Publications

The Middle Devonian Marcellus Shale in the Appalachian basin extends from central Ohio on the west to eastern New York on the east, and from north-central New York on the north to northern Tennessee on the south. Its thickness ranges from 0 feet (ft) where it pinches out to the west to as much as 700 ft in its eastern extent. Within the Broadtop synclinorium, the thickness of the...

In order to complete the 2013 U.S. Geological Survey (USGS) assessment of carbon dioxide (CO2) storage resources, a methodology was needed to determine the CO2storage efficiency of individual rock strata. The method that was used involved a storage efficiency approximation by MacMinn et al., combined with a brine viscosity model by Mao and Duan, and thermal and pressure data from...

The geologic carbon dioxide (CO2) storage resource size is a function of the density of CO2 in the subsurface. The pressure and temperature of the storage reservoir at depth affect the CO2 density. Therefore, knowing these subsurface conditions allows for improved resource estimates of potential geologic CO2 storage capacity. In 2012, the U.S. Geological Survey (USGS) completed an...

Carbonate lithofacies of the Lower Cretaceous Sligo Formation and James Limestone were regionally evaluated using established U.S. Geological Survey (USGS) assessment methodology for undiscovered conventional hydrocarbon resources. The assessed area is within the Upper Jurassic–Cretaceous–Tertiary Composite total petroleum system, which was defined for the assessment. Hydrocarbons...

Mineral resource assessments provide a synthesis of available information about distributions of mineral deposits in the Earth’s crust. The U.S. Geological Survey prepared a probabilistic mineral resource assessment of undiscovered resources in porphyry copper deposits in Central America and the Caribbean Basin in collaboration with geoscientists from academia and the minerals industry...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 3,500 million metric tons (Mt) of undiscovered copper among 225 tracts around the world. Annual U.S. copper consumption is 2 Mt; global consumption is 20 Mt. The USGS assessed undiscovered copper in two deposit types that account for about 80 percent of the world's copper supply. Results of the...

The 2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows up on previous USGS work. The methodology is non-economic and intended to be used at regional to subbasinal...

Wireline logs were used to document the stratigraphic framework of Upper Devonian–Mississippian strata in the Arkoma Basin, and maps of high-gamma ray (HGR) log response were used to analyze the spatial distribution of potential source rocks in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems. The Woodford–Chattanooga shale is a transgressive deposit that accumulated on...

During the last 80 years, Louisiana has been losing wetlands at an average rate of 62 km2/y (24 mi2/y) for an accumulated loss of approximately 4900 km2 (1900 mi2). The loss seems to be the combined result of natural and anthropogenic causes that are behind primarily land subsidence averaging about 10 mm/y (0.4 in/y) coinciding with a sea level rise now at 3 mm/y (0.1 in/y), both...

A regional sampling of gases from thermal springs near the LaBarge Field, Wyoming, USA to determine the extent of the total carbon dioxide system (TCDS) indicates that the system may extend up to 70 km to the northwest of the field. Geochemical evidence from noble gas isotopes, stable element isotopes, and gas composition provide the foundation for these conclusions. Samples from Soda...

In 2007, the U.S. Energy Independence and Security Act authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for anthropogenic carbon dioxide (CO2) and to evaluate the national technically recoverable hydrocarbon resources resulting from CO2 injection and storage through CO2-enhanced oil recovery (CO2-EOR). In addition, the USGS is...

Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired...