Sarah WM George

• PhD
• University of Oklahoma

The Magallanes-Austral foreland basin preserves an important record of orogenesis and landscape evolution in the Patagonian Andes of Chile and Argentina. Throughout the retroarc foreland basin, a regional disconformity with little to no angular discordance separates Upper Cretaceous–lower Paleocene strata from overlying deposits of diachronous Eoce...

Double-dating using the apatite UPb and fission-track systems is becoming an increasingly popular method for resolving mid- to upper- crustal cooling. However, these thermochronometers constrain dates that are often difficult to link through geological time due to the large difference in temperature window between the two systems (typically >250 °C...

The onset of orogenic shortening in the northern Andes Mountains coincided with latest Cretaceous accretion of the Caribbean oceanic plateau. We present isotopic data (εHf in zircon and εNd) coupled with arc position to test whether accretion led to abrupt crustal thickening in the northern Andes of Ecuador and Colombia. A rapid isotopic excursion...

Subduction of aseismic ridges and flat slab subduction are important processes that punctuate Cordilleran orogenesis and may enhance exhumation and rock uplift in the overriding plate. Distinguishing between the two drivers is often challenging, as many modern flat slabs spatially coincide with subducting buoyant ridges. The Peruvian flat slab is t...

Lithospheric foundering is an important mechanism of crustal deformation and recycling, basin subsidence, and surface uplift in orogenic systems. The Arizaro Basin, in the Puna region of NW Argentina, is a place where foundering was proposed to have taken place during the late Miocene. The Arizaro Basin has been described as a “bobber” basin produc...

The Manantiales basin contains >4 km of nonmarine sedimentary strata that accumulated at 31.75–32.5°S during construction of the High Andes. We report field and analytical data from the underexplored northern portion of this basin. The basin contains upper Eocene–middle Miocene strata that accumulated in back‐bulge or distal foredeep through inner‐...

Davis, G.H., Bos Orent, E., Clinkscales, C., Ferroni, F.R., Gehrels, G.E., Guns, K.A., George, S.W.M., Hanagan, C.E., Hughes, A.N., Iriondo, A., Jepson, G., Kelty, C., Krantz, R.W., Levenstein, B.M., Lingrey, S.H., Miggins, D.P., Moore, T., Portnoy, S.E., Reeher, L.J., and Wang, J.W., in press, 2023, Structural analysis and chronologic constrains o...

The subduction of bathymetric highs, such as aseismic ridges, leads to far‐reaching changes in the dynamics of subduction zones with increased plate coupling and deformation in the upper plate. Subduction of the submarine Carnegie Ridge on the Nazca Plate has fundamentally impacted late Cenozoic magmatism and tectonic activity in the northern Andes...

Located in northern Peru, at the lowest segment of the Central Andes, the Bagua Basin contains a Campanian to Pleistocene sedimentary record that archives the local paleoenvironmental and tectonic history. We present new δ18O and δ13C signatures of pedogenic carbonate nodules from paleosols in the Campanian–Maastrichtian Fundo El Triunfo Formation...

Mesozoic‐Cenozoic subduction of the Farallon slab beneath North America generated a regionally extensive orogenic plateau in the southwestern US during the latest Cretaceous, similar to the modern Central Andean Plateau. In Nevada and southern Arizona, estimates from whole‐rock geochemistry suggest crustal thicknesses reached ∼60–55 km by the Late...

Plain Language Summary Detailed relationships between crustal thickening, surface uplift, and climate remain unresolved. Although most mountains seem to be in isostatic equilibrium today, there is an imperfect correlation between elevation and crustal thickness in the modern continental lithosphere globally. We report trace element geochemical data...

The timing of assembly and tectonic origins of terranes in the northern Cordillera of Alaska, British Columbia, and the Pacific Northwest are debated. Stikinia, a long‐lived arc terrane, has an enigmatic regional Mesozoic accretionary history and its tectonic origins remain unconstrained. Zircon U‐Pb geochronology and Lu‐Hf isotopic data on Triassi...

Cenozoic sedimentary rocks of the intermontane Bagua Basin record the Andean orogenic history of northern Peru at ~4–7°S. The northern Peruvian Andes define the northern termination of the Central Andes and are comprised of a narrow, low‐elevation orogen relative to the rest of the Central Andes. New stratigraphic and sedimentologic field observati...

Continental drainage systems archive complex records of rock uplift, source area relief, precipitation, glaciation, and carbon cyclicity driven largely by tectonics and climate. Significant progress has been made in linking such external environmental forcings to the geomorphic expression of landscapes and the stratigraphic record of depositional b...

The Magallanes-Austral foreland basin records orogenesis and landscape evolution in the Patagonian Andes of Chile and Argentina. Throughout the retroarc foreland basin, a regional disconformity separates Upper Cretaceous-lower Paleocene strata from overlying diachronous Eocene-Miocene deposits. We present new data from a fossiliferous mixed marine/...

Integration of detrital zircon U-Pb geochronological analyses of modern rivers and ancient sedimentary basins in South America enables reconstruction of erosion and sediment routing patterns during uplift of the Andes. Provenance data for modern rivers in both erosional uplands and depositional basins define source-to-sink signatures for diverse se...