nodular chert
1chert — A hard, extremely dense or compact, dull to semivitreous, cryptocrystalline sedimentary rock, consisting dominantly of interlocking crystals of quartz less than about 30 mm in diameter; it may contain amorphous silica (opal). It sometimes… …
2sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… …
3Normandy Archaeological Project — The Normandy Archaeological Project was a rescue excavation designed to preserve the archaeological history of the area before it became submerged by the construction of the Normandy Reservoir Dam through funding from the Tennessee Valley… …
4желваковый кремень — — [Англо русский геммологический словарь. Красноярск, КрасБерри. 2007.] Тематики геммология и ювелирное производство EN nodular chert …
5siliceous rock — Any of a group of sedimentary rocks that consist largely or almost entirely of silicon dioxide (SiO2), either as quartz or as chert, the most common siliceous rock. It occurs in beds and in nodules. Bedded cherts may be an original organic or… …
6Nodule (geology) — A nodule in petrology or mineralogy is a secondary structure, generally spherical or irregularly rounded in shape. Nodules are typically solid replacement bodies of chert or iron oxides formed during diagenesis of a sedimentary rock. Nodules may… …
7Devonian 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… …
8Silicosis — Classification and external resources ICD 10 J62 ICD 9 502 …
9Geology of the Iberian Peninsula — The geology of the Iberian Peninsula consists of the study of the rock formations on the Iberian Peninsula, which includes Spain, Portugal, Andorra, and Gibraltar. The peninsula contains rocks from every age from Ediacaran to Recent, and almost… …
10phosphorite — phosphoritic /fos feuh rit ik/, adj. /fos feuh ruyt /, n. a sedimentary rock sufficiently rich in phosphate minerals to be used as a source of phosphorus for fertilizers. [1790 1800; PHOSPHOR + ITE1] * * * or phosphate rock Rock with a high… …
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