Coarse-grained Bar Forms in the Condor Channel Complex, Cerro Toro Formation at Lago Sarmiento, Chile
Ciarán J. O’Byrne, Brad E. Prather, Carlos Pirmez, Mark D. Barton, Gary S. Steffens, 2008. "Coarse-grained Bar Forms in the Condor Channel Complex, Cerro Toro Formation at Lago Sarmiento, Chile", Atlas of Deep-Water Outcrops, Tor H. Nilsen, Roger D. Shew, Gary S. Steffens, Joseph R. J. Studlick
Download citation file:
The Condor channel complex, part of the Campanian Cerro Toro Formation (see overview by Fildani et al., chapter 32, this volume) forms part of an extensive outcrop belt exposed in the Pare Nacional Torres Del Paine in southern chile. The data presented here illustrate large, coarse-grained, barform elements that are interpreted as deposits within a deep-water channel complex. The photomosaics in Figures 1 and 2 are from the easternmost extent of a continuous but variably dip- and strike-oriented exposure, which is more than a kilometer (0.6 mi) long. It can be traced into the younger section of the Condor channel complex described in detail by Barton et al. (chapter 39, this volume).
The lowest exposed part of the cliff section in this eastern panel (Figure 2) contains slumps and thin-bedded channel fills in a low net-to-gross background with lags, collapsed margins, and heterolithic channel fills. These are interpreted as the product of through-going, large-volume, high-density flows interstratified with deposits of sporadic, low-density flows. The upper two-thirds of the cliff face comprises three distinct sand-rich intervals here termed channel story sets (CSS; see paper by O’Byrne et al., chapter 30, this volume, for further definition). The lower two have similar erosional channel features at their base that are filled with thin-bedded tail, lag, and slump deposits (Figure 2). This implies that each channel story set initially had an efficient erosion-and bypass-dominated phase prior to accumulation of dune and interdune/suspension deposits (Figure 3),
Figures & Tables
Atlas of Deep-Water Outcrops
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