Tectonic history of the Chihuahua trough, Mexico
... over a large area of Chihuahua, that is in part coeval with emplacement of granitic rocks to the north. The Carrizo Mountain Group depositional basin (graben?) may be the earliest manifestation of the dominant northwesterly-trending structural grain of the region; timing is consistent with oldest kn ...
... over a large area of Chihuahua, that is in part coeval with emplacement of granitic rocks to the north. The Carrizo Mountain Group depositional basin (graben?) may be the earliest manifestation of the dominant northwesterly-trending structural grain of the region; timing is consistent with oldest kn ...
Tectono-stratigraphic framework of Neoproterozoic to Cambrian
... volcanic rocks in Utah, Nevada, and SE Idaho record a dynamically evolving landscape along the North American Cordillera margin, which included: (1) initial development of intracratonic basins with deposition of siliciclastic strata of the Uinta Mountain Group from ~770 to 740 Ma; (2) early rifting ...
... volcanic rocks in Utah, Nevada, and SE Idaho record a dynamically evolving landscape along the North American Cordillera margin, which included: (1) initial development of intracratonic basins with deposition of siliciclastic strata of the Uinta Mountain Group from ~770 to 740 Ma; (2) early rifting ...
Evolution of the Precambrian Rocks of Yellowstone National Park
... granitic bodies, the Crevice and Hellroaring Plutons. Montgomery (1982) determined an age of 2.73 to 2.79 Ga for one of the plutons in the northern portion of Yellowstone National Park, 0.3 km east of Tower Junction. Casella, et al. (1982) hypothesized that the plutons have a similar geologic histor ...
... granitic bodies, the Crevice and Hellroaring Plutons. Montgomery (1982) determined an age of 2.73 to 2.79 Ga for one of the plutons in the northern portion of Yellowstone National Park, 0.3 km east of Tower Junction. Casella, et al. (1982) hypothesized that the plutons have a similar geologic histor ...
Extensional Tectonics in the Basin and Range Province and the
... in reconstructions of Basin and Range extension. Such an interpretation suggests >100 km of west-north-west translation of the Grapevine Mountains away from the Sheep Range in late Cenozoic time. Correlation and re-interpretation of Cenozoic sedimentary and volcanic strata between the Sheep Range an ...
... in reconstructions of Basin and Range extension. Such an interpretation suggests >100 km of west-north-west translation of the Grapevine Mountains away from the Sheep Range in late Cenozoic time. Correlation and re-interpretation of Cenozoic sedimentary and volcanic strata between the Sheep Range an ...
The Relevance of Brittle Fault Zones in Tunnel Construction
... which in turn lead to higher costs for the contractor. In some cases, due to incalculable safety risks or for economic reasons, further advance is impossible. Gaining knowledge about the appearance and the petrography of such fault zones and their geomechanical and hydrological properties at tunnel ...
... which in turn lead to higher costs for the contractor. In some cases, due to incalculable safety risks or for economic reasons, further advance is impossible. Gaining knowledge about the appearance and the petrography of such fault zones and their geomechanical and hydrological properties at tunnel ...
online guide - Hofstra People
... Yellowstone hot spot. Here the heat of a buried hot mantle plume and associated cooling pluton at a mile deep have created a huge domal uplift scattered with over thousands of active hot springs and other thermal features (see cover). Our trip will visit Yellowstone National Park to see all of the w ...
... Yellowstone hot spot. Here the heat of a buried hot mantle plume and associated cooling pluton at a mile deep have created a huge domal uplift scattered with over thousands of active hot springs and other thermal features (see cover). Our trip will visit Yellowstone National Park to see all of the w ...
Steady, balanced rates of uplift and erosion of the Santa Monica
... is a dissected remnant of a recently uplifted peneplain, which implies that erosion rates are significantly lower than uplift rates (Hoots, 1931; Dibblee, 1982). ...
... is a dissected remnant of a recently uplifted peneplain, which implies that erosion rates are significantly lower than uplift rates (Hoots, 1931; Dibblee, 1982). ...
Papers presented to the conference on Plateau Uplift, Mode and
... an ovoid of uplift whose major axis is alined with the maximum depocentra1 isopachs. The highest uplift of this structural inversion (the present Ponta Grossa Arch) is 7 1/2 km or more. Although the autogeosync1ine appears to have developed entirely on cratonic rocks, evidently the load of accumulat ...
... an ovoid of uplift whose major axis is alined with the maximum depocentra1 isopachs. The highest uplift of this structural inversion (the present Ponta Grossa Arch) is 7 1/2 km or more. Although the autogeosync1ine appears to have developed entirely on cratonic rocks, evidently the load of accumulat ...
North America`s Midcontinent Rift: When Rift Met LIP
... Broader Impact: MCR gave rise to Lake Superior, the basis of the surrounding area’s water-‐based history and economy, copper and building stone deposits that shaped the area’s seElement and growth, and ...
... Broader Impact: MCR gave rise to Lake Superior, the basis of the surrounding area’s water-‐based history and economy, copper and building stone deposits that shaped the area’s seElement and growth, and ...
Field Trip Guide
... rocks that have not been significantly transported from their site of formation/deposition) in New York by a major unnamed fault that lies beneath Lake Champlain. In the autochthon, Mesoproterozic metamorphic rocks of the Adirondack Massif are unconformably overlain by sedimentary rocks of the Beekm ...
... rocks that have not been significantly transported from their site of formation/deposition) in New York by a major unnamed fault that lies beneath Lake Champlain. In the autochthon, Mesoproterozic metamorphic rocks of the Adirondack Massif are unconformably overlain by sedimentary rocks of the Beekm ...
2. Geophysics and the Structure of the Lesser Antilles Forearc
... The Barbados Ridge complex lies east of the Lesser Antilles volcanic arc along the eastern margin of the Caribbean Plate. The complex dates in part from the Eocene, and elements of the arc system have been dated as Late Cretaceous and Late Jurassic, although most of the volcanic rocks date from the ...
... The Barbados Ridge complex lies east of the Lesser Antilles volcanic arc along the eastern margin of the Caribbean Plate. The complex dates in part from the Eocene, and elements of the arc system have been dated as Late Cretaceous and Late Jurassic, although most of the volcanic rocks date from the ...
Geology and Hydrothermal Alteration of the Flin Flon–Triple 7
... The premise of this study is that most VMS hydrothermal systems result in alteration of not only the strata underlying the massive sulphide deposit, but may also affect overlying strata. Hanging-wall alteration may be a function of one of two processes. The first is the continuation of hydrothermal ...
... The premise of this study is that most VMS hydrothermal systems result in alteration of not only the strata underlying the massive sulphide deposit, but may also affect overlying strata. Hanging-wall alteration may be a function of one of two processes. The first is the continuation of hydrothermal ...
An integrated geophysical analysis of crustal structure in the Wichita
... the Wichita Mountains. The geology of the SOA can be divided into three stages spanning ~1200 Ma: 1) pre-rift, 2) active rifting from Middle Cambrian until Late Mississippian, and 3) post-rift deformation including Pennsylvanian compression and Pennsylvanian-Permian strike-slip faulting (Gilbert, 19 ...
... the Wichita Mountains. The geology of the SOA can be divided into three stages spanning ~1200 Ma: 1) pre-rift, 2) active rifting from Middle Cambrian until Late Mississippian, and 3) post-rift deformation including Pennsylvanian compression and Pennsylvanian-Permian strike-slip faulting (Gilbert, 19 ...
Precambrian stratigraphy of Manzanita and north Manzano
... financial support for the field work. ...
... financial support for the field work. ...
Late Miocene to Pliocene stratigraphic evolution of northeast
... faults on the east and west margins of the island. The bedrock geology of Carmen Island consists primarily of dipping Miocene volcanic rocks (Comondu Formation of Hausback, 1984; Sawlan, 1991) overlain by less steeply dipping Pliocene sedimentary rocks and smaller patches of raised Quaternary limes ...
... faults on the east and west margins of the island. The bedrock geology of Carmen Island consists primarily of dipping Miocene volcanic rocks (Comondu Formation of Hausback, 1984; Sawlan, 1991) overlain by less steeply dipping Pliocene sedimentary rocks and smaller patches of raised Quaternary limes ...
Paleogene Foredeep Basin Deposits of North
... and document the Paleogene sedimentary successions of north-central Cuba. We discuss the implications of the Paleogene stratigraphy of the northcentral fold-and-thrust belt of Cuba for the timing of the arc-continent collision between the Caribbean plate and the Bahamas. ...
... and document the Paleogene sedimentary successions of north-central Cuba. We discuss the implications of the Paleogene stratigraphy of the northcentral fold-and-thrust belt of Cuba for the timing of the arc-continent collision between the Caribbean plate and the Bahamas. ...
- International Association of Geomorphologists
... Barrier (Coastal barrier) An elongated ridge of deposited sediment (sand, pebbles, occasionally boulders) that has been built up by wave action above high tide level along the coast or across an embayment (bay barrier). It differs from a bar, which is submerged at least at high tide. Typically a bar ...
... Barrier (Coastal barrier) An elongated ridge of deposited sediment (sand, pebbles, occasionally boulders) that has been built up by wave action above high tide level along the coast or across an embayment (bay barrier). It differs from a bar, which is submerged at least at high tide. Typically a bar ...
Divergent Plate Boundaries - North Coast Distance Education
... Remarkably, the midoceanic ridge is a nearly continuous feature around the entire globe, like the seam of a baseball (Figure 19.1). The ridge extends from the Arctic Basin, down through the center of the Atlantic, into the Indian Ocean, and across the South Pacific, ending in the Gulf of California, ...
... Remarkably, the midoceanic ridge is a nearly continuous feature around the entire globe, like the seam of a baseball (Figure 19.1). The ridge extends from the Arctic Basin, down through the center of the Atlantic, into the Indian Ocean, and across the South Pacific, ending in the Gulf of California, ...
Mountain Building Web Activity
... Melting and cooling of magma Erosion, crustal shortening, and uplift Decrease in density of the rocks after they form Erosion down to the depth where the rocks originated The reason for my answer is because: Deep crust uplifts as upper crustal layers are removed Rocks can buoyantly rise through the ...
... Melting and cooling of magma Erosion, crustal shortening, and uplift Decrease in density of the rocks after they form Erosion down to the depth where the rocks originated The reason for my answer is because: Deep crust uplifts as upper crustal layers are removed Rocks can buoyantly rise through the ...
Geomorphology_Dics
... Any artificial pond or other water-filled excavation for the natural oxidation of sewage or disposal of animal manure. Skid trail Irregularly spaced, roughly linear to radial depressions or small mounds associated with shallow to deep soil disturbance caused by dragging logs across a slope from wher ...
... Any artificial pond or other water-filled excavation for the natural oxidation of sewage or disposal of animal manure. Skid trail Irregularly spaced, roughly linear to radial depressions or small mounds associated with shallow to deep soil disturbance caused by dragging logs across a slope from wher ...
Significance of seismic reflections beneath a tilted
... Figure 2. (a) Map showingmajor active structuralfeaturesand present-dayexposuresof P½lona-Orocopia-Rand schists. The Vincent-Chocolate-Randthrustsystem,indicatedby teeth on the schistbodies,is of Mesozoic age. Using U.S. GeologicalSurvey,COCORP, and industryseismicdata,Lawson [1989], for example,has ...
... Figure 2. (a) Map showingmajor active structuralfeaturesand present-dayexposuresof P½lona-Orocopia-Rand schists. The Vincent-Chocolate-Randthrustsystem,indicatedby teeth on the schistbodies,is of Mesozoic age. Using U.S. GeologicalSurvey,COCORP, and industryseismicdata,Lawson [1989], for example,has ...
Cenozoic geology of the Yerington district, Nevada, and implications
... purposes, the sequences has been divided into 10 units, which are fairly uniform and continuous throughout and beyond the district. Individual mapping units are distinctive enough to be identifiable, even in drill holes and isolated outcrops. This has helped immeasurably in working out the geometry ...
... purposes, the sequences has been divided into 10 units, which are fairly uniform and continuous throughout and beyond the district. Individual mapping units are distinctive enough to be identifiable, even in drill holes and isolated outcrops. This has helped immeasurably in working out the geometry ...
Geology of the Jolon and Williams Hill Quadrangles Monterey County, California (USGS BUlletin 1181-Q 1965)
... The oldest sedimentary rocks that crop out in the map area are sandstone, conglomerate, and mudstone beds in the southwestern part of the Jolon quadrangle. They form an unnamed unit that may be thicker than 3,700 feet. Fossil Foraminifera indicate a probable Paleocene age for at least part of the un ...
... The oldest sedimentary rocks that crop out in the map area are sandstone, conglomerate, and mudstone beds in the southwestern part of the Jolon quadrangle. They form an unnamed unit that may be thicker than 3,700 feet. Fossil Foraminifera indicate a probable Paleocene age for at least part of the un ...
GSA Bulletin: Late Cenozoic tectonics of the central and southern
... Each of the Coast Ranges is flanked by alluvial fans except where these have been prevented from developing, or have been removed by destructive processes. Many (most?) of the fans show abrupt changes in sediments or gradients that can be related to abnormal rainfall or, very often, episodic uplift ...
... Each of the Coast Ranges is flanked by alluvial fans except where these have been prevented from developing, or have been removed by destructive processes. Many (most?) of the fans show abrupt changes in sediments or gradients that can be related to abnormal rainfall or, very often, episodic uplift ...
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.