An Introduction To The Petroleum Geology Of Southeast Turkey

Author : Ismail Özkaya
Publisher :
ISBN 13 :
Total Pages : 314 pages
Book Rating : 4.:/5 (45 download)

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Download or read book The Mio-eugeosynclinal Thrust Interface and Related Petroleum Implications in the Sason-Baykan Area, Southeast Turkey written by Ismail Özkaya and published by . This book was released on 1972 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A detailed investigation of the stratigraphy, structure and petroleum geology of the Sason-Baykan region in 600 square km area of the thrust belt of southeast Turkey was completed at a scale 1: 25 000. Geosynclinal sediments within the area were redated. Results of field study indicate a massive plate of metamorphic rocks and crystalline limestones was thrust southward over geosynclinals sediments. These in turn were thrust over the southern marginal basin deposits. A stratigraphic sequence of the allochthonous geosynclinals sediments was reconstructed and correlated with the autochthonous Tertiary section. Contrary to earlier views the allochthonous sediments and accompanying igneous rocks are not Upper Cretaceous-Paleocene but of Oligocene-Miocene age. Radioactive age determination of two spilite samples from this series confirmed this result. These facts suggest that eugeosynclinal conditions and submarine basic volcanic activity persisted until the end of Miocene in the Foothills Belt of southeast Turkey. Uplift and sedimentation migrated from north to south in time. Geosynclinal type backdeeps existed to the north on the Bitlis Massif during Upper Cretaceous-Paleocene times. After a quiet period of shallow seas in Eocene time the northern areas were uplifted and the frontal portion of the Massif downwarped. This frontal Lice-Baykan geosyncline was linked by a northwest trending hinge to a southern marginal basin. A non-clastic stage of sedimentation was followed by a clastic stage in the Lice-Baykan geosynclinal and southern marginal basin. Lice grey marls, shales and graywackes accumulated on the southern outer flanks of the northern geosyncline. Red marl, flysch and red clastic sequence of the Sason-Baykan group with accompanying basic igneous rocks was deposited in the inner eugeosynclinal portions of the same trough. Germik evaporites and Selmo red sandstones were deposited in the southern marginal basin. The hinge belt was the site of deposition for Silvan reef limestone and lower Selmo salts. The south to north facies change of these deposits reflect changing tectono-environments from moderately negative unstable shelf into deeply subsiding eugeosynclinal trough. Major diastrophism occurred at the end of Miocene and resulted in southward thrusting of the geosynclinal sediments and plates of the northern massif. Orogenic activity may have also migrated southward in time. Field criteria suggest a possible early Oligocene thrusting in the northern areas of the Bitlis Massif where Upper Cretaceous-Paleocene backdeeps had been present. Metamorphic rocks and crystalline limestones were thrust over these early geosyncline sediments. Today the latter occur as a tectonic slice within the allochthonous metamorphic block. A Late Miocene orogeny affected the southern frontal areas of the Bitlis Massif where the Lice-Baykan geosyncline was present. Tangential compressional forces were the main driving mechanism of deformation. Thrusting and folding took place under the action of north to south oriented stress. A final stage of tension resulted in east-west normal faults. Gravity sliding played a minor role in outlining the structure of the area but did result in the emplacement of a few exotic limestone and serpentine blocks within the geosynclinal sediments. Despite its setting within a geosynclinal zone and thrust belt, the area does have oil potential. The presence of source rocks, reservoir horizons, cap rocks and broad fold structures within the autochthonous block of Tertiary sediments, absence of Upper Cretaceous subsurface intraformational ophiolites, and the surficial nature of thrust plates which cover the Tertiary section are all favorable factors"--Abstract, pages ii-iv.