Facies Architecture of a Submarine-slope Channel Complex, Condor West Channel, Cerro Toro Formation, chile
Mark D. Barton, Gary S. Steffens, Ciarán J. O’Byrne, 2008. "Facies Architecture of a Submarine-slope Channel Complex, Condor West Channel, Cerro Toro Formation, chile", Atlas of Deep-Water Outcrops, Tor H. Nilsen, Roger D. Shew, Gary S. Steffens, Joseph R. J. Studlick
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Deep-water-slope channel complexes of the Cerro Toro Formation are exposed in the Parque Nacional Torres del Paine, southern chile (Figure 1A). A one-kilometer (3300-ft)-wide photomosaic, oriented oblique to paleoflow, provides the basis for a detailed cross-section that documents the facies architecture within a portion of one of these channel complexes. The channel complex, informally referred to as the Condor channel, is exposed along a northeast–southwest-trending ridge located about 4 km (2.5 mi.) to the south of Lago Sarmiento (Figure 1B). The Condor channel is a set of three distinct channel complexes that aggrade and stack to the west (Figure 2A). Each channel complex is 60–80 m (200–260 ft) thick and 1–2 km (3250–6500 ft) wide. A photo panel from the northeast side of channel complex 2 outlines the area of detailed mapping (Figure 2B). The northeast half of the outcrop is nearly perpendicular to the principle flow direction (165°), whereas the southwest half of the exposure (210°) is at a 45-degree angle to the principle paleoflow direction.
Four facies were identified on the basis of grain size and bedding character. They include in order of abundance: amalgamated conglomerate beds (50%), a pebbly-mudstone facies (25%), a facies composed of thinly bedded, interbedded sandstone and mudstone (15%), and amalgamated sandstone beds (10%). The stratal architecture is described in terms of a hierarchy of surface-bounded architectural elements that include channel stories and story sets (Figure 2C). A channel story consists of a relatively conformable
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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