Petrologic study of sillimanite-garnet-cordierite-bearing pegmatite intrusives from Takato, central Japan.

11. MYRMEKITE IN GARNET-SILLIMANITE- CORDIERITE GNEISSES AND Al-Ti-Zr TRENDS, GOLD BUTTE, NEVADA

Four generations of accessory-phase growth in low-pressure migmatites from SW NewHampshire

Mineral compositions and reaction textures found in migmatitic gneisses from near Gilsum, New Hampshire, constrain both peak metamorphic pressure (P) and temperature (T) conditions and the PT path. Large K-feldspar porphyroblasts indicate isobaric heating of the samples at P < 4 kb (Spear et al. 1999), and relict cordierite + garnet assemblages record the occurrence of biotite vapor-absent melt...

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...

A study of various occurrences of the Al2SiO5 polymorphs in the rocks/veins of the Hamedan region, Iran: with special reference to origin of quartz-kyanite veins

The study area is a part of so-called Sanandaj-Sirjan zone or Zagros imbricate zone of the Zagros Orogen, Iran. The Hamedan region comprises a metamorphic sequence of low- to high-grade regional and contact metamorphic rocks intruded by mafic, intermediate and felsic plutonic bodies. The sequence comprises pelitic, psammitic, mafic, calc-pelitic and calc-silicate rocks.  Pelitic rocks are the m...

Cation Exchange Between Piemontite and Garnet in Piemontite-Quartz Schists from Asemi-Gawa Area of Central Shikoku, Sanbagawa Metamorphic Belt, Japan

In the Asemi-gawa area of intermediate high-pressure and low-temperature Sanbagawa metamorphic belt in central Shikoku, Japan, piemontite-quartz schists are common in which cation exchange between piemontite and garnet has been studied. Piemontite in contact with garnet usually contains two zones in which core is enriched in Mn3+ and surrounded by a rim rich in Fe3+. Garnet is Ca-Fe-bearing spe...