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The Salumber–Ghatol Metallogenic Belt (SGMB) in southeastern Rajasthan forms a part of volcano-sedimentary sequence of Debari Group, Aravalli Supergroup and hosts several copper-gold prospects. Tourmalinites in the Mahuri Khera area of SGMB are exposed in the form of 30–40 cm thick dark grey black bands that can be traced discontinuously for about 1 km along strike present at the contact of schist and marble and also within the marble. The chemical similarity of tourmalinite and schist with high Fe/Al ratio, higher ∑REE and LREE/HREE ratio, and negative Eu anomaly as well as the similar Fe/Al, Mg/Al and Na/Al molar ratios suggest that the tourmalinite from SGMB are formed by the replacement of clastic sediments with little input from exhalative fluids. It is further inferred that the local clastic metasediments provided the necessary Fe, Mg and Na for the formation of tourmalinite. The average W concentration in the bulk rock samples of tourmalinite is 380 ppm with some samples showing W values above 1000 ppm. The higher values of W are supported by the presence of small grains (10–50 micron) of scheelite in the tourmalinite. Anomalous values for tungsten along with scheelite disseminations from these tourmalinites make this area an interesting tungsten prospect. [ABSTRACT FROM AUTHOR]

The Mesoproterozoic A-type granites from Chapoli– Chowkri area, South Khetri Belt (SKB) of Aravalli craton are characterized by high content of thorium and uranium with variable Th/U ratio. Average radiogenic heat production of Udaipurwati granite, Chapoli granite and albitite are 6.67 μWm–3, 6.90 μWm–3 and 6.92 μWm–3 respectively, which are much higher than the average RHP values for continental crust and the granites of North Khetri Belt (NKB). Average contribution of RHP due to thorium (56.86%) is higher than uranium (40.84%) and potassium (2.28%). Based on the heat production and their geochemical behaviour, these granites from South Khetri Belt are classified as moderate to high heat producing granites. Study on heat flow suggested that the high levels of radiogenic heat production in the uppermost crust could be the reason for high heat flow in the area. [ABSTRACT FROM AUTHOR]