Soil development and rock weathering in the Ellsworth ...
Soil development and rock weathering in the Ellsworth Mountains, Antarctica
the condition of surface boulders on moraines at
22 sites in
the Heritage and Sentinel Ranges. Field methods were described previously (Bockheim 1979). Poorly developed soils (weathering stages 1 and 2 of Campbell and Claridge 1975) occur on moraines in the
2,100 meters and in the Sentinel 3,000 meters. The soils lack horizonation and
Heritage Range below
J.
G. BOCKHEIM and J . E. LEIDE
Range below
Department of Soil Science University of Wisconsin Madison, Wisconsin 53706
From 3-27 December 1979, we worked with glacial geologists George Denton, Robert Rutford, and Björn Andersen in the Ellsworth Mountains (1) to use soils as a relative-age indicator in reconstructing the history of the west antarctic ice sheet and
(2) to study soil-forming processes, including
the nature, distribution, and origin of salts and clay mineral weathering. We described and sampled soils and identified
generally have few ghosts ("shadows" of former cobbles) and visible salts below the surface (table 1). Boulders (predominantly quartzite) on moraines show staining, pitting, spalling, and some striations, but unlike boulders on older surfaces in the Transantarctjc Mountains, do not show venti faction, honeycombing (cavernous weathering), and planing to the ground surface (table
2).
Soils and surface boulder weathering features in the Heritage and Sentinel Ranges are comparable to those on Ross Sea drift in eastern Taylor Valley (77°31'S 163°45'E) (Bockheim 1977; Pastor and Bockheim 1980), Trilogy drift in eastern Wright Valley (77°27'S 162°45'E) (Bockheim 1979), and Britannia drift in the Darwin and Byrd Glaciers area
Table 1. Morphology of soils on moraines in the Ellsworth Mountains Depth to ice Depth of Depth of cemented cohesion ghosts frost table Salt Weathering Location Coordinates Horizonation8 (centimeters) (centimeters) (centimeters) stage stager
Profile number
Heritage Range 79-15 79-16 79-17 79-18 79-19 79-20 79-21 79-22 79-23 79-24
Edson Hills 79048'S 83°45'W Cln, llC2n, R 57
Edson Hills 79048S 83 0 45'W Cm, C2n, C3n 80+ Edson Hills 79048'S 83 0 45'W CIn, C2n 15 Anderson Massif 79 0 07'S 84 0 40'W Clox, A 13 Carnell Peak 79028'S 85 0 15'W Cln, llC2ox 42 Edson Hills 79044'S 83 0 55'W Cln, C2sa, llC3ox 59
Welcome Nunatak 79 0 07'S 85 0 51'W Cln, CR
24
Edson Hills 79044S 83 0 55'W Clox, llCn 17 Edson Hills 79044'S 84 0 00'W Clox, C2n, C3n 50 Mt. Dolence 79051'S 83 0 15'W Cm, C2ic 17
79-33 79-34 79-35 79-36
Mt. Dolence 79 0 51'S 83015'W Clox, C2ox, C3ox 75+ Mt. Twiss 79 0 22'S 850351W Clox, C2n, C3n 75+ Mt. Twiss 79 0 22'S 85035W Clox, C2n, C3n 100+ Mt. Twiss 79 0 22'S 85035'W Cic 5 Beaudoin Peak 79 0 48'S 81000'W Clox, C2ox, C3n 14 Mt. Fordell 80 0 17'S 82010'W Cln, C2n, C3n 100+ Parrish Peak 79 0 47'S 81050'W Clox, C2n, C3n 75+ Cagle Peaks 79 0 35'S 85030'W Cm, C2n, C3n 33
79-27 79-28 79-29 79-30
Dickey Peak Flowers Hills Flowers Hills Peak 1600
79-25 79-26 79-31 79-32
0 >60 0 2 0 >80 2 70+ >70 0 2 20 >25 3 0 >42 2 0 >100 lv 3 0 >24 2 0 2 >17 38 2 50 0 17 1 0 >80 lv 2 0 >80 lv 2-3 0 >100 lv 2 0 3 0 1 0 33 2 0 >100 2 0 >85 2 5 >110 2
Sentinel Range
a b C
78 0 20'S 84 0 30'W Clox, lICRic 18 78°20'S 84°15'W Cox, hR 20 78 0 22'S 84 0 01'W Cln, llC2n 20 78 0 50'S 83 0 45'W Clsa, C2ic 15
0 18 Ill 2 0 >20 2 0 20 2 0 15 lv 2
Follows nomenclature of Birkeland (1974). 0 = none visible; I = salt encrustations beneath clasts; II = few salt flecks (0.5 to 2 millimeters diameter); Ill = abundant salt
flecks; IV = salt cemented horizon (weakly cemented).
1 = no salts or soil horizonation, fresh boulders; 2 = few salt flecks, weak horizonation, light staining and some disintegration of
boulders; 3 = many salt flecks, distinct horizonation, distinct polish and some cavernous weathering and ventifaction (Campbell and Claridge 1975).
1980 REvIEw
33
(Bockheim and Wilson 1979). The Ross Sea glaciation has been dated by Stuiver, Denton, and Hughes (1980) at 17,000 to 21,000 years ago. In conjunction with the findings of Denton, Rutford, and Andersen (Antarctic Journal of the U.S., this volume), these data suggest that most of the peaks in the Heritage Range were overrun by ice from the expanded west antarctic ice sheet during the last glaciation (about 18,000 years ago). Preliminary X-ray diffraction analysis of salt encrustations revealed the widespread occurrence of gypsum (CaSO4 21-120) in the Heritage Range. Other salt minerals include calcite (CaCO 3 ) and thenardite (NaSO 4). Soda niter Table 2. Weathering of surface bounders on moraines in the Ellsworth Mountains
Surface boulder frequency % of quartzite boulders (per 314 Site square meters) Striated Polished SpaUed Pitted 79-15 525 14 90 24 2 79-16 710 0 34 4 7 79-17 525 37 92 14 28 79-19 205 3 93 25 3 79-20 310 0 97 18 17 79-23 405 0 93 47 24 79-24 420 0 69 30 1 79-25 710 1 34 20 0 79-26 575 0 55 18 7 79-32 250 0 32 4 4 79-35 365 0 81 60 31 79-36 750 0 45 6 0
Paleomagnetic investigation in the Ellsworth Mountains DOYLE R. WArrs
and
ANDREW M. BRAMALL
Department of Earth Sciences University, Leeds, LS2 91T United Kingdom
Many scientific activities took place at Camp Macalester in the Ellsworth Mountains during the 1979-80 austral field season. One was a systematic collection of oriented drill cores from Cambrian through Devonian sedimentary rocksin the northern Heritage Range and the southern Sentinel
34
(NaNO3) was discovered on Dickey Peak (78°2(YS 84°30'W) in the Sentinel Range. Chemical and mineralogical analysis of 150 soil samples and salt encrustations are in progress. This work was supported by National Science Foundation grant DPP 74-20991 to G. H. Denton. We are grateful to civilian and VXE-6 personnel at Camp Macalester for logistic support. H. Conway and M. Prentice provided field assistance.
References Birkeland, P. W. 1974. Pedology, weathering, and geomorphological research. New York: Oxford University Press. Bockheim, J . C. 1977. Soil development in the Taylor Valley and McMurdo Sound area. Antarctic Journal of the U.S., 12(4), 105-108. Bockheim, J. C. 1979. Relative age and origin of soils in eastern Wright Valley. Soil Science, 128(3), 142-152. Bockheim, J. G., and Wilson, S. C. 1979. Pedology of the Darwin Glacier area, Antarctica. Antarctic Journal of the U.S., 14(5), 58-59. Campbell, I. B., and Claridge, C. G. C. 1975. Morphology and age relationships of antarctic soils. Quaternary Studies, New Zealand Royal Society Bulletin, 13, 83-88. Denton, G. H., Rutford, R. H., and Andersen, B. G. 1980. Glacial history of the Ellsworth Mountains. Antarctic Journal of the U.S., 15(5). Pastor, J . , and Bockheim, J. G. 1980. Soil development on moraines of Taylor Glacier, lower Taylor Valley, Antarctica. Soil Science Society of America Journal, 44(2), 341-348. Stuiver, M., Denton, G. H., and Hughes, T. J . 1980. History of the marine ice sheet in West Antarctica during the last glaciation: A working hypothesis. In G. H. Denton and T. J. Hughes (Eds.), The last great ice sheet. New York: Wiley-Interscience.
Range. The investigation, which took place between December 1979 and January 1980, is part of a larger program using paleomagnetic methods to determine the tectonic relationship between West Antarctica and East Antarctica and to document relative motions (or lack thereof) between the crustal units that comprise West Antarctica (Alley and Watts 1979; Elliot, Watts, Alley, and Gracanin 1978; Watts in press). The sampling program in the Ellsworth Mountains was planned on the basis of a preliminary study of the magnetic properties of a suite of unoriented rock samples provided by C. Craddock of the University of Wisconsin-Madison. In the preliminary study, it was demonstrated that the argillites of the Upper Heritage Group and the hematitic quartzites of the Crashsite Quartzite Group were especially promising targets for detailed investigation. Samples were collected from more than 70 sites spanning a distance of 224 kilometers through the two ranges that comprise the Ellsworth Mountains. The sampled units
ANTARCTIC JOURNAL
the condition of surface boulders on moraines at
22 sites in
the Heritage and Sentinel Ranges. Field methods were described previously (Bockheim 1979). Poorly developed soils (weathering stages 1 and 2 of Campbell and Claridge 1975) occur on moraines in the
2,100 meters and in the Sentinel 3,000 meters. The soils lack horizonation and
Heritage Range below
J.
G. BOCKHEIM and J . E. LEIDE
Range below
Department of Soil Science University of Wisconsin Madison, Wisconsin 53706
From 3-27 December 1979, we worked with glacial geologists George Denton, Robert Rutford, and Björn Andersen in the Ellsworth Mountains (1) to use soils as a relative-age indicator in reconstructing the history of the west antarctic ice sheet and
(2) to study soil-forming processes, including
the nature, distribution, and origin of salts and clay mineral weathering. We described and sampled soils and identified
generally have few ghosts ("shadows" of former cobbles) and visible salts below the surface (table 1). Boulders (predominantly quartzite) on moraines show staining, pitting, spalling, and some striations, but unlike boulders on older surfaces in the Transantarctjc Mountains, do not show venti faction, honeycombing (cavernous weathering), and planing to the ground surface (table
2).
Soils and surface boulder weathering features in the Heritage and Sentinel Ranges are comparable to those on Ross Sea drift in eastern Taylor Valley (77°31'S 163°45'E) (Bockheim 1977; Pastor and Bockheim 1980), Trilogy drift in eastern Wright Valley (77°27'S 162°45'E) (Bockheim 1979), and Britannia drift in the Darwin and Byrd Glaciers area
Table 1. Morphology of soils on moraines in the Ellsworth Mountains Depth to ice Depth of Depth of cemented cohesion ghosts frost table Salt Weathering Location Coordinates Horizonation8 (centimeters) (centimeters) (centimeters) stage stager
Profile number
Heritage Range 79-15 79-16 79-17 79-18 79-19 79-20 79-21 79-22 79-23 79-24
Edson Hills 79048'S 83°45'W Cln, llC2n, R 57
Edson Hills 79048S 83 0 45'W Cm, C2n, C3n 80+ Edson Hills 79048'S 83 0 45'W CIn, C2n 15 Anderson Massif 79 0 07'S 84 0 40'W Clox, A 13 Carnell Peak 79028'S 85 0 15'W Cln, llC2ox 42 Edson Hills 79044'S 83 0 55'W Cln, C2sa, llC3ox 59
Welcome Nunatak 79 0 07'S 85 0 51'W Cln, CR
24
Edson Hills 79044S 83 0 55'W Clox, llCn 17 Edson Hills 79044'S 84 0 00'W Clox, C2n, C3n 50 Mt. Dolence 79051'S 83 0 15'W Cm, C2ic 17
79-33 79-34 79-35 79-36
Mt. Dolence 79 0 51'S 83015'W Clox, C2ox, C3ox 75+ Mt. Twiss 79 0 22'S 850351W Clox, C2n, C3n 75+ Mt. Twiss 79 0 22'S 85035W Clox, C2n, C3n 100+ Mt. Twiss 79 0 22'S 85035'W Cic 5 Beaudoin Peak 79 0 48'S 81000'W Clox, C2ox, C3n 14 Mt. Fordell 80 0 17'S 82010'W Cln, C2n, C3n 100+ Parrish Peak 79 0 47'S 81050'W Clox, C2n, C3n 75+ Cagle Peaks 79 0 35'S 85030'W Cm, C2n, C3n 33
79-27 79-28 79-29 79-30
Dickey Peak Flowers Hills Flowers Hills Peak 1600
79-25 79-26 79-31 79-32
0 >60 0 2 0 >80 2 70+ >70 0 2 20 >25 3 0 >42 2 0 >100 lv 3 0 >24 2 0 2 >17 38 2 50 0 17 1 0 >80 lv 2 0 >80 lv 2-3 0 >100 lv 2 0 3 0 1 0 33 2 0 >100 2 0 >85 2 5 >110 2
Sentinel Range
a b C
78 0 20'S 84 0 30'W Clox, lICRic 18 78°20'S 84°15'W Cox, hR 20 78 0 22'S 84 0 01'W Cln, llC2n 20 78 0 50'S 83 0 45'W Clsa, C2ic 15
0 18 Ill 2 0 >20 2 0 20 2 0 15 lv 2
Follows nomenclature of Birkeland (1974). 0 = none visible; I = salt encrustations beneath clasts; II = few salt flecks (0.5 to 2 millimeters diameter); Ill = abundant salt
flecks; IV = salt cemented horizon (weakly cemented).
1 = no salts or soil horizonation, fresh boulders; 2 = few salt flecks, weak horizonation, light staining and some disintegration of
boulders; 3 = many salt flecks, distinct horizonation, distinct polish and some cavernous weathering and ventifaction (Campbell and Claridge 1975).
1980 REvIEw
33
(Bockheim and Wilson 1979). The Ross Sea glaciation has been dated by Stuiver, Denton, and Hughes (1980) at 17,000 to 21,000 years ago. In conjunction with the findings of Denton, Rutford, and Andersen (Antarctic Journal of the U.S., this volume), these data suggest that most of the peaks in the Heritage Range were overrun by ice from the expanded west antarctic ice sheet during the last glaciation (about 18,000 years ago). Preliminary X-ray diffraction analysis of salt encrustations revealed the widespread occurrence of gypsum (CaSO4 21-120) in the Heritage Range. Other salt minerals include calcite (CaCO 3 ) and thenardite (NaSO 4). Soda niter Table 2. Weathering of surface bounders on moraines in the Ellsworth Mountains
Surface boulder frequency % of quartzite boulders (per 314 Site square meters) Striated Polished SpaUed Pitted 79-15 525 14 90 24 2 79-16 710 0 34 4 7 79-17 525 37 92 14 28 79-19 205 3 93 25 3 79-20 310 0 97 18 17 79-23 405 0 93 47 24 79-24 420 0 69 30 1 79-25 710 1 34 20 0 79-26 575 0 55 18 7 79-32 250 0 32 4 4 79-35 365 0 81 60 31 79-36 750 0 45 6 0
Paleomagnetic investigation in the Ellsworth Mountains DOYLE R. WArrs
and
ANDREW M. BRAMALL
Department of Earth Sciences University, Leeds, LS2 91T United Kingdom
Many scientific activities took place at Camp Macalester in the Ellsworth Mountains during the 1979-80 austral field season. One was a systematic collection of oriented drill cores from Cambrian through Devonian sedimentary rocksin the northern Heritage Range and the southern Sentinel
34
(NaNO3) was discovered on Dickey Peak (78°2(YS 84°30'W) in the Sentinel Range. Chemical and mineralogical analysis of 150 soil samples and salt encrustations are in progress. This work was supported by National Science Foundation grant DPP 74-20991 to G. H. Denton. We are grateful to civilian and VXE-6 personnel at Camp Macalester for logistic support. H. Conway and M. Prentice provided field assistance.
References Birkeland, P. W. 1974. Pedology, weathering, and geomorphological research. New York: Oxford University Press. Bockheim, J . C. 1977. Soil development in the Taylor Valley and McMurdo Sound area. Antarctic Journal of the U.S., 12(4), 105-108. Bockheim, J. C. 1979. Relative age and origin of soils in eastern Wright Valley. Soil Science, 128(3), 142-152. Bockheim, J. G., and Wilson, S. C. 1979. Pedology of the Darwin Glacier area, Antarctica. Antarctic Journal of the U.S., 14(5), 58-59. Campbell, I. B., and Claridge, C. G. C. 1975. Morphology and age relationships of antarctic soils. Quaternary Studies, New Zealand Royal Society Bulletin, 13, 83-88. Denton, G. H., Rutford, R. H., and Andersen, B. G. 1980. Glacial history of the Ellsworth Mountains. Antarctic Journal of the U.S., 15(5). Pastor, J . , and Bockheim, J. G. 1980. Soil development on moraines of Taylor Glacier, lower Taylor Valley, Antarctica. Soil Science Society of America Journal, 44(2), 341-348. Stuiver, M., Denton, G. H., and Hughes, T. J . 1980. History of the marine ice sheet in West Antarctica during the last glaciation: A working hypothesis. In G. H. Denton and T. J. Hughes (Eds.), The last great ice sheet. New York: Wiley-Interscience.
Range. The investigation, which took place between December 1979 and January 1980, is part of a larger program using paleomagnetic methods to determine the tectonic relationship between West Antarctica and East Antarctica and to document relative motions (or lack thereof) between the crustal units that comprise West Antarctica (Alley and Watts 1979; Elliot, Watts, Alley, and Gracanin 1978; Watts in press). The sampling program in the Ellsworth Mountains was planned on the basis of a preliminary study of the magnetic properties of a suite of unoriented rock samples provided by C. Craddock of the University of Wisconsin-Madison. In the preliminary study, it was demonstrated that the argillites of the Upper Heritage Group and the hematitic quartzites of the Crashsite Quartzite Group were especially promising targets for detailed investigation. Samples were collected from more than 70 sites spanning a distance of 224 kilometers through the two ranges that comprise the Ellsworth Mountains. The sampled units
ANTARCTIC JOURNAL
