This study documents the effects of igneous dike intrusion on organic geochemical parameters of a shallow marine originated, Late Jurassic black shale (av. TOC = 2.2 wt%) in the Kutch rift basin in western India. The dike intrusion forms extremely to mildly altered, meter-scale zones around them. The primary wrinkled micro texture of the shale is lost completely, and organic matter is charcoalized in the extremely altered zone recording a Rock-Eval T-max > 458 degrees C. Immature type-III kerogen dominating the unaltered shale records abundant coniferal biomarkers such as retene, ent-beyerane, phyllocladane, ent-kaurane, abietane, labdane and norisopimarane, besides n-alkanes, hopanes and steranes. The transition from the unaltered (Rock-Eval T-max < 432 C) to the altered zone involves a decrease in carbon preference index (CPI), pristane/n-C-17, phytane/n-C-18, C-30 hopane/C-29 alpha alpha alpha-sterane and gradual increase in C-29 diasterane/sterane, trisnorneohopane/trisnorhopane (Ts/Tm), Ts/C-30 hopane, C-29/C-30 hopane and C-29 20S/(20S + 20R) sterane ratios. Although most saturate biomarkers disappear in the extremely altered zone, it records a high abundance of thermogenic polycyclic aromatic hydrocarbons (PAHs), commonly found in palaeo-fire deposits. Besides the PAH ratios, methylphenanthrene index-1, pristane/phytane, CPI and C-29/C-30 hopane ratios are found to be influenced significantly by thermal maturation in the extremely altered zone. The fluoranthene/(fluoranthene + pyrene) ratio correctly distinguishes different intensities of combustion products, while other PAH ratios behave differently at the immediate contact of the dike. Pr/Ph ratio may correctly interpret the redox condition up to a Rock-Eval T-max similar to 520 degrees C, while it is ineffective at high maturity. The results of the investigation are significant for the assessment of stability of biomarkers in highly matured source rocks, recording potential redox-sensitive biomarkers in highly matured shales and detection of palaeo-fire deposits in ancient sedimentary succession.