Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 16 September 1966:
Vol. 153. no. 3742, pp. 1373 - 1376
DOI: 10.1126/science.153.3742.1373
Prev | Table of Contents | Next

Articles

Airborne Geophysical Study in the Pensacola Mountains of Antarctica

John C. Behrendt 1, Laurent Meister 1, and John R. Henderson 1

1 U.S. Geological Survey, Menlo Park, California, and Denver

A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to —80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explainl the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 gamma associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anominaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Aeromagnetic and Radio Echo Ice-Sounding Measurements Show Much Greater Area of the Dufek Intrusion, Antarctica.
J. C. Behrendt, J. C. BEHRENDT, D. J. DREWRY, E. JANKOWSKI, and M. S. GRIM (1980)
Science 209, 1014-1017
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)