Introduction We investigated two processes in a series of the Hungarian L-chondrites: shock and thermal metamorphism. Thermal metamorphism transforms the textures in the relatively small chondritic planetary body. Shock metamorphism is caused by hypervelocity impact processes transforming texture and mineral structure mainly in the outermost layers of the chondritic planetary body [1,2]. The pu...

Abstract The Mesoproterozoic MARA terrane of western South America is a composite igneous-metamorphic complex that important for Paleozoic paleogeographic reconstructions and the relative positions Laurentia Gondwana. magmatic detrital records are consistent with Laurentian origin; however, metamorphic deformation lack sufficient detail to constrain correlation units within timing mechanisms ac...

We present thermodynamic estimates of pressures, temperatures, and volatile activities in vailably deformed, gabbroic to granitic, Cretaceous (115-100 Ma) batholithic and framework rocks of the Tehachapi Mountains, southernmost Sierra Nevada, California. A1 contents of hornblende in granitoids imply igneous emplacement at --8 kbar in the southernmost Tehachapi Mountains, with lower pressures (3...

Abstract The Seve Nappe Complex (SNC) comprises continental rocks of Baltica that were subducted and exhumed during the Caledonian orogeny prior to collision with Laurentia. tectonic history central SNC is investigated by applying in-situ zircon monazite (Th-)U–Pb geochronology trace element analysis (ultra-)high pressure (UHP) paragneisses in Avardo Marsfjället gneisses. Zircons Gneiss exposed...

Study of the concentration and isotopic composition of strontium and rubidium in hornblende diorite dikes and sills of Precambrian age from the Panamint Mountains of California showed that these rock systems were enriched in radiogenic Sr during a late Mesozoic metamorphism. Enrichments in radiogenic Sr were observed for total-rock samples which yielded apparent ages of up to 34,000 m.y., altho...

Robat-e Zengejeh rocks affected by a variety of events began from Precambrian. This research studied preserved effects of the events. Regional metamorphism is the oldest event in this rocks include schist, amphibolite and orthogneiss, that reached up to amphibolite facies. After this regional metamorphism, it seems that mesocratic (624±5Ma) and hololeucocratic granitoides intruded respectively....

Rapid extensive magmatism may have a profound effect on global climate by liberating and releasing greenhouse gases to the atmosphere through contact metamorphism of lithologically heterogeneous host rocks degassing magma associated lava flows. The high Arctic Archipelago Svalbard offers accessible, superbly exposed outcrops revealing Early Cretaceous with High Large Igneous Province (HALIP). I...

Archean supracrustal sequences of pelitic, quartzitic, calcareous and mafic compositions in the central Laramie Mountains, Wyoming, have been affected by two metamorphic events: a 1.78 Ga amphibolitegrade regional metamorphism, and a 1.43 Ga contact metamorphism resulting from the intrusion of the Laramie Anorthosite Complex (LAC). Rb–Sr whole-rock isotopic data from both outside and within the...