In the Junggar basin, northwest China, many high gamma-ray (GR) sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs' recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reser...

Adsorption of calcium and magnesium on a sandstone from a bicarbonate solution has been demonstrated. On elution with water saturated with carbon dioxide, the magnesium passes off first. The chromatographic separation of magnesium from calcium can thus occur under conditions which can prevail in nature. We ask: Does chromatography play a part in geochemistry? More specifically we ask: Can calci...

The fossil calvaria known as the Mojokerto child's skull was discovered in 1936, but uncertainties have persisted about its paleoenvironmental context and geological age because of difficulties in relocating the discovery site. Past relocation efforts were hindered by inaccuracies in old base maps, intensive post-1930s agricultural terracing, and new tree and brush growth. Fortunately geologic ...

The purpose of this study was to investigate whether a previously developed computer model, named Pore-Cor, could simulate the subtle changes in void space dimensions which occur during the artificial deposition of small amounts of illite and kaolinite within Fontainebleau sandstone. Clay precipitation was carried out by placing a sandstone plug in a gold capsule, with an aluminosilicate gel, a...

Hypervelocity impact tests were carried out at 4.8 km/s using the Open University's All Axis Light Gas Gun (AALGG) in the Planetary and Space Sciences Research Institute (PSSRI)’s Hypervelocity Impact Laboratory. A first estimate of the peak loading pressures was made using preliminary hydrocode simulations, supported by calculations. Following a review of existing published quartz and sandston...

New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Fo...

Petrographic study of the Frewens sandstone, Upper Cretaceous Frontier Formation, documents reservoir-scale diagenetic heterogeneity. Iron-bearing calcite cement occurs as large concretions that generally follow bedding and are most common near the top of the sandstone. Median thickness of the concretions is 0.6 m, length 4.5 m, and width 5.7 m; median volume is 5.2 m. Concretions comprise 12% ...

The late Early Permian (273–271 Ma) Wandrawandian Siltstone in the southern Sydney Basin of New South Wales represents a marine highstand that can be correlated over 2000 km. A mainly fine-grained terrigenous clastic succession, the Wandrawandian Siltstone contains evidence for cold, possibly glacial conditions based on the presence of outsized clasts and glendonites, mineral pseudomorphs after...

Extensive development in the St. George, Utah area resulted in the temporary exposure of fresh rock at and near the St. George Dinosaur Discovery Site at Johnson Farm (SGDS), facilitating examination and description of the Lower Jurassic stratigraphy of the vicinity in some detail. Since this study, construction has covered much of what we observed, making this the only detailed record of the M...

Pulsed column experiments using Co, fulvic acid and porous sediment packing, along with up/down-flooding experiments using Eu, humic acid and intact sandstone blocks have been performed. The elution of metal and humic and their distribution along the sandstone columns have been measured. A mixed equilibrium and kinetic coupled chemical transport model has been used to simulate the results. In b...