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BEACON STUDIES (K6A) - B. Walker.

Geological studies of the Triassic part of the Beacon Supergroup were conducted by postgraduate students from Victoria university. The party consisted of Barry Walker, event leader, PhD student, geology, Isobel Gabites, MSc student, Palaeobotany, and Mike Hosted, DSIR field assistant.

Sixty-four days were spent camped on four mountains situated on the edge of the polar plateau, of these twenty-eight days were at Mt Bastion, seventeen at Portal Mt, eleven at Shapeless Mt and eight at Allan Hills. Adverse weather conditions at Portal Mountain and shapeless Mountain this year delayed helicopter movements by up to nine days. Overall 21 days (32% of the time in the field) were 24 hour "tent days". 38 days (59%) were work days and of this number several were only 1 to 3 hours long due to poor weather. The remaining 5 days (8%) were spent waiting for helicopters.

A scheduled move on December 7 from Portal Mountain to Shapeless Mountain was postponed due to VIP and DV helicopter commitments. During the following 9 days, the party was confined to the tent as we experienced gale force and stronger winds, blowing snow, white out conditions and −20°C temperatures. It was during this time that the party suffered mild carbon monoxide poisoning from the primus stoves. Our freedom of movement was considerably hindered during the next few days. During the last 3 days at Portal Mountain communication with Scott Base was confined to Yes/No morse key operation after our last battery became flat after only 5 days operation.

December 16 to December 27 was spent at Shapeless Mountain. During the last 6 days, heavy snow falls from the north completely covered all rock exposure and this still appeared to be the situation when flying past on January 5. A rapidly fluctuating low cloud cover frequently reduced visibility to under 1 kilometre. At the same time the dry valley regions and other mountains of similar altitude were experiencing relatively fine conditions. Following later talks with helicopter pilots it became apparent that Shapeless Mountain is at times prone to accumulating a local cloud cover capable of preventing helicopter entry.

At Mount Bastion and Allan Hills work days greatly outnumbered tent days and considerable scientific work was achieved. As temperatures warm later in the season Mount Bastion is commonly covered in thick snow and the relatively sheltered nature of the mountain hinders a quick clearance. Weather conditions at Allan Hills appeared to be consistently better than the dry valley region.

Radio batteries remained good for an average of only 10 days with one lasting 5 days. Radio signal strength from Scott Base was good. However, our signal was poor and no direct communication with Scott Base was possible once leaving Mount Bastion (November 29). Signal strength both to and from Vanda Station was nearly always good.

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The North Face Dome Tent proved to be excellent and its lightness enabled an important extra camp to be put in by foot at Allan Hills.

No difficulty in movement in the field was encountered at any of the areas visited.

Overall, despite the season at times being difficult, all objectives were achieved.