Outer-fan Sheet Sandstones at Klip Fontein Farm, Tanqua Karoo, South Africa
Arnold H Bouma, Anne M Delery, Erik D. Scott, 2008. "Outer-fan Sheet Sandstones at Klip Fontein Farm, Tanqua Karoo, South Africa", Atlas of Deep-Water Outcrops, Tor H. Nilsen, Roger D. Shew, Gary S. Steffens, Joseph R. J. Studlick
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Excellent exposures of Fans 3 and 4 in an L-shaped outcrop are present at the Klip Fontein Farm. Some parts of Fan 5 can also be seen. The east-west arm is 1800 m (5900 ft) long and the north-south arm is 1000 m (3280 ft) long. Fan 3 is fed from the south, making the east-west arm a strike section. Fan 4 is fed from the west and shows a dip section on the east-west outcrop. Fan 5 is fed from the south. The outcrops are a classic example of a high net-to-gross, fine-grained, amalgamated sheet package deposited in the outer fan. The strike and dip sections show very similar features. Fan 3 is about 13.5 m (44 ft) thick, and Fan 4 is 54–60 m (177–197 ft) thick. The shale separating the two fans has a thickness of about 16 m (54 ft). Both fans represent outer-fan sheet sands (depositional lobes). This paper will concentrate only on Fan 4. At first view, the sandstone layers appear to be parallel. However, detailed drafting of shale contacts shows rather flat bottoms and the convex upper contacts show a gradual lateral thinning of the sandstones. Fan 4 shows laterally continuous sandstone and shale beds and occasional amalgamation in the center of succeeding sandstone beds. The thin interbedded shales are comprised of alternations of very thin sandstones and shales. Plant fragments are common on the top of most silt-rich shale laminae. Thickening-upward sequences and some incomplete Bouma sequences can be detected. Paleocurrent directions vary widely due to bathymetric compensation.
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Tor H. Nilsen, a red-haired Scandinavian who stood more than six feet tall, died October 9, 2005, at his San Carlos, California, home. This was after a valiant five-year fight with melanoma cancer. He was 63. His ashes were scattered at his family plot in Norway in 2006.
He was born in New York City on November 29, 1941, to Mollie Abrahamson and Nils Marius Nilsen of Mandal, Norway, and was the first of their children to be born in the United States. After graduating from Brooklyn Tech, he earned his B.S. in geology from City College of New York in 1962. While there, his prowess on the basketball court impressed a scout from the New York Knicks, but Tor went on to graduate school and earned his M.S. and Ph.D. degrees in geology from the University of Wisconsin at Madison in 1964 and 1967, respectively. His M.S. thesis was a study of Precambrian metasedimentary deposits in the Lake Superior area, and his Ph.D. thesis was a study of Devonian alluvial-fan deposits of the Old Red Sandstone in western Norway.
Dr. Nilsen’s principal expertise was in depositional systems analysis, stratigraphic analysis, and the relationships among tectonics, eustasy, and sedimentation. He began his industry career in 1967 as a research geologist with the Shell Development Company in Houston, Texas, and Ventura, California, where he worked on the tectonics and sedimentation of Tertiary shelf systems of coastal California. He subsequently spent two years with the U.S. Army Corps of Engineers as the Military