Geology topics

Research about Gulf Coastal Plain

Source-linked reports with geographic coverage including Gulf Coastal Plain.

3 recordsLinked to original sources

USGS2012

Estimating shorebird populations during spring stopover in rice fields of the Louisiana and Texas Gulf Coastal Plain

Migrating shorebird populations using approximately 2% of Louisiana and Texas Gulf Coastal rice fields were surveyed during spring migration (March–May of 1997 and 1998) using biweekly stratified random surveys conducted at 50 roadside survey points and approximately 30,000 shorebirds were observed. Shorebird counts were extrapolated and almost 1.4 million birds in 1997 and over 1.6 million birds of 31 species in 1998 were estimated to use rice field habitat for stopover sites in Louisiana and Texas. Greater than 50% of the estimated North American populations were estimated to use rice field habitats for five species, including a species of concern, Buff-breasted Sandpiper (Tryngites subruficollis) at 187%. Because of predictability of suitable rice field habitat acreage, timing of field preparation and water availability, coastal rice prairies are identified as critical spring migration stopover sites.

Louisiana;Texas↗

USGS1998

Summary of hydrology of the regional aquifer systems, Gulf Coastal Plain, south-central United States

There is potential for further development of ground-water supplies in the Gulf Coastal Plain because of the abundance of water in streams, lakes, and swamps and the generally good hydraulic connection between the water table and underlying water-yielding units. The most favorable conditions for further development of ground-water supplies are generally in the upper permeable zones and aquifers, and the potential for development typically increases from west to east.

Alabama, Arkansas, Louisiana, Mississippi, Oklahom↗

USGS1952

The geology of the Florida land-pebble phosphate deposits

The land-pebble phosphate district is on the Gulf Coastal Plain of Florida. The phosphate deposits are in the Bone Valley formation, dated Pliocene by most writers. These strata overlie the Miocene Hawthorn formation and are overlain by consolidated sands 3 to 20 feet thick. The minable phosphate deposits, called “matrix” in the district, range from a featheredge to about 50 feet in thickness and consist of phosphatic pellets and nodules, quartz sand, and montmorillonitic clay in about equal proportions. Locally the matrix displays cross-bedding and horizontal laminations, but elsewhere it is structureless. The phosphorite particles, composed largely of carbonate-fluorapatite, range in diameter from less than 0.1 mm to about 60 cm and in P 2 O 5 content from 30 to 36 percent. Coarse-pebble deposits, containing 30 to 34 percent P 2 O 5 are found mainly on basement highs; and fine-pebble deposits, containing 32 to 36 percent P 2 O 5 are, are found in basement lows. Deposits in the northern part of the field contain more phosphate particles and their P 2 O 5 content is higher than those in the southern part. The upper part of the phosphatic strata is leached to an advanced degree and consists of quartz sand and clay-sized particules of pseudowavellite and wavellite. The leached zone ranges in thickness from a featheredge to 60 feet. The origin of the land-pebble deposits is incompletely known. Possible modes of origin are a residuum of Miocene age, or a reworked residuum of Pliocene or Quaternary age.

Florida↗