Aeromagnetic traverses over some of the sedimentary basins in Alaska have been flown by the U. S. Geological Survey in order to obtain a better understanding of the regional geology and an estimate of the thickness of sedimentary rocks in these areas. The magnetic data are presented in the form of profiles.

The basin areas under investigation are Yukon Flats and the adjacent Kandik Segment, the Middle Tanana and the Susitna Lowlands north of Cook Inlet. In the Susitna area, the magnetic data delineate the contact between the rocks of the Talkeetna geanticline and the Alaska Range geosyncline on the northwest, and indicate that the north end of the Cook Inlet Tertiary basin is shallow. North-south profiles near the eastern edge of the Yukon Flats basin south of the Arctic Circle indicate the probable presence of near-surface volcanic rocks.

A long profile from Anchorage to Nome, across many of the major tectonic elements in Alaska, is also presented. Examination of this profile yields the following: (1) the west and east edges of the Talkeetna geanticline may be delineated; (2) the Alaska Range geosyncline, the Tanana geanticline, and most of the Kuskokwim geosyncline are magnetically featureless, indicating that the sedimentary section is thick or that the basement rocks are nonmagnetic; (3) there is no great thickness of sedimentary rocks under Norton Sound.

End_of_Article - Last_Page 260------------