Images

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

USGS scientists drilling a research core near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

A drill core from near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

A drill core from near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

A drill core from near Waco, Texas. This core was drilled by USGS during field work for an oil and gas assessment for the Eagle Ford of the Gulf Coast Basins. Cores like these provide information on the various rock layers, such as their make-up, their age, etc.

U.S. Geological Survey (USGS) scientist measuring dissolved oxygen in a stream water sample. The scientist is part of a USGS team of scientists that are investigating the potential environmental effects of activities at an oil and gas wastewater injection facility in West Virginia.

A view of the New River from the New River Gorge Bridge, West Virgina. Wolf Creek is a tributary of the New River. Photo: Denise M. Akob, USGS.

This sample is of bituminous coal, a middle rank coal (between subbituminous and anthracite) formed by additional pressure and heat on lignite.

Peat is the precursor to coal. It's made up of decayed plant materials or other organic matter that, over time, can undergo heat and pressure to become lignite.

A former uranium mill tailings site near Rifle, Colorado, is next to the Colorado River.

This is anthracite, the highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Anthracite is not as commonly mined as other ranks of coal.

Clinker coal is the result of a seam of coal catching fire and burning so hot that it baked surrounding rock layers into brick-like formations.

A sample of lignite, the lowest rank of coal. It is primarily mined for burning in steam-generation power plants.

USGS scientist records information at a sampling site on a stream in Pennsylvania. The stream was sampled immediately downstream of the point of discharge of treated wastewater. 

This is anthracite, the highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Anthracite is not as commonly mined as other ranks of coal.

Clinker coal is the result of a seam of coal catching fire and burning so hot that it baked surrounding rock layers into brick-like formations.

A sample of lignite, the lowest rank of coal. It is primarily mined for burning in steam-generation power plants.