A. TRANSPORT

Our event was very dependent on Helo support. We had 7 moves and especially during the latter part of our field time some set backs were caused to our programme through delays in scheduled helicopter movements.

Our first put-in, to Portal Mt. was close to maximum helicopter range with a full pay load. Nevertheless it was accomplished with little difficulty apart from a slight navigation problem due to our being off the helicopter grid maps. Although no subsequent difficulty with navigation was encountered, we prepared maps with the entire route on one sheet, which we could hand to the helicopter pilot. Our two moves at long range were carried out with two helicopters; Portal Mt. - Alligator peak and Alligator peak - Mt. Kempe. We had suspected they might do this and had budgeted Helo hours accordingly.

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From Table Mountain onwards, (5th December onward) weather had deteriorated, so that we had cloudier conditions. A fairly stable pattern did develop, so that it was generally clear in the morning, clouding over about midday. Accordingly, we requested our helo moves for the early morning, but Helo Ops did not appear to take these factors into account since all our moves and attempts at moves were made either in the evening shift or late in the day. Both Hugh Webb (DOIC) and Roger Clark (OIC) were aware of this situation and we are grateful for their efforts on our behalf. This is particularly the case for two incidents - The first was on our move Knobhead - Mt. Crean, when we were picked up together with K32 at 1900 on 15th December, but could not proceed beyond Depot Nunatak because of low cloud over Skelton Nevee. They really tried, but had to abandon the attempt and deposit us at L. Fryxell. A lift was arranged for us early the next morning so that we were at Mt. Crean in the morning and that day had completed over 1/3 of our sampling. This was fortunate as next day the weather deteriorated and we were only just able to get all samples before a blizzard confined us to tents for four days.

Our final move from Mt. Crean - Scott Base also showed some misunderstanding. The intention was to fly us out with one helo making a shuttle flight. It was almost midday when the first flight arrived. It had four crewmen and 7 seats, so under the rules operating could only lift out three passengers, leaving 5 for the following flight. In addition, the weather was rapidly deteriorating, with a cloud bank hovering 1km away on the plateau. Mainly by strenuous intercessions on our behalf by the OIC and DOIC, the helo was persuaded to drop us and a crewman Marble Pt., reorganise its seating and return immediately to collect the remainder of the party. The plan was successful and we all returned to Scott Base by about 1800.

B. MAIN AREAS COVERED

The specific objectives were to sample rocks from two sets of red beds, regarded as overbank and lake deposits in an alluvial plain. The youngest, the Aztec siltstone is Upper Devonian in age and we sampled at reported suitably exposed outcrops. These were all at the head of the Skelton Nevee, at Portal Mt., Alligator Peak and Mt. Crean. At Portal Mt. we camped on the Nevee at the foot of the Eastern side of the slope and about 100m below the rock exposures. The site was easy to land at and reasonably sheltered on drift snow.

The Alligator Peak site to the South was up a gully immediately at the foot of the rock exposure. It provided a confined landing site and a rather confined campsite on a patch of snow on the side of a slope. Our proximity to the rocks paid dividends as even with our limited time we were able to collect a full set of very friable rocks.

The second set of red lake bed deposits were in the Terra cotta siltstone of Lower Devonian age. The best outcrops are at Mt. Kempe, Table Mt. and Knobhead.

The Mt. Kempe site at an elevation of 2,600m was on the Kempe Glacier, overlooking the Koetlitz G1. It was a magnificent site with a view to Ross I. and beyond. We could regularly see Beaufort I, 230km distant. We were about 3/4 hr walk from the rock sections up the N.B. ridge of the mountain.

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The Table Mt. site was on a small snow patch in a valley looking out to the junction of the Ferrar and Taylor Glaciers. The rocks were a 20 rain walk up a hillside and were exposed mainly under two overhangs.

The Knobhead site was in a rocky valley between Knobhead and Mt. Handsley. These rock exposures were the best and most complete of the Terra Cotta. They showed evidence of extensive burrowing and were more purple than those at Table Mt. We sampled the complete section in two different places. Our camp was in the valley, about 200m below the section. There is a large flat platform on the E. ridge level with the top of the section. It has a commanding view of the Taylor and Ferrar Glaciers and of Mt. Lister in the Royal Society Range. It would make an ideal campsite.

The site at Mt. Crean was on the south shoulder of the mountain. It was almost level with the Polar Plateau to the W. but fell away sharply to the Skelton Nevee on the East. Geologically it was in the Weller Coal Measures of Permian age. We took over the site vacated by Event K14. The Aztec red beds were on the southern buttress of the ridge, about 3/4 hr walk, where we obtained samples throughout the 100m extent of the Aztec exposure. The sun got onto the face at about 1900 hrs but owing to restraints of time and weather most of the sampling was undertaken in the morning or cloudy conditions without the sun. We looked directly down to the Portal, one of the access routes from the Skelton Nevee to the Polar Plateau.

During my second visit to Antarctica this season with Event K9, whilst awaiting the departure of the Benjamin Bowring, I was able to obtain more samples from the following areas:

Wright Valley. Samples were obtained from about 12 lamprophyre dykes outcropping on the south side of Lake Vanda. They are intruded into the granite basement and are believed to be of Ordovician age.

Miers Valley. We landed on the north side of Miers Valley, on a tableland dotted with small tarns, which at that time of year were ice-free and circled by algae. We sampled the numerous dykes which criss-crossed the region and again are believed to be of Ordovician age. Our pick up helo came earlier than scheduled, but we still managed to collect good samples from 12 sites.

C. WEATHER

(See Appendix VI and Transport sections).

D. COMMUNICATIONS

All our sites were at relatively high altitude and we had very little difficulty with communications. The only time was during the blizzard at Mt. Crean, Saturday 20th and Sunday 21st December.

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E. LOSS/DAMAGE TO EQUIPMENT

The only trouble we had was with the antifreeze dispenser on our drilling equipment. Despite the care taken with draining the water from the system before entering the field, when we started operating at Portal Mt., the pipes and hand gun were frozen. We thawed the system out with the motor exhaust and primus and flushed through with pure antifreeze. The piston seals on one handpiece were damaged, but after replacement the equipment gave little further trouble.

The calf-length boots with green soles issued to Stephen were very slippery and the soles cracked, so that another pair had to be sent in. The stitching also failed on his used muklaks, requiring replacement.

Our glove combination proved more successful than on VUWAE 23. We used woollen finger gloves with an outer lightweight industrial mesh glove woven from a very tough synthetic thread. They stood up very well to handling the samples, and our hands although becoming a little damp from the antifreeze mixture kept reasonably warm by donning overmitts whenever possible.

We had the customary small amount of trouble with primus seals, but one has learned to be wary of this problem.

F. RECOMMENDATIONS

The VUWAE outer clothing and boots were well used. With the continuously cool conditions we experienced, the older generation clothing caused some inconvenience. The boot problem has been mentioned. Our overtrousers were very still and cumbersome and could not be put on over our boots. We had to anticipate weather conditions before venturing out and for our work, mobility, which was lost with the overtrousers, was a great asset. Our duvets were sufficiently warm but the toggles and zips were either broken or broke in use. Although adequately clothed we were not the most suitably dressed (in contrast to our DSIR field assistant). For high altitude field work, some effort should be made to equip the personnel with up-to-date and relatively new clothing.