VUW

The study involved collaboration with Dr. Stephen Hicock, an associate professor at the University of Western Ontario in Canada. A concurrent study was done by Mark Lloyd-Davies, a Dutch student under the supervision of Dr. Jaap van der Meer based at the University of Amsterdam. Lloyd-Davies studied micro-scale subglacial deformational features of the Sirius Group at several sites including Allan Hills. Jeremy Mitchell conducted a study of ridge sets at Allan Hills for the purpose of determining their depositional agent(s).

The main focus of the work at Allan Hills was the investigation of Sirius Group deposits. The initial tasks in this continuing investigation were to conduct reconnaissance (recce) to familiarise ourselves with the area and then continue the mapping of Sirius distribution begun the previous season. During this time major outcrops were selected for later detailed investigation. These recces proved to be very fruitful as much was learned about the glacial deposits and they provided an opportunity to examine the variety of diamicts found in the area. As additional event members arrived, detailed studies of outcrops began and continued until the end of the season. Data collected from the outcrop and mapping work include the following: orientational measurements of 300 clasts and 90 deformational features in the Sirius Group at both measured outcrops and stop locations, recorded orientations on 270 abraded (striated) and faceted clasts throughout the study area, collected 37 rock samples for lab analysis.

Recent glacial deposits near the edge of the Manhaul Glacier discovered by Barrett and Atkins during the 1997-1998 field season were studied in more detail this season. This page break study was the focus of Atkins, while Barrett, Hicock and Holme contributed expertise as well. The study of these deposits was a major focus for van der Meer and Lloyd-Davies as they outline below. Glacial abrasions on bedrock and stone surfaces were documented and their orientations measured. These deposits occur as sparse patches of crushed and comminuted the underlying Beacon Supergroup. This work included delimiting the southern extent of the deposits in central Allan Hills using differentially corrected GPS. A benefit of mapping the distribution of these deposits was establishing their stratigraphic relationship to the Sirius Group.

Most fieldwork was conducted using standard geological field tools (eg. geological hammers, compasses, cameras) with the exception of a Trimble GPS rover unit to which we had access for three days. The GPS rover unit operated adequately in the cold conditions with shortened battery life being the only significant impact of the cold environment on the system.