It is estimated that reports on Marie Byrd Landand Ellsworth Land will be completed on or beforeSeptember 1, 1973. This work is supported by Na-tional 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 adamel-lite, Clark Mountains, West Antarctica. U.S. GeologicalSurvey. Professional Paper, 550-D: 190-194.

Halpern, M. 1968. Ages of Antarctic and Argentine rocksbearing on continental drift. Earth and Planetary ScienceLetters, 5(3): 159-167.

Halpern, M. In press. Rubidium-strontium total-rock andmineral ages from the Marguerite Bay area, Kohler Rangeand Fosdick Mountains, West Antarctica. In: AntarcticGeology and Geophysics (R. J . Adie, ed.). Oslo, Uni-versitetsforlaget.

Jitchenko, L. N. In press. Late Precambrian acritarcha ofAntarctica. In: Antarctic Geology and Geophysics (R. J.Adie, ed.). Oslo, Universitetsforlaget.

Lopatin, B. G., and E. M. Lorenko. In press. Outlines of thegeology of Marie Byrd Land and Eights Coast. In: Antarc-tic Geology and Geophysics (R. J . Adie, ed.). Oslo, Uni-versitetsforlaget.

LeMasurier, W. E. 1972. Volcanic record of antarctic glacialhistory: implications with regard to Cenozoic sea levels.In: Polar Geomorphology (C. Embleton, ed.). Institute ofBritish Geographers. Special Publication, 4.

Wade, F. A. 1969. Geology of Marie Byrd Land. AntarcticMap Folio Series, 12; plate XVII.

present in lesser proportions are basalt, andesite,shale, sandstone, and siltstone. The sandstones, withfew exception, are lithic sandstones, or litharenites(fig.) according to the classification of Folk (1968).

The sandstones of the Trinity Peninsula Series ofCarboniferous(?) age (Adie, 1957) are markedly dif-ferent from those of the Latady Formation. Elliot(1965) has shown that the Trinity Peninsula seriessandstones are arkoses. Feldspar, dominantly plagio-clase, and quartz are much more abundant than rockfragments, which are mostly particles derived fromrhyolite and granite, but include subordinate sedi-mentary and metamorphic rocks. A fine-grainedmatrix comprising half the rock is typical of TrinityPeninsula Series sandstones.

Rocks of both the Latady Formation and theTrinity Peninsula Series are commonly poorly ex-posed. The two units are similar in appearance; bothare dark colored, are tightly folded, and have welldeveloped slaty cleavage. Fossils are rare and poorlypreserved in all known exposures of the Trinity Penin-sula Series and in many exposures of the Latady For-mation. Comparison of sandstone composition is themost useful method for distinguishing between thetwo formations.

This work was supported by National ScienceFoundation grant AG-187.

References

Composition of Jurassic sandstones,Lassiter Coast

P. L. WILLIAMS and P. D. ROWLEY

U.S. Geological SurveyDenver, Colorado

Sandstone comprises 10-60 percent of measuredstratigraphic sections of the Latady Formation ofLate Jurassic age in the Lassiter Coast and adjacentareas of southern Palmer Land. Other rock typespresent are carbonaceous siltstone, shale, and mud-stone; conglomerate is absent (Williams, 1970; Wil-liams and Rowley, 1971; Williams et al., in press).Major components of the sandstones are, on the aver-age, quartz, 20 percent; feldspar, 17 percent; rockfragments, 33 percent; and quartz-sericite matrix,commonly with minor amounts of carbonate, 30 per-cent. Plagioclase feldspar (An 20-30) is slightly moreabundant than potassium feldspar, which is almostentirely orthoclase with rare grains of microcine.Rock fragments are dominantly felsic volcanic rocks;

Publication authorized by the Director, U. S. GeologicalSurvey.

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.

Quartz

Feldspar Rock fragments

Composition of clastic particles of sandstones of the TrinityPeninsula Series (0) (after Elliot, 1965) and the Latady

Formation (i). Generalized from Folk (1968).

September-October 1972 145

Folk, R. L. 1968. Petrology of Sedimentary Rocks. AustinUniversity, Texas. 170 p.

Williams, P. L. 1970. Geology of the Lassiter Coast. Antarc-tic Journal of the U.S., V(4) : 98-99.

Williams, P. L., and Rowley, P. D. 1971. Geologic studiesof 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, Antarc-tic Peninsula: a preliminary report. In: Antarctic Geologyand Geophysics. Oslo, Universitetsforlaget.

Geologic mapping in thecentral Transantarctic Mountains:

a progress reportD. A. COATES

Institute of Polar StudiesThe Ohio State University

andDepartment of Geological Sciences

Cleveland State University

As an outgrowth of the past several seasons of fieldwork in the central Transantarctic Mountains, theInstitute of Polar Studies at The Ohio State Univer-sity is preparing a series of reconnaissance geologicmaps covering the area between the Beardmore andScott Glaciers (fig.). The current work is being doneunder National Science Foundation grant GV-26652with the cooperation of the U.S. Geological Survey,which publishes the maps.

In the last year, preparation of the Mount Eliza-beth-Mount Kathleen and Buckley Island quad-rangles was completed, with publication scheduledfor 1972 and 1973, respectively. Under David H.Elliot, Plunket Point and The Cloudmaker quad-rangles are in advanced stages of preparation. Duringthe summer of 1972, Donald A. Coates, with Paul A.Mayewski and Edmund Stump, is preparing theMount Goodale and Nilsen Plateau quadrangles.

References

Barrett, P. J ., J . F. Lindsay, and J . Gunner. 1970. Recon-naissance geologic map of the Mount Rabot quadrangle,Transantarctic Mountains, Antarctica. U.S. GeologicalSurvey, Antarctic Map No. 1. Scale 1:250,000.

Barrett, P. J . , and D. H. Elliot. In press. Reconnaissancegeologic map of the Buckley Island quadrangle, Trans-antarctic 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. Re-connaissance geologic map of the Mount Elizabeth-MountKathleen quadrangles, Transantarctic Mountains, Antarc-tica. U.S. Geological Survey, Antarctic Geologic MapNo. 2. Scale 1: 250,000.

Status of geologic quadrangle maps In the central TransantarcticMountains as of July 1972. A: Mount Robot, published (Barrettet al., 1970). B: Mount Elizabeth-Mount Kathleen, in press. C:Buckley Island, in advanced preparation. D: The Cloudmaker, Inadvanced 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 blackand White Island white?

WILLIAM J . BREEDMuseum of Northern Arizona

Black Island and White Island are prominent fea-tures on the southern horizon as viewed from Mc-Murdo Station. Captain R. F. Scott discovered theislands in 1902 during the British Naval AntarcticExpedition. He named Black Island for its blackvolcanic rocks; White Island for its mantle of snow.Both islands are about 30 kilometers from McMurdo,and each has an average width of approximately 15kilometers. Black Island is slightly higher, for itshighest point is 1,041 meters; the highest point onWhite Island is 761 meters. Both are of volcanicorigin. The puzzling question about these two islandsis: why is one white and the other black when they

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