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Victoria University Antarctic Research Expedition Science and Logistics Reports 1969-70: VUWAE 14

PROPOSED SCIENTIFIC PROGRAMME

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PROPOSED SCIENTIFIC PROGRAMME

For the 1969-70 expedition, Neall proposed an investigation of a Recent marine deposit at Cape Barne, Ross Island. Previously, Professor A.T. Wilson (formerly of Chemistry Department, V.U.W.) and Dr. C.H. Hendy (Institute of Nuclear Sciences, D. S.I. R.) discovered the deposit during geochemical research in the 1967-68 summer field season. They found a number of well-preserved shell layers exposed beside the frozen lakes behind Cape Barne, at 30 m altitude above sea level. On identifying the molluscan and bryozoan fragments it became apparent that living shells similar to the discovered fossils have only been trawled from waters deeper than 63 metres. This clearly reflected the mode of formation of the deposit was not that of a near shore littoral environment as was previously thought. Furthermore, in Antarctica ice movement erodes most hard shelled living organisms from the shore-line environment. A deeper mode of formation was suggested for the deposit, similar to areas now found on the sea bottom of McMurdo Sound. The uplift of the deposit to this height was attributed to isostatic uplift. Radioactive carbon 14 dating of the shells revealed an age between 32,000 and 37,000 years old (Hendy, Neall and Wilson, 1969).

Because Hendy and Wilson collected only the largest shells visible for chemical analysis, a proposal was made by Neall to investigate the shell layer stratigraphy and the fossil content of these beds in detail. A full investigation of such deposits around the shores of McMurdo Sound might assist in establishing that a number of fossiliferous so-called 'raised beaches' may in fact be raised marine sediments. The proposal was approved in March 1969, and Neall and Kyle travelled to Cape Barne in collaboration with the Waikato University Expedition, who were studying the geochemistry of Deep Lake at Cape Barne.

After this, Neall and Kyle proposed to investigate the geology of Cape Crozier, at the easternmost tip of Ross Island (an area only previously visited briefly by two geologists, Dr. L. Harrington and Dr. S. Treves (see Treves 1967)). In an unpublished account, Dr. Harrington recognised a sequence of moraines, volcanic craters and eruptive rock types at Crozier, which he considered warranted 'a summer's field work'. As the area was readily accessible to a Victoria University geological party, it was proposed to investigate the geology of the coastal section at the Cape, in particular searching for marine deposits and also collecting rock samples for petrological and geochemical work.

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A report of shell layers from Cape Bird, together with a request by the Waikato Expedition to visit this locality, prompted the combined party to include a call there. The group was then scheduled to return to Scott Base by December 5th.

Neall and Kyle then parted with the Waikato Expedition members and planned to join Vucetich and Topping at the Labyrinth, in the Upper Wright Valley. The Labyrinth is an unusual area of very steep gullies with flat treads between, which form a box-canyon type topography. The mode of origin of the area is a controversial issue;

Cotton (1966) considers it to have formed under the influence of glacial action, whilst Smith (1965) thought it was formed by a catastrophic flood.

Whilst Neall and Kyle were visiting Ross Island, Vucetich and Topping planned to investigate large areas of the Wright Valley to try to elucidate the history of the most famous of the Dry Valleys. Quaternary geology focuses attention on glaciations and on superficial deposits which are glacial in origin, or which are linked with periglacial environments. These deposits commonly include soils or paleosols (fossil soils), and are consequently studied by pedologists. In the Dry Valleys, glacial deposits are poorly exposed, so glacial geologists and pedologists study the same deposits, unfortunately using a different terminology. They rarely study together and much confusion exists over terms used in expressing erosional and depositional processes. There is even much conjecture between various workers as to the validity of Antarctic glaciations and their correlatives elsewhere in the world. Vucetich and Topping had as their main objectives:
(a)Mapping of glacial and associated deposits, together with a study of their soil character and their weathering in the Wright Valley. VUWAE 10 (1965-66) initiated this study near Lake Vanda and reported dry frozen tills which are easy to expose by digging. (Most soils in Antarctica are rather shallow because a few inches beneath the surface is a permafrost layer of hard ice, which is as hard as concrete). The aim of this study was to try and link the sequence of glacial deposits, the past lake levels of Lake Vanda, some radio-metrically dated basalts and some fossil pecten shells near Bull Pass. This work involves much levelling for height control and the investigators proposed to use Lake Vanda Station as their camp site.page 3
(b)A limited study of the Labyrinth together with Neall and Kyle.
(c)To describe and sample critical sections in the Lower Taylor Valley where VUWAE's 12 and 13 had nominated stratigraphic columns of glacial and fluvioglacial sediments. Correlation of selected members with Cape Bernacchi marine benches was also to be attempted.

From the Labyrinth, the 4 man party was scheduled to camp in the Lower Taylor Valley, to describe in detail one of the best sections of Pleistocene sediments in Antarctica yet discovered. Due to an unusual succession of events, a stream draining the Commonwealth Glacier has eroded into the sediments as it drains to the sea, exposing a number of cliffs, which we intended to describe.

The party was then scheduled to return to Scott Base on 29th December, with Vucetich and Topping returning to New Zealand on the next available flight. Neall and Kyle then planned to travel over sea and shelf ice to White Island, camping in a wannagan (a hut on skis). There, fossil deposits, glacial cut benches and volcanic rock samples were to be studied and Neall and Kyle expected to return to New Zealand on 16th January, 1970.