Hi all, Below is an announcement about a topical session to be held at the annual Geological Society of America meeting in Reno, Nevada this fall. I encourage anyone who has found geophysical evidence of subsurface structures or tectonic trends related to mineral trends to submit an abstract. Our session would benefit from your experience and ideas! Please submit the abstract through GSA (http://www.geosociety.org), but feel free to contact me if you have any questions or suggestions. V.J.S. "Tien" Grauch [EMAIL PROTECTED] -------------------------- GSA topical session, Geological Society of America Annual Meeting, Reno, NV, November 13-15, 2000 sponsored by Society of Economic Geologists Conveners: V.J.S. Grauch (USGS), Elizabeth Jones Crafford (GeoLogic Services) Short description: DEEP CRUSTAL CONTROLS ON MINERAL TRENDS - EVIDENCE FROM THE SUBSURFACE This session is a multidisciplinary effort to understand the nature and origin of deep crustal controls on the spatial distribution of mineral deposits. We will examine evidence of tectonic or crustal features related to mineral trends from a variety of methods and perspectives, such as geophysics, geochemistry of deep fluids, radiogenic isotopes, and tectonics. Rationale: DEEP CRUSTAL CONTROLS ON MINERAL TRENDS - EVIDENCE FROM THE SUBSURFACE Mineral trends and other lineaments have often been the center of controversy, mostly because there was little independent evidence of their origin. However, several recent studies of the subsurface have provided independent evidence of buried tectonic features that are spatially related to mineral trends. The subsurface evidence comes from a variety of methods: several types of deep-looking geophysical techniques; geochemical and stable isotopic techniques that can trace the source of fluids; radiogenic isotopic techniques that examine the imprint of deep crustal lithologies on magma that flowed through them; and modern structural techniques and paradigms that guide understanding of the tectonism through time and space. Integration of the evidence from the different methods constrains our understanding of the history and role of tectonics and the crust on the spatial distribution of mineral deposits. As we head into the next millenium, we should not be satisfied with just finding alignments of mineral deposits, we should be asking how we can gain evidence from the subsurface to substantiate the apparent alignments and to understand their origin. _______________________________________________________ List archive: http://www.mail-archive.com/[email protected]
