Post-lease sale exploraton of the Navarin Basin, Bearing Sea, Alaska
Although the basin had optimistic beginnings, interest in further exploration of the Navarin Basin is waning because of disappointing d r i g results. Eight exploratory wells were drilled in the Navarin Basin in the year following Lease Sale 83 in 1984. All of these wells tested Tertiary fill that drapes or folds over simple, broad basement highs. Significant reservoir rocks were absent in all of these wells. Immature to mature Eocene kerogen with possible hydrocarbon-generating characteristics was found in a stratigraphic test well and two exploratory wells located on the flanks of the Pervenets subbasin. However, no signs of oil or oil migration were evident. A third exploratory well d r i ed on the southeast flank of the Pinnacle Island subbasin encountered thermogenic gas from a thin, probably lenticular Paleocene sandstone. The gas was probably sourced from interbedded, resinous coal. The geologic information collected from seven of the eight exploratory wells has now been released to the public. Of the leases acquired in Sale 83, 74 percent have been relinquished as of January 1988.
Review of Petroleum Geology of Anadyr and Khatyrka Basins, USSR
Two sedimentary basins bordering the Bering Sea in northeastern Siberia, the Anadyr and the Khatyrka, have been the targets of recent Soviet exploration for oil and gas. Drilling in the Anadyr basin has produced noncommercial quantities of gas and condensate from Tertiary volcaniclastic rocks. The Anadyr basin lies due west of Norton basin, a large unexplored sediment-filled Tertiary basin that underlies Norton Sound. Geologically, Anadyr basin lies between a late Mesozoic belt of volcanic and plutonic rocks similar to the Sierra Nevada of California and a complex foldbelt on the south that is structurally and lithologically similar to Franciscan terrane of the California Coast Ranges. Less extensive exploration in the Khatyrka basin has discovered only noncommercial quantities of oil and gas. The Khatyrka basin extends offshore between Capes Rubicon and Navarin near the northwest end of the Navarin basin on the Bering Shelf, and contains Tertiary sediment deposited within a structurally complex Mesozoic foldbelt that parallels the edge of the continental shelf.
Archaeological Survey of Dangoyama Kofun by 3DGPR
We presented a three-dimensional ground penetrating radar (3DGPR) system for the archeological investigation in a harsh site, where we have to deal with many trees and/or great topographic variations. This system consists of a commercial GPR system with a laser positioning system. With this system, we can move the GPR antenna freely, on which a positioning detector can record accurate position for each GPR data trace. We applied our 3DGPR system at Dangoyama Kofun, a burial mound, in Fukushima prefecture, Japan. A lot of trees and bushes covered the survey area and cannot be cut. We acquired six datasets in two days in this area. We successfully imaged the boundary between the original surface of the burial mound and the covering soil clearly at about 0.3 m depth around the mound. Furthermore, we found some strong reflections appeared at 0.8 m depth in the top area of the mound, which can be from the artificial parts of the burial mound. The results would greatly aid the following archaeological excavation. In addition, we compared the non-interpolated depth slice with interpolated depth slice at same position and demonstrated that the interpolation process on threedimensional GPR data may introduce some artifacts which might mislead our interpretation.