نتایج جستجو برای: hercynian orogeny
تعداد نتایج: 876 فیلتر نتایج به سال:
There has been controversy over the number and timing of orogenies in the Precambrian Moine block in the Scottish Caledonides since the earliest radiometric dating in the 1960s. This work challenges a recent hypothesis, that this sector of the Laurentian margin was subjected to continuous crustal extension between .900 and 470 Ma. U–Pb dating (thermal ionization mass spectrometry) of titanite f...
The Andes are known to have influenced speciation patterns in many taxa, yet whether species diversification occurred simultaneously with their uplift or only after uplift was complete remains unknown. We examined both the phylogenetic pattern and dates of branching in Adelomyia hummingbirds in relation to Andean uplift to determine whether diversification coincides with the chronological phase...
Apatite fission-track analysis was applied to Triassic and Cretaceous sediments from the South-Iberian Continental Margin to unravel its thermal history. Apatite fission-track age populations from Triassic samples indicate partial annealing and point to a maximum temperature of around 100–110 °C during their post-depositional evolution. In certain apatites from Cretaceous samples, two different...
Travel times of 11,612 Pn arrivals collected from 7675 earthquakes are inverted to image the uppermost mantle velocity and anisotropy structure beneath the southern half of the Iberian Peninsula and surrounding regions. Pn phases are routinely identified and picked for epicentral distances from 200 to 1200 km. The method used in this study allows simultaneous imaging of variations of Pn velocit...
U–Pb ages of individual detrital zircon grains from deltaic and turbidite sandstones of the lower to middle Pennsylvanian Haymond Formation (Marathon basin, west Texas) range from 320 Ma to 3 Ga, indicating a mixed provenance broadly similar to that of Ouachita Carboniferous turbidites and related fluvio-deltaic facies of Arkansas–Oklahoma. Differences with the Ouachita assemblage are attribute...
the metamorphic complexes of south iran (namely sirdjan, hadji-abad and dolat-abad) are conspicuously related to two different cycles of orogeny and metamorphism . these two cycles are distinctly separate and have been mapped as such throughout the hadji - abad area . the older phase is definitely pre-cambrin, whereas the younger is considered to be early - kimmerian .
the kasian volcanic body is located in the eastern margin of the zagros thrust belt, close to the sanandaj-sirjan metamorphic zone. these volcanic rocks are mainly composed of andesite and andesite-basalt rocks with porphyritic, hypocrystalline porphyritic, hyalo-porphyritic and hyalo-microlitic porphyritic textures. analyses of the distributions of major, rare earth and trace elements reveal a...
Defining the fracture network and active fluid pathways are fundamental to characterizing a fractured reservoir. With this goal, we chose Saint Pierre Bois quarry (Vosges Massif, France) as natural analogue for Permian-Stephanian cover (arkoses)/Hercynian basement (granite) transition that serve geothermal reservoirs, example at Rittershoffen, Landau Insheim, where plants exploit kind of reserv...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید