Calcareous soil contains calcium carbonate and effervesces when treated with hydrochloric acid.• Caliche consists of gravel, sand, and clay cemented together by calcium carbonate.• Collovial soils (collovium) are soils found at the base of mountains that have been eroded by thecombination of water and gravity.• Eolian soils are sand-sized particles deposited by wind.• Expansive soils are clays that undergo large volume changes from cycles of wetting and drying.• Glacial soils are mixed soils consisting of rock debris, sand, silt, clays, and boulders.• Glacial till is a soil that consists mainly of coarse particles.• Glacial clays are soils that were deposited in ancient lakes and subsequently frozen. The thawingof these lakes revealed soil profi les of neatly stratifi ed silt and clay, sometimes called varved clay.The silt layer is light in color and was deposited during summer periods, while the thinner, darkclay layer was deposited during winter periods.• Gypsum is calcium sulfate formed under heat and pressure from sediments in ocean brine.• Lacustrine soils are mostly silts and clays deposited in glacial lake waters.• Lateritic soils are residual soils that are cemented with iron oxides and are found in tropicalregions.• Loam is a mixture of sand, silt, and clay that may contain organic material.• Loess is a wind-blown, uniform, fine-grained soil.• Marine soils are sand, silts, and clays deposited in salt or brackish water.• Marl (marlstone) is a mud (see defi nition of mud below) cemented by calcium carbonate or lime.
• Mud is clay and silt mixed with water into a viscous fluid.
đang được dịch, vui lòng đợi..