1. n. []

A rock rich in organic matter which, if heated sufficiently, will generate oil or gas. Typical source rocks, usually shales or limestones, contain about 1% organic matter and at least 0.5% total organic carbon (TOC), although a rich source rock might have as much as 10% organic matter. Rocks of marine origin tend to be oil-prone, whereas terrestrial source rocks (such as coal) tend to be gas-prone. Preservation of organic matter without degradation is critical to creating a good source rock, and necessary for a complete petroleum system. Under the right conditions, source rocks may also be reservoir rocks, as in the case of shale gas reservoirs.

See related terms: argillaceous,  basin,  bitumen,  coal,  critical moment,  generation,  geochemistry,  hydrocarbon,  hydrocarbon kitchen,  immature,  kerogen,  lacustrine,  limestone,  marine,  maturity,  migration,  natural gas,  overmature,  petroleum system,  pinch-out,  pinch-out,  play,  postmature,  primary migration,  prospect,  pyrolysis,  secondary migration,  sedimentary basin,  sequence stratigraphy,  shale,  swamp,  vitrinite,  vitrinite reflectance