Data release for Geologic Map of the Poncha Pass Area, Chaffee, Fremont, and Saguache Counties, Colorado

This release presents the GIS data (in GDB, shapefile, and e00 [coverage] formats) and metadata for a 1:24,000-scale geologic map of the Poncha Pass area in central Colorado. A cartographic version of the geologic map, including map unit descriptions, interpretative text, and accessory figures and tables, is being separately published as a U.S. Geological Survey Scientific Investigations Map (SIM). The map area is irregular in shape, covering all of one 7.5' quadrangle (Poncha Pass) and parts of five others (Mount Ouray, Maysville, Salida West, Salida East, and Wellsville). The map boundaries were drawn to cover all of the "Poncha mountain block", coincident with the approximately 15-kilometer-long northwestern...

Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 40Ar/39Ar age, Arkansas River, Bear Creek, Bonanza Tuff, Bull Lake glaciation, All tags... Chaffee County, Cleveland Mountain, Clover Creek, Colorado, Conejos Formation, Droz Creek, Dry Union Formation, Fremont County, Geomorphology, Laramide orogeny, Little Cochetopa Creek, Mears Junction, Methodist Mountain, Mineral Resources, Mount Ouray, Murphys Hole, O’Haver Lake, Pinedale Glaciation, Poncha Creek, Poncha Mountain, Poncha Pass, Poncha Springs, Rio Grande rift, Round Hill, Saguache County, Salida, San Luis Creek, San Luis Valley, Sand Gulch, Sangre de Cristo Mountains, Sawatch Range, Silver Creek, Simmons Peak, South Arkansas River, Stratigraphy, Structural Geology, U-Pb age, USA, USGS Science Data Catalog (SDC), United States, Upper Arkansas Valley, Volcanology, basement rocks, basin-fill deposits, dike, fault slip, intrusive rocks, metamorphic rocks, mountain block, normal fault, oblique-slip fault, pre-Bull Lake glaciation, range-front fault, reverse fault, sedimentary rocks, sill, strike slip, surficial deposits, uplift, volcanic rocks, Fewer tags

Seismic reflection imaging of the low-angle Panamint normal fault system, eastern California, 2018

A fundamental question in seismic hazard analysis is whether <30º-dipping low-angle normal faults (LANFs) slip seismogenically. In comparison to more steeply dipping (45-60º) normal faults, LANFs have the potential to produce stronger shaking because of their increased possible rupture area in the seismogenic crust. While LANFs have been documented globally, examples of seismogenically active LANFs are limited. The western margin of the Panamint Range in eastern California is defined by an archetypal LANF that dips west beneath Panamint Valley. In addition, high-angle dextral-oblique normal faults displace mid-to-late Quaternary alluvial fans near the range front. To image shallow (<1 km depth), crosscutting relationships...

Categories: Data; Tags: California, Fault, Geophysics, Low-angle, Normal Fault, All tags... Panamint Valley, Seismic, Seismology, Slip, Slipping, Structural Geology, USGS Science Data Catalog (SDC), Fewer tags

Alamagan Volcano - contacts and faults

Alamagan Volcano is a Quaternary stratovolcano along the Mariana Arc, an active subduction zone in the western Pacific Ocean. Although primarily submerged, its peak reaches above sea level, with subaerially-exposed volcanic deposits dating back through the Holocene to the late Pleistocene. These feature data represent such deposits and other geologic features of Alamagan Volcano, describing its interpreted eruptive history.

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Alamagan Island, Andesite, ContactsAndFaults, Intermediate volcanic rock, Lava flow, All tags... Northern Islands, Northern Mariana Islands, Pacific, Pacific Islands, Pyroclastic rock, United States, Volcanic rock, coastline, contact, fault, geologic maps, normal fault, topographic crater rim, volcanic activity, Fewer tags