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Crosswicks Clay
The Crosswicks Clay is a geologic formation in Delaware. It preserves fossils dating back to the Cretaceous period. See also * List of fossiliferous stratigraphic units in Delaware This article contains a list of fossil-bearing stratigraphic units in the state of Delaware, U.S. Sites See also * Paleontology in Delaware References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Delaware Delaware Stratigraph ... * Paleontology in Delaware References * Cretaceous Delaware {{delaware-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
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 (geology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (geology)
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] |
Delaware
Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent Delaware Bay, in turn named after Thomas West, 3rd Baron De La Warr, an English nobleman and Virginia's first colonial governor. Delaware occupies the northeastern portion of the Delmarva Peninsula and some islands and territory within the Delaware River. It is the second-smallest and sixth-least populous state, but also the sixth-most densely populated. Delaware's largest city is Wilmington, while the state capital is Dover, the second-largest city in the state. The state is divided into three counties, having the lowest number of counties of any state; from north to south, they are New Castle County, Kent County, and Sussex County. While the southern two counties have historically been predominantly agricultural, New Castle is more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Delaware
This article contains a list of fossil-bearing stratigraphic units in the state of Delaware, U.S. Sites See also * Paleontology in Delaware References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Delaware Delaware Stratigraphic units A stratigraphic unit is a volume of Rock (geology), rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrology, petrographic, lithology, lithologic or paleontology, p ... Stratigraphy of Delaware Delaware geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Delaware
The location of the state of Delaware Paleontology in Delaware refers to paleontological research occurring within or conducted by people from the U.S. state of Delaware. There are no local rocks of Precambrian, Paleozoic, Triassic, or Jurassic age, so Delaware's fossil record does not begin until the Cretaceous period. As the Early Cretaceous gave way to the Late Cretaceous, Delaware was being gradually submerged by the sea. Local marine life included cephalopods like ''Belemnitella americana'', and marine reptiles. The dwindling local terrestrial environments were home to a variety of plants, dinosaurs, and pterosaurs. Along with New Jersey, Delaware is one of the best sources of Late Cretaceous dinosaur fossils in the eastern United States. Delaware was still mostly covered by sea water through the Cenozoic era. Local marine life included manatees, porpoises, seals, and whales. Delaware was worked over by glaciers during the Ice Age. The Cretaceous belemnite ''Belemnitella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
