The Diwani hills are located SE of Balaram–Abu Road in the Banaskantha district of north Gujarat. The crystalline rocks of the Diwani hill area are a diverse assemblage of Precambrian metamorphic and igneous rocks. These rocks are petrologically more complex and date back to the Aravallis or earlier. The mineralogical assemblages such as grt–sp–opx–qz of these rocks indicate their origin in anhydrous or dry conditions, implying metamorphism under pyroxene granulite facies. These granulitic rocks were subjected to Delhi orogenic deformation and were later intruded by the Erinpura granite. Textural and microstructural relationships, mineral chemistry, P–T–X pseudosection modelling and the oxidation state of pelitic granulites from the Diwani hill area of north Gujarat are all part of the current approach. The winTWQ program and pseudosection modelling in the NCKFMASHTO model system utilizing Perple_X software were used to restrict the P–T evolution of these pelitic granulites. The unification of these estimates shows that the pelitic granulites reached their pressure and temperature maxima at 8.6 kbar and 770 °C, respectively. The oxygen fugacity (log fO2) versus temperature computations at 6.2 kbar revealed log fO2–T values of −13.0 and 765 °C, respectively. The electron microprobe dating of monazite grains separated from the granulites of the Diwani hills yields ages ranging from 769 Ma to 855 Ma. The electron microprobe dating presented here from the Diwani hills provides evidence for a Neoproterozoic (Tonian) metamorphic event in the Aravalli–Delhi Mobile Belt.

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An attempt has been made to illustrate the evolution of pelitic granulite from south of the Balaram-Abu road, which lies in the South Delhi Terrane (SDT) of the Aravalli-Delhi Mobile Belt (ADMB), using geochemistry and geochronology. The current work offers a plausible explanation for the protolith of pelitic granulite, nature of the sediments and its provenance. The elemental geochemistry of the pelitic granulites reveals that the protolith is an arkosic to shaley type. The rare earth elements pattern shows that there is a negative Eu anomaly and a small excess of LREE over HREE. This means that the source of sediments probably has the same elements as the upper crust. However, the amounts of Sr, Nd and Pb vary a lot, which shows that the sediments supplied from two different types of sources (felsic and mafic) in different proportions from a Proterozoic terrain. The monazite geochronology indicates that the metamorphic overprint occurred between 797 Ma and 906 Ma. Additionally, the ages correlate to the debris that was formed between the 1188 Ma and 1324 Ma from magmatic/sedimentary sources for pelitic granulite. The present research provides a more in-depth understanding of the evolutionary history of the pelitic granulite that comprises the SDT in the ADMB region during the Proterozoic era.

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