Mountain belts form Earth?s highest topography, thus affecting global atmospheric and oceanic circulation, ocean chemistry, biological evolution and ecology. Nevertheless, one of the outstanding scientific question remains: how does plate tectonics produce mountains? One of the largest mountain belts on Earth are the Andes of South America. The Andes are especially important because they span ~70° of latitude across several global climate zones and exert first-order controls on ocean circulation and climate. The Andes also contain some of the highest elevations and thickest crust (upper layer of rock that we live on) on Earth. Yet, there is not a comprehensive framework for understanding how the Andes are formed and how they relate to the subduction zone where the oceanic Nazca plate is descending beneath the western edge of the South America Plate. This project will build a framework incorporating new geologic, geochemical and seismic data to understand the present day structure of the Andes incorporating high resolution seismic images and to evaluate through geologic studies how the Andean Mountains formed and the conditions necessary to build large mountain belts.
This project will produce an integrated diverse Earth subsystem (mantle-lithosphere-surface) 3D model based on the Andes and advance our understanding of the dynamics of cordilleran-type orogenic systems and the relative roles of the lithosphere, asthenosphere and lower mantle. The new geologic and geophysical data collected will test existing mantle- and lithosphere-scale models of cordillera mountain building. This research will integrate geophysics, geodynamic modeling, structural geology, basin analysis, petrology and geochemistry to investigate the effects of slab geometry, slab penetration (into the lower mantle), forearc underplating, and the presence or absence of a craton on crustal thickening and surface evolution (subsidence and uplift). This project will evaluate different controls on mountain building, surface uplift and paleo-environments with implications for biodiversity, ocean circulation, climate, and geohazards. Results from this study will aid in a deeper understanding of the interactions between deep Earth and the crustal structure of the Central Andes and the location and behavior of active faults in one of the most seismically active regions of South America, thereby contributing to better seismic hazard assessment. Results from this research will be used to build on an ongoing effort to apply artificial intelligence (AI) to Geosciences. A new student exchange program between the UA and Argentina will enhance international collaborations and provide a unique opportunity for students to learn the geology of the North and South American Cordilleras.
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.
