[en] The Proterozoic Shillong Basin of Meghalaya in north-eastern India is one of the promising thrust areas for unconformity type uranium deposits. The unconformity contact between the Lower Tyrsad Formation and Upper Barapani Formation of Shillong Group of rocks is a favorable loci for unconformity type uranium mineralization. The Shillong Group of rocks are traversed by the shear/fault/fractures forming dilatant structures such as Tyrsad-Barapani Shear (TBS) and Jongkaksha Shears (JS) are favourable for uranium mineralisation. High resolution heliborne magnetic data acquired over the Shillong Basin helped in demarcating various magnetic domains and structures which inturn facilitated in mapping the subsurface geology. Processed magnetic images highlighted the NE-SW trending curvilinear sheared basement-basin contact near Mariang. Along the TBS, prominent NE-SW trending linear magnetic anomalies are observed over the Barapani and Tyrsad Formation. These anomalies are terminated due to the younger granitic intrusive (South Khasi Batholith) in the south-west of the surveyed area. The strong magnetic signature over the TBS is inferred to be due to metavolcanics of Khasi greenstone and Tyrsad metasediments. High amplitude curvilinear magnetic anomalies on the reduced to the pole map clearly demarcated the sheared contact of basement with Tyrsad Formation to the south-east of Mairang. A magnetic profile extending from Mariang to Mangwap that runs across the basement-sediment contact and TBS zone was modeled considering the available surface geological information. A maximum sediment thickness of 1200 m is inferred from modeling of magnetic data. High magnetic anomalies are inferred to be caused by two mafic bodies occurring at a depth of around 300 m. Modeling and interpretation of magnetic data along the TBS provided valuable subsurface geological and structural information that aided uranium exploration in Shillong Basin. (author)