Results 221 to 230 of about 139,956 (281)

Sedimentary Rocks and the Oceans

1972
Interest in the isotopic composition of strontium in sedimentary rocks is increasing rapidly. Recent work includes dating of argillaceous sedimentary rocks as well as studies of the variation of the 87Sr/86Sr ratios of the oceans in the geologic past. While much progress has been made, many challenging problems remain to be solved.
James L. Powell, Gunter Faure
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The sedimentary rocks of macaronesia

Geologische Rundschau, 1974
In all the archipelagos forming Macaronesia, volcanis predominate, but pre-Quaternary sediments are also present, though playing a humble role. Calcareous deposits have by far the greatest significance throughout the known stratigraphic record. Tertiary occurrences tend to be thin, show more gentle dips, whereas the Mesozoics attain thicknesses of 400 ...
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Zeolites in Sedimentary Rocks [PDF]

SEPM Journal of Sedimentary Research, 1959
ABSTRACT Zeolite minerals, especially analcime and clinoptilolite, are known to occur widely in sedimentary rocks both as nearly monomineralic beds and as accessory minerals. Because of the extremely fine grain size of the zeolite rocks, identifications are made most readily with X-ray diffraction techniques.
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A Classification of Sedimentary Rocks

The Journal of Geology, 1948
A simple field and laboratory classification of sedimentary rocks is proposed. It is based fundamentally on composition and texture, with the primary divisions determined by the mode of origin of the constituents. Tt is tripartite in nature, consisting of (1) a dominantly fragmental division, including conglomerates, sandstones, and shales; (2) a ...
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Petrology of the Sedimentary Rocks

1988
Soils: soil-forming processes soil classification modern and ancient soil types. Sedimentary structures: bedding ripples, dunes and cross-bedding turbidites, graded beds and sole structures deformational structures biogenic structures. Rudaceous deposits: classification composition of pebbles shape and roundness of pebbles sedentary rudaceous deposits ...
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Nomenclature for Sedimentary Rocks

AAPG Bulletin, 1970
Despite the many excellent papers on classification of sedimentary rocks, there is still so much loose and variable usage of names that it is not possible to be certain of--or in some cases even to guess at--the intended meanings of terms found in the literature.
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Sedimentary rock classification

1987
Sedimentary rock is composed of framework grains, matrix, chemically precipitated cement, and pores (Fig. 8.1). Framework grains and matrix are generally deposited from a fluid medium after transport. Transport distances may be thousands of kilometers or only a few meters. The grains, as the name indicates, form the framework of the rock.
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Sedimentary Rocks of Early Mars

Science, 2000
Layered and massive outcrops on Mars, some as thick as 4 kilometers, display the geomorphic attributes and stratigraphic relations of sedimentary rock. Repeated beds in some locations imply a dynamic depositional environment during early martian history.
Kenneth S. Edgett, Michael C. Malin
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Sedimentary Rocks—Descriptive

1978
The factor of grade size is the one most used for the classification of sedimentary rocks (p. 190). Four groups may be distinguished:— 1. Rudaceous 1—Rocks consisting chiefly of gravel, pebbles, cobbles, or boulders. Loose materials of this class are gravels, pebble-beds, shingle, boulder-beds, scree, talus, etc.
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Sediments and Sedimentary Rocks

2020
Thus sediments are products of mechanical and/or chemical weathering and they are transported by different media and over variable distances to a site of deposition, be it marine or terrestrial. Transport can be achieved simply by gravity, leading to bulk downward transfer of rock masses such as in the case of landslides or mountain creeps.
Hartwig E. Frimmel, Martin Okrusch
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