the meter scale or a boulder pavement, overlain by structurelessdiamictite (interpreted as lodgment till) is indicative of glacialadvance. Glacial retreat is typically recorded by: (1) struc-tureless diamictite (lodgment till) overlain by diamictite withdiscontinuous stringers of sandstone and conglomerate (melt-out till) and then by diamictite interbedded with sandstone andconglomerate (redeposited till and glaciofluvial deposits; figure2) or (2) structureless diamictite (lodgment till) overlain by peb-bly, cross-bedded sandstone (glaciofluvial outwash) and thenby siltstone (indicating glaciolacustrine conditions). Silty di-amictite, overlain by clast-free siltstone probably reflects glacialretreat under lacustrine conditions. Variations of these typicalsequences exist in the Pagoda. In places, advance-retreat eventsare not clear; elsewhere, combinations of sequences record ad-vance followed by retreat, retreat followed by readvance, oradvance followed by a pause and readvance. As many as fouradvance-retreat cycles exist in some Pagoda sections. Furtheranalysis of these sequences should assist in correlation betweenPagoda sections and in reconstructing the paleogeography ofthe Beardmore Glacier area. In addition, extensive analyticalwork will be performed on the samples, including petrography,X-radiography, palynology, selected geochemistry, and analy-sis of organic content.

This project formed part of a nine-person Vanderbilt andOhio State University research team. We thank other membersof our field party for their help and the helicopter pilots andcrews of VXE-6 for logistic support.

The research was supported by National Science Foundationgrant DPP 84-18445.

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References

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Figure 2. Interbedded arenaceous diamictite, showing internal strat-ification, and sandstone. Sandstone beds labelled "55." (Hammer is45 centimeters long.)

Advance and retreat sequences are 5 to 50 meters thick. Asharp contact, marked by a striated surface, erosional relief on

Eyles, N., C.H. Eyles, and A.D. Miall. 1983. Lithofacies types andvertical profile models; an alternative approach to the description andenvironmental interpretation of glacial diamict and diamictite se-quences. Sedimentology, 30, 393-410.

Lindsay, J.F. 1968. Stratigraphy and sedimentation of the lower Beacon rocks ofthe Queen Alexandra, Queen Elizabeth, and Holland Ranges, Antarctica,with emphasis on Paleozoic glaciation. (Doctoral dissertation, Ohio StateUniversity.)

Lindsay, J.F. 1970. Depositional environment of Paleozoic glacial rocksin the central Transantarctic Mountains. Geological Society of AmericaBulletin, 81, 1149-1172.

Stratigraphic correlation of FerrarDolerite sills,

Queen Alexandra Range

C. FAURE, T.M. MENSING

and B.K. LORD

Department of Geology and Mineralogyand

Institute of Polar StudiesOhio State University

Columbus, Ohio 43210

During the 1985-1986 austral summer eight sills of the FerrarDolerite in the Beacon Supergroup were sampled at 3-meterintervals from the bottom to the top. The locations of thesesections are indicated in the figure. A total of 236 documenteddolerite samples was collected for a study of the origin of thesesills and their relationship to the flows of the Kirkpatrick Basalton Storm Peak and Mount Falla (Faure et al. 1974; Hoefs, Faure,and Elliot 1980; Faure, Pace, and Elliot 1982).

In a previous study, two sills at Roadend Nunatak (79°48'S158°01'E) at the confluence of the Darwin and TouchdownGlaciers in the Brown Hills yielded identical rubidium-stron-tium whole-rock isochron dates of 182 ± 29 and 187 ± 40 millionyears. However, their initial strontium isotope compositionsdiffered significantly (strontium-87/strontium-86 equals0.71167 ± 0.00031 and 0.71047 ± 0.00028, Faure et al. in press).

46 ANTARCTIC JOURNAL

160°E

Storm Peak

Mt. Achernar

mt.840S

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1. Mt. Stonehouse, Falla Fm.2. Prebble Glacier, Fremouw Fm.3. Mt. Achernar, Buckley Fm.4. Portal Peak, Mckellar Fm.5. Tilliie Glacier, Mckellar Fm.

9 Kirkpatrick Basalt

El Beacon Sandstones and Farrar Doler,te

Granite Harbour Intrusive

Beardmore Group

kilometersIII

0 10 20 30 40 50

Geologic sketch map of the Queen Alexandra Range showing the locations of the sections of the Ferrar Dolerite sills measured in the field.("Fm" denotes "Formation.")

Therefore, these results suggest that the two sills in the BrownHills can be identified by the initial isotope composition ofstrontium.

The sills in the Queen Alexandra Range occur within theMcKellar Formation (one sill), the Buckley Formation (threesills), the Fremouw Formation (three sills), and in the FallaFormation (one sill). The top sill in the Fremouw Formation, atthe base of Mount Falla along the Prebble Glacier, locally cutsup-section and forms a fourth sill. The sill within the FallaFormation on Mount Stonehouse contains amygdules of paleblue agate, indicating that it was intruded at shallow depthbelow the surface of the Earth.

The relationship between the three sills within the BuckleyFormation on Mount Achernar and the sills in the FremouwFormation exposed along the Prebble Glacier is not clear. Thesills on Mount Achernar may be identical to those along thePrebble Glacier which would imply that the sills cut across theBeacon strata on a regional scale. Cross-cutting relationships ona local scale were observed both at Mount Achernar and alongthe Prebble Glacier.

Petrographic, geochemical and isotopic studies of the rocksamples by Joseph G. Cunningham at Ohio State Universityand by Janet Hergt at the Australian National University may

ultimately provide a basis for such stratigraphic correlationsbased on the initial strontium isotope compositions.

This study is supported by National Science Foundationgrant DPP 84-17275.

References

Faure, C., J.R. Bowman, D.H. Elliot, and L.M. Jones. 1974. Strontiumisotope composition and petrogenesis of the Kirkpatrick Basalt,Queen Alexandra Range, Antarctica. Contributions to Mineralogy andPetrology, 48, 153-169.

Faure, C., K.K. Pace, and D.H. Elliot. 1982. Systematic variations of"Sr/"Sr ratios and major element concentrations in the KirkpatrickBasalt of Mt. Falla, Queen Alexandra Range, Transantarctic Moun-tains. In C. Craddock (Ed.), Antarctic Earth sciences. Madison: Univer-sity of Wisconsin Press.

Faure, C., T.M. Mensing, E.M. Kibler, L.M. Jones, and J . Hoefs. Inpress. Petrogenesis of Ferrar Dolerite sills, Roadend Nunatak, Dar-win Glacier, Transantarctic Mountains. New Zealand Journal of Geologyand Geophysics.

Hoefs, J., G. Faure, and D.H. Elliot. 1980. Correlation of h 18" and initial`Sr/"Sr ratios in Kirkpatrick Basalt on Mt. Falla, Transantarctic Moun-tains. Contributions to Mineralogy and Petrology, 75, 199-203.

1986 REVIEW 47