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The Genesis of Certain Calcareous Floodplain Soils of Virginia
Author(s) -
Mathews H. L.,
Prescott G. W.,
Obenshain S. S.
Publication year - 1965
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1965.03615995002900060036x
Subject(s) - tufa , floodplain , calcareous , soil water , hydrology (agriculture) , geology , groundwater , streams , weathering , carbonate , spring (device) , flood myth , geochemistry , environmental science , soil science , chemistry , ecology , archaeology , geotechnical engineering , paleontology , mechanical engineering , history , computer network , organic chemistry , engineering , computer science , biology
A study was made to determine the origin of the calcareous material found in certain floodplain soils of the limestone valleys of Virginia. The CaCO 3 in these soils was derived from the highly fractured and faulted limestone underlying the area. Groundwater, high in dissolved CO 2 , percolated through the crushed limestone, dissolving an appreciable amount of Ca and Mg carbonate. This water issued at the surface in the form of large springs and lost some of the dissolved CO 2 which resulted in a saturated solution with respect to calcium. The CaCO 3 depositing alga Oocardium stratum Näg was found below the point of saturation in the streams and was thought to be of major importance in the deposition of CaCO 3 . In a 200‐foot section of stream channel beginning 450 feet below a spring having a rate of flow of 104 gallons/min, approximately 2.85 tons of CaCO 3 were deposited annually as tufa. Algal‐deposited tufa is torn from stream channels during heavy rains and redeposited downstream by flood waters. Calcareous material occurs several miles from the source area and is a constituent of the flood plain soils along the creeks and rivers of the area.