Land Based Drilling 19731974

While DSDP was planning its first Antarctic and Southern Ocean cruises, the US Office of Polar Programs was also decided to address the ~ 180 million years gap in Antarctic geological history, as well as develop a more collaborative approach to major Antarctic science problems. This decision resulted in the launch of the Dry Valley Drilling Project (DVDP), an initiative sponsored by the United States, Japan and New Zealand to explore the late Cenozoic history of the McMurdo Dry Valleys (McGinnis, 1981; Smith, 1981), using a standard ''slim-hole'' diamond drilling system widely used in mineral exploration. The rig selected was a ''Longyear 44'', designed to take continuous core of 85, 64 or 48 mm diameter to depths of around 500m. In the first two field seasons (1973-1974 and 1974-1975), the project drilled 3 test holes at McMurdo Station, 1 over 300 m deep, and 11 holes in the McMurdo Dry Valleys (Fig. 3.3; Torii, 1981). The most successful of these recovered 320 m of interbedded glacial and interglacial fiordal sediments of late Miocene to recent age in the lower Taylor Dry Valley (Powell, 1981; Webb and Wrenn, 1982), indicating several advances and retreats of the ice in that time. Wrenn and Webb (1982) used microfossils in the deposits to provide approximate ages on several geomorphic surfaces in the lower Dry Valleys.

0 0

Post a comment