<p>Tectonic degassing along active fault zones in continental collisional orogens has attracted increasing attention due to its critical role as a major pathway for the release of deeply sourced CO₂ to Earth’s surface. Active faults are generally characterized by three forms of deep CO₂ emissions (i.e., dissolved inorganic carbon (DIC) in spring water, bubbling gases, and diffuse soil micro-seepage), but their fluxes were rarely estimated simultaneously in a single study area. Here, we focus on the Sangri-Cona rift (SCR) in the southern Tibetan Plateau, carrying out the estimation of three forms of deep carbon fluxes based on field observations and geochemical analysis of carbon sources. The calculated percentages of deeply sourced CO₂ in the DIC of spring water, CO₂ of bubbling gases, and diffuse soil CO₂ degassing are 75.8%, 72.2%, and 35.7%, respectively. The deeply sourced CO₂ fluxes from the spring water, bubbling gases, and diffuse soil CO₂ in the SCR are estimated to be 1586 ± 26 t yr⁻¹, 801 ± 54 t yr⁻¹, and 0.46 ± 0.09 Mt yr⁻¹, suggesting that diffuse soil CO₂ emissions account for &gt; 99% of the total deep CO₂ output of the SCR. In the Himalayan block, deeply sourced CO₂ in the geothermal fluids mainly originates from metamorphic decarbonation of crustal carbonaceous rocks at different depths. Within the extensional tectonic setting of the SCR, the deeply sourced CO₂ is able to migrate upward through the active fault system, ultimately manifesting at the surface as spring DIC, bubbling gases and diffuse soil CO₂. Our results indicate that the SCR serves as an excellent example for the Himalayan orogenic CO₂ degassing associated with post-collisional lithospheric extension.</p> Graphical abstract <p></p>