Showing papers in "Sedimentary Geology in 1986"

TL;DR: Adachi et al. as mentioned in this paper analyzed 42 Cretaceous rock samples from Deep Sea Drilling Project (DSDP) Leg 32, in tile northern Pacific, show that chert and porcellanite are enriched in Fe, Mn, P, etc.

TL;DR: In this paper, a model for the local stratigraphic frequency of earthquake-induced soft-sediment deformation structures in fluvial sedimentary basins is proposed, which combines the style of sedimentation and the characteristics of the earthquake source to determine the pattern of incidence of the structures in a basin.

TL;DR: The geometry of anastomosing channel-fills in the Magdalena consists of stratigraphically nonuniform, low sinuous, narrow stringers of sand up to 30 m thick by 600 m wide, a width-depth ratio of 20.8 mm yr−1 based on 18 14C dates from five bore holes drilled to depths of 55 m and sediment transport budgets from 35 years of measurement as discussed by the authors.

TL;DR: In this paper, two types of carbonate apron models are presented for paleoenvironmental analysis and hydrocarbon exploration for mass-transported carbonate facies: carbonate slope aprons and carbonate base-of-slope apron.

TL;DR: In this article, the Late Proterozoic-Early Paleozoic sequence of the Tethys Himalaya provides evidence of an orogenic episode close to the Cambrian-Ordovician boundary (Late Pan-African event), where pre-middle Cambrian sediments were deposited on a terrigenous tidal flat gradually passing upward to a peritidal carbonate platform.

TL;DR: The evolution of the Arabian continental margin from Permian and Triassic rifting to ocean basin closing with the Late Cretaceous obduction of the Semail Ophiolite can be inferred from exposures of these slope sediments at Jebel Sumeini in the Western Oman Mountains.

TL;DR: In this article, an idealised annual cycle of sedimentation is proposed, where light and variable winds carry silt in suspension to the site of deposition whilst the sandy saltation load is left behind in a throughput zone farther upwind.

TL;DR: In this paper, a study of zibars located on the southwestern margin of the Algodones dune field, California, shows that Zibars and their associated interzibar areas are migrating features oriented transverse to oblique to the resultant sand-transport direction.

TL;DR: In the central Apennines, during most of the Mesozoic, a carbonate platform shed detrital material that was discharged by turbidity currents into an adjacent basin this article.

TL;DR: The grain-size characteristics of the sand upon two dunes (a 40 m high longitudinal dune in the central Namib Desert and a 6.0 m high barchan in the Jafurah sand sea of Saudi Arabia) vary with position on the dunes as mentioned in this paper.

TL;DR: In this paper, the relationship of porosity to depth of burial, geologic age, and lithology has been investigated, which gives satisfactory results: φ=φ 0 exp −0.014(13.3 log A−83.3 + 2.79)×10 −3 D where φ0 = initial porosity of the argillaceous sediment.

TL;DR: A sequence of soft-sediment deformation structures occurs in Late Quaternary sediments near Ottawa, Canada as discussed by the authors, which are attributed to deposition on subaqueous outwash fans in the Champlain Sea, at the submerged front of the retreating Wisconsin glacier.

TL;DR: In this article, the heavy-mineral assemblages are recognized in the Nubian Sandstone of southern Israel, southern Jordan and Sinai and eight assemblage zones of wide lateral continuity are established.

TL;DR: In this article, the surface textures of subglacially derived quartz sand grains are typically those associated with brittle fracture of larger particles, which is not a satisfactory technique for the discrimination of active and passive transport paths through glaciers.

TL;DR: The anatomy of the sedimentary and volcanic fill of a Middle Triassic continental rift at the western margin of the Tethys is illustrated by the study of a 250 m thick sequence on the Tyrrhenian coasts of the Northern Apennines as discussed by the authors.

TL;DR: The sedimentary and stratigraphic characteristics of eolian Permian deposits exposed in Mendoza, La Rioja and San Juan Provinces (west and northwest Argentina) are described in this article.

TL;DR: The exposed part of the Lower Pliensbachian Hasle Formation is composed of coarse siltstone and fine-grained sandstone and is hummocky cross-stratified throughout as mentioned in this paper.

TL;DR: In this article, a 250 m stratigraphic interval corresponding to the uppermost Hasandong and lowermost Jinju Formations of the Cretaceous Sindong Group has been studied in terms of facies transition.

TL;DR: In this article, particle-size data have been obtained from sieved samples of sand from beach and coastal dune environments at Ainsdale, northwest England, and four parameters of the hyperbolic distribution were calculated for each sample.

TL;DR: The late Pleistocene Scarborough Formation of the Lake Ontario Basin represents a lacustrine-deltaic sequence strongly affected by a nearby glacier as discussed by the authors, which shows gradual upward coarsening and thickening of layers from varve-like, clay-rich rhythmites at the base to channelized cross-bedded sands at the top.

TL;DR: The fine braided channel subfacies occur in the upper part of the meanderbelt facies, which was deposited by ephemeral, meandering mixed-load streams of variable discharge and sinuosity, under dry, semi-arid climatic conditions as discussed by the authors.

TL;DR: One hundred and twenty point counts of Oligocene to Recent sands and sandstones from DSDP sites in the Japan and Mariana intraoceanic forearc and backarc basins demonstrate that there is a clear compositional difference between the continentally influenced Japan forearc, backarc and seafloor sediments, and the totally oceanic Mariana forearc.

TL;DR: In this paper, electron microscopic examinations revealed interstitial rutile, anatase and brookite to be common in Upper Proterozoic sandstones of the Visingso Group in southern Sweden.

TL;DR: The Upper Cretaceous-Lower Tertiary rocks around Wadi Qena, Egypt represent a mixed siliciclastic-carbonate-phosphorite succession including (from base to top) the Nubia Sandstone, Quseir Shale, Duwi Formation, Dakhla Shale and Thebes Formation Facies and microfacies investigations were carried out as mentioned in this paper.

TL;DR: In this article, a geometrical model is described which shows how these mechanisms operate to produce either concave-up or convex-up polygons, depending on the direction of the gradient of water loss or shrinkage capacity.

TL;DR: A Paleocene carbonate sequence occurs in the southwestern part of the Sivas-Refahiye Basin, Sarkisla province (Sivas, Turkey) and is located in the northeast of Central Anatolia as mentioned in this paper.

TL;DR: The Lombriz Formation as mentioned in this paper is interpreted as a major fan delta complex and it passes conformably into marine carbonates of the Tableado Formation signifying the complete drowning of the basin in lower Cretaceous times.

TL;DR: In this paper, the authors show that the formation of basin-fills in the late Cenozoic around the Tanzawa Mountains can be explained by a collision of the Izu Peninsula (Izu Block) with the south of the youngest basin-slope developed in the southern front of the Tanzava Mountains since the Middle Pleistocene.

TL;DR: In this article, the authors classified the Cretaceous Nimar Formation in the area around Chakrud, Madhya Pradesh, India, into five marine facies: (A) polymictic conglomerate resting on granite basement, largely representing a lag deposit; (B) coarse-grained pebbly sandstone with normal and reverse coarse-tail grading and also frequency grading; sandstone, with alternate hummocky cross-stratified and small-scale wave-rippled units; (D) mudstone; and (E) limestone.

TL;DR: In the Upper Triassic to Lower Jurassic conglomerate sequences of the Passaic and succeeding formations along the northwest bounding fault of the Newark Basin in eastern Pennsylvania, New Jersey and New York, have six relatively distinct lithofacies that record continental basin filling under arid to semi-arid conditions as discussed by the authors.