Sedimentary Deposits

Sedimentary Deposits

 

mineral deposits formed during the accumulation of sediment on the bottom of rivers and other bodies of water. According to their place of formation they are divided into river, swamp, lake, sea, and ocean deposits. Among ocean deposits a distinction is made between platform and geo-synclinal deposits. Depending on the type of sediment accumulation, sedimentary deposits may be mechanical, chemical, biochemical, or volcanic-sedimentary.

The physicochemical and geological conditions under which sedimentary deposits are formed are related to the general process of the formation of sedimentary rocks. Sedimentary deposits are conformable with respect to the sedimentary rocks enclosing them. They usually occupy a strictly defined stratigraphic position and occur in the form of layers or flat lenses. Sometimes, as a result of metamorphism and tectonic movements, they become deformed and acquire more complex contours. Some layers may stretch for dozens of kilometers and reach thicknesses of 500 m (the Solikamsk salts). The mineral composition of sedimentary deposits is determined by three groups of minerals: (1) weathering-resistant detrital minerals carried from the continent (quartz, rutile, and sometimes feldspar, pyroxene, amphibole, and mica), (2) products of chemical weathering (kaolinite, mont-morillonite, hydromica, opal, hydroxides of Fe and Mn), and (3) new sedimentary formations (carbonates, salts, phosphates, ore minerals, siliceous products, hydrocarbons).

Sedimentary deposits are extremely important industrially. They include all deposits of combustible minerals (petroleum, gas, coal, and combustible shales), some ores of iron, manganese, and aluminum, and several nonferrous and rare metals (U, Cu, V). Among sedimentary deposits are mineral salts, phosphorites, and large deposits of such building materials as gravel, sand, clay, slate, limestone, chalk, dolomite, marl, gypsum, jasper, and tripoli.

REFERENCE

Smirnov, V. I. Geologiia poleznykh iskopaemykh, 2nd ed. Moscow, 1969.
References in classic literature ?
And what an amount of degradation is implied by the sedimentary deposits of many countries
But if, as some geologists suppose, a range of older rocks underlies the Weald, on the flanks of which the overlying sedimentary deposits might have accumulated in thinner masses than elsewhere, the above estimate would be erroneous; but this source of doubt probably would not greatly affect the estimate as applied to the western extremity of the district.
Yet it may be doubted whether in any quarter of the world, sedimentary deposits, including fossil remains, have gone on accumulating within the same area during the whole of this period.
Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still--up to perhaps 800 meters above the crater floor, and possibly representing tens of millions of years.
to correct sedimentary deposits profiles, obtained from exploration seismology, basing on research of core material of exploration and production and parametric drilling holes.
This is a large and virtually unexplored area in a basin with a proven petroleum system and thick sedimentary deposits.
Analysis of sedimentary deposits gathered by Nasa's Mars rover Curiosity shows the lake existed for at least tens of thousands of years, and possibly longer, geologist John Grotzinger, with the California Institute of Technology in Pasadena, told reporters at the American Geophysical Union conference in San Francisco.
The craters are found primarily at higher latitudes, a location that correlates with thick, fine-grained sedimentary deposits rich with subsurface ice.
Its igneous rock formations are less enriched with residual elements compared to the sedimentary deposits exploited by its peers.
There are mainly three types of oil shale deposits in NW China: (i) littoral-neritic facies sedimentary deposits in the Late Carboniferous; (ii) residual lake bay-lake phase sedimentary deposits of the Late Permian; (iii) inland lake system sedimentary deposits (including lake facies and delta phase).
The potential to find key evidence indicative of life--biofabrics, microbial remains, chemical fossils in minerals--is high when sedimentary deposits form from hydrothermal fluids.
Zone B includes those areas known to have flooded in the past evidenced by sedimentary deposits, and Zone C refers to those areas of the floodplain having a high risk from flooding.