Notes on Rock-Forming Minerals (11)Jadeite and Hornblende from the Kamuikotan Metamorphic Belt

Biotite and Hornblende Composition Used to Investigate the Nature and Thermobarometry of Pichagchi Pluton, Northwest Sanandaj-Sirjan Metamorphic Belt, Iran

Pichagchi pluton is situated in the northeastern part of the Soursat complex in Sanandaj-Sirjan metamorphic belt of Iran. The pluton with the age of 74.20 Ma is composed mainly granodiorite, diorite, and tonalite in which mafic minerals are biotite and amphibole. In this study, composition of minerals used to describe the nature of the granitic magma and estimate the pressure and temperature at...

Coexisting hornblende and cummingtonite from the Khetri copper belt, Rajasthan, India

Coexisting hornblende and cummingtonite in an amphibolite near Peliwali have been analysed. The rock formed by Fe-Mg addition and Ca removal from pre-existing amphibole quartzites within the altered wall rocks surrounding sulphide lodes. The amphibole compositions are controlled by the bulk composition of the rock. The Mg/(Mg+Fe 2+) ratio of the hornblende (o.66) is only slightly higher than th...

On Experimentally and Naturally Produced Shock Effects in Rock Forming Minerals

High-Pressure Marbles from the Nahavand Area in the Sanandaj-Sirjan Metamorphic Belt, Iran

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 ...

Rock-Fluid Interaction Along Seismogenic Faults Infered from Clay Minerals in Okitsu Mélange, the Cretaceous Shimanto Belt, SW Japan