Looking South from Gobi desert toward Nan Shan overthrust and Piedmont outwash on North side of Tibetan plateau.
Laochunmiao oil field on northward overturned anticline can be seen in foreground. (Aerial photograph by the author.) 88 PROCEEDINGS THIRD WORLD PETROLEUM CONGRESS-SECTION I sins intérieurs la possibilité qu'ils contiennent du pétrole ou du gaz est la plus faible. On donne des exemples de bassins de chaque type.
Si l'on reconnait de bonne heure les types géosynclinaux moyennant des études de caractère régional, on aboutira à une classification de la plupart des bassins sédimentaires et à une évaluation préliminaire des perspectives de production du pétrole, et on simplifiera sensiblement les programmes d'exploration future qu'il faut pour corroborer les classifications et les perspectives établies à titre provisoire pour des régions de dépôts sédimentaires.
Petroleum geology has advanced through many stages of development during the last forty. years from seepage-seeking through the anticlinal, salt dome and faultzone eras, to the stratigraphic trap, sedimentary facies and reef phases. Any serious work within the last three catagories inevitably leads to studies in basin formation and sedimentation.
With oil companies rapidly becoming more conscious of the need and value of broader basin studies, many have established geological research groups whose function is to correlate all pertinent data from various sources into a coherent picture of the regional stratigraphy and tectonics of potential oil-producing areas throughout the world.
Such research groups use data from many sources.
Library facilities are essential, but of greater importance are the observations by their own specialists in field geology, photogeology, stratigraphy, sedimentary petrology, mineralogy and geophysics.
Structural data are compiled from surface and subsurface surveys, which may be controlled in geologically blind areas by geophysical surveys. From such structural data, together with stratigraphic information from the field geoIogists, paleontologists and petrographers, it is usually possible to define the geotectonics that have controlled the position and character of sediments and thus to predict more accurately the favorable and unfavorable areas for the origin and accumdation of oil.
With this explanation of the petroleum geologists' invasion of the academic geologists' s ecial preserve in the field of dynamic geology, it is ];ioped that the following sketch of the tectonic framework of the Far East, its possible origin, and the sedimentary basins which are draped upon it, will prove interesting to both petroleum geologists and
