Permian and Triassic rocks of the Appleby district (part of Sheet 30
... Permian sequence between Hoff and Appleby. Up to 10 m of irregularly bedded breccias and sandstones are exposed in the quarry face at Burrells [6768 1801]. Beds are mainly sheet-like, though lenticular units with erosive bases also occur. The breccias are polymictic, and both clastand matrix-support ...
... Permian sequence between Hoff and Appleby. Up to 10 m of irregularly bedded breccias and sandstones are exposed in the quarry face at Burrells [6768 1801]. Beds are mainly sheet-like, though lenticular units with erosive bases also occur. The breccias are polymictic, and both clastand matrix-support ...
Geology of Southwestern Alaska (3.0MB, PDF)
... Mountains and serve as depositional basement for Paleozoic shelf deposits. A nearly continuous sequence of Paleozoic continental margin rocks underlies much of the southwestern Alaska Range and northern Kuskokwim Mountains. The most extensive unit in southwest Alaska is the predominantly Upper Creta ...
... Mountains and serve as depositional basement for Paleozoic shelf deposits. A nearly continuous sequence of Paleozoic continental margin rocks underlies much of the southwestern Alaska Range and northern Kuskokwim Mountains. The most extensive unit in southwest Alaska is the predominantly Upper Creta ...
New Hypothesis for the Formation of the Catalina
... believed by some to also represent a product of Middle Jurassic nascent subduction (e.g., Stern and Bloomer, 1992). Although the nascent subduction model may generally explain the genesis of Middle Jurassic high-grade rocks within the Franciscan Complex, initiation of a new subduction zone off the ...
... believed by some to also represent a product of Middle Jurassic nascent subduction (e.g., Stern and Bloomer, 1992). Although the nascent subduction model may generally explain the genesis of Middle Jurassic high-grade rocks within the Franciscan Complex, initiation of a new subduction zone off the ...
The western margin of Mexico is ideally - Earth Science
... once more, in a kind of “accordion” tectonics along the continental margin, referred to by Collins(2002) as tectonic switching. This “accordion” tectonics may be modified by alongstrike translations. The Cordillera of western North America recordsmost of the global crustal growth during Phanerozoi ...
... once more, in a kind of “accordion” tectonics along the continental margin, referred to by Collins(2002) as tectonic switching. This “accordion” tectonics may be modified by alongstrike translations. The Cordillera of western North America recordsmost of the global crustal growth during Phanerozoi ...
ABSTRACT Callovian to early Kimmeridgian (Unitary Keywords: ophiolite, age, CRO, cordillera,
... formed more or less in place along the western margin of North America; others in the Sierra Nevada Foothills metamorphic belt may represent exotic or fringing arc terranes that were welded to the continental margin during Late Jurassic or older collisions (Girty et al., 1995; Saleeby, 1983a; Schwei ...
... formed more or less in place along the western margin of North America; others in the Sierra Nevada Foothills metamorphic belt may represent exotic or fringing arc terranes that were welded to the continental margin during Late Jurassic or older collisions (Girty et al., 1995; Saleeby, 1983a; Schwei ...
GSA TODAY - Geological Society of America
... forearc basin in fault contact with the Franciscan subduction complex of the California Coast Ranges. Three contrasting hypotheses for genesis of the ophiolite as seafloor are each based on internally consistent logic within the framework of plate tectonics, but are mutually exclusive and lead to st ...
... forearc basin in fault contact with the Franciscan subduction complex of the California Coast Ranges. Three contrasting hypotheses for genesis of the ophiolite as seafloor are each based on internally consistent logic within the framework of plate tectonics, but are mutually exclusive and lead to st ...
The Guerrero Composite Terrane of western Mexico
... interbedded with limestone and shallow-marine volcaniclastic rocks. The Guanajuato and Arcelia Terranes are characterized by Lower Cretaceous supra-subduction ophiolite successions formed by deep-marine volcanic and sedimentary rocks with mid-oceanic-ridge basalt (MORB), oceanic-island basalt (OIB), ...
... interbedded with limestone and shallow-marine volcaniclastic rocks. The Guanajuato and Arcelia Terranes are characterized by Lower Cretaceous supra-subduction ophiolite successions formed by deep-marine volcanic and sedimentary rocks with mid-oceanic-ridge basalt (MORB), oceanic-island basalt (OIB), ...
accepted manuscript
... oceanic crust within the Yarlung-Tsangpo Suture Zone, between India and Eurasia, predominantly date to the Late Jurassic or mid Cretaceous (Barremian-Aptian). The various ophiolites along strike and a hiatus in subduction-related magmatism during the Tithonian-Aptian suggest that there was at least ...
... oceanic crust within the Yarlung-Tsangpo Suture Zone, between India and Eurasia, predominantly date to the Late Jurassic or mid Cretaceous (Barremian-Aptian). The various ophiolites along strike and a hiatus in subduction-related magmatism during the Tithonian-Aptian suggest that there was at least ...
GEOLOGIC MAP OF SOUTHEASTERN ALASKA INTRODUCTION
... they are found in geologic units that grade from relatively intact stratigraphic sequences to metamorphic or structural units, or (3) they are known or interpreted to include two or more geologic units of formation rank that are not generally coeval. Most units of this category probably consist of, ...
... they are found in geologic units that grade from relatively intact stratigraphic sequences to metamorphic or structural units, or (3) they are known or interpreted to include two or more geologic units of formation rank that are not generally coeval. Most units of this category probably consist of, ...
Fulltext - ETH E-Collection
... the maximum age of obduction of the Jurassic ophiolites and calc-alkaline granitoids in the Apuseni Mountains. This thesis consists of three chapters, which were written as co-authored papers of which I am the leading author. The first chapter was published in ‘Tectonics’. Included are also an overa ...
... the maximum age of obduction of the Jurassic ophiolites and calc-alkaline granitoids in the Apuseni Mountains. This thesis consists of three chapters, which were written as co-authored papers of which I am the leading author. The first chapter was published in ‘Tectonics’. Included are also an overa ...
Wadhwan Formation of Western India
... rift basin represent deposits of a general transgression proceeding from SW to NE consequent upon progressive downwarping with intermittent rifting of the basin. A large part of the lithofacies of the rift-fill represents deposition in the nearshore coastal delta plain with a gradual northeastward t ...
... rift basin represent deposits of a general transgression proceeding from SW to NE consequent upon progressive downwarping with intermittent rifting of the basin. A large part of the lithofacies of the rift-fill represents deposition in the nearshore coastal delta plain with a gradual northeastward t ...
Ghikas et al.IGR2010
... episodes of the break-up of Gondwana and evolved as latitudinal, east –west-oriented basins separated by discrete continental fragments. Most eastern Mediterranean ophiolites are spatially associated with both Triassic –Jurassic volcanic rocks and subophiolitic mélanges that rest tectonically on pa ...
... episodes of the break-up of Gondwana and evolved as latitudinal, east –west-oriented basins separated by discrete continental fragments. Most eastern Mediterranean ophiolites are spatially associated with both Triassic –Jurassic volcanic rocks and subophiolitic mélanges that rest tectonically on pa ...
Evolution of the Eastern Alps
... directions of plate movements. This led to continent-continent collisions that occurred in different regions of the Alps at different geologic stages. This is also visible from the map displaying grades of metamorphism in the Alps (Fig 3. after Pfiffner, 2010): For example, the Eastern Alps are the ...
... directions of plate movements. This led to continent-continent collisions that occurred in different regions of the Alps at different geologic stages. This is also visible from the map displaying grades of metamorphism in the Alps (Fig 3. after Pfiffner, 2010): For example, the Eastern Alps are the ...
Plate Tectonic Evolution and Mineral Resource
... Granite. The petrology and geochemistry of the basalts along the Lancang River are identical to the continental flood basalts of the Emeishan Large Igneous Province (LIP), which are proposed to be mantle-plume related (Xu et al., 2001; Chung, 1998). Hence, the new plate tectonic model excludes a Mes ...
... Granite. The petrology and geochemistry of the basalts along the Lancang River are identical to the continental flood basalts of the Emeishan Large Igneous Province (LIP), which are proposed to be mantle-plume related (Xu et al., 2001; Chung, 1998). Hence, the new plate tectonic model excludes a Mes ...
t - bibsys brage
... imately 40 million years ago, a period of north-south rifting was initiated and Svalbard began drifting away from Greenland; the Greenland Sea open ed. In response to these huge plate movements in what is now the North At lantic region, tremendous volumes of lava poured out of fractures to build u ...
... imately 40 million years ago, a period of north-south rifting was initiated and Svalbard began drifting away from Greenland; the Greenland Sea open ed. In response to these huge plate movements in what is now the North At lantic region, tremendous volumes of lava poured out of fractures to build u ...
FOSI BeritaSedimentologi BS 23 March2012
... crust then sank of its own accord and pulled the subduction zone across the Banda Sea area in a horseshoe shape. The overlying arc migrated south and east and the northern margin was largely a strike-slip margin. Backarc spreading occurred NW of the arc in the present Banda Sea. Hall (2002) infers t ...
... crust then sank of its own accord and pulled the subduction zone across the Banda Sea area in a horseshoe shape. The overlying arc migrated south and east and the northern margin was largely a strike-slip margin. Backarc spreading occurred NW of the arc in the present Banda Sea. Hall (2002) infers t ...
preview PDF only - California State University Stanislaus
... Previous Tectonic Models for the Origin of the Chortis Block The Chortis block of northern Central America (Honduras, Nicaragua, El Salvador, southern Guatemala, and part of the Nicaragua Rise) forms the only emergent area of Precambrian to Paleozoic continental crust on the present-day Caribbean pl ...
... Previous Tectonic Models for the Origin of the Chortis Block The Chortis block of northern Central America (Honduras, Nicaragua, El Salvador, southern Guatemala, and part of the Nicaragua Rise) forms the only emergent area of Precambrian to Paleozoic continental crust on the present-day Caribbean pl ...
Tectonic Framework of Basin Evolution in Peru
... characterises the overall tectonic setting, and by inference expresses the nature of the stress fields. Late Triassic – Middle Jurassic events were dominated by extensional processes that resulted in the fragmentation of east Gondwana and opening of the Indian Ocean. From Late Jurassic (Callovian) t ...
... characterises the overall tectonic setting, and by inference expresses the nature of the stress fields. Late Triassic – Middle Jurassic events were dominated by extensional processes that resulted in the fragmentation of east Gondwana and opening of the Indian Ocean. From Late Jurassic (Callovian) t ...
The Geology of Antarctica
... Antarctica is the last discovered and most inhospitable of the continents. It is also the driest, the coldest and -- with a mean surface elevation of 2500 meters -- the highest of all continents. With 13,661,000 square kilometers it is nearly twice the size of Australia and only 2% of the continent ...
... Antarctica is the last discovered and most inhospitable of the continents. It is also the driest, the coldest and -- with a mean surface elevation of 2500 meters -- the highest of all continents. With 13,661,000 square kilometers it is nearly twice the size of Australia and only 2% of the continent ...
Geol.Soc Australia Spec Publ.22 2003
... the margin west of the Tasman Line underwent substantial extension and rifting, with major microcontinents breaking away in the Early Palaeozoic and the Permo-Carboniferous (Metcalfe 1996, 1998) (Figure 3). The thick, relatively undeformed Palaeozoic section in mainland Irian Jaya is consistent with ...
... the margin west of the Tasman Line underwent substantial extension and rifting, with major microcontinents breaking away in the Early Palaeozoic and the Permo-Carboniferous (Metcalfe 1996, 1998) (Figure 3). The thick, relatively undeformed Palaeozoic section in mainland Irian Jaya is consistent with ...
introduction - KFUPM Faculty List
... EVOLUTION AND FORMATION OF THE SHIELD o To understand the evolution processes of the Arabian Shield, the evolution of the surrounding Shields is also need to be understood. The nearest Shield to the Arabian Shield is the Nubian Shield. The two shields were attached to each other and separated by the ...
... EVOLUTION AND FORMATION OF THE SHIELD o To understand the evolution processes of the Arabian Shield, the evolution of the surrounding Shields is also need to be understood. The nearest Shield to the Arabian Shield is the Nubian Shield. The two shields were attached to each other and separated by the ...
1.8 Billion Years of Detrital Zircon Recycling Calibrates a
... [1]. Starting with the proposition that detrital zircons within Upper Cretaceous strata are likely derived from erosion of older strata within the Cordillera [1], we assume that if sedimentary rocks are eroded, then the main components of the entire age spectrum will be recycled. The portion of the ...
... [1]. Starting with the proposition that detrital zircons within Upper Cretaceous strata are likely derived from erosion of older strata within the Cordillera [1], we assume that if sedimentary rocks are eroded, then the main components of the entire age spectrum will be recycled. The portion of the ...
Article
... [1]. Starting with the proposition that detrital zircons within Upper Cretaceous strata are likely derived from erosion of older strata within the Cordillera [1], we assume that if sedimentary rocks are eroded, then the main components of the entire age spectrum will be recycled. The portion of the ...
... [1]. Starting with the proposition that detrital zircons within Upper Cretaceous strata are likely derived from erosion of older strata within the Cordillera [1], we assume that if sedimentary rocks are eroded, then the main components of the entire age spectrum will be recycled. The portion of the ...
Paleogeography, Southwestern US
... It's interesting in this context to note that, if the Antarctic ice cap melts, Antarctica itself may rise: "The continental shelf of the South Polar land lies four times lower than normal," New Scientist reported, "suggesting that if the ice (more than a mile thick below sea level at some points) we ...
... It's interesting in this context to note that, if the Antarctic ice cap melts, Antarctica itself may rise: "The continental shelf of the South Polar land lies four times lower than normal," New Scientist reported, "suggesting that if the ice (more than a mile thick below sea level at some points) we ...
Jurassic to Holocene tectonics, magmatism, and metallogeny of
... Figure 3. Temporal distribution of igneous and deformational events in northwestern Mexico, denoted as the numbers of outcrops per mountain range. (A) Abundance of exposed plutonic and volcanic rocks. Younger rocks are more extrusive-dominated, and magmatism has been active in different parts of the ...
... Figure 3. Temporal distribution of igneous and deformational events in northwestern Mexico, denoted as the numbers of outcrops per mountain range. (A) Abundance of exposed plutonic and volcanic rocks. Younger rocks are more extrusive-dominated, and magmatism has been active in different parts of the ...
Mesozoic
The Mesozoic Era /mɛzɵˈzoʊɪk/ is an interval of geological time from about 252 to 66 million years ago. It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by reptiles such as Iguanodon, Megalosaurus, Plesiosaurus and what are now called Pseudosuchia.Mesozoic means ""middle life"", deriving from the Greek prefix meso-/μεσο- for ""between"" and zōon/ζῷον meaning ""animal"" or ""living being"". It is one of three geologic eras of the Phanerozoic Eon, preceded by the Paleozoic (""ancient life"") and succeeded by the Cenozoic (""new life""). The era is subdivided into three major periods: the Triassic, Jurassic, and Cretaceous, which are further subdivided into a number of epochs and stages.The era began in the wake of the Permian–Triassic extinction event, the largest well-documented mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction which is known for having killed off non-avian dinosaurs, as well as other plant and animal species. The Mesozoic was a time of significant tectonic, climate and evolutionary activity. The era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would eventually move into their current positions. The climate of the Mesozoic was varied, alternating between warming and cooling periods. Overall, however, the Earth was hotter than it is today. Non-avian dinosaurs appeared in the Late Triassic and became the dominant terrestrial vertebrates early in the Jurassic, occupying this position for about 135 million years until their demise at the end of the Cretaceous. Birds first appeared in the Jurassic, having evolved from a branch of theropod dinosaurs. The first mammals also appeared during the Mesozoic, but would remain small—less than 15 kg (33 lb)—until the Cenozoic.