Source rock potential and depositional environment of Upper Cretaceous sedimentary rocks, Abu Gharadig Basin, Western Desert, Egypt: An integrated palynological, organic and inorganic geochemical study

Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d

“…This includes major and trace elements, such as Fe, Ca, Zn, Cr, Mn, Sr, V, Ni, Co, Mo, K, Ti, and relationships between Cr versus V + Ni, S total /Fe versus Mn/S total , V/Cr versus S total , and S total versus S 2 (Table , Appendix S3). They were qualitatively utilized herein to provide further information about the prevailed redox status during deposition of the upper part of the Kharita Formation (Ghassal et al, ; Jarvis, Mabrouk, Moody, Murphy, & Sandman, ; Jarvis, Murphy, & Gale, ; Jones & Manning, ; Lewan & Maynard, ; Niebuhr, ;Ocubalidet, Rimmer, & Conder, ; Tribovillard et al, ). High abundance of V (1862–457, avg.…”

“…Despite the minor sedimentological change in facies, the palynofacies analysis of the Kharita Formation indicates a cascading vertical transition from PFA‐1 to PFA‐2 that can be used to interpret the depositional paleoenvironment (Tyson, ). Several studies focused on interpreting the depositional environment based on palynofacies and palynomorphs analyses over NE African territory, particularly the Cretaceous of the Western Desert (Gentzis et al, ; Ghassal et al, ; Mansour et al, ; Mansour & Tahoun, ; Tahoun et al, ). The upper part of the Kharita Formation contained moderate abundances of both AOM and phytoclasts, which plotted mainly in the palynofacies field VI (Figure a), with high proportions of opaque phytoclasts (Figure , Appendix S2), thus revealing deposition in a proximal high energetic suboxic–anoxic shelf (Tyson, ).…”

“…Dean and Arthur () suggested the S total /Fe ratio and calibration with the DOP (Raiswell et al, ), which markedly increase in more reducing conditions. This proposition gave us the opportunity to test the relationship between the Mn/S total and S total /Fe as a paleoredox proxy (Figure c, Appendix S3), where the lower values of Mn/S total compared to the higher S total /Fe infers more oxygen‐depleted conditions (Ghassal et al, ). There was a reverse relationship between Mn/S total and S total /Fe for the upper part of the Kharita Formation, acted as an overwhelming evidence of the proposed relationship during the OAE 1d.…”

“…The upper part of the Kharita Formation comprises a siliciclastic shelf facies, mainly of sandstone and shale with some siltstone, with varied sedimentation rates. The relationship between S total /Fe and Al 2 O 3 /TOC is used as an indicator of sediment supply together with oxygenation regimes at bottom water (Ghassal et al, ). Herein, the relationship between both variables is very low with R 2 value of .08 (Figure e).…”

The hydrocarbon generation and expulsion features of source rocks and tight oil potential of the second member of the Qiketai Formation, Shengbei area in the Turpan–Hami Basin, NW China

“…Source rocks are the material factors that control petroleum generation and accumulation; furthermore, they are prerequisites in hydrocarbon exploration and prospect appraisal (Ghassal et al, 2018; Hakimi & Abdullah, 2014; Hu et al, 2018; Jia, Zou, Li, Li, & Zheng, 2012; Katz, 2001; Katz, 2005; Ndip, Agyingi, Nton, Hower, & Oladunjoye, 2019), especially for unconventional resources, which are mainly retained within the source rock (Chen & Osadetz, 2013; Ehsan, Gu, Akhtar, Abbasi, & Ullah, 2018; Fu, Yan, Meng, & Liu, 2019; Jarvie, Hill, Ruble, & Pollastro, 2007; Katz & Lin, 2014; Kumar et al, 2017; Li et al, 2019; Liu et al, 2020; Ndip et al, 2019; Schmoker, 2002; Zou et al, 2019). Tight oil is an unconventional resource produced from source rocks and stored in tight sandstone, carbonate, and mixed rocks reservoirs that are adjacent to source rocks (Cao et al, 2017; Hu et al, 2018; Jia et al, 2012; Li et al, 2015; Liu et al, 2019; Smith & Bustin, 2000).…”