen, A. Rutford, V. Samsonov, J. Splettstoesser, B. Sporli, C. Vavra, W. Vennum, D. Watts, E. Yochelson, M. Yoshida, and J. Zawiskie. d Other personnel were B. Andersen, J. Bockheim, H. Conway, J. Leide, and M. Prentice. Other Investigator was M. Thomson. Other personnel were T. Henderson and R. Pearsall. "Other personnel were K. Bulla, G. Dreschhoff, and V. Thoste.
References
Craddock, C. 1969. Geology of the Ellsworth Mountains. In V. C. Bushnell and C. Craddock (Eds.), Geologic maps of Antarctica (Antarctic map folio series, folio 12, plate 4). New York: American Geographical Society.
38
Craddock, C., Anderson, J . J. , and Webers, G. F. 1964. Geologic outline of the Ellsworth Mountains. In R. J. Adie (Ed.), Antarctic geology, Proceedings of the First International Symposium on Antarctic Geology, Cape Town, 1963. Amsterdam: North-Holland. Hjelle, A., Ohta, Y., and Winsnes, T. S. 1978. Stratigraphy and igneous petrology of southern Heritage Range, Ellsworth Mountains, Antarctica. Norsk Polarinstitutt Skrifter, 169, 5-43.
ANTARCTIC JOURNAL
NO
Table 2. Generalized Geologic Sections in the Ellsworth Mountains Craddock 1969 Age
Formation
Hjelle, Ohta, and Winsnes 1978
Thickness, meters Age
Polarstar Formation
Permian Interbedded slate, argillite, 1,370 quartzite, graywacke, coal Whiteout Conglomerate
Thickness, Formation meters Age Not discussed
White, gray and buff quartzite Lower Dark Member 1,830
Green and buff quartzite, argillite
Formation
Thickness, meters
Polarstar Formation
Permian Interbedded slate, argillite, 1,370 quartzite, graywacke, coal Whiteout Conglomerate 400+
Permo- Unsorted bouldery gray- 915 Carbon- wacke (Marine tillite?) iferous (?) Crashsite Quartzite Crashsite Quartzite Devonian Upper Dark Member 305 Mid- White, gray, and green and older Brown micaceous quartzite Paleozoic quartzites Middle Light Member 1,070
Tentative section, this paper
Whiteout Conglomerate
Permo- Black diamictite (tillite) 915 Carboninterous Crashsite Quartzitec Devonian Upper Dark Member to Upper Brown micaceous quartzite Cambrian
Upper Dark Member—
not seen Middle Light Member 800-850
305
Middle Light Member 1,070
White, gray and buff quartzite Lower Dark Member
1,830
Green and buff quartzite, argillite
Lower Dark Member 750-1,000 Cambrian Dunbar Ridge Formation Minaret Formation Cambrian Phyllite, argillite, slate, 6,710 and Middle Slate and black 700-1,200 Upper Marble, minor conglomerate, 0-800 and Pre- quartzite, conglomerate, Cambrian calcareous shale Cambrian "breccia bodies" cambrian (?) minor marble, lava flows Heritage Group
Heritage Group Heritage Groupd Middle Edson Hills Formation 3,500 Upper Phyllite, argillite, black shale, 7,000 Cambrian Volcanic-clastic sequence Cambrian limestone, conglomerate, or older and Middle polymictic and diamictic Cambrian conglomerates, lava flows, Minaret Group Middle Horseshoe Formation 500 marble, quartzite, graywacke Pre- Marble, minor conglomerate, 975 Precambrian Volcanic-calcareous sequence cambrian (?) "breccia bodies" TOTAL 13,175 a b
0
Based on southern Heritage Range only. Sentinel Range only; Heritage Range undivided. Crashsite stratigraphy will be extended/ modified to the Heritage Range. Heritage Group will be subdivided into new formations and members.
Minaret Group
TOTAL 13,290
50
'JII'M,"
Sr ndon.
C>.
90* W -
EIGHTS COAST
C)
O)
EAST ANTARCT IC CRATON IMInI
Ellsworth •
Minny S tation
I
Mine
-90•E
0
13"0 LAND
Taylor Valley !^Q
ISO.
Figure 2. Map showing major crustal units of Antarctica with mean declinations of paleomagnetic vectors from Upper! Late Cambrian and Early Ordovician rocks. The result from the Ellsworth Mountains is approximately 900 different from those of the east antarctic craton.
This research was supported by the Scott Turner Fund of the University of Michigan and by National Science FounFoundation grant DPP 78-21730. The authors wish to thank Rob Van der Voo for providing facilities at the University of Michigan for the preliminary study of unoriented samples.
Geological investigations and logistics in the Ellsworth Mountains, 1979-80 JOHN F. SPLETrSTOESSER Minnesota Geological Survey University of Minnesota St. Paul, Minnesota 55108 GERALD F. WEBERS Macalester College St. Paul, Minnesota 55105
36
References Alley, R. B., and Watts, D. R. 1979. Paleomagnetic investigation of the northern antarctic peninsula. EQS. Transactions, American Geophysical Union, 60, 240. Dalziel, I. W. D. In press. The pre-Jurassic history of the Scotia Arc: A review and progress report. In C. Craddock (Ed.), Antarctic Geoscience. Madison: The University of Wisconsin Press. deWit, M. J . 1977. The evolution of the Scotia Arc as a key to the reconstruction of southwestern Gondwanaland. Tectonophysics, 37, 53-82. Elliot, D. H., Watts, D. R., Alley, R. B., and Gracanin, T. M. 1978. Geologic studies in the northern antarctic peninsula, R/V Hero cruise 78-lB. February 1978. Antarctic Journal of the U.S., 13(4), 12-13. Elston, D. R., and Purucker, M. E. 1979. Detrital magnetization in red beds of the Moenkopi Formation (Triassic), Gray Mountain, Arizona. Journal of Geophysical Research, 84, 1653- 1666. Graham, J . W. 1949. The stability and significance of magnetism in sedimentary rocks. Journal of Geophysical Research, 59, 131 - 137. Manzoni, M., and Nanni, T. 1977. Paleomagnetism of Ordovician Lamprophyres from Taylor Valley, Victoria Land, Antarctica. Pure and Applied Geophysics, 115, 961-978. McQueen, D. M., Scharnberger, C. K., Scharon, L., and Halpern, M. 1972. Cambro-Ordovician paleomagnetic pole position and rubidium-strontium total rock isochron for charnockitic rocks from Mirnyy Station, East Antarctica. Earth and Planetary Science Letters, 16, 433-438. Schopf, J . M. 1969. Ellsworth Mountains: Position in West Antarctica due to sea floor spreading. Science, 164, 63-66. Stump, E. 1976. On the late Precambrian-early Paleozoic metasediments and metasedimentary rocks of the Queen Maud Mountains, Antarctica, and a comparison with rocks of similar age from southern Africa (Report 62). Columbus: The Ohio State University, Institute of Polar Studies. Watts, D. R. In press. Potassium-argon and paleomagnetic results from King George Island, South Shetland Islands. In C. Craddock (Ed.), Antarctic Geoscience. Madison: The University of Wisconsin Press. Zijderveld, J . D. A. 1968. Natural remanent magnetizations of some intrusive rocks from the Sor Rondane Mountains, Queen Maud Land, Antarctica. Journal of Geophysical Research, 73, 3773-3785.
The most ambitious field project of the 1979-80 austral summer season in Antarctica was conducted in the Ellsworth Mountains between 3 December and 12 January. The area studied included both the Sentinel Range (north) and the Heritage Range (south), from about 77 0 15'S to 80°30'S latitude and 80°W to 87°30'W longitude (see figure 1). The camp, Ellsworth Camp (also known as Camp Macalester), was located adjacent to Minnesota Glacier at 79°05'S 85°58'W, about midway between the northern and southern extremities of the mountains. Camp elevation was about 1,250 meters above sea level. This was the largest field program in the Ellsworth Mountains in the 20-year history of studies there. Participating were 42 scientists and technicians representing eight countries (U.S., 28; West Germany and New Zealand, 4
ANTARCTIC JOURNAL
transportation to outcrop areas that could be reached on 1-day trips. The scientific projects conducted during the field season are summarized in table 1. The largest contingent of scientific personnel, under the direction of C. F. Webers, included numerous senior investigators studying a variety of topics related to a comprehensive analysis of the geology of the
ma
po, M1ULMA -
---
ROW" 71777 \! VINSON MASSIF
•.
/fr
cy I
CAMPM*LES1ER
GLACEP
l4
Af
ELLSWORTH MOUNTAINS
! Qç
/
Figure 1. Location map of the Ellsworth Mountains (modified from Figure 1 in Craddock, Anderson, and Webers 1964).
each; England, 2; Japan, Norway, Switzerland, and the U.S.S.R., 1 each). Scientific priorities were determined by C. F. Webers, and flight schedules for the three UH-1N turbine ("Huey") helicopters (figure 2) were made up daily by J . F. Splettstoesser. A total of 353 helicopter hours were flown during the season in direct support of science projects. The flying operation was under the command of LCDR W. Ferrell from 3 December to 26 December, and under LCDR D. Ellison thereafter. The camp, constructed by personnel employed by Holmes and Narver, Inc., consisted of five Jamesway buildings. The Holmes and Narver camp manager for the season was David Waidrip. Many geologic investigations were conducted using the main camp as a base of operations. For long-term studies in remote areas, tent camps were established. A total of 15 different camp sites were occupied during the period from 11 December to 10 January. Up to 22 people were in a maximum of six camps at one time. Most of the field studies in the areas of tent camps were conducted on foot, but often the local topography and distances prevented this and helicopters transported investigators to critical outcrops. Skidoos were also used in remote field operations for local
1980 REvIEw
-0
Figure 2. UK-IN helicopter at Polarstar Peak (left) and Mt. Ulmer (right) in northern Sentinel Range, about 100 nautical miles from base camp.
Ellsworth Mountains. The goals were: (1) to conduct a detailed study of significant areas that composed parts of the 13,000-meter stratigraphic section of the Ellsworths; (2) to obtain extensive collections of the fossil floras and faunas throughout the stratigraphic section for correlative, environmental, and evolutionary study; (3) to examine the evolution of landforms beginning with a probable Jurassic uplift through continental glaciation and partial recession; (4) to chart the sequence of major structural geologic events in the area; (5) to analyze the tectonic relationship of the Ellsworths to the Antarctic Peninsula and to the East Antarctic Shield; and (6) to obtain information on the nature and composition of a variety of igneous rocks exposed in the Heritage Range. These goals were accomplished. The success of the pro- gram was due largely to the helicopter support, which permitted a large amount of research within a relatively large area. All stratigraphic units exposed in the Ellsworth Mountains were studied in detail for paleoecological, paleontological, sedimentological, and stratigraphic characteristics. The Whiteout Conglomerate was found to contain stratified sediments at two stratigraphic positions and to contain boulder pavements. Crashsite Quartzite stratigraphy will be extended to the Heritage Range and modified. The Heritage Group will be subdivided into a number of new units. The Minaret Group was found to overlie the Heritage Group. No major unconformities (except for boulder pavements) were found anywhere in the stratigraphic column. Table 2 shows a tentative stratigraphic
37
column compared with Craddock's (1969) and Hjelle, Ohta, and Winsnes' (1978). Seven new faunas of Middle and Late Cambrian age, and one of Devonian age, were found. Previously known faunas and the Glossopteris flora were re-collected. A single major deformational phase occurred in the Late Triassic-Early Jurassic, as was previously known. Possible smaller scale deformations and their timing are being evaluated. Preliminary paleomagnetic
data indicate a major rotation of the Ellsworth Mountains block. All known igneous rocks in the Ellsworth Mountains were collected for further study. Landform sequences were examined and paleo-karst features were studied and collected. This project was supported by National Science Foundation grant DPP 78-21720 to Macalester College, St. Paul,
Minnesota.
Table 1. Summary of scientific investigations in the Ellsworth Mountains, 1979-80
Scientific project
Principal investigator
Number in party
Helicopter hours flown in support of project
Dates In field
24'
177.8
Dec. 3-Jan. 17
102.5
Dec. 3-Jan. 11
Comprehensive geologic study
G. F. Webersb
Glacial history
G. Dentond
6
Evolution of West Antarctic-Andean Cordillera
I. Daiziel'
2
Geodetic control
D. Knutzen9
3
48.7
Dec. 3-Jan. 11
Radiometric survey
E. Zeller"
4
11.7
Dec. 12-Dec. 19
Meteorite search
W. Cassidy
3.5
Dec. 20-Dec. 26
Soil development
I. Campbell/G. Claridge
8.8
Dec. 9-Dec. 18
2
Dec. 20-Jan. 17
42 353.0'
Total
Includes foreign exchange scientists. 'Included with Webers' total. 'Test flights and other flying not directly associated with science support raised this total to 364.1 hours. Time periods for individual field personnel varied.
C
b Other personnel were J. Anderson, A. Bramall, W. Buggisch, J. Collinson, C. Craddock, J. Craddock, P. von Gizycki, P. Gould, C.
Hudak, C. Matsch, A. Ojakangas, J. Pojeta, L. Rosen, A. Rutford, V. Samsonov, J. Splettstoesser, B. Sporli, C. Vavra, W. Vennum, D. Watts, E. Yochelson, M. Yoshida, and J. Zawiskie. d Other personnel were B. Andersen, J. Bockheim, H. Conway, J. Leide, and M. Prentice. Other Investigator was M. Thomson. Other personnel were T. Henderson and R. Pearsall. "Other personnel were K. Bulla, G. Dreschhoff, and V. Thoste.
References
Craddock, C. 1969. Geology of the Ellsworth Mountains. In V. C. Bushnell and C. Craddock (Eds.), Geologic maps of Antarctica (Antarctic map folio series, folio 12, plate 4). New York: American Geographical Society.
38
Craddock, C., Anderson, J . J. , and Webers, G. F. 1964. Geologic outline of the Ellsworth Mountains. In R. J. Adie (Ed.), Antarctic geology, Proceedings of the First International Symposium on Antarctic Geology, Cape Town, 1963. Amsterdam: North-Holland. Hjelle, A., Ohta, Y., and Winsnes, T. S. 1978. Stratigraphy and igneous petrology of southern Heritage Range, Ellsworth Mountains, Antarctica. Norsk Polarinstitutt Skrifter, 169, 5-43.
ANTARCTIC JOURNAL
NO
Table 2. Generalized Geologic Sections in the Ellsworth Mountains Craddock 1969 Age
Formation
Hjelle, Ohta, and Winsnes 1978
Thickness, meters Age
Polarstar Formation
Permian Interbedded slate, argillite, 1,370 quartzite, graywacke, coal Whiteout Conglomerate
Thickness, Formation meters Age Not discussed
White, gray and buff quartzite Lower Dark Member 1,830
Green and buff quartzite, argillite
Formation
Thickness, meters
Polarstar Formation
Permian Interbedded slate, argillite, 1,370 quartzite, graywacke, coal Whiteout Conglomerate 400+
Permo- Unsorted bouldery gray- 915 Carbon- wacke (Marine tillite?) iferous (?) Crashsite Quartzite Crashsite Quartzite Devonian Upper Dark Member 305 Mid- White, gray, and green and older Brown micaceous quartzite Paleozoic quartzites Middle Light Member 1,070
Tentative section, this paper
Whiteout Conglomerate
Permo- Black diamictite (tillite) 915 Carboninterous Crashsite Quartzitec Devonian Upper Dark Member to Upper Brown micaceous quartzite Cambrian
Upper Dark Member—
not seen Middle Light Member 800-850
305
Middle Light Member 1,070
White, gray and buff quartzite Lower Dark Member
1,830
Green and buff quartzite, argillite
Lower Dark Member 750-1,000 Cambrian Dunbar Ridge Formation Minaret Formation Cambrian Phyllite, argillite, slate, 6,710 and Middle Slate and black 700-1,200 Upper Marble, minor conglomerate, 0-800 and Pre- quartzite, conglomerate, Cambrian calcareous shale Cambrian "breccia bodies" cambrian (?) minor marble, lava flows Heritage Group
Heritage Group Heritage Groupd Middle Edson Hills Formation 3,500 Upper Phyllite, argillite, black shale, 7,000 Cambrian Volcanic-clastic sequence Cambrian limestone, conglomerate, or older and Middle polymictic and diamictic Cambrian conglomerates, lava flows, Minaret Group Middle Horseshoe Formation 500 marble, quartzite, graywacke Pre- Marble, minor conglomerate, 975 Precambrian Volcanic-calcareous sequence cambrian (?) "breccia bodies" TOTAL 13,175 a b
0
Based on southern Heritage Range only. Sentinel Range only; Heritage Range undivided. Crashsite stratigraphy will be extended/ modified to the Heritage Range. Heritage Group will be subdivided into new formations and members.
Minaret Group
TOTAL 13,290
