Explanation of how geologists date rocks (to determine the ages of the Earth, fossils, mineral deposits, and other geologic events) and processes using radiometric dating techniques based on radioactive isotopes of carbon and potassium/argon.
Describes project to identify sources of fecal coliform bacteria by ribotyping to develop the use of Maximum Daily Load (TMDL) values for contaminated stream segments in Virginia.
Explains sources of mercury in the air, ways in which mercury is concentrated in animals, and describes how we measure deposition of atmospheric mercury, with summaries of observations.
Report presents an abridged guide for laboratory technicians and students using X-ray powder diffraction methodology to study crystalline structure and to determine the mineralogy of finer grained sediments, especially clays.
Brief overview of luminescence dating is presented, including a description of the method, its uses, and proper sample collection techniques. Links to other U.S. laboratories for luminescence dating are also provided.
Description of the work on paleomagnetism at the USGS Rock Magnetics Laboratory in Menlo Park, California with an overview of geomagnetic polar reversals, paleosecular variation, intensity, magnetic susceptibility, and rock magnetism analysis.
Special handling must be used because these one-celled organisms break down easily if dried, and the scientific analysis is enhanced by identifying smaller specimens. Shows how they are sampled, prepared, and studied using optical and electon microscopy.
Plan for an upcoming study, at the microbiological scale, of the benthic communities (including corals) that reside in and around mid-Atlantic canyons, which are located at the edge of the continental shelf.