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List Of Fossiliferous Stratigraphic Units In Maine
This article contains a list of fossil-bearing stratigraphic units in the state of Maine, Maine, U.S. Sites See also * Paleontology in Maine References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Maine Fossiliferous stratigraphic units of the United States, Maine Paleontology in Maine, Stratigraphic units Stratigraphy of Maine Maine geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, paleontologic features (facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary rock, sedimentary and volcanic rocks are subdivided the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are Bed, Member, Formation, Group and Supergroup. Formal names of lithostratigraph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy Of Maine
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossiliferous Stratigraphic Units Of The United States
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] |
Paleontology In Maine
The location of the state of Maine Paleontology in Maine refers to paleontological research occurring within or conducted by people from the U.S. state of Maine. The fossil record of Maine is very sparse. Maine came into existence during the Ordovician as other ancient land masses accreted onto North America. At the time Maine was covered by a sea inhabited by a menagerie of invertebrates which included graptolites. During the Devonian, geologic uplift raised Maine above sea level. Early land plants flourished in the terrestrial environments. There is a gap in the local rock record spanning the remainder of the Paleozoic, the Mesozoic, and the Tertiary period of the Cenozoic era. During the Ice Age, Maine was varyingly covered by glaciers or seawater. The Devonian Pertica plant, '' Pertica quadrifaria'', is the Maine state fossil. Prehistory Maine came into existence during the Ordovician as other ancient land masses accreted onto North America. At the time, however, Maine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trout Valley Formation
The Trout Valley Formation is a geologic formation in Maine. It preserves fossils dating back to the Devonian period. Description Situated in north-central Maine, the Trout Valley Formation is located in a fault-bounded basin. An erosional unconformity separates it from underlying felsites. The formation exists entirely within the confines of Baxter State Park, and collecting of materials without authorization is prohibited. The formation represents an alluvial fan draining an active volcanic source and has a basal cobble conglomerate, consisting only of rounded fragments of the underlying volcanic felsite, known formally as the Traveler Rhyolite. The conglomerate is overlain by sandstone, which contains lenses of gray shale, black shale and fine conglomerate, in a generally fining-upward sequence. The unit's distal portions terminate in tidal mudflats, which have produced a bivalve-dominated fauna that also yielded the first relatively complete Eurypterid found in north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarratine Formation
The Tarratine Formation is a geologic formation in Maine. It preserves fossils dating back to the Devonian period. Description The Tarratine Formation is part of the larger Gaspé Group which extend from the Gaspé Peninsula to Long Island Sound. The Seboomoook Formation is interpreted as grading into the sandstones of the Tarratine Formation. In the late 20th century, geologists debated the origin of the sandstone in the formation. Some attributed the sand to islands, while geologists in Quebec suggested that the sand resulted from erosion associated with the Acadian orogeny. The formation is present in the Moose River synclinorium in north-central Maine. See also * List of fossiliferous stratigraphic units in Maine * Paleontology in Maine The location of the state of Maine Paleontology in Maine refers to paleontological research occurring within or conducted by people from the U.S. state of Maine. The fossil record of Maine is very sparse. Maine came into existence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shin Brook Formation
The Shin Brook Formation is a geologic formation in Maine. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in Maine * Paleontology in Maine The location of the state of Maine Paleontology in Maine refers to paleontological research occurring within or conducted by people from the U.S. state of Maine. The fossil record of Maine is very sparse. Maine came into existence during the O ... References * Ordovician Maine Ordovician southern paleotemperate deposits {{Maine-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
