Accession Number : ADA018959

Title :   Factors Affecting Development, and Optimal Photomapping Technique, of Calcium Carbonate Cementation of Arid Region Sediments.

Descriptive Note : Final rept. Jul 71-Sep 75,


Personal Author(s) : Lattman,Laurence H.

Report Date : 06 OCT 1975

Pagination or Media Count : 30

Abstract : Caliche (secondary calcium carbonate cementation) occurs as six different types in southern Nevada. Two of these types, petrocalcic horizons and laminar layers, markedly reduce infiltration on alluvial fans and increase flooding hazards. The most important factor apparently controlling development of caliche in the southwestern United States is the lithology of the alluvial fan detritus. Availability of eolian dust, Containing calcite and gypsum, and increasing age of the deposit are factors which increase calichification. The thickest caliche deposits are adjacent to or downwind from gypsum outcrops. Using black-and-white film and filter combinations it was found that a orange filter gave the most reliable results in distinguishing calichified from non-calichified fans. A blue filter gave greatest contrast between calichified fan surfaces and uncalichified modern drainage washes. Because of variation in caliche types, no clear correlation was found between degree of calichification and photographic expression.

Descriptors :   *Carbonate minerals, *Alluvium, *Aerial photography, Mapping, Arid land, Calcite, Gypsum, Calcium compounds, Lithology, Nevada

Subject Categories : Cartography and Aerial Photography
      Geology, Geochemistry and Mineralogy

Distribution Statement : APPROVED FOR PUBLIC RELEASE