Introduction
The Neoproterozoic magmatism associated with continental rifting to the West of the Aravallis at the
NW margin of the Indian Shield, is represented by the Nagarparkar, and Kirana Complexeswhich
constitute a distinct anorogenic igneous cratonic rift assemblage of widespread magmatic activity and
which is a part of widespread Late Proterozoic Malani Igneous suites extending from western Rajasthan
to Sindh Province in Pakistan.
Geology and Stratigraphy
Kazmi and Khan (1973) presented a Geological map of the area describing different units of the complex
based on field relationships. Muslim et al (1989, 1997) partially amended the stratigraphy. The granites
and gabbro are the main exposed rocks, occupying 90% volume of the crystalline rocks of the complex.
These exposed units are present as scattered hillocks jutting out of the Thar Desert and extend in to the
Southeast towards Rajasthan, India. The complex is generally covered by Quaternary Bar-tala formation,
comprising basal conglomerates and sandstone, marking an unconformity. Dhedvero gabbros are the
oldest exposed rock unit, intruded by Karai dolerite and Nagarparkar Granite. Both these units are
placed in early Proterozoic period. Stratigraphically, granites are comparatively younger phases and are
placed in the late Proterozoic age (Table.1). Nagarparkar Granite postdates the Grey Granite (Fig. 1).
Churio Granite and Grey Granite are considered older on the basis of field relationship. Dolerite and
rhyolite are the youngest crystalline units, which are present as cross cutting bodies post dating the
entire complex and trending NW-SE and NE-SW directions.