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Buda Limestone
The Buda Limestone is a geological formation in the High Plains and Trans-Pecos regions of West Texas and in southern New Mexico, whose strata date back to the Late Cretaceous. Pterosaur remains are among the fossils that have been recovered from the formation.Barrett, P.M., Butler, R.J., Edwards, N.P., & Milner, A.R. Pterosaur distribution in time and space: an atlas. p61-107. in Flugsaurier: Pterosaur papers in honour of Peter Wellnhofer. 2008. Hone, D.W.E., and Buffetaut, E. (eds). Zitteliana B, 28. 264p/ref> Description The Buda Limestone is a dense white to yellow sparry limestone with numerous calcite veins that weathers to yellowish or pinkish due to its iron content. In far western Texas, the formation overlies the Del Rio Formation and is in turn overlain by the Eagle Ford Group. The total thickness is about . In trans-Pecos Texas, the formation rests on the Grayson Formation and is overlain by the Boquillas Formation. In the Big Bend National Park area, the formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. There were two major types of pterosaurs. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or 'rhamphorhynchoids') were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected the hind legs. On the ground, they would have had an awkward sprawling posture, but the anatomy of their joints and strong claws would have made them effective climbers, and some may have even lived in trees. Basal pterosaurs were insectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alectryonia
''Lopha'' is a genus of marine bivalve molluscs in the family Ostreidae. The genus ''Lopha'' is present from the Triassic period in the Lower Norian age (216.5 ± 2.0 – 203.6 ± 1.5 Mya) to the recent age. Description ''Lopha'' species have thick, strongly ribbed shells with unequal valves. The margins of the valves have a characteristic zig-zag pattern. The lower valve shows finger-like outgrowths, by which the molluscs adhere to the substrate. These molluscs are stationary, epifaunal, suspension feeders, as they feed by filtering sea water to extract the nutrients. Species * ''Lopha affinis'' Sowerby, 1871 * ''Lopha capsa'' Fischer von Waldheim, 1808 * ''Lopha chemnitzii'' Hanley, 1846 * ''Lopha cristagalli'' C. Linnaeus, 1758 * ''Lopha frons'' C. Linnaeus, 1758 * ''Lopha imbricata'' J. B. Lamarck, 1819 * ''Lopha rosacea'' G. P. Deshayes, 1836 Fossil species *''Lopha gregarea'', Oxfordian (stage) (160 mya) *''Lopha marshii'' (Sowerby, 1914), Bajocian In the geologic tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelecypod
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances. The shell of a bivalve is composed of ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gryphaea
''Gryphaea'', one of the genera known as devil's toenails, is a genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae. These fossils range from the Triassic period to the middle Paleogene period, but are mostly restricted to the Triassic and Jurassic. They are particularly common in many parts of Britain. These oysters lived on the sea bed in shallow waters, possibly in large colonies. The complete fossils consist of two articulated valves: a larger gnarly-shaped shell (the "toenail") and a smaller, flattened shell, the "lid". The soft parts of the animal occupied the cavity between the two shells, just like modern oysters. The shells also feature prominent growth bands. The larger, curved shell sat within the mud on the sea floor. These shells are sometimes found in fossil plates along with ''Turritella'', clams, and sometimes sharks' teeth and fossilized fish scales. Its distribution is common in areas of both Europe. A classic location to find thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globigerina
''Globigerina'' () is a genus of planktonic Foraminifera, in the order of Rotaliida.Globigerina World Foraminifera Database, accessed 3 December 2018 It has populated the world's oceans since the Middle . ''Globigerina'' ooze Vast areas of the ocean floor are covered with ''Globigerina'' ooze, dominated by the foraminiferous shells of ''Globigerina'' and other |
Foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and other uses; and commonly an external shell (called a "Test (biology), test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthos, benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test (biology), test, or shell, which can have eithe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marl
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part of the cliffs of Dover, and the Channel Tunnel follows these marl layers between France and the United Kingdom. Marl is also a common sediment in post-glacial lakes, such as the marl ponds of the northeastern United States. Marl has been used as a soil conditioner and neutralizing agent for acid soil and in the manufacture of cement. Description Marl or marlstone is a carbonate-rich mud or mudstone which contains variable amounts of clays and silt. The term was originally loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay and calcium carbonate, formed under freshwater conditions. These typically contain 35–65% clay and 65–35% carbonate. The te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argillaceous
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals form in the presence of water and have been important to life, and many theories of abiogenesis involve them. They are important constituents of soils, and have been useful to humans since ancient times in agriculture and manufacturing. Properties Clay is a very fine-grained geologic material that develops plasticity when wet, but becomes hard, brittle and non–plastic upon drying or firing. It is a very common material, and is the oldest known ceramic. Prehistoric humans discovered the useful properties of clay and used it for making pottery. The chemistry of clay, including its capacity to retain nutrient cations such as potassium and ammonium, is important to soil fertility. Because the individual particles in clay are less than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bend National Park
Big Bend National Park is an American national park located in West Texas, bordering Mexico. The park has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, and was named after a large bend in the Rio Grande/Río Bravo. The park protects more than 1,200 species of plants, more than 450 species of birds, 56 species of reptiles, and 75 species of mammals. Additional park activities include scenic drives, programs led by Big Bend park rangers, and stargazing. The area has a rich cultural history, from archeological sites dating back nearly 10,000 years to more recent pioneers, ranchers, and miners. The Chisos Mountains are located in the park, and are the only mountain range in the United States to be fully contained within the boundary of a national park. Geological features in the park include sea fossils and dinosaur bones, as well as volcanic dikes. The park encompasses an area of , entirely within Brewst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Society Of Exploration Geophysicists
The Society of Exploration Geophysicists (SEG) is a learned society dedicated to promoting the science and education of exploration geophysics in particular and geophysics in general. The Society fosters the expert and ethical practice of geophysics in the exploration and development of natural resources, in characterizing the near-surface, and in mitigating earth hazards. SEG has more than 14,000 members working in more than 114 countries. SEG was founded in 1930 in Houston, Texas but its business office has been headquartered in Tulsa, Oklahoma since the mid-1940s. While most SEG members are involved in exploration for petroleum, SEG members also are involved in application of geophysics methods to mineral exploration as well as environmental and engineering problems, archaeology, and other scientific endeavors. SEG publishes ''The Leading Edge'' (''TLE''), a monthly professional magazine, ''Geophysics'', a peer-reviewed archival publication, and ''Interpretation'', a peer-review ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for Lime (material), lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeology, archaeologists and stone trade pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
