Images

Diabase is a mafic (meaning high in magnesium and iron), igneous rock that usually forms below the Earth’s surface. This particular one has large amounts of augite and labradorite minerals, and comes from the Lucke Quarry, which is southeast of Leesburg, VA.

Granite is an igneous rock that we’ve used for building materials for thousands of years. It’s name comes from the Latin word “granum,” meaning “grain,” which refers to the grains of quartz and feldspar that define granite. This one is from the Barre formation in Vermont.

Conglomerates are sedimentary rocks that are made up of various fragments of rock interspersed with finer grained material. This particular conglomerate was deposited as a fan on the northwest side of the Culpeper Basin.

Marble is a famous metamorphic rock known for its use in sculpture and architecture. This particular marble came from the Campbell Quarry in Texas, Maryland.

Diopside crystals are made up of Magnesium, Calcium, Silicon and Oxygen, and are usually found in metamorphic rocks. These crystals have developed in some Cockeysville Marble from Texas, Maryland.

The USGS National Center

Hornfels rocks are metamorphic rocks. They usually start out as sedimentary rocks like sandstone or shale, but then volcanic material pushes up from below and bakes the sedimentary rock into a metamorphic one. Hornfels are known for being exceptionally tough and durable. This one is from Chantilly, VA.

Cannel coal is a type of bituminous coal, which is the second-highest rank of coal (just behind anthracite). This particular sample has a high carbon content with high pollen and spore content as well. Unlike most bituminous coal, Cannel coal can be carved into ornaments. This sample came from the Eastern Interior Coalfield in Kentucky.

Spring sampling location along Little Sandy River in southern Wyoming. Groundwater discharge that flows into the Upper Colorado River Basin varies in response to drought, which is likely due to aquifer systems that contain relatively young groundwater, according to a new U.S.

Water quality and sampling equipment deployed at spring site near Roaring Judy, Colorado. Groundwater discharge that flows into the Upper Colorado River Basin varies in response to drought, which is likely due to aquifer systems that contain relatively young groundwater, according to a new U.S

A USGS benchmark at the USGS National Center.

Granite is an igneous rock that we’ve used for building materials for thousands of years. It’s name comes from the Latin word “granum,” meaning “grain,” which refers to the grains of quartz and feldspar that define granite. This one is from the Barre formation in Vermont.

Landsat image taken in 1992 shows the Uinta Mountains east of Salt Lake City. The shades of dark green indicate healthy, undisturbed forest. Landsat image of the same area in 2010 captures the dramatic assault of mountain pine beetles. The dark red stains reveal widespread pine beetle destruction.

Pallid sturgeon free embryo at approximately 2 days post-hatch, approximately 11-12 mm (about 0.45 of an inch) in length.

Figure 3. Pallid sturgeon free embryo at approximately 5 days post-hatch, approximately 14-15 mm (about 0.57 of an inch) in length.

Pallid sturgeon free embryo at approximately 10 days post-hatch, approximately 19-20 mm (about 0.77 of an inch) in length.

Pallid sturgeon free embryos on the day of hatch, approximately 8-9 mm (about 0.33 of an inch) in length.

Lake trout historically supported the most valuable freshwater commercial fisheries in North America, but their populations crashed in parts of the Great Lakes during the 1950s and 1960s due to overfishing and invasive species.

USGS hydrologist Mark Reid examines an extensional basin in the middle of the Oso landslide deposit.  The headscarp (near-vertical cliff at the back of the landslide) is visible at the top of the image.  The prominent tree is one of many that fell and became perched as the landslide spread out over the river valley.

USGS scientists monitor the water quality off a bridge near Sedgwick, Kansas. A new USGS study shows that water quality on the Little Arkansas River and in the Equus Beds aquifer has not substantially changed since 2007 recharge activities began in the Equus Beds aquifer.

The City of Wichita's Equus Beds Aquifer Storage and Recovery Phase II river intake structure near Sedgwick, Kansas. A new USGS study shows that water quality on the Little Arkansas River and in the Equus Beds aquifer has not substantially changed since 2007 recharge activities began in the Equus Beds aquifer.