Publications

The Alaska Division of Geological and Geophysical Surveys has an ongoing program aimed at evaluating the Mesozoic forearc stratigraphy, structure, and petroleum systems of lower Cook Inlet. Most of our field studies have focused on the Jurassic component of the petroleum system[this report.] However, in late July and early August of 2012, we initiated a study of the stratigraphy and...

The geologic map of the Satan Butte and Greasewood 7.5’ quadrangles is the result of a cooperative effort of the U.S. Geological Survey (USGS) and the Navajo Nation to provide regional geologic information for management and planning officials. This map provides geologic information useful for range management, plant and animal studies, flood control, water resource investigations, and...

The Alaska Division of Geological & Geophysical Surveys (DGGS) and Alaska Division of Oil and Gas (DOG), in collaboration with the U.S. Geological Survey (USGS) performed reconnaissance field studies for ten days in late June 2011, in the Susitna basin, directly north of Cook Inlet, south-central Alaska (fig. 1). The purpose of our investigation was to reconnoiter outcrops in the basin...

This report provides a comprehensive overview of the stratigraphy, structure, tectonics, and petroleum systems of the Cook Inlet basin, an important oil- and gas-producing region in south-central Alaska.

The Franciscan Complex accretionary prism was assembled during an ∼165-m.y.-long period of subduction of Pacific Ocean plates beneath the western margin of the North American plate. In such fossil subduction complexes, it is generally difficult to reconstruct details of the accretion of continent-derived sediments and to evaluate the factors that controlled accretion. New detrital zircon...

A new isostatic residual gravity map of the Newfoundland Mountains and east of the Wells 30×60 quadrangles of Utah is based on compilation of preexisting data and new data collected by the Utah and U.S. Geological Surveys. Pronounced gravity lows occur over Grouse Creek Valley and locally beneath the Great Salt Lake Desert, indicating significant thickness of low-density Tertiary...

This field guide provides a road log to and geologic descriptions of selected sites in the Idaho cobalt belt, and at the Beartrack gold mine, in the eastern Salmon River Mountains.

The type section of the Barstow Formation in the Mud Hills, north of Barstow, is a reference section for early to middle Miocene paleontology, magnetostratigraphy, and dated volcanic episodes. Thanks to this robust chronologic framework, much of the interpretation of the paleogeography of the region from about 18 Ma to 13 Ma is based on study of the rocks in the Mud Hills. Eastward from...

The Idaho cobalt belt (ICB) is a northwest-trending belt of cobalt (Co) +/- copper (Cu)-bearing deposits and prospects in the Salmon River Mountains of east-central Idaho, U.S.A. The ICB is about 55 km long and 10 km long in its central part, which contains multiple strata-bound ore zones in the Blackbird mine area. The Black Pine and Iron Creek Co-Cu prospects are southeast of Blackbird...

Estimation of product distributions of two factors was simulated by conventional Monte Carlo techniques using factor distributions that were independent (uncorrelated). Several simulations using uniform distributions of factors show that the product distribution has a central peak approximately centered at the product of the medians of the factor distributions. Factor distributions that...

Laboratory tests to examine hysteresis in the hydrologic and mechanical properties of partially saturated soils were conducted on six intact specimens collected from a landslide-prone area of Alameda County, California. The results reveal that the pore-size distribution parameter remains statistically unchanged between the wetting and drying paths; however, the wetting or drying state...

A thick sequence of limestone, dolomite, and minor sandstone assigned to the Pennsylvanian and lower Permian Bird Spring Formation is exposed in the Ship Mountains about 85 kilometers (km) southwest of Needles, California, in the eastern Mojave Desert. These strata provide a valuable reference section of the Bird Spring Formation in a region where rocks of this age are not extensively...