Tar seeps found in 100-200 feet of water offshore Point Conception exhibit heavy oil and little gas. Benthic communities common on rocky reefs colonize older portions of the tar.
Reminds me of:
http://www.datadubai.com/oil2.htm
The “bulls,” Hieronymus discovered, were great iceberg-like mounds of jellied crude oil - bitumen - that floated up from the depths of the murky water and drifted aimlessly with the wind...
Harvesting bitumen 'bulls' on the Dead Sea.
The KTB HoleKTB = Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland... Temperatures in the drill hole rose far faster than predicted. The expected boundary ("suture") between two old tectonic plates thought to exist at 3 km according to surface geology had not yet appeared at 7.5 km. Most interestingly, crevicular structure (crevices and pores) existed at almost all depths, even though theory said they could not because of intense pressures. And these voids were filled with fluids... Deep-living bacteria were not mentioned in the above article, but Soviet scientists claim to have pumped them up from 12 km down!
by William Corliss
Science Frontiers #90
Nov-Dec 1993