Composition of Jurassic sandstones, Lassiter Coast
It is estimated that reports on Marie Byrd Land and Ellsworth Land will be completed on or before September 1, 1973. This work is supported by National Science Foundation grant GV-22901. References Boudette, E. L., R. F. Marvin, and C. E. Hedge. 1966. Biotite, potassium-feldspar, and whole rock ages of adamellite, Clark Mountains, West Antarctica. U.S. Geological Survey. Professional Paper, 550-D: 190-194. Halpern, M. 1968. Ages of Antarctic and Argentine rocks bearing on continental drift. Earth and Planetary Science Letters, 5(3): 159-167. Halpern, M. In press. Rubidium-strontium total-rock and mineral ages from the Marguerite Bay area, Kohler Range and Fosdick Mountains, West Antarctica. In: Antarctic Geology and Geophysics (R. J . Adie, ed.). Oslo, Universitetsforlaget. Jitchenko, L. N. In press. Late Precambrian acritarcha of Antarctica. In: Antarctic Geology and Geophysics (R. J. Adie, ed.). Oslo, Universitetsforlaget. Lopatin, B. G., and E. M. Lorenko. In press. Outlines of the geology of Marie Byrd Land and Eights Coast. In: Antarctic Geology and Geophysics (R. J . Adie, ed.). Oslo, Universitetsforlaget. LeMasurier, W. E. 1972. Volcanic record of antarctic glacial history: implications with regard to Cenozoic sea levels. In: Polar Geomorphology (C. Embleton, ed.). Institute of British Geographers. Special Publication, 4. Wade, F. A. 1969. Geology of Marie Byrd Land. Antarctic Map Folio Series, 12; plate XVII.
present in lesser proportions are basalt, andesite, shale, sandstone, and siltstone. The sandstones, with few exception, are lithic sandstones, or litharenites (fig.) according to the classification of Folk (1968). The sandstones of the Trinity Peninsula Series of Carboniferous(?) age (Adie, 1957) are markedly different from those of the Latady Formation. Elliot (1965) has shown that the Trinity Peninsula series sandstones are arkoses. Feldspar, dominantly plagioclase, and quartz are much more abundant than rock fragments, which are mostly particles derived from rhyolite and granite, but include subordinate sedimentary and metamorphic rocks. A fine-grained matrix comprising half the rock is typical of Trinity Peninsula Series sandstones. Rocks of both the Latady Formation and the Trinity Peninsula Series are commonly poorly exposed. The two units are similar in appearance; both are dark colored, are tightly folded, and have well developed slaty cleavage. Fossils are rare and poorly preserved in all known exposures of the Trinity Peninsula Series and in many exposures of the Latady Formation. Comparison of sandstone composition is the most useful method for distinguishing between the two formations. This work was supported by National Science Foundation grant AG-187. References
Composition of Jurassic sandstones, Lassiter Coast P. L. WILLIAMS and P. D. ROWLEY
Adie, R. J . 1957. The petrology of Graham Land, III. Metamorphic rocks of the Trinity Peninsula Series. Falk-
land Island Dependencies Surveys. Scientific Reports, 20.
26 p. Elliot, D. H. 1965. Geology of North-west Trinity Peninsula, Graham Land. British Antarctic Survey. Bulletin, 7. 24 p.
U.S. Geological Survey Denver, Colorado Sandstone comprises 10-60 percent of measured stratigraphic sections of the Latady Formation of Late Jurassic age in the Lassiter Coast and adjacent areas of southern Palmer Land. Other rock types present are carbonaceous siltstone, shale, and mudstone; conglomerate is absent (Williams, 1970; Williams and Rowley, 1971; Williams et al., in press). Major components of the sandstones are, on the average, quartz, 20 percent; feldspar, 17 percent; rock fragments, 33 percent; and quartz-sericite matrix, commonly with minor amounts of carbonate, 30 percent. Plagioclase feldspar (An 20-30) is slightly more abundant than potassium feldspar, which is almost entirely orthoclase with rare grains of microcine. Rock fragments are dominantly felsic volcanic rocks; Publication authorized by the Director, U. S. Geological Survey.
September-October 1972
Quartz
Feldspar
Rock fragments
Composition of clastic particles of sandstones of the Trinity Peninsula Series (0) (after Elliot, 1965) and the Latady Formation (i). Generalized from Folk (1968).
145
Folk, R. L. 1968. Petrology of Sedimentary Rocks. Austin University, Texas. 170 p. Williams, P. L. 1970. Geology of the Lassiter Coast. Antarctic Journal of the U.S., V(4) : 98-99. Williams, P. L., and Rowley, P. D. 1971. Geologic studies
of the Lassiter Coast. Antarctic Journal of the U.S.,
VI (4): 120. Williams, P. L., Schmidt, D. L., Plummer, C. C., and Brown, L. E. In press. Geology of the Lassiter Coast Area, Antarctic Peninsula: a preliminary report. In: Antarctic Geology and Geophysics. Oslo, Universitetsforlaget.
Geologic mapping in the central Transantarctic Mountains: a progress report D. A. COATES Institute of Polar Studies The Ohio State University and Department of Geological Sciences Cleveland State University As an outgrowth of the past several seasons of field work in the central Transantarctic Mountains, the Institute of Polar Studies at The Ohio State University is preparing a series of reconnaissance geologic maps covering the area between the Beardmore and Scott Glaciers (fig.). The current work is being done under National Science Foundation grant GV-26652 with the cooperation of the U.S. Geological Survey, which publishes the maps. In the last year, preparation of the Mount Elizabeth-Mount Kathleen and Buckley Island quadrangles was completed, with publication scheduled for 1972 and 1973, respectively. Under David H. Elliot, Plunket Point and The Cloudmaker quadrangles are in advanced stages of preparation. During the summer of 1972, Donald A. Coates, with Paul A. Mayewski and Edmund Stump, is preparing the Mount Goodale and Nilsen Plateau quadrangles.
References
Barrett, P. J . , J . F. Lindsay, and J . Gunner. 1970. Reconnaissance geologic map of the Mount Rabot quadrangle, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Map No. 1. Scale 1:250,000. Barrett, P. J . , and D. H. Elliot. In press. Reconnaissance geologic map of the Buckley Island quadrangle, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Geologic Map No. 3. Scale 1:250,000. Lindsay, J . F., J . Gunner, and P. J . Barrett. In press. Reconnaissance geologic map of the Mount Elizabeth-Mount Kathleen quadrangles, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Geologic Map No. 2. Scale 1: 250,000.
146
Status of geologic quadrangle maps In the central Transantarctic Mountains as of July 1972. A: Mount Robot, published (Barrett et al., 1970). B: Mount Elizabeth-Mount Kathleen, in press. C: Buckley Island, in advanced preparation. D: The Cloudmaker, In advanced preparation. E: Shackleton Glacier, In preparation. F: Plunket Point, in press. G: Liv Glacier, in preparation. H: Mount Goodale, in preparation. I: Nilsen Plateau, in preparation.
Why is Black Island black and White Island white? WILLIAM J . BREED Museum of Northern Arizona Black Island and White Island are prominent features on the southern horizon as viewed from McMurdo Station. Captain R. F. Scott discovered the islands in 1902 during the British Naval Antarctic Expedition. He named Black Island for its black volcanic rocks; White Island for its mantle of snow. Both islands are about 30 kilometers from McMurdo, and each has an average width of approximately 15 kilometers. Black Island is slightly higher, for its highest point is 1,041 meters; the highest point on White Island is 761 meters. Both are of volcanic origin. The puzzling question about these two islands is: why is one white and the other black when they ANTARCTIC JOURNAL
present in lesser proportions are basalt, andesite, shale, sandstone, and siltstone. The sandstones, with few exception, are lithic sandstones, or litharenites (fig.) according to the classification of Folk (1968). The sandstones of the Trinity Peninsula Series of Carboniferous(?) age (Adie, 1957) are markedly different from those of the Latady Formation. Elliot (1965) has shown that the Trinity Peninsula series sandstones are arkoses. Feldspar, dominantly plagioclase, and quartz are much more abundant than rock fragments, which are mostly particles derived from rhyolite and granite, but include subordinate sedimentary and metamorphic rocks. A fine-grained matrix comprising half the rock is typical of Trinity Peninsula Series sandstones. Rocks of both the Latady Formation and the Trinity Peninsula Series are commonly poorly exposed. The two units are similar in appearance; both are dark colored, are tightly folded, and have well developed slaty cleavage. Fossils are rare and poorly preserved in all known exposures of the Trinity Peninsula Series and in many exposures of the Latady Formation. Comparison of sandstone composition is the most useful method for distinguishing between the two formations. This work was supported by National Science Foundation grant AG-187. References
Composition of Jurassic sandstones, Lassiter Coast P. L. WILLIAMS and P. D. ROWLEY
Adie, R. J . 1957. The petrology of Graham Land, III. Metamorphic rocks of the Trinity Peninsula Series. Falk-
land Island Dependencies Surveys. Scientific Reports, 20.
26 p. Elliot, D. H. 1965. Geology of North-west Trinity Peninsula, Graham Land. British Antarctic Survey. Bulletin, 7. 24 p.
U.S. Geological Survey Denver, Colorado Sandstone comprises 10-60 percent of measured stratigraphic sections of the Latady Formation of Late Jurassic age in the Lassiter Coast and adjacent areas of southern Palmer Land. Other rock types present are carbonaceous siltstone, shale, and mudstone; conglomerate is absent (Williams, 1970; Williams and Rowley, 1971; Williams et al., in press). Major components of the sandstones are, on the average, quartz, 20 percent; feldspar, 17 percent; rock fragments, 33 percent; and quartz-sericite matrix, commonly with minor amounts of carbonate, 30 percent. Plagioclase feldspar (An 20-30) is slightly more abundant than potassium feldspar, which is almost entirely orthoclase with rare grains of microcine. Rock fragments are dominantly felsic volcanic rocks; Publication authorized by the Director, U. S. Geological Survey.
September-October 1972
Quartz
Feldspar
Rock fragments
Composition of clastic particles of sandstones of the Trinity Peninsula Series (0) (after Elliot, 1965) and the Latady Formation (i). Generalized from Folk (1968).
145
Folk, R. L. 1968. Petrology of Sedimentary Rocks. Austin University, Texas. 170 p. Williams, P. L. 1970. Geology of the Lassiter Coast. Antarctic Journal of the U.S., V(4) : 98-99. Williams, P. L., and Rowley, P. D. 1971. Geologic studies
of the Lassiter Coast. Antarctic Journal of the U.S.,
VI (4): 120. Williams, P. L., Schmidt, D. L., Plummer, C. C., and Brown, L. E. In press. Geology of the Lassiter Coast Area, Antarctic Peninsula: a preliminary report. In: Antarctic Geology and Geophysics. Oslo, Universitetsforlaget.
Geologic mapping in the central Transantarctic Mountains: a progress report D. A. COATES Institute of Polar Studies The Ohio State University and Department of Geological Sciences Cleveland State University As an outgrowth of the past several seasons of field work in the central Transantarctic Mountains, the Institute of Polar Studies at The Ohio State University is preparing a series of reconnaissance geologic maps covering the area between the Beardmore and Scott Glaciers (fig.). The current work is being done under National Science Foundation grant GV-26652 with the cooperation of the U.S. Geological Survey, which publishes the maps. In the last year, preparation of the Mount Elizabeth-Mount Kathleen and Buckley Island quadrangles was completed, with publication scheduled for 1972 and 1973, respectively. Under David H. Elliot, Plunket Point and The Cloudmaker quadrangles are in advanced stages of preparation. During the summer of 1972, Donald A. Coates, with Paul A. Mayewski and Edmund Stump, is preparing the Mount Goodale and Nilsen Plateau quadrangles.
References
Barrett, P. J . , J . F. Lindsay, and J . Gunner. 1970. Reconnaissance geologic map of the Mount Rabot quadrangle, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Map No. 1. Scale 1:250,000. Barrett, P. J . , and D. H. Elliot. In press. Reconnaissance geologic map of the Buckley Island quadrangle, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Geologic Map No. 3. Scale 1:250,000. Lindsay, J . F., J . Gunner, and P. J . Barrett. In press. Reconnaissance geologic map of the Mount Elizabeth-Mount Kathleen quadrangles, Transantarctic Mountains, Antarctica. U.S. Geological Survey, Antarctic Geologic Map No. 2. Scale 1: 250,000.
146
Status of geologic quadrangle maps In the central Transantarctic Mountains as of July 1972. A: Mount Robot, published (Barrett et al., 1970). B: Mount Elizabeth-Mount Kathleen, in press. C: Buckley Island, in advanced preparation. D: The Cloudmaker, In advanced preparation. E: Shackleton Glacier, In preparation. F: Plunket Point, in press. G: Liv Glacier, in preparation. H: Mount Goodale, in preparation. I: Nilsen Plateau, in preparation.
Why is Black Island black and White Island white? WILLIAM J . BREED Museum of Northern Arizona Black Island and White Island are prominent features on the southern horizon as viewed from McMurdo Station. Captain R. F. Scott discovered the islands in 1902 during the British Naval Antarctic Expedition. He named Black Island for its black volcanic rocks; White Island for its mantle of snow. Both islands are about 30 kilometers from McMurdo, and each has an average width of approximately 15 kilometers. Black Island is slightly higher, for its highest point is 1,041 meters; the highest point on White Island is 761 meters. Both are of volcanic origin. The puzzling question about these two islands is: why is one white and the other black when they ANTARCTIC JOURNAL
