Other formats

    Adobe Portable Document Format file (facsimile images)   TEI XML file   ePub eBook file  


    mail icontwitter iconBlogspot iconrss icon

Victoria University Antarctic Research Expedition Science and Logistics Reports 1994-95: VUWAE 39

Field Work

Field Work

Camp 1: Table Mountain, 77°58′S, 160°E, 18-23 November

This was the first site for sampling the Sirius tillites. We established camp within metres of the upper end of the deposit. This was not a planned palaeomagnetic sampling site so all three of us worked on the Sirius programme. We surveyed the page 5 deposits and found them to be draped for about 2 km along the edge of the slope facing the Ferrar Gl.; more extensive than previously reported. Exposures were good at the upper end but were sparse in the middle and became more continuous towards the lower end. It was misty for most of the time so we flagged a route along the ridge. There were frequent snow showers so we had to clear the rocks before commencing to take samples. Considerable effort was needed, at times even to loosen a few cm depth of deposit. Fifteen samples were taken in the top section and seven in the bottom section. The in situ fabric (ie the orientation and size distribution of the pebbles) was measured to find the mean flow direction of the glacier which deposited the moraine. For all but one day, when the survey was carried out, conditions were misty and it frequently snowed. Temperatures were between −22° and −27° so despite the effort of hammering, working conditions were a little cool and slowed progress. Nevertheless our objectives were achieved.

Camp 2: Mt Feather, 77°56′S, 160°28′E, 23-30 Nov.

Our camp was at 2500 m altitude on a bench covered with Sirius tillite. We were flown in on the second attempt, one day later than scheduled. Rachel Brown joined our Event, to gain first hand experience of field work and to assist Nerida with sampling since we also hoped to collect palaeomagnetic samples. On the first day we had gale force winds and were confined to camp. The second was clear and we reconnoitred to determine the extent of the Sirius formation and to look for a section suitable for palacomagnetic sampling. The .Sirius was extensive but we wore unable to reach the Aztec red beds, which were overlain by a thick dolerite sill. In any case this would have made them unsuitable for sampling. However, we found an accessible exposure of Permian Weller coal measures and decided to sample them. The following three days were spent by Nerida and Rachel surveying and collecting 15 samples from three sites of the Sirius deposits. Adam and Chris surveyed the Weller coal section, finding a series of thin beds suitable for sampling. Again, by flagging a route along the valley edge both parties were able to work in poor visibility without danger of getting lost. Fifty cores were obtained - some from positions under overhangs, making drilling difficult. Weather conditions were again indifferent. By 1000 a mist would come up from the Beacon Valley to the north and stay all day. Temperatures were around −25°. Working conditions were similar to those at Table Mt except it was generally a little colder. We exceeded our objectives.

Camp 3: Mt Crean, 77°55′S, 159°32 E, 30 Nov - 6 Dec.

We camped at 2200 m on an ice covered section of the ridge leading to the south facing Aztec red beds. We arrived a day behind schedule, again due to poor weather conditions. There was no Sirius programme although a sample of glacial regolith and a sample from melted snow were collected to check for airborne diatoms. Rachel left our party and Nerida helped with the coring. Our section was located 30 mins from the campsite. During the next five days we experienced whiteout conditions, strong winds, snow and temperatures down to −27° with a storm on Dec 2 which confined us to our tents. However, we obtained 150 cores from sites we had previously identified as the most promising. This more than fulfilled our objective.

page 6

Camp 4: Lashly Mts, 6-8 Dec.

This site was on The Portal at the south end of the Lashly massif. Our objective had been to land at the foot of the SE ridge of Portal Mt but due to lack of fuel and some confusion about its location we were dropped here. No suitable section was accessible from this site and after some delay from helicopter mechanical problems, we returned to Scott Base on Thurs. 8 Dec.