marbles containing high-pressure mineral assemblage was found from the sanandaj-sirjan metamorphic belt in the nahavand area in western iran.  the high-pressure marbles occur as small bodies or lenses within pelitic schist layers and show compositional banding of carbonate- and silicate- rich bands.  textural analysis revealed two metamorphic stages.  the early stage is testified by relicts of ...

The study area is located about 110 kilometers southeast of Mashhad and approximately 40 kilometers southeast of Fariman. The area is considered to be a part of the central Iran zone. It includes metamorphic rocks with different protoliths consisting of pelitic, carbonate and quartz - feldspathic rocks. The metamorphism in the study area is considered to be a contact regional metamorphism with ...

3 INTRODUCTION 4 Aim and approach 4 Structural domains in the Swedish part of the Baltic Shield defined by deformation zones and formline patterns 4 Age and character of high-T deformation zones in the Baltic Shield 6 GEOLOGY OF EAST CENTRAL SWEDEN 7 Rocks and ages 7 Metamorphism 8 Typical features of low pressure-high temperature metamorphism 9

Marbles containing high-pressure mineral assemblage was found from the Sanandaj-Sirjan metamorphic belt in the Nahavand area in western Iran.  The high-pressure marbles occur as small bodies or lenses within pelitic schist layers and show compositional banding of carbonate- and silicate- rich bands.  Textural analysis revealed two metamorphic stages.  The early stage is testified by relicts of ...

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 ...

Where plates converge, one-sided subduction generates two contrasting thermal environments in the subduction zone (low dT/dP) and in the arc and subduction zone backarc or orogenic hinterland (high dT/dP). This duality of thermal regimes is the hallmark of modern plate tectonics, which is imprinted in the ancient rock record as penecontemporaneous metamorphic belts of two contrasting types, one...

Microdiamonds from the Akluilâk minette dykes (Nunavut, Canada) are similar to diamonds formed in subducted metamorphic rocks. High concentrations of unaggregated nitrogen and positive delta(15)N suggest that the microdiamonds formed within rocks subducted to ultrahigh pressures before being sampled by the minette magma 1.8 billion years ago. This ultrahigh pressure metamorphism in North Americ...

Large earthquakes occur in rocks undergoing high-pressure/low-temperature metamorphism during subduction. Rhythmic major-element zoning in garnet is a common product of such metamorphism, and one that must record a fundamental subduction process. We argue that rhythmic major-element zoning in subduction zone garnets from the Franciscan Complex, California, developed in response to growth-dissol...