This document discusses different types of organic matter found in sediments and sedimentary rocks, including kerogen. It describes four main types of kerogen (Types I-IV) which are distinguished based on their chemical properties and hydrogen content. Type I kerogen is the most oil-prone and is typically found in marine depositional environments, while Type III is more gas-prone and found in terrestrial environments. The quality of a source rock depends on the type of kerogen present, with Type I being the highest quality. Kerogen maturity is determined by temperature and time, and vitrinite reflectance is used to measure the level of organic maturity. Macerals are microscopic organic components in coal that are classified into groups including li