Intrusion of the Kalaybar nepheline syenite into the Cretaceous pelitic and calcareous sediments has produced a thermal aureole up to 1km thick. Six mineralogical zones are developed in the pelitic rocks with minerals such as cordierite, K feldspar, sillimanite and corundum. Chemically suitable rocks are partially melted in response to the heat from the pluton. Five mineralogical zones are deve...

for the first time, an unusual assemblage of talc-phengite-chlorite-k-feldspar was found in quartz schists from the sanandaj-sirjan zone in the nahavand area in western iran. the talc-bearing quartz schists occur as small bodies or lenses within pelitic schist layers and contain talc, phengite, chlorite, k-feldspar and quartz as major mineral constituents with subordinate amounts of calcite ...

Ordinary chondrites are the most common type of chondrites. As a non-destructive, rapid, and semi-quantitative technology, Raman spectroscopy is widely used in geoscience. This paper presents results spectroscopic study that we conducted for 16 ordinary with different chemical groups variable degrees shock metamorphism. We found that: (1) relationship between Fe composition olivine pyroxene cha...

Abstract Continental arcs in active continental margins (especially deep-seated arc magmatism, anatexis, and metamorphism) can be extremely significant evaluating continent building processes. In this contribution, a Paleozoic section is constructed based on coeval granulite-facies metamorphism, magmatism the northern margin of Qilian Block, which record two episodes crust growth. The deeper la...

The formation of porphyroblasts by replacement and displacement of pre-existing S surfaces is examined in the light of textural evidence displayed by sediments hornfelsed by the Bushveld Igneous Complex. Helicitic biotite, staurolite, and cordierite all show replacement and displacement textures, the former being more common. The evidence indicates that porphyroblasts arc capable of creating lo...

Highly cracked and isomerized archaeal lipids and bacterial lipids, structurally changed by thermal stress, are present in solvent extracts of 2,707- to 2,685-million-year-old (Ma) metasedimentary rocks from Timmins, ON, Canada. These lipids appear in conventional gas chromatograms as unresolved complex mixtures and include cyclic and acyclic biphytanes, C36-C39 derivatives of the biphytanes, a...

Ar–Ar and fission-track dating from four low-grade sections in the Alpujárride Complex sheds light on the timing of the early contractional history of these high-pressure metamorphic units, and their subsequent exhumation during the early Miocene extensional collapse of the Betic orogen. White mica grains from the lowest-grade rocks yield partly reset detrital Ar–Ar ages; where deformation and ...