The Messoyakh gas field of Northwestern Siberia was discovered in 1967. This field has been thoroughly studied and described in many publications, including References 1–9. At least one‐third and, most likely, two‐thirds of the Messoyakh reservoir, which for 13 years has been in commercial production, occurs in the form of natural gas hydrates.

Reference: D.S. Department of Energy (DOE) Morgantown Energy Technology Center (ME'rc)) Contract No. DE-AC21-84MC21181 '/_((-f I PERSONNEL During the reporting period, the following staff personnel were involved in the contract'sexecution:Dr. Jan Krason (PrincipalInvestigator); Mr. Marek Ciesnik (Geologist); Mr. Patrick Finley (Geochemist-Geologist); and Ms. Margaret Krason (TeclmiealAssistant-Graphic Artist).

Price: Printed copy A15 Microfiche A01 Codes are used for pricing all publications. The code is determined by the number of pages in the publication. Information pertaining to the pricing codes can be found in the current issues of the following publications, which are generally available in most libraries: Energy Research Abstracts (ERA), Government Reports Announcements and Index (GRA and I); Scientific and Technical Abstracts Reports (STAR); and publication NTIS-PR-360 available from NTIS at the above address. 4.4 x lo1* m3 (150 tcf) of free gas is present in these sub-hydrate traps. Alaska of 1.2 x 10 a m3 or 400 trillion cubic feet (tcf). The continental slope and

This document is Volume X of a series of reports entitled "Geological Evolution and Analysis of Confirmed or Suspected Gas Hydrate Localities." Volume X is a study titled "Basin Analysis, Formation and Stability of Gas Hydrates of the Aleutian Trench and Bering Sea." This report presents a geological description of offshore Alaska, including regional and local structural settings, geomorphology, geological history, stratigraphy, and physical properties. It provides a the necessary regional and geological background for more in-depth research of the area. Detailed discussion of bottom simulating acoustic reflectors, sediment acoustic properties, and distribution of hydrates within the sediments are also included in this report. The formation and stabilization of gas hydrates in sediments are considered in terms of phase relations, nucleation, and crystallization constraints, gas solubility, pore fluid chemistry, inorganic diagenesis, and sediment organic content. Together with a depositional analysis of the area, this report is a better understanding of the thermal evolution of the locality. It should lead to an assessment of the potential for both biogenic and thermogenic hydrocarbon generation.

Uranium solutility index should be calculated for well waters in areas potentially favorable for uranium. 3. Areas of uranium potential should be field checked for the presence of source rocks, aquifers and reductants. 4. Pegmatites should be field checked for the presence of industrial minerals.