Rocks similar to the Mawson tillite of Allan Hills found to contain a microflora and a microplankton are present on Carapace Nunatak beneath volcanic similar to those in the Minna Bluff specimen, but sandstones assigned by Ballance et al. (1965) to the preserved in a different facies (McIntyre and Wilson, Beacon group. We concur with the Jurassic age as- 1966; Wilson, 1967). More recently Wilson (1968) signment of the Mawson by Gunn and Warren has found that derived palynomorphs of Lower Ter- (1962). In addition to the conchostracans and ostra- tiary age are widespread in Holocene sediments on cods previously reported from Carapace (Gunn and the floor of the Ross Sea. In the 1968-1969 summer, Warren, 1962; Ballance et al., 1965), a newly discov- Tertiary macrofossils were found in a glacial erratic ered locality produced well-preserved, large insect and boulder at Cape Crozier, Ross Island. crustacean remains. Their paleoclimatic and paleo- In January 1969, the writer, assisted b y R. Korsch, geographic significance has not yet been assessed. spent a week of intensive re-collecting at Minna Bluff. References Three days and over 60 km of slow and careful tra- versing yielded only two pieces of Tertiary mucistone, Ballance, P. F., G. Warren, and W. A. Waiters. 1965. A but during the remainder of the week, several hun- re-interpretation of the Mawson Tillite, Antarctica. Ab- stracts, Australian and New Zealand Associations for the dreds of fragments of mudstones, calcareous sand- Advancement of Science Conference, Hobart. stone, and conglomerate or diamictite were found. Gunn, B. M. and G. Warren. 1962. Geology of Victoria Land The distribution of the erratics is, in fact, erratic or between the Mawson and Mulock Glaciers, Antarctica. unpredictable, being governed by the fact that the New Zealand Geological Survey Bulletin, 71: 157 p. different lateral and terminal moraines on the north side of Minna Bluff form distinctive groups. Some consist of basaltic rocks from the McMurdo volcanics, others of blocks of trachyte and calcareous sandstone, Fossiliferous Rocks in Moraines at and yet others of plutonic and metasedimentary rocks Minna Bluff, McMurdo Sound with scattered patches and streamlines of Tertiary rnudstones. The microfossils in the sediments will be processed in 1969 by L. M. Cranwell and others. H. J. HARRINGTON The source of the fossiliferous erratics is a matter of Department of Geology considerable interest. It is considered very unlikely University of New England that they have been derived from the west side of the Armidale, N.S.W., Australia Transantarctjc Mountains in East Antarctica. It is considered probable, however, that a Cretaceous and In 1959, limited exploration of moraines at Minna Tertiary sedimentary sequence of the New Zealand Bluff and White Island in McMurdo Sound yielded a type is widespread in Marie Byrd Land and possibly few fragments of gray, white-weathering rnudstones or also under the floor of the Ross Sea and the ad- vitric tuffs, similar to diachronous facies in New Zea- joining continental terrace. Any attempt to he more land that range in age from Late Cretaceous to Early specific is difficult. Crary (1961, 1966) and Crary et Oligocene. It was naturally assumed that the ant- al. (1962) have shown, by seismic investigations, that arctic erratics would be within that age range. over 1,300 iii of low-velocity sediments occur beneath From a small Minna Bluff erratic, C. H. Scott ex- the eastern Ross Sea near Kainan Bay and cover 645 tracted a few Foraminifera, and L. M. Cranwell ob- of higher-velocity sediments, which Crary thought tained a small pollen component and abundant hystri- might he of the same general type as the B-acon chosphaerids and dinoflagellates. The age of this sandstones, but which could be a Cretaceous and Ter- fossil biota, probably Paleocene or Eocene, has been tiary sequence. Crary has also shown that there are discussed in a number of papers (Cranwell et al., thick sediments beneath the Ross Ice Shelf south of 1960; Cranwell, 1962, 1963, 1964a, 1964b, 1966: Minna Bluff. Harrington, 1965). The biota is of paleoclimatic and The discovery of Tertiary fossiliferous sediments paleogeographic significance in indicating that the sea (and other rocks such as ignimbrites) as glaHal er- in which it accumulated was "normal" and was adja- ratics in McMurdo Sound is important in itself, but it cent to land warm enough to support a Nothofagus also indicates that very little is yet known about the forest. It also proved that this part of Antarctica age and tectonic, history of the Ross Sea. It could be, could have acted as a migration route or dispersal in part, a new ocean formed by rifting during the center for Tertiary plants, linking the Andean region Cenozoic. That problem, and others related to it, with New Zealand and eastern, Australia. point the way to research which could have economic Further searches were unsuccessful until 1966, significance in future exploration for hydrocarbons when some calcareous sandstone blocks, collected at beneath the Ross Ice Shelf and adjoining oceanic Black Island by P. Vella and A. 0. Frame, were areas.

134 ANTARCTIC JOURNAL References Munizaga (geochronologist from Instituto Antártico Cranwell, L. M. 1962, Antarctica: Cradle or grave for Cisileno, Santiago de Chile, Navy Photographer First Nothofagus? Pollen et Spores, 4: 190-192 (Abstract). Class Bruce F. Moore, and the author was lifted out Cranwell, L. M. 1963. Nolhofagus: Living and fossil. In: of Ellsworth Land to McMurdo Station on December Pacific Basin Biogeography (ed. J . L. Gressitt), Bishop 16, 1968, and relocated for a weeks invstigation of Museum Press, Honolulu, p. 387-400. Cranwell, L. M. 1964a. Hystrichospheres as an aid to ant- the Roberts Massif, on the edge of the polar plateau, arctic dating with special reference to the recovery of on December 21. Cordosphaeridium in erratics at McMurdo Sound. Grana A tent camp was established adjacent to the Massif, Palynologica, 5: 397-405. Cranvvell, L. M. 1964b. Antarctica: Cradle or grave for its immediately south of Misery Peak. Motor toboggans I r othofagus ? In: Ancient Pacific Floras (ed. L. M. Cran- provided transportation in the field. Objectives of the well) , University of Hawaii Press, Honolulu, p. 87-93. short survey were to determine the age and correla- Cranwell, L. M. 1966. Senoriian dinoflagellates and micro- tion of exposures of Beacon sedimentary rocks by spores from Snow Hill and Seymour Island. Arizona measuring sections and collecting a suite of plant and Academy of Science. Journal, 4: 136 (Abstract). Cranwell, L. M. 1967. Some older angiospermous pollen possible animal fossils. This information was needed types of Chile and Antarctica. Abstracts of Papers Pre- to complete the survey of the Shackleton Glacier area. vented, American Association for the Advancement of Beacon Group sediments cropping out at Roberts Science and the Arizona Academy of Science, 1967, p. 13. Massif consist of about 450 rn of massive, light-gray, Cranwell, L. M., H. J . Harrington, and I. C. Speden. 1960. Lower Tertiary niicrofossils from McMurdo Sound, Ant- feldspathic sandstone alternating with thin to massive arctica. Nature (London), 186: 700-702. units of gray shale. The age of the sediments is indi- Crary, A. P. 1961. Marine-sediment thickness in the eastern cated to be Triassic by the presence of Dicroidium Ross Sea area, Antarctica. Geological Society of America. dutoitii sp. in beds exposed at Misery Peak Bulletin, 72: 787-790. Crary, A. P. 1966. Mechanism for fiord fcrmation indicated (Townrow, 1967). A thin, coaly section crops out by studies of an ice-covered inlet. Geological Society of near the ice level on the north side of the Massif and America. Bulletin, 77: 911-930. prolzably represents sediments of the Permian Buckley Crary, A. P., E. S. Robinson, H. F. Bennett, and W. W. Boyd, Formation, first described in the Beardmore area by Jr. 1962. Glaciological Studies of the Ross Ice Shelf, Grindley (1963). Massive diabase sheets of Jurassic Antarctica, 1957-1960. ICY Glaciological Report Number 6, American Geographical Society, New York, N.Y. 193 p. age are coexistent with the sediments. Harrington, II. J . 1965. Geology and Morphology of Ant- Beacon rocks have been named Mount Kenyon arctica. In: Biogeography and Ecology in Antarctica (ed. P. van Oyc and Formation for thick exposures in Mount Kenyon J . van Mieghem), Monographiae Bio- (85°13S. 171°25W.), 45 km to the northeast. The logicae, 15, W. Junk Publication The Hague, p. 1-71. McIntyre, D. J . and G. J . Wilson, 1966. Preliminary paly- Mount Kenyon Formation correlates with either, or liology of some antarctic Tertiary erratics. New Zealand both, of the Fremouw and Falla Formations of the Journal of Botany. 4(3) : 315-321. Beardmore area, as recently redefined by Barrett (un- Wilson, G. J . 1967a. Some new species of Lower Tertiary published National Science Foundation report). (lliiollagcllatcs fromMcMurdo Sound, Antarctica. New Zealand Journal of Botany, 5 (1): 57-83. Sedimentary rocks of the Roberts Massif were for- Wilson, G. .J . 19676. Microplankton from the Garden Cove merly identified as Triassic Dominion Formation Formation, Campbell Island. New Zealand Journal of (Grindley et al.,1964; Wade et al., Botany, 5(2): 223-240. 1965a, 1965b; and Wils in, C. J. 1968. On the occurrence of inicrospores, pollen McGregor, 1965), because Dicroidium was believed grains and nncroplankton in bottom seilimncnts of the Ross distinctive for the Dominion Formation, which was Sea, Antarctica. New Zealand Journal of Marine and described by Grindley et al. (1964) as overlying the Freshwater Research, 2(3) : 381-389. I:alla Formation, reported to he nonfossiliferous (Grindley, 1963). Barrett (unpublished National Sci- ence Foundation report) reinvestigated the Beard- Geology of the Roberts Massif, Queen more area in 1966-1967 and found the Dominion and Falla Formations to be one and the same, with both Maud Range, Transantarctic Mountains, carrying the Dicroidium flora. Antarctica Fossils collected at Roberts Massif during last seaon have not been identified. It is expected they KERBY E. La PRADE will include additional Triassic Dicroidium fossils. Department of Geology References Texas Technological College Barrett, P. J. Unpublished NSF report. Stratigraphy of the The Texas Technological College field party con- Postglacial Beacon Rocks in the Queen Alexandra-Queen Elizabeth Range area, Antarctica. The Ohio State Uni- sisting of Charles King, William Schaefer, Fernando versity Research Foundation Report, 67 pages.

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