Geophysical Studies in Barents and Kara Seas: ABSTRACT

Abstract

A reconnaissance geophysical survey of the Barents and Kara Seas, conducted from icebreakers in 1965 and 1966, consisted of about 10,000 line km of bathymetric-magnetic data, 57 gravity measurements, and 2 short end-to-end seismic refraction profiles. Magnetic data do not support a continuation of Caledonian or Precambrian basement structures under the Barents Sea at shallow depth. A broad 400 ^ggr anomaly due to a source about 20 km below sea level strikes NNW between Norway and Bear Island. Magnetized basement approaches the sea floor only near Bear Island and 74.5°N, 33°E. Free-air anomalies in the north-central Barents Sea are within 20 mgals of zero. Kara Sea magnetic anomalies parallel, but do not connect, tectonic structures of Taimyr and Novaya Zemlya. M gnetic basement is deep in the southwestern Kara Sea, but shoals northeast of a line connecting northern Novaya Zemlya with the Yenisey estuary. Anomalies with amplitudes greater than 500 ^ggr occur End_Page 2511------------------------------ only within 100 km of the Precambrian Izvestiy Tsik Islands. The East Novaya Zemlya trench is slightly under compensated, having a median free-air gravity of -9 mgals and extremes of -33 and +11. Two refraction measurements in the eastern Barents Sea yielded 400 m unconsolidated sediments over a 3.1 km/sec basement and 700-1,100 m of 2.8 km/sec sediment over a 4.1 km/sec basement. The basement is probably Paleozoic sandstone or shale. End_of_Article - Last_Page 2512------------