Calc tufa associated with waterfalls and rapids from Ane Ghat in the western Deccan Traps have been studied on the basis of their field occurrence, morphology and microtextures. The calc tufas are semi-consolidated and show porous, spongy morphology and occasionally ‘soda straw’ structure. Blue green algae, moss and diatoms are the predominant biotic components of the calc tufa. The growth of such calcifying biota has played a constructive role in building calc tufa deposits at Ane Ghat. Mineralogically, the tufas are made of calcite and contain variable carbonate percentage (53 to 78%). Petrographically, they contain fragments of basalt, devitrified glass, plagioclase, quartz, agate, zeolites, etc. set in a clay-rich and clay-poor micrite. Irregular pore spaces and voids are partially filled with spary calcite lined by thin layers of clay. SEM images of pristine calc tuffa surfaces reveal micromorphological and textural features that dominantly reflect precipitation. Images of insoluble residue of phases like glass, plagioclase and zeolites indicate some dissolution and corrosive features indicating post depositional diagenetic processes. δ¹⁸O _V-SMOW values range from 27.03 to 28.92‰ and δ¹³C _V-PDB values of −3.58 to −6.02‰ are recorded for the Ane Ghat samples. The calc tufas were precipitated from waters at paleotemperatures of 16.3 to 27.1°C. The calc tufa from Ane Ghat represents biological and physico-chemical calcification processes in response to variability in calcium carbonate saturation and water chemistry in temperate to semi-arid climate.