Images

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.

This sample is of peacock coal. Peacock coal is not a specific class of coal, but rather the name for an effect in which oxidizing materials in the coal create a dazzling array of colors on the surface of the coal. Usually it is short-lived, as the material fully oxidizes away shortly after exposed to air.

Most fossils occur in sedimentary rocks including shale, limestone and sandstone. The sandstone block shown here contains a large fossil palm leaf, found at the Coryell Coal mines in Colorado.

Faulted and folded Triassic, Jurassic, and Cretaceous rocks along Surprise Creek in southern part of Western North Slope. The Triassic and Jurassic rocks include petroleum source rocks from which oil was generated. Geologists in orange vests for scale.

Geologists measuring petroleum source rocks in Triassic rocks along Surprise Creek in southern part of Western North Slope.

Geologist describes petroleum source rocks in Triassic and Jurassic rocks along Surprise Creek in southern part of Western North Slope.

A field assistant pans for monazite and rare earth minerals in Wolf Creek, which cuts through the Melozitna granite. This area is part of the Bureau of Land Management's Central Yukon Planning Area, where USGS did a critical mineral assessment in 2015.

Productive tallgrass prairie with potential for growing biofuel crops.

A carbon dioxide (CO₂) injection well drilled by the Southeast Regional Carbon Sequestration Partnership (sponsored by the U.S. Department of Energy) at the Cranfield CO₂ test site in Mississippi. The well was drilled to test the effectiveness of injecting and storing CO₂ in a deep saline reservoir.

A geothermal power plant at The Geysers near Santa Rosa, California. The USGS researches and assesses geothermal resources.

USGS researchers used a small-scale commercial windmill as an essential part of its new device to measure snowfall in remote areas.

Scientists have found that wind turbines are causing fatalities of certain species of migratory insect-eating bats, although a March 2011 study in Science suggests that solutions to reduce the impacts of wind turbines on bats may be possible.

A drill rig at the Mount Elbert test site in Alaska's North Slope, just west of Prudhoe Bay. USGS joined BP Exploration (Alaska) and the U.S. Department of Energy to drill a test well to study natural gas production from gas hydrate deposits. Read more about the Mt.

Trans-Alaska Pipeline, northern Brooks Range, Alaska. Rocks in the background produce oil on the North Slope.

Bed sediment sampling, Suwanee Creek, Gwinnett Co, Georgia

Mount Elbert gas hydrate stratigraphic test well on the North Slope of Alaska.

This image shows gas hydrates (the white material) in marine sediments from a test well drilled in the Indian Ocean in 2006 during the Indian National Gas Hydrate Program (NGHP) Expedition 01.

This image shows gas hydrates (the white material) in marine sediments from a test well drilled in the Indian Ocean in 2006 during the Indian National Gas Hydrate Program (NGHP) Expedition 01.

This image shows gas hydrates (the white material) in marine sediments from a test well drilled in the Indian Ocean in 2006 during the Indian National Gas Hydrate Program (NGHP) Expedition 01.

This image shows gas hydrates (the white material) in marine sediments from a test well drilled in the Indian Ocean in 2006 during the Indian National Gas Hydrate Program (NGHP) Expedition 01.