نتایج جستجو برای: hercynian orogeny

تعداد نتایج: 876  

Journal: :Ore Geology Reviews 2022

The Bou Azzer district in Morocco has a long mining history since the beginning of XXst century during which it become only world producer Co from primary, hydrothermal arsenide ores. Orebodies are structurally controlled, and mainly distributed along fault contacts between Cryogenian ophiolite-related serpentinite bodies intrusive quartz diorite or, locally, ophiolitic gabbros or Ediacaran vol...

2004

The northern Asia, including the southern territories of Russia, Kazakhstan, Uzbekistan, Mongolia and the northern China is known as an important distribution region of uranium deposits and occurrences. Since the 60s of 20th century, after the successful development of in-situ leach technology for sandstone-hosted uranium deposits, numerous uranium deposits previously discovered in Kazakhstan a...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2005
John F Dewey

In contrast to continent/continent collision, arc-continent collision generates very short-lived orogeny because the buoyancy-driven impedance of the subduction of continental lithosphere, accompanied by arc/suprasubduction-zone ophiolite obduction, is relieved by subduction polarity reversal (flip). This tectonic principle is illustrated by the early Ordovician Grampian Orogeny in the British ...

The Paleozoic sediments of the Chal-i-Sheh area in southwestern Iran comprising of Mila Formation, Ilebek Formation and Faraghan Formation, were studied palynologically. The samples containing well-preserved palynomorphs include acritarchs, chitinozoans, scolecodonts and pollenlspores. A palynological zonation has been established and comparison was made with other parts of the world. Based...

2007

reservas, similares procesos metalogenéticos habrian actuado en el Paleozoico Inferior del Brea. La deformación y el metamorfisme regional hercinicos no han actuado en este sector como un importante reconcentrador de menas, y la mayor parte de indicios epigenéticos Many mineralizations, showings and geochemical anomalies de edad tardihercinicaestán relacionados alas células hidrotermales have b...

Journal: :Minerals 2021

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) is classically used in U-Pb dating to measure U and Pb isotopic concentrations. Recently, it has become frequently fission-track (FT) chronometry too. As an advantage, the FT double will enable efficiently determining crystallization ages thermo-tectonic history concurrently as samples volume, analytical time, efforts, cost...

The Geirud Formation consists mainly of clastic sediments which are interbedded with limestone stringers. This rock unit is well-exposed along the Central Alborz Range in northern Iran. The Geirud Formation rests unconformably on the Mila Formation (Upper Cambrian) and is conformably overlain by the Mobarak Formation (Lower Carboniferous). This study was undertaken to determine the geologi...

2007
H. DURAN

In the Catalonian Coastal Ranges, Paleozoic sedimentary and meta-sedimentary rocks crop out in severa1 areas, intruded by late tectonic Hercynian granitoids and separated by Mesozoic and Tertiary cover sediments. Large structures are often difficult to recognize, although a general east-west trend can be observed on the geological map. Deformation was accompanied by the development of cleavages...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید