Deformation phases and tectonic evolution of the Lhasa block
... ing. This cleavage is more developed in pelitic metasediments and preserved within psammitic layers. Some rare intersection lineations S0-S, are originally dispersed in orientation between N040 and N150 E (Fig.8). The folds are overturned to the south as indicated by sedimentary structures (graded-b ...
... ing. This cleavage is more developed in pelitic metasediments and preserved within psammitic layers. Some rare intersection lineations S0-S, are originally dispersed in orientation between N040 and N150 E (Fig.8). The folds are overturned to the south as indicated by sedimentary structures (graded-b ...
Tectonically restricted deep-ocean circulation at the end of the
... thought to have been closely linked to the transition from extreme mid-Cretaceous warmth to the cooler Cenozoic climate. The relative influences of climate cooling and the opening and closure of oceanic gateways on the mode of deep-ocean circulation are, however, still unresolved. Here we reconstruct ...
... thought to have been closely linked to the transition from extreme mid-Cretaceous warmth to the cooler Cenozoic climate. The relative influences of climate cooling and the opening and closure of oceanic gateways on the mode of deep-ocean circulation are, however, still unresolved. Here we reconstruct ...
Pull-apart basins at releasing bends of the sinistral Late Jurassic
... America is pervaded by northwest- and east-trending faults that flank basins containing thick deposits of locally derived conglomerate and sedimentary breccia. These deposits that crop out mainly in the northern part of mainland Mexico, or southern parts of Arizona and New Mexico are unconformable a ...
... America is pervaded by northwest- and east-trending faults that flank basins containing thick deposits of locally derived conglomerate and sedimentary breccia. These deposits that crop out mainly in the northern part of mainland Mexico, or southern parts of Arizona and New Mexico are unconformable a ...
Deep structure of the Mid Norway rifted margin
... Mid-Triassic and younger succession, development of the basement topography must mainly have pre-dated Middle Triassic deposition. This is confirmed by the deep seismic data, which provide a good image of the configuration of deep structures and basins. T he level interpreted as the top of basement ...
... Mid-Triassic and younger succession, development of the basement topography must mainly have pre-dated Middle Triassic deposition. This is confirmed by the deep seismic data, which provide a good image of the configuration of deep structures and basins. T he level interpreted as the top of basement ...
Evidence of rain shadow in the geologic record
... in the Sahara (Benazzouz 1993), and the Empty Quarter or Rhub al Khali of Arabia (Glennie 1997; Howell, and Mountney 1997) and central Australia (Woods et al. 1990, and Nanson and Price 1998). 2) The occurrence of uplifted crust marginal to linear belts of depressed crust forming intermountain basin ...
... in the Sahara (Benazzouz 1993), and the Empty Quarter or Rhub al Khali of Arabia (Glennie 1997; Howell, and Mountney 1997) and central Australia (Woods et al. 1990, and Nanson and Price 1998). 2) The occurrence of uplifted crust marginal to linear belts of depressed crust forming intermountain basin ...
Formation of Arizona Minerals through Geologic Time Jan C
... Bisbee. Coal deposits formed in northern Arizona in the Black Mesa basin. The Laramide orogeny (85 – 43 Ma) (Late Cretaceous and Early Tertiary) represents flattening subduction, in which the magmatic arc migrated eastward through geologic time. The Laramide orogeny has been subdivided into four pha ...
... Bisbee. Coal deposits formed in northern Arizona in the Black Mesa basin. The Laramide orogeny (85 – 43 Ma) (Late Cretaceous and Early Tertiary) represents flattening subduction, in which the magmatic arc migrated eastward through geologic time. The Laramide orogeny has been subdivided into four pha ...
Argyll and the Islands - Scottish Natural Heritage
... are around 1,800 million years old, much older than the Dalradian rocks, but not as old as the oldest rocks on the British Isles, the Lewisian gneisses of the Outer Hebrides and North-west Highlands. The rocks of the Rhinns are also gneisses; they are coarsely crystalline and have a strongly banded ...
... are around 1,800 million years old, much older than the Dalradian rocks, but not as old as the oldest rocks on the British Isles, the Lewisian gneisses of the Outer Hebrides and North-west Highlands. The rocks of the Rhinns are also gneisses; they are coarsely crystalline and have a strongly banded ...
the cretaceous sanfranciscan basin, eastern plateau of
... cobbles of quartzite, with lenses of red sandstones associated. Directional structures like imbrication of clasts and cross-bedding in sands and gravels also indicate sense of paleoflow approximately from south to north. This conglomerate seems to have a low diamond content. Tompkins and Gonzaga (19 ...
... cobbles of quartzite, with lenses of red sandstones associated. Directional structures like imbrication of clasts and cross-bedding in sands and gravels also indicate sense of paleoflow approximately from south to north. This conglomerate seems to have a low diamond content. Tompkins and Gonzaga (19 ...
Hot spot activity and the break-up of Pangea (PDF
... The Mesozoic and Cenozoic positions of the continents that formed Pangea in the Triassic–Jurassic were derived from paleomagnetic and intraplate volcanic data, paleoclimatic observations, such as reef and fossil flora distribution, and geological observations. Major hot spots helped to determine the ...
... The Mesozoic and Cenozoic positions of the continents that formed Pangea in the Triassic–Jurassic were derived from paleomagnetic and intraplate volcanic data, paleoclimatic observations, such as reef and fossil flora distribution, and geological observations. Major hot spots helped to determine the ...
GEOL 109 - Continuing Education
... Evolution is the cornerstone for the interpretation of the fossil record and is accepted by virtually all scientists as a fact. Charles Darwin and Alfred R. Wallace recognised the importance of variability in offspring as an important component in the process of natural selection, although the expla ...
... Evolution is the cornerstone for the interpretation of the fossil record and is accepted by virtually all scientists as a fact. Charles Darwin and Alfred R. Wallace recognised the importance of variability in offspring as an important component in the process of natural selection, although the expla ...
Sequence stratigraphy of source and reservoir rocks in the
... marine Neill Klinter Group along the eastern, western and northern basin margins. High-resolution sequence stratigraphic analysis of the lacustrine Kap Stewart Group indicates that deposition took place in response to two orders of lake-level variations. The lake was low-lying and marine areas were ...
... marine Neill Klinter Group along the eastern, western and northern basin margins. High-resolution sequence stratigraphic analysis of the lacustrine Kap Stewart Group indicates that deposition took place in response to two orders of lake-level variations. The lake was low-lying and marine areas were ...
Sample pages 2 PDF
... ago, in the Mesoproterozoic, two or more large landmasses collided to form the great continent of Rodinia (Russian for ‘motherland’), producing intense volcanic activity, mountain building and the formation of sedimentary basins. Rodinia started to break up by rifting some 850 million years ago. Afr ...
... ago, in the Mesoproterozoic, two or more large landmasses collided to form the great continent of Rodinia (Russian for ‘motherland’), producing intense volcanic activity, mountain building and the formation of sedimentary basins. Rodinia started to break up by rifting some 850 million years ago. Afr ...
Document
... sequence includes gabbro, pillow and massive lavas, diorite, and plagiogranite. Plagiogranitic veins commonly crosscut the isotropic gabbro (Fig. 3). Extrusive rocks of the Shahr Babak Ophiolite are basaltic andesite to rhyodacite–rhyolite and trachyandesite (Shafaii Moghadam and Stern 2011). Shafai ...
... sequence includes gabbro, pillow and massive lavas, diorite, and plagiogranite. Plagiogranitic veins commonly crosscut the isotropic gabbro (Fig. 3). Extrusive rocks of the Shahr Babak Ophiolite are basaltic andesite to rhyodacite–rhyolite and trachyandesite (Shafaii Moghadam and Stern 2011). Shafai ...
tethyan evolution of turkey: a plate tectonic approach
... The Tethyan evolution of Turkey may be divided into two main phases, namely a Palaeo-Tethyan and a Neo-Tethyan, although they partly overlap in time. The PalaeoTethyan evolution was governed by the main south-dipping (present geographic orientation) subduction zone of Palaeo-Tethys beneath northern ...
... The Tethyan evolution of Turkey may be divided into two main phases, namely a Palaeo-Tethyan and a Neo-Tethyan, although they partly overlap in time. The PalaeoTethyan evolution was governed by the main south-dipping (present geographic orientation) subduction zone of Palaeo-Tethys beneath northern ...
Prepared by Erhan Turgut
... found in some coal seams. They often contain petrified fragments of the plants from which the coal was made. Methods of Study: The method used in studying plant fossils depends upon the type of preservation. Traces of the original tissue structure sometimes retained in compressions can be examined a ...
... found in some coal seams. They often contain petrified fragments of the plants from which the coal was made. Methods of Study: The method used in studying plant fossils depends upon the type of preservation. Traces of the original tissue structure sometimes retained in compressions can be examined a ...
M44-2003-A4-eng - Publications du gouvernement du Canada
... Along the northern margin of the Bella Coola map area, centred on Jumble Mountain, nearly continuous Jurassic stra tigraphy forms a superbly layered, east-dipping homocline more than 4 km thick. The lower part of this succession is dominated by maroon and green, massively bedded basalt and basaltic ...
... Along the northern margin of the Bella Coola map area, centred on Jumble Mountain, nearly continuous Jurassic stra tigraphy forms a superbly layered, east-dipping homocline more than 4 km thick. The lower part of this succession is dominated by maroon and green, massively bedded basalt and basaltic ...
Geology of the Southern Carnarvon Basin
... marine sandstones and carbonate units of the Southern Carnarvon Basin (Figure 8). In the mid Carboniferous the Devonian-Mississippian sequences were folded and faulted along north-trending axes (Mobil, 1994), possibly as a result of the collision of Gondwana with Laurasia. Pennsylvanian/Cisuralian – ...
... marine sandstones and carbonate units of the Southern Carnarvon Basin (Figure 8). In the mid Carboniferous the Devonian-Mississippian sequences were folded and faulted along north-trending axes (Mobil, 1994), possibly as a result of the collision of Gondwana with Laurasia. Pennsylvanian/Cisuralian – ...
porphyry copper-type mineralization and geosynclinal
... north-south and about 30 to 50 kilometers wide, lies on or adjacent to the Recent Andean Volcanic Chain. In northernmost Chile, as extension of the Peruvian belt, it lies on the western side of the volcanic chain, coinciding approximately with it, between latitudes 31° to 36° south, and continuing a ...
... north-south and about 30 to 50 kilometers wide, lies on or adjacent to the Recent Andean Volcanic Chain. In northernmost Chile, as extension of the Peruvian belt, it lies on the western side of the volcanic chain, coinciding approximately with it, between latitudes 31° to 36° south, and continuing a ...
3D restoration of a Cretaceous rift basin in Kilen, eastern North
... The semi-nunatak Kilen is a key area to understand the setting of the Cretaceous sedimentary basin in eastern North Greenland. The basin geometry has been obscured by later N–S compression and inversion of presumable Palaeocene–Eocene age. A 3D restoration of the Cretaceous basin is presented based ...
... The semi-nunatak Kilen is a key area to understand the setting of the Cretaceous sedimentary basin in eastern North Greenland. The basin geometry has been obscured by later N–S compression and inversion of presumable Palaeocene–Eocene age. A 3D restoration of the Cretaceous basin is presented based ...
Preliminary Geologic Map of the - New Mexico Bureau of Geology
... Rocky Mountain Mountain Peñasco highland (Woodward 1987) located just southwest of the quadrangle, which occupied the current locality of the Sierra Nacimiento. Latest Pennsylvanian to Permian Starting about 300 million years ago, the ocean shoreline retreated toward the south, and a south-flowing r ...
... Rocky Mountain Mountain Peñasco highland (Woodward 1987) located just southwest of the quadrangle, which occupied the current locality of the Sierra Nacimiento. Latest Pennsylvanian to Permian Starting about 300 million years ago, the ocean shoreline retreated toward the south, and a south-flowing r ...
The Early Cretaceous Arperos oceanic basin
... oceanic basin by Freydier et al. and therefore, it constitutes neither a continental, nor oceanic basement for the latter unit. More recently, high-grade gneiss xenoliths with Sm–Nd model ages typical of Grenvillian age rocks in Mexico have been reported as extruded samples of the crust underlying t ...
... oceanic basin by Freydier et al. and therefore, it constitutes neither a continental, nor oceanic basement for the latter unit. More recently, high-grade gneiss xenoliths with Sm–Nd model ages typical of Grenvillian age rocks in Mexico have been reported as extruded samples of the crust underlying t ...
Alternative global Cretaceous paleogeography
... Indian Ocean basins. North America, Eurasia, and Africa were crossed by shallow meridional seaways. This classic view of Cretaceous paleogeography may be incorrect. The revised view of the Early Cretaceous is one of three large continental blocks— North America–Eurasia, South America–Antarctica-Indi ...
... Indian Ocean basins. North America, Eurasia, and Africa were crossed by shallow meridional seaways. This classic view of Cretaceous paleogeography may be incorrect. The revised view of the Early Cretaceous is one of three large continental blocks— North America–Eurasia, South America–Antarctica-Indi ...
Chukchi arctic continental margins: tectonic evolution, link to the
... fold belt) comprises two tectonic units, namely the Anyui-Chukotka fold system (the ACh) and the South Anyui suture (the SAS). In terms of the paleotectonic reconstructions, the ACh represents the Chukotka microcontinent whereas the SAS is the suture, which is the result of collision of the Chukotka ...
... fold belt) comprises two tectonic units, namely the Anyui-Chukotka fold system (the ACh) and the South Anyui suture (the SAS). In terms of the paleotectonic reconstructions, the ACh represents the Chukotka microcontinent whereas the SAS is the suture, which is the result of collision of the Chukotka ...
Geology of Paraná
... reflects how resistant to weathering its rocks are. From the Devonian scarp known as São Luiz do Purunã to the western border of the state, the Paraná Shield is overlain by the PARANÁ BASIN, a massive sequence of sedimentary and volcanic rocks of Silurian to Cretaceous age that sustains the state's ...
... reflects how resistant to weathering its rocks are. From the Devonian scarp known as São Luiz do Purunã to the western border of the state, the Paraná Shield is overlain by the PARANÁ BASIN, a massive sequence of sedimentary and volcanic rocks of Silurian to Cretaceous age that sustains the state's ...
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.