Sheet Sandstones at Kleine Gemsbok Fontein Farm, Tanqua Karoo, South Africa
Arnold H Bouma, Anne M Delery, Erik D. Scott, 2008. "Sheet Sandstones at Kleine Gemsbok 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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Although the cleanly visible portion of the outcrop at Kleine Gemsbok Fontein Farm is quite small (36 m [118 ft] long) and lacks third dimensionality, it is a good example of the transition from thicker amalgamated sheet sandstones to thinner sandstones in a very short distance. In addition, details of amalgamation are well preserved in this high net-to-gross, fine-grained outer-fan setting. The Fan 2 outcrop, interpreted as outer-fan sheet sandstones, is an example of local connectivity in an overall nonamalgamated outer-fan layer sheet sand deposit (Rozman, 1998, 2000; Bouma and Rozman, 2000). This small outcrop, orientated northeast-southwest, shows massive, amalgamated sandstones that change laterally to bedded silty shales and thin sandstones. Some of the layers show vertical connections where the shale is locally eroded and filled with sandstone (Figure 1, arrows point to the locations). This outcrop is oriented at 45° with respect to the paleocurrent direction. No third dimension is available to determine whether these sand-on-sand contacts are localized or extensive, or in which direction they are oriented. If they are extensive, they may represent filled gullies (furrows).
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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