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Los Angeles Basin
The Los Angeles Basin is a sedimentary basin located in Southern California, in a region known as the Peninsular Ranges. The basin is also connected to an anomalous group of east-west trending chains of mountains collectively known as the Transverse Ranges. The present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills that is located on the edge of the Pacific Plate. The Los Angeles Basin, along with the Santa Barbara Channel, the Ventura Basin, the San Fernando Valley, and the San Gabriel Basin, lies within the greater southern California region. On the north, northeast, and east, the lowland basin is bound by the Santa Monica Mountains and Puente, Elysian, and Repetto hills. To the southeast, the basin is bordered by the Santa Ana Mountains and the San Joaquin Hills. The western boundary of the basin is marked by the Continental Borderland and is part of the onshore portion. The California borderland is characterized by n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Basin
The Los Angeles Basin is a sedimentary basin located in Southern California, in a region known as the Peninsular Ranges. The basin is also connected to an anomalous group of east-west trending chains of mountains collectively known as the Transverse Ranges. The present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills that is located on the edge of the Pacific Plate. The Los Angeles Basin, along with the Santa Barbara Channel, the Ventura Basin, the San Fernando Valley, and the San Gabriel Basin, lies within the greater southern California region. On the north, northeast, and east, the lowland basin is bound by the Santa Monica Mountains and Puente, Elysian, and Repetto hills. To the southeast, the basin is bordered by the Santa Ana Mountains and the San Joaquin Hills. The western boundary of the basin is marked by the Continental Borderland and is part of the onshore portion. The California borderland is characterized by n ... [...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] |
Catalina Schist
The Catalina Schist is a metamorphic rock complex primarily exposed on Santa Catalina Island of the Channel Islands of California. It formed during the Cretaceous Period of the Mesozoic Era. Geology The Catalina Schist is broadly correlated with the Franciscan Complex, a similar metamorphic complex formed along the California margin.Rowland, Stephan M., ''Geology of Santa Catalina Island,'' California Geology, 1984 Both of these units record high-pressure/low-temperature metamorphism associated with the subduction of the Farallon plate beneath North America during the Mesozoic Era. The Catalina Schist is differentiated from the Franciscan primarily in the style of mélange formed during subduction. In the Los Angeles Harbor Region, Catalina Schist is associated with the Wilmington Oil Field The Wilmington Oil Field is a prolific petroleum field in Los Angeles County in southern California in the United States. Discovered in 1932, it is the third largest oil field in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newport–Inglewood Fault
The Newport–Inglewood Fault is a right-lateral strike-slip fault in Southern California. The fault extends for from Culver City southeast through Inglewood and other coastal communities to Newport Beach at which point the fault extends east-southeast into the Pacific Ocean where it is known as the Rose Canyon Fault. The fault can be inferred on the Earth's surface as passing along and through a line of hills extending from Signal Hill to Culver City. The fault has a slip rate of approximately /year and is predicted to be capable of a 6.0–7.4 magnitude earthquake on the moment magnitude scale. A 2017 study concluded that, together, the Newport–Inglewood Fault and Rose Canyon Fault could produce an earthquake of 7.3 or 7.4 magnitude. The fault was first identified after a magnitude 4.9 earthquake struck near Inglewood, California on June 21, 1920. Due to the lack of earthquake-resistant construction in southern California at this time, this quake caused considerable dama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasing temperature and pressure characterize ''retrograde metamorphism''. Metamorphic petrology is the study of metamorphism. Metamorphic petrologists re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust. Geological significance Igneous and metamorphic rocks make up 90–95% of the top ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone (sedimentary rocks) through lithification. Sediments are most often transported by water (fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Classification Sediment can be classified based on its grain size, grain shape, and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the northern hemisphere and the metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Unconformity
Of the many unconformities (gaps) observed in geological strata, the term Great Unconformity is frequently applied to either the unconformity observed by James Hutton in 1787 at Siccar Point in Scotland,Rance, H (1999''Historical Geology: The Present is the Key to the Past.'' QCC Press, New York or that observed by John Wesley Powell in the Grand Canyon in 1869. Both instances are exceptional examples of where the contacts between sedimentary strata and either sedimentary or crystalline strata of greatly different ages, origins, and structure represent periods of geologic time sufficiently long to raise great mountains and then erode them away. Background Unconformities tend to reflect long-term changes in the pattern of the accumulation of sedimentary or igneous strata in low-lying areas (often ocean basins, such as the Gulf of Mexico or the North Sea, but also Bangladesh and much of Brazil), then being uplifted and eroded (such as the ongoing Himalayan orogeny, the older Larami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fernando Formation
The Fernando Formation is a Plio-Pleistocene marine mudstone, siltstone and sandstone formation in the greater Los Angeles Basin, Ventura Basin, and Santa Monica Mountains, in Los Angeles County of Southern California. Geology Outcrops of the formation in Santa Monica Mountains National Recreation Area have produced fossil shark teeth.Hunt, Santucci, and Kenworthy (2006). "Santa Monica Mountains National Recreation Area", page 67. Classification The underlying Repetto Formation is equivalent in age to the Fernando Formation, and some researchers consider it as well as the overlying Pico Formation to be a junior synonym based on benthic 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 ot ... stages. Other researchers maintain that the Repetto and Pico Formations are di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pico Formation
The Pico Formation is a Pliocene epoch stratigraphic unit and geologic formation in the greater Los Angeles Basin, the Santa Monica Mountains, and the Santa Susana Mountains, in Los Angeles County of Southern California. Geology It was formed during the Neogene period of the Cenozoic Era, and overlies the Repetto Formation.Blake, Gregg H. 1991. "Review of the Neogene biostratigraphy and stratigraphy of the Los Angeles Basin and implications for basin evolution," In: Biddle, Kevin T. (ed), "Active Margin Basins", AAPG Memoir 52, 319pp. Outcrops of the formation in Santa Monica Mountains National Recreation Area have produced fossil shark teeth from the Pliocene."Santa Monica Mountains National Recreation Area," Hunt, Santucci, and Kenworthy (2006); page 67. In addition to fossils, armored mud balls were found by Cartwright (1928) in possible fluvial or coastal deposits of the Pico Formation, though they were referred to as "pudding balls" in the article. Classification The und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
