Structural features of the northern West Siberian geosyneclise and new exploration targets

The northern part of the West Siberian geosyneclise is characterized by a thick sedimentary cover and widespread Triassic sedimentary and volcanosedimentary rocks and Paleozoic platform structures. New targets have been recognized in the basement and deeply buried horizons of the geosyneclise cover. Reservoirs might be found in the following formations: Paleozoic cover deposits, weathering crusts, zones of Paleozoic rock deconsolidation, Triassic sedimentary and volcanosedimentary deposits, buried structures in the lower part of the cover, Lower and Middle Jurassic basal layers, pinch-outs of Jurassic horizons, Upper Jurassic bituminous shales and cavernous carbonates. Exploration of these potential structures will change the structure of the existing resource base toward the long-term replenishment of hydrocarbon resources and a stable rate of production replacement.     

Determination of proper motions for AC stars: First results

Proper motions of the stars of the Astrographic Catalogue are being derived, using the Hubble Space Telecope Guide Star Catalogue as second epoch. Results on the San Fernando and Cordoba AC zones are presented. Identification with GSC stars (i.e. determination of proper motion) was successful for 97 percent of all AC stars. Comparison of the proper motions thus derived with those of Preliminary PPM South shows that the accuracy is about 0.8 to 0.9 arcsec per century. Thus we can derive proper motions for about 4 million stars, with an accuracy higher than that of the SAO Catalogue.