Geology of Southern California
... sandstone, shale, and chert, are very common along the southern California coast in the western Transverse Ranges. These ancient sediments commonly contain, or sometimes even consist almost entirely of, the fossil remains of marine plants and animals. Farther inland, thick sequences of Cenozoic sand ...
... sandstone, shale, and chert, are very common along the southern California coast in the western Transverse Ranges. These ancient sediments commonly contain, or sometimes even consist almost entirely of, the fossil remains of marine plants and animals. Farther inland, thick sequences of Cenozoic sand ...
Field Trip Guide to the Upper Cretaceous Hornbrook Formation and
... occupies approximately 19,000 km2 in southwestern Oregon and northern California. The Klamath Mountains are made-up of numerous terranes that accreted during the Antler (Devonian), Sonoman (Permian to Late Triassic), and Nevadan (Jurassic to Early Cretaceous) orogenies (Mortimer, 1984). These terran ...
... occupies approximately 19,000 km2 in southwestern Oregon and northern California. The Klamath Mountains are made-up of numerous terranes that accreted during the Antler (Devonian), Sonoman (Permian to Late Triassic), and Nevadan (Jurassic to Early Cretaceous) orogenies (Mortimer, 1984). These terran ...
cadernos 34
... Palaeozoic. The plutonic rocks are known as Older Granite and have been dated to about 500 to 600 million years, representing the Pan-African orogeny in Nigeria. The granite bodies are widespread in the north and range in size from the smaller elliptical plutons to the masses of batholithic dimensio ...
... Palaeozoic. The plutonic rocks are known as Older Granite and have been dated to about 500 to 600 million years, representing the Pan-African orogeny in Nigeria. The granite bodies are widespread in the north and range in size from the smaller elliptical plutons to the masses of batholithic dimensio ...
Range Front Structural Geometries and Décollement related
... of Surghar Range, representing the sub-Himalayan frontal structural signatures of northwest Pakistan. Acquisition of outcrop data and structural mapping in the area revealed that the Surghar Range is delimited by a prominent frontal thrust fault which is laterally extended from Kurrum River of Dera ...
... of Surghar Range, representing the sub-Himalayan frontal structural signatures of northwest Pakistan. Acquisition of outcrop data and structural mapping in the area revealed that the Surghar Range is delimited by a prominent frontal thrust fault which is laterally extended from Kurrum River of Dera ...
Preliminary Geologic Map of the - New Mexico Bureau of Geology
... tectonic evolution of central New Mexico. The Paleoproterozoic rocks of the Becker quadrangle and adjacent Scholle quadrangle had been mapped by Myers et al. (1981) and Myers (1977), respectively, as a west-dipping homoclinal succession with Sais Quartzite at the base and Sevilleta Metarhyolite at t ...
... tectonic evolution of central New Mexico. The Paleoproterozoic rocks of the Becker quadrangle and adjacent Scholle quadrangle had been mapped by Myers et al. (1981) and Myers (1977), respectively, as a west-dipping homoclinal succession with Sais Quartzite at the base and Sevilleta Metarhyolite at t ...
Deep-Seated Mass Rock Creep Along The Karakoram
... This site may illustrate the nature of a pure toppling feature. The most interesting outcrop is given there by a strangly prominent outstanding slab of rock. It represents a surprising feature of local relief at the outermost end or spur of a glacially abraded smooth ridge. As one can see on the pic ...
... This site may illustrate the nature of a pure toppling feature. The most interesting outcrop is given there by a strangly prominent outstanding slab of rock. It represents a surprising feature of local relief at the outermost end or spur of a glacially abraded smooth ridge. As one can see on the pic ...
Teachers guide to geologic trails in Delaware Water Gap National
... summits and peneplains, the formation of wind and water gaps, and the origin of waterfalls as they relate to the complex glacial history of the area. ...
... summits and peneplains, the formation of wind and water gaps, and the origin of waterfalls as they relate to the complex glacial history of the area. ...
Chortis block: where did it come from - Centro de Geociencias
... rest unconformably beneath Middle Jurassic rocks of the Agua Fría Formation (Viland et al., 1996), or Late Triassic-Jurassic sedimentary rocks of the El Plan Formation (Carpenter, 1954; Maldonado-Koerdell, 1953). The Cacaguapa Group or Schist (locally called Petén and Palacaguina formations) is desc ...
... rest unconformably beneath Middle Jurassic rocks of the Agua Fría Formation (Viland et al., 1996), or Late Triassic-Jurassic sedimentary rocks of the El Plan Formation (Carpenter, 1954; Maldonado-Koerdell, 1953). The Cacaguapa Group or Schist (locally called Petén and Palacaguina formations) is desc ...
Oil, natural gas and helium potential of the Chupadera Mesa area
... Pennsylvanian strata, and northward pinchout of Ordovician carbonate rocks in the southern part of the region. There is also a very limited coalbed methane potential in Cretaceous strata in the Jornada del Muerto and Sierra Blanca basins. The Chupadera Mesa project area also has favorable potential ...
... Pennsylvanian strata, and northward pinchout of Ordovician carbonate rocks in the southern part of the region. There is also a very limited coalbed methane potential in Cretaceous strata in the Jornada del Muerto and Sierra Blanca basins. The Chupadera Mesa project area also has favorable potential ...
Map of the 77th Annual Field Conference of Pennsylvania
... Topset and foreset beds in a glacial delta exposed in sandpit to left. Exposure of Marcellus Shale on right. The Marcellus in this area is a medium dark-gray to grayish-black, laminated to poorly bedded, shale and silty shale. It lies more than 4,000 ft (1,219 m) above the Martinsburg Formation. Cle ...
... Topset and foreset beds in a glacial delta exposed in sandpit to left. Exposure of Marcellus Shale on right. The Marcellus in this area is a medium dark-gray to grayish-black, laminated to poorly bedded, shale and silty shale. It lies more than 4,000 ft (1,219 m) above the Martinsburg Formation. Cle ...
Permian Cyclic Strata, Northern Midland and Delaware Basins, West
... steep depositional topography. Foreslope deposits are distinguished from shallow-water bank and reef beds by their darker color, common presence of silicified fossils, and by numerous shelf-derived lithoclasts. Deposition was the result of several mass-transport processes such as slow creep and susp ...
... steep depositional topography. Foreslope deposits are distinguished from shallow-water bank and reef beds by their darker color, common presence of silicified fossils, and by numerous shelf-derived lithoclasts. Deposition was the result of several mass-transport processes such as slow creep and susp ...
Students report
... Mead); it consists of coarse, red Miocene sandstones on the foot, overlain by a large basaltic lava flow (Fortification Hill basalt). Located further east are the Black Mountains, where Miocene plutonic and volcanic rocks are exposed (Wilson Ridge pluton), as well as some proterozoic metamorphic and ...
... Mead); it consists of coarse, red Miocene sandstones on the foot, overlain by a large basaltic lava flow (Fortification Hill basalt). Located further east are the Black Mountains, where Miocene plutonic and volcanic rocks are exposed (Wilson Ridge pluton), as well as some proterozoic metamorphic and ...
Geologic Quadrangle Map No. 40: Gravity, Magnetic, and
... the Texas andPacific Railway on the south and the south-facing escarpment of Sierra Diablo on the north. The Allamoore consists of about 2,500 feet of limestone and dolomite, but minor thicknesses of conglomerate, talcose phyllite, and volcanic flow and pyroclastic rock are included. The Hazel consi ...
... the Texas andPacific Railway on the south and the south-facing escarpment of Sierra Diablo on the north. The Allamoore consists of about 2,500 feet of limestone and dolomite, but minor thicknesses of conglomerate, talcose phyllite, and volcanic flow and pyroclastic rock are included. The Hazel consi ...
Volcanic activity is the process of molten rock flowing
... The site of the Lamont Odett Vista Point provides a sweeping view across the Antelope Valley to the Tehachapi Range portion of the Sierra Nevada Mountains in the far distance. The Antelope Valley is a triangularly shaped region that constitutes the western-most extension of the Mohave Desert. The Te ...
... The site of the Lamont Odett Vista Point provides a sweeping view across the Antelope Valley to the Tehachapi Range portion of the Sierra Nevada Mountains in the far distance. The Antelope Valley is a triangularly shaped region that constitutes the western-most extension of the Mohave Desert. The Te ...
DWM-132 - Idaho Geological Survey
... quartzite in beds as thick as 2 m. Dark hematite lamination internal to beds commonly define trough cross beds, more rarely smaller sedimentary structures. Floating pebbles as large as 2.5 cm in diameter of quartz, quartzite with little or no feldspar, gneiss, and hornblende granite are characterist ...
... quartzite in beds as thick as 2 m. Dark hematite lamination internal to beds commonly define trough cross beds, more rarely smaller sedimentary structures. Floating pebbles as large as 2.5 cm in diameter of quartz, quartzite with little or no feldspar, gneiss, and hornblende granite are characterist ...
rocks and geology in the SF bay region
... Geology is also the story of processes and products formed on or below the Earth’s surface. To simply identify the name of a rock is a relatively elementary task (don’t let them kid you... even the most experienced petrologist can have a hard time without sophisticated tools). However, developing an ...
... Geology is also the story of processes and products formed on or below the Earth’s surface. To simply identify the name of a rock is a relatively elementary task (don’t let them kid you... even the most experienced petrologist can have a hard time without sophisticated tools). However, developing an ...
Hoggar Shield gold mineralization- Khoudour
... well as relicts of Eburnean basement and original basite-granulite crust, underlying Riphean geosynclines. The oldest Eburnean Archean middle massifs having relics of granulites and charnokites are exposed at In-Uzzal block (Figure 4) as well as in the north of the Central Hoggar. Kibar formations a ...
... well as relicts of Eburnean basement and original basite-granulite crust, underlying Riphean geosynclines. The oldest Eburnean Archean middle massifs having relics of granulites and charnokites are exposed at In-Uzzal block (Figure 4) as well as in the north of the Central Hoggar. Kibar formations a ...
The Nuneaton Millennium Project
... Caldecote Volcanic Formation (this includes: crystal-lapilli tuff, lithic-crystal-lapilli tuff, coarse crystal tuff, stratified and graded crystal vitric tuff and lapilli tuff, stratified lapilli tuff-breccia, tuffaceous mudstones, siltstones (some laminated) and sandstones, granophyric diorite (Mar ...
... Caldecote Volcanic Formation (this includes: crystal-lapilli tuff, lithic-crystal-lapilli tuff, coarse crystal tuff, stratified and graded crystal vitric tuff and lapilli tuff, stratified lapilli tuff-breccia, tuffaceous mudstones, siltstones (some laminated) and sandstones, granophyric diorite (Mar ...
The Geological Concept
... Literally, the word "mountain" (LatinMontanus) is described as "a landmass that projects conspicuously above its surroundings and is higher than a hi/I" (34). The Dictionary of Geological Terms (p 289) defines a mount or a mountain as a high hill (but mount is used always instead of mountain before ...
... Literally, the word "mountain" (LatinMontanus) is described as "a landmass that projects conspicuously above its surroundings and is higher than a hi/I" (34). The Dictionary of Geological Terms (p 289) defines a mount or a mountain as a high hill (but mount is used always instead of mountain before ...
Bulletin 113: Geology of East Portillo Mountains and Vicinity, Doña
... Mexico, the East Potrillo Mountains area reveals important details about Laramide, middle Tertiary, and late Tertiary deformation in the region, as well as data on Permian, Lower Cretaceous, and Cenozoic stratigraphy. The oldest rocks exposed in the area are limestone, dolomitic limestone, and minor ...
... Mexico, the East Potrillo Mountains area reveals important details about Laramide, middle Tertiary, and late Tertiary deformation in the region, as well as data on Permian, Lower Cretaceous, and Cenozoic stratigraphy. The oldest rocks exposed in the area are limestone, dolomitic limestone, and minor ...
Metamorphic core complexes
... granitoids as one of the main results of decompression. The granitoids may ductilely overprinted dependent on uplift process. The granitoids, especially as sills or sill swarms, are found in the central part of gneiss domes and are emplaced into shallow crustal levels. Gravity lows and aeromagnetic ...
... granitoids as one of the main results of decompression. The granitoids may ductilely overprinted dependent on uplift process. The granitoids, especially as sills or sill swarms, are found in the central part of gneiss domes and are emplaced into shallow crustal levels. Gravity lows and aeromagnetic ...
Ophiolithic Placer Deposits and Their Ore Potential, Çamköy
... Paleotethys. The Philippines and Japan samples were reported from Permian shallow-marine limestones contained in Jurassic accretionary complexes. The Alaska specimens are from a large limestone block within mélange of the McHugh Complex. Thus the distribution of alatoconchids was of distinctive Pale ...
... Paleotethys. The Philippines and Japan samples were reported from Permian shallow-marine limestones contained in Jurassic accretionary complexes. The Alaska specimens are from a large limestone block within mélange of the McHugh Complex. Thus the distribution of alatoconchids was of distinctive Pale ...
CHAPTER 4 PRE-TERTIARY GEOLOGY OF NEVADA
... age in the Silver Peak district; the epithermal precious-metal deposits at Delamar, and some gold-quartz veins in the Johnnie district are hosted in quartzites of this assemblage. Lower Paleozoic Carbonate Assemblage (North America) In middle Cambrian time, the mostly terrigenous, coarse, quartzose, ...
... age in the Silver Peak district; the epithermal precious-metal deposits at Delamar, and some gold-quartz veins in the Johnnie district are hosted in quartzites of this assemblage. Lower Paleozoic Carbonate Assemblage (North America) In middle Cambrian time, the mostly terrigenous, coarse, quartzose, ...
Miller et al., 1983
... Fig. 1: Index map showing location of the northern Snake Range (NSR), Ruby Mountains (RM), and Grouse Creek-Raft River (GC-RR) metamorphic core complexes with respect to the Sevier fold and thrust belt. Lower plates of core complexes show ...
... Fig. 1: Index map showing location of the northern Snake Range (NSR), Ruby Mountains (RM), and Grouse Creek-Raft River (GC-RR) metamorphic core complexes with respect to the Sevier fold and thrust belt. Lower plates of core complexes show ...
Merguerian, Charles, 2008h, Geology of the Cortlandt igneous
... In the Manhattan Prong, a basal unit (Layer I) of Proterozoic gneiss (the Fordham Gneiss, 1.1 billion years old) is overlain by Layer II, metasedimentary- and metavolcanic rocks that are inferred to have been deposited along the margin of the ancient North American continent in a long-disappeared o ...
... In the Manhattan Prong, a basal unit (Layer I) of Proterozoic gneiss (the Fordham Gneiss, 1.1 billion years old) is overlain by Layer II, metasedimentary- and metavolcanic rocks that are inferred to have been deposited along the margin of the ancient North American continent in a long-disappeared o ...
Geology of the Death Valley area
The exposed geology of the Death Valley area presents a diverse and complex set of at least 23 formations of sedimentary units, two major gaps in the geologic record called unconformities, and at least one distinct set of related formations geologists call a group. The oldest rocks in the area that now includes Death Valley National Park are extensively metamorphosed by intense heat and pressure and are at least 1700 million years old. These rocks were intruded by a mass of granite 1400 Ma (million years ago) and later uplifted and exposed to nearly 500 million years of erosion.Marine deposition occurred 1200 to 800 Ma, creating thick sequences of conglomerate, mudstone, and carbonate rock topped by stromatolites, and possibly glacial deposits from the hypothesized Snowball Earth event. Rifting thinned huge roughly linear parts of the supercontinent Rodinia enough to allow sea water to invade and divide its landmass into component continents separated by narrow straits. A passive margin developed on the edges of these new seas in the Death Valley region. Carbonate banks formed on this part of the two margins only to be subsided as the continental crust thinned until it broke, giving birth to a new ocean basin. An accretion wedge of clastic sediment then started to accumulate at the base of the submerged precipice, entombing the region's first known fossils of complex life. These sandy mudflats gave way about 550 Ma to a carbonate platform which lasted for the next 300 million years of Paleozoic time.The passive margin switched to active margin in the early-to-mid Mesozoic when the Farallon Plate under the Pacific Ocean started to dive below the North American Plate, creating a subduction zone; volcanoes and uplifting mountains were created as a result. Erosion over many millions of years created a relatively featureless plain. Stretching of the crust under western North America started around 16 Ma and is thought to be caused by upwelling from the subducted spreading-zone of the Farallon Plate. This process continues into the present and is thought to be responsible for creating the Basin and Range province. By 2 to 3 million years ago this province had spread to the Death Valley area, ripping it apart and creating Death Valley, Panamint Valley and surrounding ranges. These valleys partially filled with sediment and, during colder periods during the current ice age, with lakes. Lake Manly was the largest of these lakes; it filled Death Valley during each glacial period from 240,000 years ago to 10,000 years ago. By 10,500 years ago these lakes were increasingly cut off from glacial melt from the Sierra Nevada, starving them of water and concentrating salts and minerals. The desert environment seen today developed after these lakes dried up.