Sedimentological characterization of earthquake-generated turbidites in fault-proximal glacial lakes: a case study from Jenny Lake, Teton range, Wyoming

• DOI: 10.3389/feart.2024.1391441
• Publication Date: 2024-04-10T04:55:15Z
• Authors: Darren J. Larsen; Aria R. Blumm; Sarah E. Crump; Amelia P. Muscott; Mark B. Abbott; Alexandra Hangste...; Maya Porcelli
• Keywords: turbidite; Science; Q; lake sediments; neotectonics; Teton fault; paleoseismology; Jenny Lake; 01 natural sciences; 0105 earth and related environmental sciences

Lakes in seismically active regions preserve valuable sedimentary archives of paleoseismic activity within their catchment and beyond. A series glacially-excavated lakes positioned directly along the surface trace Teton normal fault at base Range, WY, are ideally situated to record past since formation approximately 15,000 years ago. Here, we focus on sediment fill contained Jenny Lake (5 km 2 ; 73 m max depth) located bottom Cascade Canyon, central Tetons, where postglacial slip rates greatest. Past earthquakes that generated slope failures around expressed stratigraphically as coseismic turbidite deposits. These deposits were previously identified dated sub-bottom profiles cores taken from multiple locations basin. In this study, six thickest turbidites (ranging 6 34 cm thick) present recovered depositional basin analyze them sub-centimeter resolution for changes physical, biological, geochemical parameters, including density, magnetic susceptibility, grain size distributions, organic content, elemental composition. Results reveal each deposit contains a well-defined, three-component sequence composed relatively homogenous thick basal sandy unit with sharp contact, similarly silt-rich middle unit, thin top very fine-grained sediments. The characteristics these components similarity between individual suggest consistent sources transport pathways during successive earthquake events. Based our analyses unique local geomorphic setting, create mechanistic model Lake, which may provide an improved framework identifying, characterizing, correlating earthquake-generated disturbance other similar tectonic-geomorphological settings, example, Basin Range Province, USA or