<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The Zhob Ophiolite is divided into three detached blocks including the Omzha block. The Omzha block is mapped and divided into lithological units such as ultramafic rock, mafic-felsic rock, and volcanic–volcaniclastic–pelagic rocks. These units are quite deformed and mixed up and are associated with one another by thrust faults. Petrography and geochemistry divide them into gabbro, diorite, plagiogranite, pheno-tephrite and trachy-andesite basalt, trachy basalt, chert, limestone, and mudstone. The ultramafic rocks are dominantly serpentinized harzburgite, dunite, and a minor lherzolite. Petrography of peridotite shows that it may be depleted in nature and may have residual after processes such as partial melting and the melt-rock reaction of a lherzolitic source. The gabbroic rocks are less well-developed and highly deformed. They are cross-cut by diorite, plagiogranite and anorthosite’ intrusions. The gabbro may be the plutonic section of Omzha block’ crust while the intermediate-felsic igneous rocks may have formed by the anataxis of crustal gabbro. The volcanic–volcaniclastic–pelagic rocks unit may be corrected with Bagh complex found underneath the Muslim Bagh Ophiolite. The metamorphic sole rocks of Omzha block are highly deformed and dismembered are comprising of metamorphic facies such as amphibolite, quartz-mica schist, and greenschist.</p></abstract>

The Zhob Ophiolite is divided into three detached blocks including the Omzha block. The Omzha block is mapped and divided into lithological units such as ultramafic rock, mafic-felsic rock, and volcanic–volcaniclastic–pelagic rocks. These units are quite deformed and mixed up and are associated with one another by thrust faults. Petrography and geochemistry divide them into gabbro, diorite, plagiogranite, pheno-tephrite and trachy-andesite basalt, trachy basalt, chert, limestone, and mudstone. The ultramafic rocks are dominantly serpentinized harzburgite, dunite, and a minor lherzolite. Petrography of peridotite shows that it may be depleted in nature and may have residual after processes such as partial melting and the melt-rock reaction of a lherzolitic source. The gabbroic rocks are less well-developed and highly deformed. They are cross-cut by diorite, plagiogranite and anorthosite’ intrusions. The gabbro may be the plutonic section of Omzha block’ crust while the intermediate-felsic igneous rocks may have formed by the anataxis of crustal gabbro. The volcanic–volcaniclastic–pelagic rocks unit may be corrected with Bagh complex found underneath the Muslim Bagh Ophiolite. The metamorphic sole rocks of Omzha block are highly deformed and dismembered are comprising of metamorphic facies such as amphibolite, quartz-mica schist, and greenschist.

Geology and Petrology of Omzha Block, Zhob Ophiolite, northern Balochistan, Pakistan

Department of Earth & Environmental Sciences

Pakistan Journal of Geology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The Zhob Ophiolite is divided into three detached blocks including the Omzha block. The Omzha block is mapped and divided into lithological units such as...

Geology and Petrology of Omzha Block, Zhob Ophiolite, northern Balochistan, Pakistan

Published Online: Jan 05, 2021

Page range: 72 - 80

DOI: https://doi.org/10.2478/pjg-2020-0008

Keywords
Ophiolitic mélange, ultramafic rocks, gabbro, plagiogranite, volcanics- volcaniclastics. metamorphic sole rocks

© 2020 Ali Ahmed et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Geology and Petrology of Omzha Block, Zhob Ophiolite, northern Balochistan, Pakistan

Published Online: Jan 05, 2021

Page range: 72 - 80

DOI: https://doi.org/10.2478/pjg-2020-0008

KeywordsOphiolitic mélange, ultramafic rocks, gabbro, plagiogranite, volcanics- volcaniclastics. metamorphic sole rocks

© 2020 Ali Ahmed et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Ophiolitic mélange, ultramafic rocks, gabbro, plagiogranite, volcanics- volcaniclastics. metamorphic sole rocks