USGS Science⌕ Search

Geology topics

Research about Georgia

Source-linked reports with geographic coverage including Georgia.

At least 595 records · Page 33Linked to original sources
USGS1973

Stratigraphy of an archeological site, Ocmulgee flood plain, Macon, Georgia

Archeological excavations on the Ocmulgee River flood plain at Ocmulgee National Monument revealed eight sedimentary units of Holocene age. Types of deposits found are natural levee, oberbank deposit, and a probable point bar. Since the 18th century, locally more than 10 feet of sediment has been deposited. These modern sediments are similar to those on other flood plains in the southeastern United States and probably resulted from erosion that began when extensive areas were laid bare for farming. They are red to reddish brown in contrast to underlying sediment, which is various shades of gray, brown, and yellow. Earliest traces of man are "spinner-type" projectiles in the lower sand member (Qls). Marrow mountain-type points are found in mottled silty sandy clay (Qmssc). Triangular stemmed Savannah River points were found throughout the intermediate sand (Qis). Fiber tempered pottery shards and steatite bowls were found in upper one half of the intermediate sand member (Qis).

Georgia↗
USGS1972

Ground-water resources and geology of Cook County, Georgia

Aquifer-performance tests and aquifer studies indicate that the limestone beneath the city of Adel and probably most of Cook County contains potable water to a depth of only about 400 to 500 feet and that "deep" wells that tap these limestones obtain most of their water from a few thin, highly permeable zones rather than from the entire thickness of the rocks. Below about 500 feet the water is mineralized and not potable without treatment. The yield of "shallow wells" is variable and the water generally is corrosive and at places contains appreciable dissolved iron. The volume of ground water flowing through the Suwannee and Marianna Limestones in Cook County and available for development to properly spaced wells and well fields is estimated to be about 18,000,000 gallons per day. That in the Tampa Foundation is estimated to be about 1,500,000 gallons per day. Water levels near the center of the Adel well field have declined 38 feet since 1890 and presently are declining at a rate of 1.6 feet per year.

Georgia↗
USGS1971

Residual enrichment and supergene transport of gold, Calhoun mine, Lumpkin County, Georgia

Gold is present in weathered wall rock and quartz veins of the opencut of the Calhoun mine, Lumpkin County, Georgia. Eleven samples of mica schist saprolite contain 0.02 to 0.1 parts per million (ppm) gold and three samples of weathered vein quartz, 0.04 to 0.6 ppm (limit of detection is 0.02 ppm). Gold was not found in any of the 18 samples of fresh mica schist and was found in only 3 of 16 samples of fresh vein quartz from underground workings 40-100 feet below the opencut. Whole-rock chemical analyses of the unweathered schist and schist saprolite show large losses of minor elements and addition of water during weathering. The average specific gravity of the unweathered schist is 2.8 and of the schist saprolite, 1.65. The chemical analyses recalculated to weight per volume show a loss during weathering of large amounts of all major constituents including silica, alumina, and total iron. Of the minor elements, gold and arsenic show the most residual enrichment, but boron, beryllium, cobalt, lanthanum, niobium, nickel, lead, zinc, and zirconium show some enrichment in the saprolite as compared with the fresh rock. Most of the other minor elements have been at least partly removed, the greatest loss being shown by calcium, potassium, magnesium, sodium, and strontium. Fresh limonite coating the wall of the adit contains 2.9 ppm gold and appreciable amounts of these elements leached from the schist, particularly barium, calcium, and manganese. Some layers of unweathered schist contain as much as 1 percent gold-bearing pyrite and may have a gold content of 0.01 and 0.02 ppm, or just at or below the limit of detection. Loss of 30 to 45 percent of the rock during weathering increases the gold content above the lower limit of detection. The gold in recently deposited limonite shows that some gold is also being transported with iron during weathering. If a concentration of limonite were found near the water table, it might be expected to show supergene enrichment in gold.

Georgia↗
USGS1965

Water in Georgia

Explore the source record for details and available documents.

Georgia↗
USGS1964

Exploration for mineral deposits in White County, Georgia

White County is in the Northeast Georgia Highland. It comprises 243 square miles and has abouit 7,000 Inhabitants. The county seat is Cleveland. Although the scene of considerable mining activity in the past, White County now has few operating mines: a small production of clay 1 for the manufacture of miscellaneous potter near Cleveland, and three sand-gravel operations 2 at Helen. Minerals are one of White County's three basic resources, and the one whose development has been most neglected. This special study has been undertaken to expand mineral production, increase employment and create new economic opportunities in White County and adjacent areas.

Georgia↗