calcareous
61Tufa — Not to be confused with tuff, a porous volcanic rock. This article is about the geological formation. For the historic Chinese name, see Southern Liang. Tufa columns at Mono Lake, California Tufa is a variety of limestone, formed by the… …
62Pelagic sediments — Pelagic sediment or pelagite is a fine grained sediment that has accumulated by the settling of particles through the water column to the ocean floor beneath the open ocean far from land. These particles consist primarily of either the… …
63cirripede — ▪ crustacean Introduction any of the marine crustaceans of the infraclass Cirripedia (subphylum Crustacea). The best known are the barnacles. Adult cirripedes other than barnacles are internal parasites of marine invertebrates such as crabs …
64lamp shells — ▪ animal Introduction also called brachiopod, any member of the phylum Brachiopoda, a group of bottom dwelling marine invertebrates. They are covered by two valves, or shells; one valve covers the dorsal, or top, side; the other covers… …
65integument — /in teg yeuh meuhnt/, n. 1. a natural covering, as a skin, shell, or rind. 2. any covering, coating, enclosure, etc. [1605 15; < L integumentum a covering. See IN 2, TEGUMENT] Syn. 1. cortex, involucre, involucrum. * * * Covering of the body,… …
66sinter — /sin teuhr/, n. 1. siliceous or calcareous matter deposited by springs, as that formed around the vent of a geyser. 2. Metall. the product of a sintering operation. v.t. 3. Metall. to bring about agglomeration in (metal particles) by heating.… …
67Devonian Period — Interval of geologic time from 417 to 354 million years ago; it was the fourth period of the Paleozoic Era. During the Devonian, a giant continent was situated in the Southern Hemisphere (see Gondwana), and other landmasses were located in the… …
68Colorado Group — Stratigraphic range: middle Albian to Santonian …
69Operculum (gastropod) — Gastropod shell of the freshwater snail Viviparus contectus with corneous operculum in place …
70Geography of Western Australia — Western Australia occupies nearly one third of the Australian continent.Due to the size and the isolation of the state, considerable emphasis has been made of these features; it is the second largest administrative territory in the world, after… …
