Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Lithological and microstructural study of Soresat metamorphic complex (South Eastern of Shahin-Dej)

Document Type : Original Research Paper

Authors
Abbas Ghasemi 1, 2
Mohsen Pour-Kermani 3
1 Department of Geology, Faculty of Sciences, Tarbiat Moalem University, Tehran, Iran
2 Geological Survey of Iran, Tehran, Iran
3 Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
Abstract
Field and microscopic studies and geochemical analyses suggest that granitoid rocks may be subdivided into three main groups. The first group of granitoid rocks is S-type syn-tectonic granitic gneiss sheets, the second group is I-type volcanic arc granite and granodiorite and the third group is S-type post-collision alkali-granite.
The rocks of Soresat metamorphic complex are different kinds of schist. Andalusite, staurolite, garnet, sillimanite (fibrolite) are the main metamorphic porphyroblasts in these rocks. The protolith of Soresat metamorphic complex are a sequence including shale, siltstone and graywacke with carbonate, arkosic sandstone and pyroclastic intercalations.
A prominent,regionally penetrative foliation(S2) is distinguished in studied area. S2 is generally parallel to meta-sedimentary bedding plane. Thin section studies reveal two discrete deformational events. The first deformational event (D1) is preserved as straight inclusion trails in Pre -S2 Post-S1 andalusite, staurolite porphyroblasts. The S2 is generated by the second deformational event. The retrograde metamorphic event follows the second deformational event. The proposed P-T-t path shows a clock-wise path for Soresat metamorphic complex (Pmax=3.7 Kbar, Tmax=600ºC).
Keywords
Deformational events
porphyroblast
Trail inclusion
P-T-t curve
Tectonic setting of granite
Thermometry

Subjects

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Scientific Quarterly Journal of Geosciences
Volume 13, 51-52
Spring & Summer 2004, Vol. 13, No. 51-52
Summer 2004
Pages 18-27