Monday, November 5, 2007
106-4

Carbonate Accumulation along a Chronosequence in the Presidio Bolson, Texas.

Nelson Rolong1, Susan Casby-Horton1, and B. L. Allen2. (1) USDA-NRCS, USDA-NRCS, POBox 1557, Marfa, TX 79843, (2) MS 42122, Texas Tech University, Texas Tech University, Plant, Soil Department, Lubbock, TX 79409-2122

Increasing accumulation of carbonates occur in gravelly soils along a sequence of landforms ranging from Holocene age to early to mid-Pleistocene age in the arid Presidio Bolson in the Trans-Pecos area, Texas.  Shallow, weakly to moderately developed petrocalcic horizons are found on summit and shoulder positions in highly dissected fans of early to mid-Pleistocene ages.  Thick calcic horizons are formed on either steeper back slopes of these old surfaces or in broad undulated fans probably of late-Pleistocene age.  In younger surfaces, such as stream terraces and inset fans, secondary carbonate accumulates as discontinuous filament and thin discontinuous coatings around rock fragments, enough to qualify as cambic horizon.  No visible carbonate segregation occurs in soils on the flood plains.

Back to The Genesis, Geomorphology, and Characterization of Soils
Back to S05 Pedology

Back to The ASA-CSSA-SSSA International Annual Meetings (November 4-8, 2007)