Abstract

The present contribution reports on the field, petrographical and geochemical observations of the volcano-plutonic rocks of the Nakora Ring Complex (NRC) from the Neoproterozoic, Malani Igneous Suite (MIS) (Northwestern Peninsular India) and confers about their magmatic evolution and tectonic implications. Three magmatic phases are notable in the NRC which is Extrusive, Intrusive and Dyke phase where with small quantities of basaltic flows was initiated and accompanied by extensive/voluminous acidic flows. Petrographically, rhyolite shows flow bands, porphyritic, spherulitic, aphyritic and perlitic textures whereas basalt flows are distinguished by the presence of labradorite in lath-shaped crystals (plagioclase feldspar) and clinopyroxene (augite). The presence of high silica and total alkalis in NRC rocks, as well as high field strength elements (HFSE), enrichment of trace elements and negative anomalies of Sr., Eu, P, and Ti indicates that the emplacement of the lava flows was controlled by complex magmatic processes such as fractional crystallization, crustal contamination and partial melting. The association of basalt-trachyte-rhyolite means that the magma chamber was supplied a significant amount of heat to the crust before the eruption. Moreover, a volcanic vent was also reported at NRC where rhyolite was associated with agglomerate, volcanic breccia, perlite and tuff. The current research proposed that the Neoproterozoic magmatism at NRC was controlled by rift-related mechanism and produced from crustal source where the heat was supplied by mantle plume.

Highlights

  • Volcano mentions as the magma and associated ingredients erupt to the surface from the vent and refer to the landform formed by solidified lava and volcanic debris near the vent

  • The rock types exposed in Nakora Ring Complex were classified into three major lithological divisions: basalt and rhyolite as first phase, second phase of granites of different colors and third and last phase magmatism of dykes of fine-grained granites and rhyolites

  • It is suggested that rhyolites show ophitic, sub-ophitic, porphyritic, granophyric, glomeroporphyritic, aphyritic, spherulitic, perlitic, hypidiomorphic, granophyric and microgranophyric textures

Read more

Summary

Introduction

Volcano mentions as the magma and associated ingredients erupt to the surface from the vent and refer to the landform formed by solidified lava and volcanic debris near the vent. Volcanic vent were documented from diverse settings of the world and they are sketched with crustal provinces, platforms, shield areas and orogenic belts (Figure 1). The volcanoes such as MidAtlantic Ridge and Pacific Ring of Fire are superlative example of divergent and convergent tectonic plates respectively. MIS is India’s largest anorogenic acid volcanism and the world’s third largest with the characteristics of distinctive ring structures and radial dykes.

Geological setting
Basalt
Trachyte
Rhyolite
Rhyolite and microgranite
Analytical techniques
Bulk geochemistry
Extrusive phase
Intrusive phase
Magmatism and tectonism
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call