Preliminary results based on geochemical sedimentary constraints on the hydrocarbon potential and depositional environment of a Messinian sub-salt mixed siliciclastic-carbonate succession onshore Crete (Plouti section, eastern Mediterranean)

Abstract

This study details new geochemical analysis from an outcrop in Crete to improve understanding of the hydrocarbon potential of the southern margin of the Hellenic Arc along the continental convergent zone of the central Mediterranean Ridge. Seventeen samples were collected from the Late Miocene sub-salt sedimentary succession of Plouti section in central Crete and were studied in terms of their organic geochemical features using Rock-Eval VI pyrolysis. Results of this investigation revealed intervals with sufficient organic material of good enough quality and quantity to be considered as potential source rocks. The obtained data generally present poor to fair and/or good in some cases hydrocarbon generation potential. The TOC values range from 0.03 to 1.99%, with an average fair (2.1 mg HC/g rock) hydrocarbon potential. A Type III kerogen was identified, indicating a terrestrial origin organic matter. T max and Production Index values suggest that the most promising parts of the section (organic-rich sediments) are immature with respect to oil generation and have not experienced high temperature during burial. Overall, the present study offers the opportunity to advance our understanding on the hydrocarbon potential onshore Crete and further investigate hydrocarbon prospectivity in the adjoining area, and particularly, the Greek part of the Mediterranean Ridge, a region with crucial economic and strategic importance.

Integrated isotopic and organic geochemical constraints on the depositional controls and source rock quality of the Neogene Kalamaki sedimentary successions (Zakynthos Island, Ionian Sea)

“…The isotopic composition of the bulk sediments was focused on investigating the corresponding depositional environment. Further constraints on the impact of MSC climate changes on studied sedimentary archive by triggering sea level fluctuations (Capella et al 2019), variations in water column characteristics (e.g., temperature, salinity, stratification) (Karakitsios et al 2017a;Moissette et al 2018;Kontakiotis et al 2019), productivity and preservation in organic matter changes (Vasiliev et al 2019), diagenetic alteration (Antonarakou et al 2019), and increasing influxes of terrestrial organic matter (Mayser et al 2017;Karakitsios et al 2017b; Kontakiotis et al 2020a) that are here discussed will contribute significantly to our knowledge of this delicate system. All this information is also used to investigate the possible mechanisms of source-rock deposition and the petroleum systems onshore Zakynthos Island, which may provide important prospect for the Neogene petroleum concern of western Greece and the broader area of the eastern Mediterranean Sea.…”

“…The recent discoveries have revealed the eastern Mediterranean as an important hydrocarbon province with significant petroleum systems (Belopolsky et al 2012; Roveri et al 2016;Ratner 2016;Grohmann et al 2020). The distribution of hydrocarbons in the Mediterranean is mainly controlled by thick evaporites deposited throughout the basin during the Messinian Salinity Crisis (MSC; 5.97-5.33 Ma) (Bertoni and Cartwright 2015;Aksu et al 2018;Haq et al 2020), which function as a seal (Watts 1987;Warren 2006;Morley et al 2011;Kontakiotis et al 2020a). On this regard, the main scientific target is recently focused on the Neogene sedimentary successions that are developed under (e.g., underlying Messinian deposits) and above (e.g., Pliocene calcareous mudstones) the Messinian evaporites.…”

Thermal Properties and Burial Alteration of Deep-Sea Sediments: New Indicators of Oxic−Suboxic Diagenesis

“…In the selected samples, especially 3515-1 40-44 (or 2269 [25][26][27][28][29][30][31][32], an increase in crystallinity (=background decrease) with burial depth was observed, as well as an increase in the intensity of the selected peaks of new mineral phases. Full data of roasted samples, including diffractograms, are shown in Figure 8 and in Table 8.…”

Key Environmental Factors Controlling Planktonic Foraminiferal and Pteropod Community’s Response to Late Quaternary Hydroclimate Changes in the South Aegean Sea (Eastern Mediterranean)

“…Environmental changes related to the different water column and/or sediment characteristics can be recorded virtually instantaneously in paleoceanographic proxy data, such as stable isotope and other geochemical ratios [22][23][24][25][26][27][28][29][30][31], and micro-fossil abundances, such as planktonic foraminifera and pteropods [15,17,28,[32][33][34][35][36]. This makes them extremely valuable for both stratigraphic correlations and paleoenvironmental/paleoclimate reconstructions [15,23,28,29,32,35,[37][38][39][40][41][42][43][44][45].…”

“…This makes them extremely valuable for both stratigraphic correlations and paleoenvironmental/paleoclimate reconstructions [15,23,28,29,32,35,[37][38][39][40][41][42][43][44][45]. Their significance in the study of modern and past marine ecosystems in the eastern Mediterranean Sea is well underlined [20,31,[46][47][48][49][50][51]. Particularly, they are used as indicators of temperature, salinity, density, and nutrient content of the water column, making it possible to identify past circulation through the sedimentary record [7,15,29,47,52,53] and detect long-and short-term paleoclimatic and paleoceanographic changes in the study area [6,10,12,15,16,[53][54][55] during the last glacial cycle.…”