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Cerro Conejo Formation
The Cerro Conejo Formation is a middle to late Miocene geologic formation exposed near Albuquerque, New Mexico. Gravel beds within the formation in the Rio Puerco valley west of Albuquerque have provided clues to the paleogeography of the Grants area since the early Miocene. Description The Cerro Conejo Formation is composed of very light brown to pink or yellowish-red, fine- to medium-grained, well- sorted, medium- to thick- bedded sandstone. The beds are tabular and locally cross-stratified and include occasional thinly bedded mudstone. Sandstone grains are subrounded and frosted. The formation also contains numerous white to light greenish gray volcanic ash beds. The total thickness is . The formation overlies the Zia Formation and interfingers with the overlying Arroyo Ojito Formation. One of the ash beds within the formation yielded a K-Ar age of 13.64 +/-0.09 million years ( Ma. The overall age range is constrained to between 14.8 and 9.5 Ma. Gravel beds within t ... [...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] |
Bedding (geology)
In geology, a bed is a layer of sediment, sedimentary rock, or pyroclastic material "bounded above and below by more or less well-defined bedding surfaces".Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds., 2005. ''Glossary of Geology'' (5th ed.). Alexandria, Virginia; American Geological Institute. p 61. Specifically in sedimentology, a bed can be defined in one of two major ways.Davies, N.S., and Shillito, A.P. 2021, ''True substrates: the exceptional resolution and unexceptional preservation of deep time snapshots on bedding surfaces.'' ''Sedimentology.'' published online 22 May 2021, doi: 10.1111/sed.12900. First, Campbell and Reineck and SinghReineck, H.E., and Singh, I.B., 1980. ''Depositional Sedimentary Environments'', (2nd ed.) Berlin, Germany: Springer-Verlag, 504 pp. use the term ''bed'' to refer to a thickness-independent layer comprising a coherent layer of sedimentary rock, sediment, or pyroclastic material bounded above and below by surfaces known as beddi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barstovian
The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 16,300,000 to 13,600,000 years BP, a period of . It is usually considered to overlap the Langhian and Serravallian stages of the Middle Miocene. The Barstovian is preceded by the Hemingfordian and followed by the Clarendonian NALMA stages. The Barstovian can be further divided into the substages of: * late Late Barstovian: Lower boundary source of the base of the Langhian (approximate) * early Late Barstovian: Base of the Langhian (approximate) * early/lower Barstovian: Upper boundary source: base of Clarendonian (approximate) Correlations The Barstovian (15.97 to 13.6 Ma) correlates with: * SALMA ** Colloncuran (15.5-13.8 Ma) [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Member (stratigraphy)
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or 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 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 lithostratigraphic units are assigned by geological surveys. Units of formation or hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from '' Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog Amphicyonidae is an extinct family of terrestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grants, New Mexico
Grants is a city in Cibola County, New Mexico, United States. It is located about west of Albuquerque. The population was 9,163 at the 2020 Census. It is the county seat of Cibola County. Grants is located along the Trails of the Ancients Byway, one of the designated New Mexico Scenic Byways.Trail of the Ancients. New Mexico Tourism Department. Retrieved August 14, 2014. History Grants began as a railroad camp in the 1880s, when three Canadian brothers – Angus A. Grant, John R. Grant, and Lewis A. Grant – were awarded a contract to build a section of the Atlantic and Pacific Railroad through the region. The Grant brothers' camp was first called Grants Camp, then Grants Sta ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albuquerque
Albuquerque ( ; ), ; kee, Arawageeki; tow, Vakêêke; zun, Alo:ke:k'ya; apj, Gołgéeki'yé. abbreviated ABQ, is the most populous city in the U.S. state of New Mexico. Its nicknames, The Duke City and Burque, both reference its founding in 1706 as ''La Villa de Alburquerque'' by Nuevo México governor Francisco Cuervo y Valdés''.'' Named in honor of the Viceroy of New Spain, the 10th Duke of Alburquerque, the city was an outpost on El Camino Real linking Mexico City to the northernmost territories of New Spain. Located in the Albuquerque Basin, the city is flanked by the Sandia Mountains to the east and the West Mesa to the west, with the Rio Grande and bosque flowing from north-to-south. According to the 2020 census, Albuquerque had 564,559 residents, making it the 32nd-most populous city in the United States and the fourth largest in the Southwest. It is the principal city of the Albuquerque metropolitan area, which had 916,528 residents as of July 2020, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ma (unit)
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mean yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interfingering
A geological contact is a boundary which separates one rock body from another. A contact can be formed during deposition, by the intrusion of magma, or through faulting or other deformation of rock beds that brings distinct rock bodies into contact. The geologic subdiscipline of stratigraphy is primarily concerned with depositional contacts,Boggs 2006, p. 401 while faults and shear zones are of particular interest in structural geology. Faults and shear zones can be regarded as a form of secondary structure in the rock beds.Davis and Kluth 2011, p.21 Types of contacts Depositional Conformable Conformable contacts represent no time gap in the geologic record. They are usually planar, though they may have slightly irregular topography. These contacts represent continual, uninterrupted deposition and accumulation of sedimentary rocks, or represent lava flows. A conformable contact can be ''abrupt'', where the contact separates beds of distinct lithology. Abrupt contacts coi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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