from Georgia State Base Geologic Map, 1976 Index and Short
... The following rocks are found only north of the "Fall Line" in Georgia and outside of the Paleozoic region. These metamorphic rocks may have little or no correspondence to their original sedimentary form. Instead they are more often graded by the degree of metamorphisim than by original rock composi ...
... The following rocks are found only north of the "Fall Line" in Georgia and outside of the Paleozoic region. These metamorphic rocks may have little or no correspondence to their original sedimentary form. Instead they are more often graded by the degree of metamorphisim than by original rock composi ...
(a) Continental Margins
... Seamounts are volcanic projections from the ocean floor that do not rise above sea level. Flat-topped seamounts eroded by wave action are ...
... Seamounts are volcanic projections from the ocean floor that do not rise above sea level. Flat-topped seamounts eroded by wave action are ...
Chapter 4—Rocks and Minerals: Documents that Record
... augite (53): A dark-colored, ferromagnesian mineral which is an important member of the pyroxene family of minerals (silicates of aluminum, calcium, magnesium, and iron). It is stumpy in shape, with good cleavage developed along two planes that are nearly at right angles. basalt (58): A fine-grained ...
... augite (53): A dark-colored, ferromagnesian mineral which is an important member of the pyroxene family of minerals (silicates of aluminum, calcium, magnesium, and iron). It is stumpy in shape, with good cleavage developed along two planes that are nearly at right angles. basalt (58): A fine-grained ...
Chapter 6 Structure
... Rockhead contours， together with gravity (Kirk et al.， 2000) and boomer surveys， for the offshore area along the north Lantau coast have revealed areas of deep weathering which appear to coincide， in part， with the offshore extension of the Shek Pik Fault. The rockhead contours and data on superfici ...
... Rockhead contours， together with gravity (Kirk et al.， 2000) and boomer surveys， for the offshore area along the north Lantau coast have revealed areas of deep weathering which appear to coincide， in part， with the offshore extension of the Shek Pik Fault. The rockhead contours and data on superfici ...
Document
... propose to drill a deep hole that penetrates through a complete sequence of intra-oceanic arc upper crust and into the in situ middle crust that may be a nucleus of continental crust. The average continental crust possesses an intermediate composition (~60 wt.% SiO2), which raises the question of ho ...
... propose to drill a deep hole that penetrates through a complete sequence of intra-oceanic arc upper crust and into the in situ middle crust that may be a nucleus of continental crust. The average continental crust possesses an intermediate composition (~60 wt.% SiO2), which raises the question of ho ...
Recognizing optimum Banded-Iron Formation
... Neoarchean supracrustal rocks, surrounded by granitoid and gneissic complexes and regionally overlain by pre- to post Hudsonian Proterozoic basins and 1.83-1.75 ...
... Neoarchean supracrustal rocks, surrounded by granitoid and gneissic complexes and regionally overlain by pre- to post Hudsonian Proterozoic basins and 1.83-1.75 ...
Types of Metamorphism
... and the original fabrics are largely preserved. So, the yielded rocks are distinguished only in thin section - In Extensional regime, Diatathermal metamorphism is used ...
... and the original fabrics are largely preserved. So, the yielded rocks are distinguished only in thin section - In Extensional regime, Diatathermal metamorphism is used ...
Volcanoes and Igneous Activity Earth - Chapter 4
... 1. Granite; intrusive rock that formed from cooling of relatively high silica magma. 2. Rhyolite; extrusive rock that formed from cooling of relatively low silica magma. 3. Diorite; intrusive rock that formed from the cooling of relatively intermediate silica magma. 4. Granite; intrusive rock that f ...
... 1. Granite; intrusive rock that formed from cooling of relatively high silica magma. 2. Rhyolite; extrusive rock that formed from cooling of relatively low silica magma. 3. Diorite; intrusive rock that formed from the cooling of relatively intermediate silica magma. 4. Granite; intrusive rock that f ...
Incremental Emplacement of Nelson Batholith
... 1988). Carr and Simony (2006) hypothesized based on this data that the BMT suite was linked at depth by former magma conduits and based largely on field-mapping and structural analysis, they surmise that the deep portions of the NB and BMT suite was sheared and thrusted during the Cretaceous–Paleoce ...
... 1988). Carr and Simony (2006) hypothesized based on this data that the BMT suite was linked at depth by former magma conduits and based largely on field-mapping and structural analysis, they surmise that the deep portions of the NB and BMT suite was sheared and thrusted during the Cretaceous–Paleoce ...
- NERC Open Research Archive
... Nell 1992). This sequence is interpreted as representing an accretionary trench-fill assemblage (Suárez 1976; Doubleday et al. 1993). East of the LeMay Group on Alexander Island, mainly separated by the LeMay Fault (Fig. 1), arc-derived fluvial, deltaic and submarine fan deposits forearc basin sedim ...
... Nell 1992). This sequence is interpreted as representing an accretionary trench-fill assemblage (Suárez 1976; Doubleday et al. 1993). East of the LeMay Group on Alexander Island, mainly separated by the LeMay Fault (Fig. 1), arc-derived fluvial, deltaic and submarine fan deposits forearc basin sedim ...
Delamination, Slab Break-Off, and Slab Roll-Back
... • Mechanical properties of the crust and lithospheric mantle • Basis for series of lithospheric-scale cross sections showing collisional delamination ...
... • Mechanical properties of the crust and lithospheric mantle • Basis for series of lithospheric-scale cross sections showing collisional delamination ...
Passive Continental Margin Around East Coast India
... form a wedge-shaped structure. Their general characteristics and velocity structure suggest that they may be largely volcanic in nature, but there is no agreed upon model for their origin. Nevertheless it is generally thought that they lie at or close to the boundary between continent and ocean, and ...
... form a wedge-shaped structure. Their general characteristics and velocity structure suggest that they may be largely volcanic in nature, but there is no agreed upon model for their origin. Nevertheless it is generally thought that they lie at or close to the boundary between continent and ocean, and ...
Rocks and Minerals Readings
... feet long. Because granite is a hard and tough rock, it is used for many construction projects. Both extrusive and intrusive igneous rocks can become exposed to Earth's surface after they form. There, they are vulnerable to attack from environmental agents such as wind, water, ice, and gravity. Thes ...
... feet long. Because granite is a hard and tough rock, it is used for many construction projects. Both extrusive and intrusive igneous rocks can become exposed to Earth's surface after they form. There, they are vulnerable to attack from environmental agents such as wind, water, ice, and gravity. Thes ...
The geology of an area of approximately 500 km2, which covers
... are common assemblages; coarser pyroclastics are rare. Hornblende porphyroblasts are also present in the intermediate volcanics but are generally smaller than in the mafic volcanics. Felsic volcanics include rocks of dacitic to rhyolitic composition. They occur in two major zones: l) a l 500 m thick ...
... are common assemblages; coarser pyroclastics are rare. Hornblende porphyroblasts are also present in the intermediate volcanics but are generally smaller than in the mafic volcanics. Felsic volcanics include rocks of dacitic to rhyolitic composition. They occur in two major zones: l) a l 500 m thick ...
Possible Mesozoic sediments in fault and brecciation zones in
... to ENE-WSW-trending fault zone, with several splays, is located in Frøyfjorden, and that these faults have been active at several times since the Devonian. A similar suggestion was made by Oftedahl (1975) and Braathen (1996). This structural feature is here referred to informally as the Frøyfjorden ...
... to ENE-WSW-trending fault zone, with several splays, is located in Frøyfjorden, and that these faults have been active at several times since the Devonian. A similar suggestion was made by Oftedahl (1975) and Braathen (1996). This structural feature is here referred to informally as the Frøyfjorden ...
Geologic Trips San Francisco and the Bay Area
... go down a short wooden staircase. At the base of the stairs leave the Coastal Trail and follow the path to the edge of the bluff. The bluff here is made up of the Hunters Point melange. The melange consists of finely crushed serpentine, shale and sandstone with large random blocks of serpentine and ...
... go down a short wooden staircase. At the base of the stairs leave the Coastal Trail and follow the path to the edge of the bluff. The bluff here is made up of the Hunters Point melange. The melange consists of finely crushed serpentine, shale and sandstone with large random blocks of serpentine and ...
plate tectonic framework and gps - Perso-sdt
... The Adriatic microplate forms the central part of the Alpine-Mediterranean plate boundary area located between the African and Eurasian Plates. The Eurasia/Africa collision is closely related to continental subduction. Superimposed on the relatively slow counterclockwise rotation of the African Plat ...
... The Adriatic microplate forms the central part of the Alpine-Mediterranean plate boundary area located between the African and Eurasian Plates. The Eurasia/Africa collision is closely related to continental subduction. Superimposed on the relatively slow counterclockwise rotation of the African Plat ...
Advertising - Science Outreach
... collision of the Pacific tectonic Plate and the Australia Plate started, resulting in the uplift and folding of those sediments. This event is called the Rangitata Orogeny (see glossary). The first collision lasted for 50 million years during which some of the sediments were submerged to great dept ...
... collision of the Pacific tectonic Plate and the Australia Plate started, resulting in the uplift and folding of those sediments. This event is called the Rangitata Orogeny (see glossary). The first collision lasted for 50 million years during which some of the sediments were submerged to great dept ...
An Entirely New 3D-View of the Crustal and Mantle Structure of a
... reflective and stratified sedimentary section. Important exceptions are a few, but distinct, thin sub-horizontal short reflections clustered in a continuous and wavy pattern, cutting the crust in a diagonal direction. Their terminations downward usually merge with the ductile lower crust. These were ...
... reflective and stratified sedimentary section. Important exceptions are a few, but distinct, thin sub-horizontal short reflections clustered in a continuous and wavy pattern, cutting the crust in a diagonal direction. Their terminations downward usually merge with the ductile lower crust. These were ...
Geological summary of the Magdalena mining district, Socorro
... span after the Permian (see fig. 1 for distribution). The earlier period of intrusive activity is characterized by widespread intrusion into the Precambrian argillite by gabbro, felsite, granite and diabase, from oldest to youngest respectively as indicated by mutual relationships. All have been tru ...
... span after the Permian (see fig. 1 for distribution). The earlier period of intrusive activity is characterized by widespread intrusion into the Precambrian argillite by gabbro, felsite, granite and diabase, from oldest to youngest respectively as indicated by mutual relationships. All have been tru ...
A field guide to the geology of the Castle Hill Basin
... collision of the Pacific tectonic Plate and the Australia Plate started, resulting in the uplift and folding of those sediments. This event is called the Rangitata Orogeny (see glossary). The first collision lasted for 50 million years during which some of the sediments were submerged to great dept ...
... collision of the Pacific tectonic Plate and the Australia Plate started, resulting in the uplift and folding of those sediments. This event is called the Rangitata Orogeny (see glossary). The first collision lasted for 50 million years during which some of the sediments were submerged to great dept ...
A Geological Profile Across The Baltoro-Karakoram Range
... part, north and east of Askok and along the Biafo glacier. Deformation in the migmatites is totally ductile with early veins ptygmatically folded with the schistosity and later veins cross-cutting the early structures. North of the batholith low-grade metamorphic rocks occur along - the northern ma ...
... part, north and east of Askok and along the Biafo glacier. Deformation in the migmatites is totally ductile with early veins ptygmatically folded with the schistosity and later veins cross-cutting the early structures. North of the batholith low-grade metamorphic rocks occur along - the northern ma ...
Tectonic wedging along the rear of the offshore Taiwan accretionary
... backthrusting model interpreted for the offshore. Strike– slip faulting is also active in the Longitudinal Valley and offshore, but cannot by itself account for the large amounts of uplift in both regions. On land deformation may also be complicated by the incoming thick passive margin, but a reliab ...
... backthrusting model interpreted for the offshore. Strike– slip faulting is also active in the Longitudinal Valley and offshore, but cannot by itself account for the large amounts of uplift in both regions. On land deformation may also be complicated by the incoming thick passive margin, but a reliab ...
No Slide Title
... – a southern equatorial position during the Cambrian – to north temperate latitudes – by the end of the Silurian Period ...
... – a southern equatorial position during the Cambrian – to north temperate latitudes – by the end of the Silurian Period ...
Turning Sediment into Rock
... – Clays and shales typically indicate low energy environments, sheltered from waves and currents. – Such environments include lakes (lacustrine), river floodplains, lagoons, and portions of deep ...
... – Clays and shales typically indicate low energy environments, sheltered from waves and currents. – Such environments include lakes (lacustrine), river floodplains, lagoons, and portions of deep ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.