Stratigraphic processes and Ionian basin evolution in Kastos Island from Triassic to Eocene, for hydrocarbon fields development. Correlation with NW Peloponnesus (Araxos peninsula) outcrops

• Κύριος συγγραφέας: Μπουρλή, Νικολίνα
• Άλλοι συγγραφείς: Bourli, Nicolina
• Γλώσσα: English
• Έκδοση: 2022
• Θέματα: Hydrocarbon fields; Porosity of carbonates; Geochemistry of shales; Microfacies analysis of carbonates; Age determination of carbonates; Soft-sediment deformation; Mineralogy of siliceous concretions; Calciturbidites; Kastos island; Araxos peninsula; Ionian basin; Mesozoic era; Πεδίο υδρογονανθράκων; Πορώδες των ασβεστολίθων; Γεωχημεία των σχιστών; Μικροφασική ανάλυση των ασβεστολίθων; Προσδιορισμός την ηλικίας των ασβεστολίθων; Παραμόρφωση μαλακών ιζηματων; Η ορυκτολογία των πυριτολίθων; Ασβεστοτουρβιδίτες; Νησί της Καστού; Χερσόνησος Αράξου; Ιόνιος λεκάνη; Μεσοζωικός αιώνας

Microfacies analysis, facies zones and age determination: In Kastos Island based on lithological and sedimentological characteristics, the following depositional environments have been recognized: deep sea and deep shelf, toe of slope-to-slope and open marine to restricted. Calciturbidites and basin evolution: Calciturbidites include Ta to Te Bouma sub-divisions and are organized in cycles that form channelized deposits with a high degree of amalgamation. Statistical analysis confirms the presence of order in the sub-division sequence. The thickness of event beds in the studied section shows a lognormal statistical distribution, typical of turbidite successions. Limestone microfacies suggest deep-water deposits and reworked shelf deposits. The intense extensional tectonic activity in the Ionian basin during the Early Cretaceous, with synthetic and antithetic faults, produced active platform margins and asymmetrical grabens. The Early Cretaceous to early Eocene depositional history in the Ionian Basin indicates that the regional tectonic activity, rather than the eustatic sea-level changes, was the major factor that influenced the basin evolution, suggesting a syn-rift stage being active from the Jurassic to the early Eocene. Cherty layers and nodules diagenesis: The lower Cretaceous limestones in both areas contain abundant small chert nodules, whereas in the upper Cretaceous nodules are larger, but less abundant. Siliceous concretions represent an early diagenetic event with a strong influence from the underlying rocks. Soft sediment deformation: Different types of soft-sediment deformations were recognized, that took place synsedimentary or just after sedimentation. The different types are related with the intense of tectonic activity, the rotation of the blocks internal to the basin or due to diapiric intrusions that deformed the sedimentary basin floor. Porosity: Porosity measurements for both areas from lower and upper Cretaceous limestones showed the average diameter of mesopores. Geochemical analysis: The obtained data showed that TOC (0.02-3.45%) indicate to good oil potential and a type II/III kerogen with the ability to produce liquid and gaseous hydrocarbons for Kastos Island and TOC (0.01-0.72%) with fair oil potential and type IV kerogen for Araxos peninsula. The results based on the Odd to even predominance, was indicated an anoxic deposition environment.