Mud volcanoes have been studied on land in the Crimean-Caucasus for a long time. In recent years this phenomenon has been investigated offshore in the Black Sea. It is of interest not only for petroleum exploration in deep waters but also on shallow shelves where it can produce unexpected shoals that are a danger to shipping. The mud volcanoes of the Black Sea (Pontus Euxene) were known to the Ancient Greeks. Homer speaks of them as the entrance to the Kingdom of Pluto. In the Fifth Century Byzantine Emperor Constantin Bagryanorod wrote about erupting oil at Taman. In 1795 Pallas mentioned formation of a mud volcano island in the southeast of the Sea of Azov. Drawing on hydrographic surveys in the Black Sea Kovalevskiy (1960) proposed the presence of several mud volcanoes along the 38 degree meridian. The first demonatrated presence of mud volcanoes in the deep-water parts of the Black Sea came in 1989. They are in water depths of about 2000 m. Numerous diapiric structures were disclosed at this time in the Tuapse and Sorokina downwarps in the northeast parts of the Black Sea. See News Letter No. 15, October 18, 1999. In 1991-96 mud volcanoes of the central part of the Black Sea were studied as part of a UNESCO program. This group discovered nine submarine mud volcanoes and seven buried mud volcanoes. In 1994-97 seven cruises of the "Kiev" recorded new mud volcanoes and gas discharges in the western part of the Black Sea. They occur as cones up to 110-120 m high. The main components of the breccia of these features are Maykop clays of Oligocene-Miocene age. Rare fragments of argillite, glauconitic sandstone, and various limestones are also found. Any cone-shaped high on the flat floor of the Black Sea is of interest. Unfortunately, navigation charts are of little help because thay do not pick up such low-relief features as the mud volcanoes. In the deep-water parts of the Black Sea they do not show features up to 200 m high. However, much information was gleaned from hydrographic archives and was used in compiling a map showing location of these features. Several mud volcano features have been recognized by acoustical studies. For example, a basin has been outlined in the west-central part of the sea; it appears to be a sag depression. It is framed by systems of border faults. In the central part of this basin against a gentle background are two small cone-shaped hills some 20 m high. These are interpreted as mud volcanoes. No gas cloud was detected above them. Many other features of this type along with numerous gas seeps have now been described. The Black Sea is one of the relict basins of Para-Tethys, and present in it are vast amounts of gas that are manifest in the form of seeps, mud volcanoes, and gas-saturated muds. It is possible that the gas in the deep-water areas has been derived from destruction of gas hydrate deposits. The latter in turn could have formed by introduction of gas from depth along faults. This suggests that the gas potential of the Black Sea may be very great. (Taken from Shnyukov, 1999; digested in Petroleum Geology, vol. 34, no. 4, p. 323-327, 2000, in press; one map showing location of mud volcanoes; a table listing characteristics of 20 mud volcanoes; and an acoustical cross section). Copyright 2000 James Clarke. You are encouraged to print out this News Letter and to forward it to others. Earlier News Letters are available at http://geocities.com/internet geology/ Inquiries about Petroleum Geology can be made at (703) 759-4487.