Kristin McDougall, Geology, Minerals, Energy, and Geophysics Science Center, U.S. Geological Survey, 2255 N. Gemini Drive, Flagstaff, Arizona 86001, USA; and Adriana Yanet Miranda Martnez, Posgrado en Ciencias de la Tierra, Instituto de Geologa, Universidad Nacional Autnoma de Mxico, Mxico D.F. C.P. 04510, Mxico. Published online 29 Aug. 2014; http://dx.doi.org/GES00971.1. Themed issue: CRevolution 2: Origin and Evolution of the Colorado River System II.
From the abstract: Foraminiferal assemblages in the stratigraphically lower part of the Bouse Formation in the Blythe basin (lower Colorado River corridor, western USA) indicate marine conditions, whereas assemblages in the upper part of the Bouse Formation indicate lacustrine conditions and suggest the presence of a saline lake. Benthic foraminiferal assemblages in the lower part of the Bouse Formation are similar to lagoonal and inner neritic biofacies of the modern Gulf of California. Evidence suggesting a change from marine to lacustrine conditions includes the highest occurrence of planktic foraminifers at an elevation of 123 m above sea level (asl), the change from low diversity to monospecific foraminiferal assemblages composed only of Ammonia beccarii (between 110 and 126 m asl), and an increase in abundance of A. beccarii specimens (above ~110 m asl).
Application of LiDAR to resolving tectonic and glacial fabrics in glaciated terrain: An example from an Archean granite-greenstone belt, northeastern Minnesota
Jonathan Dyess and Vicki L. Hansen, Dept. of Geological Sciences, University of Minnesota Duluth, 1114 Kirby Drive, 229 Heller Hall, Duluth, Minnesota 55812, USA. Published online 29 Aug. 2014; http://dx.doi.org/GES00984.1.
This contribution illustrates the application of Light Detection and
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Geological Society of America