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Calcareous soils are relatively alkaline, in other words they have a high pH.They are characterized by the presence of calcium carbonate in the parent material; the carbonate-ion is a base.
The post-Pleistocene soil deposits were shallow reaching the hard calcareous soil within 7.9 inches (20 cm) or less. Surrounding pits were dug to check for deposits and only a few sites with additional cultural material were found in 1994. Radiocarbon samples were taken from 4 features on the edge of the site.
Candelariella species are found across the globe, although most commonly described in North America, Asia, and Australia. Species can be found on calcareous and non-calcareous rock, soil, tree bark, mosses, and other lichens.
Red clay, also known as either brown clay or pelagic clay, accumulates in the deepest and most remote areas of the ocean. It covers 38% of the ocean floor and accumulates more slowly than any other sediment type, at only 0.1–0.5 cm/1000 yr. [1] Containing less than 30% biogenic material, it consists of sediment that remains after the dissolution of both calcareous and siliceous biogenic ...
Calcareous sinter is a freshwater calcium carbonate deposit, also known as calc-sinter. Deposits are characterised by low porosity and well-developed lamination, often forming crusts or sedimentary rock layers. Calcareous sinter should not be confused with siliceous sinter, which the term sinter more frequently [citation needed] refers to.
Alkali, or alkaline, soils are clay soils with high pH (greater than 8.5), a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate , which causes the soil to swell ...
Tufa columns at Mono Lake, California. Tufa is a variety of limestone formed when carbonate minerals precipitate out of water in unheated rivers or lakes. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits, which are known as travertine or thermogene travertine.
The species growing on calcareous, limestone, for instance, adapt to a basic substrate. Species growing in acid to almost basic soil that have a pH level between 4.5 to 7 are P. lamerei and P. rutenbergainum. P. meridionale grows in neutral soils. And, some species tolerate both acidic and basic soil conditions.