نتایج جستجو برای: cretaceous rocks
تعداد نتایج: 30195 فیلتر نتایج به سال:
between the lower and upper cretaceous there were some diastrophic movements, belonging to the austrain phase. these movements, which can be traced in many parts of north and central iran, caused extensive precenomanian erosion. even in southwest iran a wide spread discontinuity is reported at the base of the kazhdumi formation, which is possibly related to these movements. in the kopet - dagh ...
pillow basalts, belonging to late cretaceous yüksekova complex are extensivelly exposed around elazıg in eastern turkey. this unit is a part of southeastern anatolian ophiolite belt and the southern branch of the neotethys. it represents the products of intra- oceanic subduction volcanism and mainly comprises pillow lavas, dykes and associated with sedimentary rocks. pillow lavas and feeder dyk...
The alkaline and stratoid volcanic rocks of Separdeh district (NE Qazvin), located on the central Albroz zone, are underlain conformably by Early Cretaceous limestones of Tizkuh Formation. These rocks are texturally homogenous and very fine-grained and characterized by microphenocrysts and microliths of plagioclase, pyroxene, olivine, apatite and opaque set in a hyaline matrix. However, few pyr...
It has been proposed that extensive wildfires occurred after the Cretaceous-Tertiary (K-T) impact event. An abundance of soot and pyrosynthetic polycyclic aromatic hydrocarbons (pPAHs) in marine K-T boundary impact rocks (BIRs) have been considered support for this hypothesis. However, nonmarine K-T BIRs, from across North America, contain only rare occurrences of charcoal yet abundant noncharr...
The Eskay Creek gold-silver mine, located in northwest British Columbia, is the highest-grade precious-metal volcanogenic massive sulphide deposit in the world. The mining industry continues to spend more than $2 million each year on exploration for similar deposits in the area. The geologic setting at the minesite is well studied, but large tracts in north-central British Columbia require more...
The Cheshmeh Zagh area is located on Khorasan Razavi Province, the southern parts of the Sabzevar zone, which is one of the most important metallogeny zones of Iran. Lithologically, the area includes a variety of Late Cretaceous volcanic rocks (dacite to basalt), intrusions (gabbro to synogranite), Oligo-Miocene sedimentary rocks, and Quaternary sediments. Alteration zones of propylitic, chlori...
The crab genus Rathhunopon is exclusively known from Cretaceous rocks, mainly from Europe. Here two new European localities are presented: one in the Albian/Cenomanian of northern Spain yielding well-preserved specimens of Rathhunopon ohesum, and one from the lower Aptian at the German-Austrian border yielding Rathhunopon schrattenkalkensis n. sp. Both are found in association with coral reefs....
The Siyahmansour area is located between longitude 370 46َ 07" to 370 50َ 19" N and latitude 470 53ً 13" to 470 58َ 22" E in northeastern town of Miyaneh Exposure of different igneous rocks in the studied area including Eocene to Miocene volcanic rocks, granitoids and diorites. The granitoids are different including muscovite granites and granite-granodiorite. The muscovite granites are intruded in...
of Wallowa terrane crust, as the Blue Mountains terrane assemblage The Cornucopia stock, in the Blue Mountains of northeastern collided with the continental margin during Early Cretaceous time. Oregon, is a small composite intrusion comprising five distinct Results of this study suggest that deformation and crustal melting intrusive units: a hornblende biotite tonalite, a biotite trondhjemite, ...
Cenomanian paralic deposits of Charentes (southwestern France) have yielded abundant vertebrate microremains, including rather diversified continental taxa (e.g., frogs, turtles, crocodilians, dinosaurs, pterosaurs, lizards, and mammals). In this preliminary report, the succession of faunal assemblages observed is briefly described in relation to palaeoenvironmental change resulting from the Ce...
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