Project Grant 2628202

COLLABORATIVE RESEARCH: RESOLVING CONFLICTING THERMOBAROMETRY AND STRATIGRAPHY IN THE TETHYAN HIMALAYA -METAMORPHIC ROCKS EXPOSED IN MOUNTAINS RECORD THE PROCESSES THAT BUILT THOSE MOUNTAINS. THE PRESSURES RECORDED BY THOSE ROCKS ARE OFTEN ASSUMED TO REFLECT HOW DEEP IN THE EARTH THEY WERE MADE. THOSE PRESSURES ARE THEN USED TO RECONSTRUCT THE EVOLUTION OF MOUNTAIN BELTS. THIS HELPS US UNDERSTAND FUNDAMENTAL PLATE-TECTONIC PROCESSES. HOWEVER, RECENT STUDIES SUGGEST WE CANNOT TRUST THOSE PRESSURES, WHICH MAKES THINGS COMPLICATED. THE TETHYAN HIMALAYA IN NORTHWESTERN INDIA IS A UNIQUE LOCATION TO TEST THAT CONCEPT, WHICH IS KNOWN AS ?NON-LITHOSTATIC PRESSURE.? THIS STUDY WILL INTEGRATE FIELD AND LABORATORY METHODS. IT WILL REVEAL GEOMETRIC, TEMPERATURE, AND PRESSURE RELATIONSHIPS AND ASSESS THE POTENTIAL NON-LITHOSTATIC PRESSURE CONDITIONS RECORDED IN THE HIMALAYA. THIS PROJECT WILL: (1) MAKE FUNDAMENTAL ADVANCES IN SCIENCE THROUGH TESTING AND CHALLENGING A PARADIGM IN THE EARTH SCIENCES; (2) TRAIN GRADUATE AND UNDERGRADUATE STUDENTS IN STEM; (3) SUPPORT EARLY-CAREER FACULTY; (4) STRENGTHEN INTERNATIONAL COLLABORATIONS; AND (5) DEVELOP A PUBLICLY ACCESSIBLE FIELD-TRIP GUIDE THAT WILL EXPLORE THE GEOLOGY OF THE HIMALAYA OF NORTHWESTERN INDIA. WHETHER PRESSURES RECORDED BY METAMORPHIC ROCKS ACCURATELY REFLECT BURIAL DEPTHS IS CONTROVERSIAL. THE RESEARCH TEAM HAS IDENTIFIED A UNIQUE STUDY SITE IN THE WESTERN HIMALAYA WHERE DECADES OF SEDIMENTOLOGICAL INVESTIGATIONS OF THE TETHYAN STRATIGRAPHIC SECTION ARE INCONSISTENT WITH METAMORPHIC PRESSURE ESTIMATES FROM STRATA THAT IMPLY ~28+ KM BURIAL. EXISTING KINEMATIC MODELS FROM FIELD STUDIES DO NOT SUGGEST SUCH BURIAL DEPTHS OF THE SECTION, AND THUS THE DISCREPANCY BETWEEN PRESSURE ESTIMATES AND RECONSTRUCTIONS REQUIRES FURTHER INVESTIGATION. THE RESEARCHERS HYPOTHESIZE THAT METAMORPHIC PRESSURES FROM THE BASAL TETHYAN STRATA REFLECT NON-LITHOSTATIC PRESSURE CONDITIONS AT THE REGIONAL SCALE (10?S OF KM). THIS WILL BE TESTED VIA A SYSTEMATIC RESEARCH PLAN INVOLVING GEOLOGIC MAPPING, QUANTITATIVE MICROSTRUCTURAL ANALYSIS, METAMORPHIC THERMOBAROMETRY AND PETROCHRONOLOGY, DETRITAL ZIRCON GEOCHRONOLOGY, AND LOW-TEMPERATURE THERMOCHRONOLOGY. EMPIRICAL SUPPORT OF REGIONAL-SCALE, NON-LITHOSTATIC PRESSURES WOULD REQUIRE A PARADIGM SHIFT IN METAMORPHIC PETROLOGY AND TECTONICS, WITH PROFOUND IMPLICATIONS FOR UNDERSTANDING THE EVOLUTION OF FAULT ZONES, OROGENS, AND PLATE-SCALE DYNAMICS. IF THE RESEARCH FINDS THAT NON-LITHOSTATIC PRESSURE IS NOT REQUIRED TO EXPLAIN THE GEOLOGICAL DISCREPANCIES IN THE WESTERN TETHYAN HIMALAYA, THIS STUDY WILL STILL PROVIDE IMPORTANT GEOLOGIC RELATIONSHIPS TO EVALUATE AND ADVANCE MODELS OF HIMALAYAN TECTONICS. THIS AWARD REFLECTS NSF'S STATUTORY MISSION AND HAS BEEN DEEMED WORTHY OF SUPPORT THROUGH EVALUATION USING THE FOUNDATION'S INTELLECTUAL MERIT AND BROADER IMPACTS REVIEW CRITERIA.- SUBAWARDS ARE NOT PLANNED FOR THIS AWARD.