Preferred Orientation of Quartz in Metamorphic Rocks from the Bergell Alps

Preferred orientation of quartz in a chert breccia.

Preferred orientation of minerals hitherto has been studied almost exclusively in metamorphic and igneous rocks, which show the most spectacular effects of deformation or magmatic flow. In sediments, preferred orientation of grains controlled by their shape has been discussed by Sander,' but to our knowledge no one has ever reported preferred orientation produced by deformation under diagenetic...

Metamorphic evolution of high-pressure Quartz Schists in the Chadegan metamorphic complex, Sanandaj-Sirjan zone, Iran

The Chadegan metamorphic complex is a WNW-ESE- trending antiformal structure located in Sanandaj-Sirjan structural zone, Iran.The inner core of the structure is made of orthogneiss, containing eclogitic lenses. Schists and marbles lie structurally above theorthogneiss and crop out in the external limbs of the antiformal dome. Two main deformational episodes have been documented in theschists an...

the role of russia in transmission of energy from central asia and caucuses to european union

پس ازفروپاشی شوروی،رشد منابع نفت و گاز، آسیای میانه و قفقاز را در یک بازی ژئوپلتیکی انرژی قرار داده است. با در نظر گرفتن این منابع هیدروکربنی، این منطقه به یک میدانجنگ و رقابت تجاری برای بازی های ژئوپلتیکی قدرت های بزرگ جهانی تبدیل شده است. روسیه منطقه را به عنوان حیات خلوت خود تلقی نموده و علاقمند به حفظ حضورش می باشد تا همانند گذشته گاز طبیعی را به وسیله خط لوله مرکزی دریافت و به عنوان یک واس...

Slow oxygen diffusion rates in igneous zircons from metamorphic rocks

Empirical tests of oxygen exchange rate in zircon crystals from amphiboliteand granulite-facies metamorphic rocks of the Grenville Province demonstrate preservation of igneous dO through protracted igneous and metamorphic histories, forming the basis of quantitative estimates of diffusion rate. Granitic orthogneisses, which cooled slowly after granulite-facies metamorphism, show no consistent r...

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks