AMEN! AMEN! All one has to do is stop and think for one minute about the AMOUNT of dead plants and animals there would have to have been for all those barrels to be taken out......just one minute of thinking time.
Primarily, source rocks are made up of microscopic organisms that lived in the photic zone (water shallow enough for sunlight to penetrate). They die and fall to the bottom over a long period of time. The water at the bottom of the ocean must be anoxic or bacteria and other organisms will consume this organic mush. The main component of these source rocks is dead algae, not terrestrial plants and animals. Woody material, such as leaves and parts of trees, that make it to the ocean (say, during a big flood on the Mississippi) can become source rocks but their chemical make-up only allows them to give off natural gas.