intraclast

intraclast

[′in·trə‚klast]
(geology)
A fragment of limestone formed by erosion within a basin of deposition and redeposited there to form a new sediment.
References in periodicals archive ?
Coskinolina, Dictioconus and Valvulinid) and pelloid and intraclast along with marine fauna (Echinoids), sorting and grain -supported texture proposed the deposition of JA1 and JA2 in the shallow open lagoon environment of the inner ramp.
The unit often displays other hydrodynamic structures such as ripple marks, cross-lamination thrusting, features cutting and filling gaps with intraformal conglomerates with argillaceous silt intraclast grading features at the top.
Alternation of dolomite and thick-bedded Limestone containing pellet, ooid, intraclast
The non skeletal grains identified from the petrological study are intraclast,pelletsandooidswhiletheskeletalgrainsrepresentthefossilcontent.
SWB is generally recognized by sharp erosional bases, graded bedding, hummocky cross bedding, bioturbation, intraclast lags, winnowed shell and suspension load deposits (Mohseni and Asim, 2006; Nichlos, 2009; Neumann et al.
Oncoid nuclei are formed by one of the bioclasts mentioned above or by an intraclast.
Distribution curve of bioclast in the lower part is varied and this shows its abundance in compare with plate, extraclast and intraclast.
The most common sites of intraclast formation are at marine hiatus surfaces (firm- or hardgrounds); in reefs, fore-reef slopes, or carbonate beaches where biological and chemical processes lead to rapid cementation; or on tidal flats where desiccation, cementation, and/or dolomitization may speed lithification (Scholle and Ulmer-Scholle, 2003).
Photomicrogtaphs of lime mud-wackstone showing ostracods (Os), extraclast of quartz (Qt) and iron coated intraclast (In) embedded in a matrix.
Intraclast-oncoid grainstone (al) is a poorly sorted fabric dominated by variously shaped small micritic intraclasts (20-35%) with a wide range of sizes, micritized aggregate grains or lumps (5%) and oncoids (5-10%).
The inorganic constituents described [6] are: (i) calcite of foraminifera shells and fine-grained matrix, (ii) authigenic quartz filling the chambers of some foraminifera, composing tests of siliceous algae (supposed), and very limited detrital quartz, (iii) phosphate in pellets, intraclasts, bone, teeth, and coprolites of carbonate fluorapatite, clay minerals thought to be detrital in origin, (iv) pyrite as filling the chambers of shells and voids.
Some very old mud volcano deposits, comprising mud supporting chaotically distributed angular to subrounded sandstone clasts resembling with the Dasht Murgha group and a cluster of chimney-shaped features composed of very coarse sandstone with intraclasts of the host rocks are also present.