duricrust造句

• Minerals often found in duricrust include silica, iron, calcium, and gypsum.
• Often thick, magnesite-calcrete caprock, laterite and duricrust forms over ultramafic rocks in tropical and subtropical environments.
• This is considered to have been produced during Caenozoic to Palaeocene tropical conditions, as evidenced by mottled duricrust which records fossilised tree roots, some over 60 million years old.
• It forms sheets across alluvial plains and can occur as discontinuous lines of nodular kankar or as indurated layers in stratigraphic profiles more commonly referred to as calcrete, hardpan or duricrust.
• He became foundation Professor of Geology at the University of Western Australia in 1913, remaining there until 1919 . In Western Australia he made major studies of " duricrust ", a term he coined and on other aspects of geomorphology.
• Secondly, returning to the analysis of the calcite buildup on the holes by the Florida Geological Survey, the bedrock that had been cut out to lay the tank had little or no duricrust, showing the considerable age difference between the septic tank construction and the Circle.
• The prolonged chemical weathering also dissolved silica which, transported through the regolith by the movement of groundwater, precipitated as the ambient conditions changed, forming " silcrete " ( a type of " duricrust ) ", with the silica forming a secondary cement binding the sediment grains into sheets of hard, indurated rock, generally parallel to the land surface.