Publications

We present new images and descriptions of the lithofacies and organic facies of the pebble shale unit and lower part of the Hue Shale (Lower Cretaceous) of Arctic Alaska at a high magnification that illustrates their textural characteristics. Our aims were to describe and determine the distribution of facies in these petroleum source rocks and to identify the processes that formed them...

Summary Professional Paper 1814—Studies by the U.S. Geological Survey in Alaska, Volume 15—continues a long-running series of collected volumes of U.S. Geological Survey (USGS) scientific reports on Alaska. This series presents new and sometimes preliminary findings that are of interest to Earth and biological scientists in academia, government, and industry; to land and resource...

Three aeromagnetic surveys were flown to improve understanding of the geology and structure in the Sacramento Valley. The resulting data serve as a basis for geophysical interpretations, and support geological mapping, water and mineral resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps)...

A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the preproduction and coproduction periods from 1981 to 2013, we...

Although fire was arguably the primary tool used by the Maya to alter the landscape and extract resources, little attention has been paid to biomass burning in paleoenvironmental reconstructions from the Maya lowlands. Here we report two new well-dated, high-resolution records of biomass burning based on analysis of macroscopic fossil charcoal recovered from lacustrine sediment cores...

The database in this Open-File Report describes the geology of Joshua Tree National Park and was completed in support of the National Cooperative Geologic Mapping Program of the U.S. Geological Survey (USGS) and in cooperation with the National Park Service (NPS). The geologic observations and interpretations represented in the database are relevant to both the ongoing scientific...

The southern San Andreas fault system (California, USA) provides an excellent natural laboratory for studying the controls on vertical crustal motions related to strike-slip deformation. Here we present geologic, geomorphic, and gravity data that provide evidence for active northeastward tilting of the Santa Rosa Mountains and southern Coachella Valley about a horizontal axis oriented...

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams...

Introduction Indium is rare in the Earth’s crust. The continental crust contains an average of about 50 parts per billion of indium, whereas the oceanic crust contains about 72 parts per billion, which is similar to meteoritic abundances and comparable to the crustal abundance of silver. Indium minerals are rare in nature and only 12 indium minerals are known. In its elemental form...

Introduction On April 25, 2015, a large (M7.8) earthquake shook much of central Nepal and was followed by a series of M>6 aftershocks, including a M7.3 event on May 12, 2015. This earthquake and aftershocks, referred to as the “Gorkha earthquake sequence,” caused thousands of fatalities, damaged and destroyed entire villages, and displaced millions of residents. The earthquakes also...

The Alaska Peninsula is composed of the late Paleozoic to Quaternary sedimentary, igneous, and minor metamorphic rocks that record the history of a number of magmatic arcs. These magmatic arcs include an unnamed Late Triassic(?) and Early Jurassic island arc, the early Cenozoic Meshik arc, and the late Cenozoic Aleutian arc. Also found on the Alaska Peninsula is one of the most complete

As part of a larger study, the U.S. Geological Survey undertook a study to identify the potential for phosphate deposits in Afghanistan. As part of this study, a geographic information system was constructed containing a database of phosphate occurrences in Afghanistan and adjacent countries, and a database of potential host lithologies compiled from 1:1,000,000 scale maps. Within...