Ichnofabric in the Upper Cretaceous Sego Sandstone and Anchor Mine Tongue of east-central Utah can be differentiated into two components: (1) discrete Ophiomorpha and (2) mottling and other trace fossils. The ichnofabric index method was employed to evaluate spatial variability of the ichnofabrics within depositional sequences and component systems tracts.

© Nature Publishing Group1986 ~16=2-----LETTERSTQNATUR£-----~N~A~TU~RE~v~oL~·~3~2t~s~M~AY~t~986 work, as the standard methods for obtaining this …

ABSTRACT Many types of carbonate platforms have been described, from homoclinal ramps to rimmed shelves and a full spectrum of variations in between; the distinction between these different types can be problematic. Nevertheless, classification of carbonate platforms is not just a semantic or academic issue. For example, it is clearly important for the …

Zoophycos may show expansion in the Palaeozoic (as suggested, but not demonstrated, by the sparse early Palaeozoic data), and is followed by retreat in the Mesozoic and Cenozoic. …

Most of the secondary porosity in ancient sandstones originated as a result of mesogenetic leaching of the carbonate minerals calcite, dolomite and siderite. This decarbonatization …

The preceding chapters provided information on the diagnostic criteria for 'depositional microfacies'.This chapter deals with 'diagenetic microfacies' that reflects changes during lithification and rock history (Pl. 28).Diagenesis refers to …

Upper Cambrian carbonates in western Maryland are comprised of platform facies (Conococheague Limestone) west of South Mountain and basin facies (Frederick Limestone) east of South Mountain.

The Lower Jurassic Aztec Sandstone is an aeolian-deposited quartzose sandstone that represents the western margin of the southerly-migrating Navajo-Nugget sand sea (or erg).

ABSTRACT Carbonate cements (calcite, siderite, dolomite, and ankerite) formed throughout the diagenetic history of the Sag River and Shublik Formations. The trace element and isotopic geochemistry ...

Mixed carbonate-siliciclastic sediment gravity flow deposits of Late Pennsylvanian to Early Permian age are exposed in the Death Valley - Owens Valley region of east-central California.

The Pleistocene Miami Limestone that crops out on the lower Florida Keys is overlain by thin (16 cm or less), discontinuous, Holocene calcareous crusts (caliche) that are usually laminated, composed dominantly of calcite micrite and may or may not …

Detailed scanning electron microscope analysis shows a linear increase in mean dolomite crystal size with depth; 0·4 μm near the top of the section to 1·0 μm near the base of the dolomitized …

WILLIAM L. DUKE. Department of Geosciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. Search for more papers by this author

A 1600-m-thick succession of the Miocene Horse Camp Formation (Member 2) exposed in east-central Nevada records predominantly terrigenous clastic deposition in subaerial and subaqueous fan-delta environments and nearshore and offshore lacustrine environments.

The architecture and sedimentary facies of a delta during its steady-state development varies with the type of distributary system, the basin water depth, and the different ways of sediment diffusion at the delta front.

The thinnest recognizable strata in modern eolian dune sands can be grouped into six classes. They are herein named planebed laminae, rippleform laminae, ripple-foreset crosslaminae, climbing translatent strata, grainfall laminae, and sandflow cross-strata.

Author notes. Thilo Bechstädt. Present address: Geologisches Institut der Universität, Albertstr. 23 B, D-7800, Freiburg. Maria Boni. Present address: Dip.

ABSTRACT The Wagwater Trough is a fault-bounded basin which cuts across east-central Jamaica. The basin formed during the late Palaeocene or early Eocene and the earliest sediments deposited in the t...

Floodplains along the braided gravel-bed Waimakariri River are discontinuous although generally extensive landforms composed predominantly of gravel bars capped with vertically accreted fines.

ABSTRACT Where bedforms migrate during deposition, they move upward (climb) with respect to the generalized sediment surface. Sediment deposited on each lee slope and not eroded during the passage ...

A carbonate buildup of Middle Triassic age, the Esino Limestone, outcrops in the Southern Calcareous Alps of Lombardy (N Italy). Along its margin and within the open subtidal facies, the Esino Limestone contains calcite cement-filled cavities of cm to m size.

Vorlandbecken, engl. foreland basins, sind mittlerweile seit mehr als 110 Jahren bekannt und wurden auch als solche in der klassischen Geosynklinaltheorie bezeichnet. Kay [1] nennt sie in seiner Arbeit aus dem Jahr 1951 noch Exogeosynklinalen.. In der Plattentektonik wurde dann der Begriff Vorlandbecken 1974 von W. R. Dickinson in der wissenschaftlichen Fachliteratur wieder …

The spatial and temporal distribution of diagenetic alterations in siliciclastic sequences is controlled by a complex array of interrelated parameters that prevail during eodiagenesis, mesodiagenesis and telodiagenesis.

The vertical and lateral stratigraphic relations of facies and facies associations, palaeocurrent directions, and geometry and internal organization of associated thick-bedded and coarse-grained bodies of sandstone provide the framework for distinguishing five thin-bedded turbidite facies in the Eocene Hecho Group, south-central Pyrenees, Spain.

Within zones of little or no deformation by internal shearing in debris flows at Mt Thomas, about two-thirds of the weight of large particles is supported by buoyancy and about one-third by static gr...

Friedman, G.M., Ali, S.A. (eds., 1981): Diagenesis of carbonate rocks. Cement-porosity relationships. — Soc. Econ. Paleont. Miner., Reprint Series, 10, 295 pp. Google Scholar

FRIEDMAN, G. M., 1980, Dolomite is an evaporite mineral: evidence from the rock record and from sea-marginal ponds of the Red. Sea:Soc. Econ. Paleont. Miner. Spec. Publs., …

ABSTRACT As a result of a phase of extensional tectonics in the western Tethyan region, a horst and graben topography formed during the Middle Triassic (Ladinian) in northern Italy. Horsts were sit...

Based on present knowledge of the purely chemical controls on the kinetics of massive dolomite formation, the abundance and distribution of dolomite throughout the Phanerozoic remains an enigma, sometimes referred to as the 'dolomite problem'.

Classical biofacies models 1,2 for reconstructing palaeoenvironments of strata deposited in oxygen-deficient marine settings define three principal facies: aerobic (> 1.0 ml 1 …

Markov chain analysis is a comparatively simple statistical technique for the detection of repetitive processes in space or time. Coal measure cyclothems or fluvial fining-upward cycles are good examples of sedimentary successions laid down under the control of Markovian processes.

The diagenesis of carbonate platform sediments is controlled by the original facies and mineralogy, climate, sea-level changes and burial history; these controls are clearly seen in the diagenesis of the Urgonian platform carbonates of SE France.

1.Rhoads, D. C. & Morse, J. W. Lethaia 4, 413–428 (1971). 2.Byers, C. W. Spec. Publs Soc. econ. Paleont. Miner. 25, 5–17 (1977). 3.Savrda, C. E. & Bottjer, D. J ...

Aeolian sand sheets are areas of aeolian sand where dunes with slipfaces are generally absent. Sand sheets are ubiquitous to modern, warm-climate sand seas, generally occurring marginal to dune fields, although they may exist within the interior of …

Cathodoluminescent zones reveal three principal stages of dolomite emplacement, separated by dissolution surfaces, with each stage reflecting several changes in the character …

Terra Nova, 23, 100–107, 2011. The Shannon Sandstone, one of the most controversial units in the field of stratigraphy, was first interpreted as a shelf sand-ridge deposit, but subsequent studies have furnished different interpretations, from lowstand-shoreface to incised-valley models.