The Pierre Shale is a marine deposit that accumulated in the Cretaceous Western Interior Seaway during the onset of Laramide tectonism in the southern Rocky Mountains region. In the eastern part of the Raton Basin near Trinidad, Colorado, ammonite biostratigraphy suggests that the base of the Pierre Shale lies within or slightly above the Lower Campanian Scaphites hippocrepis III ammonite range...

Sea urchins are dominant members of rocky temperate reefs around the world. They often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these "pits." However, there are no experimental data demonstrating they bore pits. If they do, what are the rates and consequences of bioerosion to nearshore systems? We sampled purple sea urchins, Strongylocentrotus...

The mechanical properties of any substance are essential facts to understand its behaviour and make the maximum use of the particular substance. Rocks are indeed an important substance, as they are of significant use in the energy industry, specifically for fossil fuels and geothermal energy. Attenuation of seismic waves is a non-destructive technique to investigate mechanical properties of res...

Deep-water massive (featureless) sands are commonly interpreted as indicators of flow conditions during or shortly after deposition and are almost never interpreted to reflect post-depositional homogenization due to bioturbation. Deep-water deposits of the lower Rio Dell Formation (Pliocene), Eel River basin (NW California), however, reveal previously unrecognized cryptically bioturbated fabric...

5 Interspecific relationships 48 INTRODUCTION 5 Predation 49 Location and geologic setting 5 Competition 50 Previous work 7 Commensalism 50 Approaches and study objectives 7 DEPOSITIONAL ENVIRONMENT AND Vertebrate paleontology 8 PALEOECOLOGIC SYNTHESIS 50 Paleobotany 8 Climate and paleogeography 50 Stratigraphy and correlation 8 Succession of the ancient communities 51 Acknowledgments 12 Summar...

Sand production is a universally encountered issue during the exploration of unconsolidated sandstone reservoirs particularly during production. The production of sand particles with the reservoir fluids depends on the stress around a wellbore and the properties of the reservoir rocks and fluids. Therefore, it is crucial to predict under what production conditions sanding will occur and when sa...

middle-late eocene deep marine deposits (483 m.) of the islam-ghaleh section, south mashhad, rich in ichnofossils in shale and sandstone layers. these flysch type sediments are composed of sandstone, shale and marl in gray to green in color and are divided into five subunits. the lower boundary of these successions is gradual with red conglomerate and sandstone and their upper boundary is gradu...

Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturi...

Bumps and other types of dynamic failure have been a persistent, worldwide problem in the underground coal mining industry, spanning decades. For example, in just five states in the U.S. from 1983 to 2014, there were 388 reportable bumps. Despite significant advances in mine design tools and mining practices, these events continue to occur. Many conditions have been associated with bump potenti...