Pub Date : 2024-09-21DOI: 10.1016/j.marpetgeo.2024.107122
Masoud Joudaki , Ali Faghih , Soumyajit Mukherjee , Mohammad Seraj , Bahman Soleimany
A comprehensive understanding of structure and kinematic characteristics of fold and thrust belts provides significant information for hydrocarbon exploration and production. The kinematic evolution and structural style of three subsurface oilfields, Zeloi, Lali and Karun, in the northern part of the Dezful Embayment, a significant petroleum province of the Zagros Fold-Thrust Belt in SW Iran, were investigated using 2D seismic data. Interpretation of the 2D seismic profiles with up to 5 km depth consisting of upper Jurassic to Pleistocene sediments and the balanced cross-sections constructed revealed diverse geometries and kinematics along the oilfields. These results demonstrate that the structural style of the oilfields was controlled by the Gachsaran and Dashtak formations as upper and middle detachment levels, respectively. Tear faults affected the along-strike variations in structural style of the oilfields. Based on the analysis of growth strata, folding evolved as limbs rotated and hinges migrated, beginning in the mid-Miocene. During the later stages of deformation, the initial detachment folds transformed into fault-bend folds.
{"title":"Structural style & kinematic analysis of deformation in the northern Dezful Embayment, Zagros Fold-Thrust Belt, SW Iran","authors":"Masoud Joudaki , Ali Faghih , Soumyajit Mukherjee , Mohammad Seraj , Bahman Soleimany","doi":"10.1016/j.marpetgeo.2024.107122","DOIUrl":"10.1016/j.marpetgeo.2024.107122","url":null,"abstract":"<div><div>A comprehensive understanding of structure and kinematic characteristics of fold and thrust belts provides significant information for hydrocarbon exploration and production. The kinematic evolution and structural style of three subsurface oilfields, Zeloi, Lali and Karun, in the northern part of the Dezful Embayment, a significant petroleum province of the Zagros Fold-Thrust Belt in SW Iran, were investigated using 2D seismic data. Interpretation of the 2D seismic profiles with up to 5 km depth consisting of upper Jurassic to Pleistocene sediments and the balanced cross-sections constructed revealed diverse geometries and kinematics along the oilfields. These results demonstrate that the structural style of the oilfields was controlled by the Gachsaran and Dashtak formations as upper and middle detachment levels, respectively. Tear faults affected the along-strike variations in structural style of the oilfields. Based on the analysis of growth strata, folding evolved as limbs rotated and hinges migrated, beginning in the mid-Miocene. During the later stages of deformation, the initial detachment folds transformed into fault-bend folds.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107122"},"PeriodicalIF":3.7,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.marpetgeo.2024.107126
Vasiliki-Grigoria Dimou , Olga Koukousioura , György Less , Maria V. Triantaphyllou , Margarita D. Dimiza , George Syrides , Martin R. Langer
Sediment, thin section, microfacies and foraminiferal analyses were conducted on middle-upper Eocene carbonate deposits to shed new light on the paleoenvironmental evolution and species richness of the Thrace Basin (Tethyan Ocean, Greece). Material from a total of 7 new sites, covering localities on the mainland and the north-eastern Aegean islands of Samothraki and Lemnos, was examined in order to analyze the general conditions and environmental evolution of the basin over as large a geographical area as possible. Analysis of the sedimentological and paleontological data allowed the identification of 5 microfacies types. These can be assigned to a sequence of interior to outer shelf environments and speak in favor of a model of a rimmed carbonate shelf with isolated platforms. Both open and restricted water circulation patterns have prevailed on and between the platforms. Triggered and driven by dynamic syn-rifting, topographic highs have developed in this area on which productive and species-rich reef structures could thrive. In the late Eocene carbonate deposits we found the highest documented species richness of larger symbiont-bearing foraminifers (LBF) to date, characterizing the Thrace Basin not only as a particularly species-rich and diverse area, but also as a LBF hotspot of diversity.
{"title":"Microfacies and species richness analysis of upper Bartonian and Priabonian carbonate shelf deposits from the Thrace Basin (Tethyan Ocean, Greece): Paleoenvironmental evolution and species-richness hotspot revealed","authors":"Vasiliki-Grigoria Dimou , Olga Koukousioura , György Less , Maria V. Triantaphyllou , Margarita D. Dimiza , George Syrides , Martin R. Langer","doi":"10.1016/j.marpetgeo.2024.107126","DOIUrl":"10.1016/j.marpetgeo.2024.107126","url":null,"abstract":"<div><div>Sediment, thin section, microfacies and foraminiferal analyses were conducted on middle-upper Eocene carbonate deposits to shed new light on the paleoenvironmental evolution and species richness of the Thrace Basin (Tethyan Ocean, Greece). Material from a total of 7 new sites, covering localities on the mainland and the north-eastern Aegean islands of Samothraki and Lemnos, was examined in order to analyze the general conditions and environmental evolution of the basin over as large a geographical area as possible. Analysis of the sedimentological and paleontological data allowed the identification of 5 microfacies types. These can be assigned to a sequence of interior to outer shelf environments and speak in favor of a model of a rimmed carbonate shelf with isolated platforms. Both open and restricted water circulation patterns have prevailed on and between the platforms. Triggered and driven by dynamic syn-rifting, topographic highs have developed in this area on which productive and species-rich reef structures could thrive. In the late Eocene carbonate deposits we found the highest documented species richness of larger symbiont-bearing foraminifers (LBF) to date, characterizing the Thrace Basin not only as a particularly species-rich and diverse area, but also as a LBF hotspot of diversity.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107126"},"PeriodicalIF":3.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.marpetgeo.2024.107124
Francesco Perri , Francesco Cavalcante , Manuel Martín-Martín , Antonio Sánchez-Navas , Francisco Javier Alcalá
A model of the Cenozoic tectono-sedimentary evolution of the External Rif Chain (Morocco) is provided by means of the study of the mineralogical and geochemical composition of mudrocks. To date there was a lack of homogeneous data and of a complete and extensive study of the whole External Rif Zone (ERZ). Therefore, this work shows the study of the whole ERZ where the most representative stratigraphic sections have been selected. This work provides important information about the geodynamic evolution and the variations in source-area provenance related to the growing of the Rif orogenic belt. Although there is still much work to be done, this study aims to improve the knowledge of the Cenozoic tectono-sedimentary evolution of the entire western ERZ with a homogeneous method, with a focus on the paleogeographic and paleotectonic evolution, the paleoweathering and the source areas deduced from mineralogical and geochemical data of the Cenozoic mudrocks. The bulk mineralogy is mainly characterized by the presence of calcite, quartz and dolomite plus ankerite. Feldspars have few percentages. The clay minerals are principally represented by mixed-layer illite/smectite (I/S). Illite and kaolinite are in little amount. Femic minerals, mixed-layer chlorite/smectite (C/S) and chlorite are the most abundant. The I/S features suggest a different thermal condition for the three domains. The chemical composition indicates that the mudrocks can be described as mixtures of carbonates with aluminosilicate components. The Al/Ti, Th/Cr, Th/Sc, La/Th and La/Sc ratios, the Cr/V vs. Y/Ni plot, the V-Ni-Th∗10 and La-Th-Sc ternary diagrams indicate a predominantly felsic source with a minor mafic input more evident in the Paleocene-Eocene samples of the External Intrarif and Mesorif. The External Rif Zones changed in the Cenozoic from a passive margin to a complex foreland system with the incoming of the Alpine tectonic phases. In general, the felsic contribution should be linked to the foreland area consisting in the Middle Atlas and Mesetas massifs made of a crystalline domain. This margin probably presented an intermediate narrow oceanic branch in the External Intrarif-Mesorif boundary that surprisingly should start to close during Paleogene times providing the mafic contribution. This Paleogene tectonic activity in these domains is corroborated by the thermal maturity indicating late diagenesis. The chemical weathering indices, such as the CIA (Chemical index of Alteration) and its modifications, show medium-high values and thus suggest generally moderate paleoweathering conditions in agreement with the predominant amount of I/S.
{"title":"Cenozoic tectono-sedimentary evolution of the external rif chain (Morocco) derived from mineralogical and geochemical analysis of mudrocks","authors":"Francesco Perri , Francesco Cavalcante , Manuel Martín-Martín , Antonio Sánchez-Navas , Francisco Javier Alcalá","doi":"10.1016/j.marpetgeo.2024.107124","DOIUrl":"10.1016/j.marpetgeo.2024.107124","url":null,"abstract":"<div><div>A model of the Cenozoic tectono-sedimentary evolution of the External Rif Chain (Morocco) is provided by means of the study of the mineralogical and geochemical composition of mudrocks. To date there was a lack of homogeneous data and of a complete and extensive study of the whole External Rif Zone (ERZ). Therefore, this work shows the study of the whole ERZ where the most representative stratigraphic sections have been selected. This work provides important information about the geodynamic evolution and the variations in source-area provenance related to the growing of the Rif orogenic belt. Although there is still much work to be done, this study aims to improve the knowledge of the Cenozoic tectono-sedimentary evolution of the entire western ERZ with a homogeneous method, with a focus on the paleogeographic and paleotectonic evolution, the paleoweathering and the source areas deduced from mineralogical and geochemical data of the Cenozoic mudrocks. The bulk mineralogy is mainly characterized by the presence of calcite, quartz and dolomite plus ankerite. Feldspars have few percentages. The clay minerals are principally represented by mixed-layer illite/smectite (I/S). Illite and kaolinite are in little amount. Femic minerals, mixed-layer chlorite/smectite (C/S) and chlorite are the most abundant. The I/S features suggest a different thermal condition for the three domains. The chemical composition indicates that the mudrocks can be described as mixtures of carbonates with aluminosilicate components. The Al/Ti, Th/Cr, Th/Sc, La/Th and La/Sc ratios, the Cr/V <em>vs.</em> Y/Ni plot, the V-Ni-Th∗10 and La-Th-Sc ternary diagrams indicate a predominantly felsic source with a minor mafic input more evident in the Paleocene-Eocene samples of the External Intrarif and Mesorif. The External Rif Zones changed in the Cenozoic from a passive margin to a complex foreland system with the incoming of the Alpine tectonic phases. In general, the felsic contribution should be linked to the foreland area consisting in the Middle Atlas and Mesetas massifs made of a crystalline domain. This margin probably presented an intermediate narrow oceanic branch in the External Intrarif-Mesorif boundary that surprisingly should start to close during Paleogene times providing the mafic contribution. This Paleogene tectonic activity in these domains is corroborated by the thermal maturity indicating late diagenesis. The chemical weathering indices, such as the CIA (Chemical index of Alteration) and its modifications, show medium-high values and thus suggest generally moderate paleoweathering conditions in agreement with the predominant amount of I/S.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107124"},"PeriodicalIF":3.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.marpetgeo.2024.107115
S. Fabbi , M. Borrelli , G. Innamorati , L. Aldega , M. Daëron , E. Perri , M. Santantonio
We report herein for the first time the occurrence of low-grade metamorphic rocks dilated by the growth of calcite veins induced by microbial communities inhabiting the cleavage planes. This process took place at the rock/sea-water interface in a rocky shore environment when the Hercynian basement rocks of the European-Iberian continental margin in Calabria (Italy) experienced stepwise flooding by a shallow tropical sea in the Early Jurassic, a process which was accompanied by synsedimentary extension, resulting in the birth of the Longobucco Basin. The veins exhibit a multiphase filling history, as, in an early phase, microstromatolites lining the walls of cleavage planes document the initial development of microbial biofilms. Subsequently, the growth of bands of radiaxial fibrous calcite enlarged the cavities through force of crystallization, also producing fissures at a high angle with respect to cleavage, which were in turn enlarged by crystal growth. Carbonate clumped isotope analysis indicates crystallization of calcite from sea water, at temperatures (T47) ranging from c. 33 to c. 44 °C. The inferred palaeoenvironment is that of a rocky coastline, locally with tide pools, where the seawater lapped cliffs made of Palaeozoic metasandstone. Microbially induced mineralization was a very rapid process, as clasts of veined metamorphic rocks are found in only slightly younger Early Jurassic deposits, like the sub-reefal carbonate bodies that grew in the Pliensbachian attached to the Palaeozoic bedrock. The occurrence of low-grade metamorphic rocks bearing calcite veins can be mapped in the field for kilometers, following the high-angle unconformity that separates the shallow-water carbonates from the basement. This microbial overprint therefore is a marker of the margins of a rift basin, where the exposure of basement rock along steep submarine surfaces was the result of footwall unroofing.
{"title":"Pervasive calcite veins and cleavage dilation in low-grade metamorphic rocks as a marker of lower Jurassic rift-basin margins: A signature of microbial colonization","authors":"S. Fabbi , M. Borrelli , G. Innamorati , L. Aldega , M. Daëron , E. Perri , M. Santantonio","doi":"10.1016/j.marpetgeo.2024.107115","DOIUrl":"10.1016/j.marpetgeo.2024.107115","url":null,"abstract":"<div><div>We report herein for the first time the occurrence of low-grade metamorphic rocks dilated by the growth of calcite veins induced by microbial communities inhabiting the cleavage planes. This process took place at the rock/sea-water interface in a rocky shore environment when the Hercynian basement rocks of the European-Iberian continental margin in Calabria (Italy) experienced stepwise flooding by a shallow tropical sea in the Early Jurassic, a process which was accompanied by synsedimentary extension, resulting in the birth of the Longobucco Basin. The veins exhibit a multiphase filling history, as, in an early phase, microstromatolites lining the walls of cleavage planes document the initial development of microbial biofilms. Subsequently, the growth of bands of radiaxial fibrous calcite enlarged the cavities through force of crystallization, also producing fissures at a high angle with respect to cleavage, which were in turn enlarged by crystal growth. Carbonate clumped isotope analysis indicates crystallization of calcite from sea water, at temperatures (T<sub>47</sub>) ranging from <em>c.</em> 33 to <em>c.</em> 44 °C. The inferred palaeoenvironment is that of a rocky coastline, locally with tide pools, where the seawater lapped cliffs made of Palaeozoic metasandstone. Microbially induced mineralization was a very rapid process, as clasts of veined metamorphic rocks are found in only slightly younger Early Jurassic deposits, like the sub-reefal carbonate bodies that grew in the Pliensbachian attached to the Palaeozoic bedrock. The occurrence of low-grade metamorphic rocks bearing calcite veins can be mapped in the field for kilometers, following the high-angle unconformity that separates the shallow-water carbonates from the basement. This microbial overprint therefore is a marker of the margins of a rift basin, where the exposure of basement rock along steep submarine surfaces was the result of footwall unroofing.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107115"},"PeriodicalIF":3.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0264817224004276/pdfft?md5=de0ac93119ea198a21b66735a1ed0846&pid=1-s2.0-S0264817224004276-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.marpetgeo.2024.107092
Yingjie Liu , Linda A. Hinnov , Mehrdad Sardar Abadi , Chunju Huang , Yaoqi Zhou , Christian Zeeden
A continuous sedimentary succession spanning the Early Cretaceous through the Latest Jurassic was retrieved from the Lingshan Island Scientific Borehole 1 (LS-1), located on Eastern Asia southwest of Qingdao. Spectral analysis of different intervals in the data reveals a hierarchy of meter-to decameter-scale cyclicity. The ratios of the cycles in several stratigraphic units are ∼20:5:2:1, corresponding to those of Milankovitch cycle periods of 405 kyr (long orbital eccentricity), 100 kyr (short orbital eccentricity), 40 kyr (obliquity), and 20 kyr (precession), indicating astronomical control on sedimentation. From interpreted 405 kyr long orbital eccentricity cycles along the magnetic susceptibility, uranium, and gamma ray stratigraphic series, a floating astronomical time scale with a duration of ∼30 Myr is established. This ATS provides numerical ages for stratigraphic boundaries and geological events, and serves as the basis for correlation of strata and events between marine and terrestrial systems. The ATS is anchored to a rather imprecise U-Pb determined age of 125 Ma for the K1l (Laiyang Formation of Early Cretaceous)-K1q (Qingshan Formation of Early Cretaceous) boundary from the Lingshan Island outcrops. The anchored time scale places the location of the Jurassic/Cretaceous (J-K) boundary at 677-674 m (∼144.6 Ma). The Purbeckian marine regression at the J/K boundary impacts the Milankovitch signals around the J/K boundary. Distinct spectral peaks with periods of ∼11-Myr are observed in the power spectra of the proxy time series, indicating a possible tectonic imprint. This ∼11-Myr cycle may be attributed to the subduction of the paleo-Pacific plate under Eurasia during the Late Mesozoic, which is being recorded in the ∼30 Ma here investigated sedimentary record. The interplay between the ∼11-Myr tectonic cycle and the ∼2.4-Myr orbital eccentricity cycle appears to jointly control the variation in depositional rates and environments.
{"title":"30 million years of orbitally influenced sedimentation across the Jurassic—Cretaceous boundary and Early Cretaceous period","authors":"Yingjie Liu , Linda A. Hinnov , Mehrdad Sardar Abadi , Chunju Huang , Yaoqi Zhou , Christian Zeeden","doi":"10.1016/j.marpetgeo.2024.107092","DOIUrl":"10.1016/j.marpetgeo.2024.107092","url":null,"abstract":"<div><div>A continuous sedimentary succession spanning the Early Cretaceous through the Latest Jurassic was retrieved from the Lingshan Island Scientific Borehole 1 (LS-1), located on Eastern Asia southwest of Qingdao. Spectral analysis of different intervals in the data reveals a hierarchy of meter-to decameter-scale cyclicity. The ratios of the cycles in several stratigraphic units are ∼20:5:2:1, corresponding to those of Milankovitch cycle periods of 405 kyr (long orbital eccentricity), 100 kyr (short orbital eccentricity), 40 kyr (obliquity), and 20 kyr (precession), indicating astronomical control on sedimentation. From interpreted 405 kyr long orbital eccentricity cycles along the magnetic susceptibility, uranium, and gamma ray stratigraphic series, a floating astronomical time scale with a duration of ∼30 Myr is established. This ATS provides numerical ages for stratigraphic boundaries and geological events, and serves as the basis for correlation of strata and events between marine and terrestrial systems. The ATS is anchored to a rather imprecise U-Pb determined age of 125 Ma for the K<sub>1</sub>l (Laiyang Formation of Early Cretaceous)-K<sub>1</sub>q (Qingshan Formation of Early Cretaceous) boundary from the Lingshan Island outcrops. The anchored time scale places the location of the Jurassic/Cretaceous (J-K) boundary at 677-674 m (∼144.6 Ma). The Purbeckian marine regression at the J/K boundary impacts the Milankovitch signals around the J/K boundary. Distinct spectral peaks with periods of ∼11-Myr are observed in the power spectra of the proxy time series, indicating a possible tectonic imprint. This ∼11-Myr cycle may be attributed to the subduction of the paleo-Pacific plate under Eurasia during the Late Mesozoic, which is being recorded in the ∼30 Ma here investigated sedimentary record. The interplay between the ∼11-Myr tectonic cycle and the ∼2.4-Myr orbital eccentricity cycle appears to jointly control the variation in depositional rates and environments.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107092"},"PeriodicalIF":3.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.marpetgeo.2024.107121
Luca Basilone , Simone Bernardini , Fausto Grassa , Attilio Sulli , Luis M. Nieto , Anas Abbassi , Luigi Jovane
Phosphatized Mn and Fe rich hardgrounds and condensed pelagic deposits in carbonate platform successions are precious archives of abrupt climate and environmental changes (redox conditions and phosphorous availability) in the past shallow-water marine environment. While numerous examples have been documented in the Cretaceous successions of the Northern Tethys, the scarcity of similar descriptions from the southern margins suggests differences in sedimentary processes or preservation conditions.
In this work we study three phosphatized Mn and Fe rich hardgrounds and pelagic condensed deposits that mark the repetitive demise of the Panormide carbonate platform developed in the Southern Tethyan margin during the Cretaceous. The integration of SEM-EDS, PXRD, and Micro-Raman spectroscopy data shows that these hardgrounds consist of fine-grained Fe (goethite and hematite) and Mn (birnessite and/or vernadite) oxides dispersed in a calcite and apatite matrix. Micro-Raman spectroscopy shows the presence of oxidized Mn species: Mn3+ and Mn4+. The oxidation of Mn2+ → Mn3+/4+ and/or Fe2+ → Fe3+ occurred at the sediment-seawater interface under oxic conditions (where both Mn and Fe oxidize) or suboxic conditions (where only Fe oxidizes). The paleoenvironmental perturbations that triggered the formation of both hardgrounds and condensed pelagic deposits were likely related to pCO2 cycle, upwelling of P-Mn-Fe-rich water masses, eutrophication and phosphatization related to the Cretaceous climate oscillations during the main Oceanic Anoxic Events. These perturbations were likely enhanced by tectonic activity. Moreover, we show that the formation of the phosphatized metals-rich hardgrounds and the recovery of shallow-water sedimentation occurred after long-term periods (6–12 Ma). Thus, the Panormide serves as a remarkable example of resilience amidst significant climatic changes.
{"title":"Paleo-redox conditions during the demise of a carbonate platform in the Tethyan ocean: Evidence from phosphatized and metals (Mn and Fe) rich hardgrounds","authors":"Luca Basilone , Simone Bernardini , Fausto Grassa , Attilio Sulli , Luis M. Nieto , Anas Abbassi , Luigi Jovane","doi":"10.1016/j.marpetgeo.2024.107121","DOIUrl":"10.1016/j.marpetgeo.2024.107121","url":null,"abstract":"<div><div>Phosphatized Mn and Fe rich hardgrounds and condensed pelagic deposits in carbonate platform successions are precious archives of abrupt climate and environmental changes (redox conditions and phosphorous availability) in the past shallow-water marine environment. While numerous examples have been documented in the Cretaceous successions of the Northern Tethys, the scarcity of similar descriptions from the southern margins suggests differences in sedimentary processes or preservation conditions.</div><div>In this work we study three phosphatized Mn and Fe rich hardgrounds and pelagic condensed deposits that mark the repetitive demise of the Panormide carbonate platform developed in the Southern Tethyan margin during the Cretaceous. The integration of SEM-EDS, PXRD, and Micro-Raman spectroscopy data shows that these hardgrounds consist of fine-grained Fe (goethite and hematite) and Mn (birnessite and/or vernadite) oxides dispersed in a calcite and apatite matrix. Micro-Raman spectroscopy shows the presence of oxidized Mn species: Mn<sup>3+</sup> and Mn<sup>4+</sup>. The oxidation of Mn<sup>2+</sup> → Mn<sup>3+/4+</sup> and/or Fe<sup>2+</sup> → Fe<sup>3+</sup> occurred at the sediment-seawater interface under oxic conditions (where both Mn and Fe oxidize) or suboxic conditions (where only Fe oxidizes). The paleoenvironmental perturbations that triggered the formation of both hardgrounds and condensed pelagic deposits were likely related to pCO<sub>2</sub> cycle, upwelling of P-Mn-Fe-rich water masses, eutrophication and phosphatization related to the Cretaceous climate oscillations during the main Oceanic Anoxic Events. These perturbations were likely enhanced by tectonic activity. Moreover, we show that the formation of the phosphatized metals-rich hardgrounds and the recovery of shallow-water sedimentation occurred after long-term periods (6–12 Ma). Thus, the Panormide serves as a remarkable example of resilience amidst significant climatic changes.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107121"},"PeriodicalIF":3.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The resource potential of the Upper Triassic Yanchang Formation in the Ordos Basin is considerably large. However, owing to the low porosity and permeability, poor connectivity, and strong heterogeneity of tight sandstone, predicting the porosity of tight sandstone in this formation poses substantial challenges. The lithology of Chang 71 sub-member is dominated by arkose and lithic arkose, wherein the porosities mainly ranged between 3 and 13% and pore types were mainly feldspar dissolution pores. Based on core sample experiments and thin section analysis, combined with conventional logging curves, we proposed a three-porosity weighted average prediction method under lithological control, and a novel method for reading logging curves controlled by logging resolution is developed. We used principal component analysis to optimise the logging curves and reduce the impact of complex coupling relationships between logging curves on lithofacies identification. The stacking algorithm, which is a combination of the random forest and extreme gradient boosting models, was applied to divide the lithofacies into five categories: homogeneous-distributary-channel fine sandstone, heterogeneous-distributary-channel fine sandstone, homogeneous-mouth-bar fine sandstone, heterogeneous-mouth-bar fine sandstone, and shallow lacustrine mudstone. Compared with the results of manual classification based on logs, the accuracy of lithofacies recognition was approximately 94.2%. Additionally, sensitivity analysis of porosity curves was conducted on four types of lithofacies (i.e., except for shallow lacustrine mudstone), and porosity models for each lithofacies were established, providing an effective and objective method for the accurate prediction of porosity. This prediction method comprehensively considers sedimentary factors and incorporates statistics that are fitted using multiple linear regression, which is highly reliable. In the Chang 71 sub-member, the fitting degree between the predicted and core porosities reached 0.912, indicating that this three-porosity weighted average method based on lithofacies constraints is reasonable, reliable, and has stronger adaptability than the those reported previously. The prediction method based on lithofacies control and weight analysis can be applied to other tight sandstones, providing reliable technical support for oil and gas exploration and development.
{"title":"Prediction method for the porosity of tight sandstone constrained by lithofacies and logging resolution","authors":"Wenwen Zhao , Zhaohui Zhang , Jianbo Liao , Jianwu Zhang , Wenting Zhang","doi":"10.1016/j.marpetgeo.2024.107114","DOIUrl":"10.1016/j.marpetgeo.2024.107114","url":null,"abstract":"<div><div>The resource potential of the Upper Triassic Yanchang Formation in the Ordos Basin is considerably large. However, owing to the low porosity and permeability, poor connectivity, and strong heterogeneity of tight sandstone, predicting the porosity of tight sandstone in this formation poses substantial challenges. The lithology of Chang 7<sub>1</sub> sub-member is dominated by arkose and lithic arkose, wherein the porosities mainly ranged between 3 and 13% and pore types were mainly feldspar dissolution pores. Based on core sample experiments and thin section analysis, combined with conventional logging curves, we proposed a three-porosity weighted average prediction method under lithological control, and a novel method for reading logging curves controlled by logging resolution is developed. We used principal component analysis to optimise the logging curves and reduce the impact of complex coupling relationships between logging curves on lithofacies identification. The stacking algorithm, which is a combination of the random forest and extreme gradient boosting models, was applied to divide the lithofacies into five categories: homogeneous-distributary-channel fine sandstone, heterogeneous-distributary-channel fine sandstone, homogeneous-mouth-bar fine sandstone, heterogeneous-mouth-bar fine sandstone, and shallow lacustrine mudstone. Compared with the results of manual classification based on logs, the accuracy of lithofacies recognition was approximately 94.2%. Additionally, sensitivity analysis of porosity curves was conducted on four types of lithofacies (i.e., except for shallow lacustrine mudstone), and porosity models for each lithofacies were established, providing an effective and objective method for the accurate prediction of porosity. This prediction method comprehensively considers sedimentary factors and incorporates statistics that are fitted using multiple linear regression, which is highly reliable. In the Chang 7<sub>1</sub> sub-member, the fitting degree between the predicted and core porosities reached 0.912, indicating that this three-porosity weighted average method based on lithofacies constraints is reasonable, reliable, and has stronger adaptability than the those reported previously. The prediction method based on lithofacies control and weight analysis can be applied to other tight sandstones, providing reliable technical support for oil and gas exploration and development.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107114"},"PeriodicalIF":3.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.marpetgeo.2024.107117
Grisel Jiménez , Abdul Halim Abdul Latiff , Wael Ben Habel , Michael Poppelreiter
In the dynamic field of carbonate reservoir Exploration, the need for specialized models is vital, assisting as a key tool to facilitate interdisciplinary collaboration and enhance strategies for predicting reservoir behavior. This study examines the use of geological process (GPM), a standard tool to simulate forward stratigraphic modelling, particularly focusing on the Central Luconia Province in the South China Sea. Central Luconia Province stands out for its extensive carbonate build-ups and is recognized as a prolific hydrocarbon reservoir. Forward Stratigraphic Modelling (FSM) leads to a paradigmatic change in geological modeling. Unlike geostatistical models controlled by geometrical parameters, FSM relies on mathematical representations of the physical rules determining erosion, transport, and sedimentation in carbonate growth. This tool, supported by various researchers, has proven its ability in quantitative sedimentary system analysis across diverse temporal and spatial scales. This study located in EX Field showcases the ability of stratigraphic forward modeling in replicating sedimentary complexities and resulting stratigraphic architecture of the EX isolated carbonate platform. The methodology links parameters from existing literature with multiscale data. Additionally, carbonate production laws, contingent on water depth, play a pivotal role in the meticulous modeling process. This work illustrates the efficacy of geological process modelling as a transformative approach for unraveling the complexities of carbonate systems, particularly in regions with prolific hydrocarbon reservoirs like Central Luconia. The incorporation of literature-derived parameters and multiscale data serves as evidence of the model's ability to offer nuanced understandings of the dynamic evolution of carbonate platforms, thereby advancing our understanding of reservoir prediction and future management strategies.
在动态的碳酸盐岩储层勘探领域，对专业模型的需求至关重要，它是促进跨学科合作和加强储层行为预测战略的重要工具。本研究考察了地质过程（GPM）的使用情况，这是一种模拟前向地层建模的标准工具，尤其侧重于中国南海的中卢克尼亚省。中部卢科尼亚海省因其广泛的碳酸盐岩堆积而脱颖而出，是公认的多产油气藏。前向地层建模（FSM）带来了地质建模的范式变革。与由几何参数控制的地质统计模型不同，前向地层模型依赖于对碳酸盐岩生长过程中决定侵蚀、迁移和沉积的物理规则的数学表达。这一工具在众多研究人员的支持下，已经证明了其在不同时空尺度上对沉积系统进行定量分析的能力。这项位于 EX 油田的研究展示了地层前向建模在复制 EX 隔离碳酸盐平台的沉积复杂性和由此产生的地层结构方面的能力。该方法将现有文献中的参数与多尺度数据联系起来。此外，取决于水深的碳酸盐生产规律在细致的建模过程中发挥了关键作用。这项工作说明了地质过程建模作为一种变革性方法在揭示碳酸盐岩系统复杂性方面的功效，尤其是在像中卢科尼亚这样拥有丰富碳氢化合物储层的地区。文献衍生参数和多尺度数据的纳入证明了该模型有能力对碳酸盐岩平台的动态演化提供细致入微的理解，从而推进我们对储层预测和未来管理策略的理解。
{"title":"Effective application of geological process modeling for unravelling carbonate build-up complexity: A case study from the EX-Carbonate build-up in central Luconia Province, Malaysia","authors":"Grisel Jiménez , Abdul Halim Abdul Latiff , Wael Ben Habel , Michael Poppelreiter","doi":"10.1016/j.marpetgeo.2024.107117","DOIUrl":"10.1016/j.marpetgeo.2024.107117","url":null,"abstract":"<div><div>In the dynamic field of carbonate reservoir Exploration, the need for specialized models is vital, assisting as a key tool to facilitate interdisciplinary collaboration and enhance strategies for predicting reservoir behavior. This study examines the use of geological process (GPM), a standard tool to simulate forward stratigraphic modelling, particularly focusing on the Central Luconia Province in the South China Sea. Central Luconia Province stands out for its extensive carbonate build-ups and is recognized as a prolific hydrocarbon reservoir. Forward Stratigraphic Modelling (FSM) leads to a paradigmatic change in geological modeling. Unlike geostatistical models controlled by geometrical parameters, FSM relies on mathematical representations of the physical rules determining erosion, transport, and sedimentation in carbonate growth. This tool, supported by various researchers, has proven its ability in quantitative sedimentary system analysis across diverse temporal and spatial scales. This study located in EX Field showcases the ability of stratigraphic forward modeling in replicating sedimentary complexities and resulting stratigraphic architecture of the EX isolated carbonate platform. The methodology links parameters from existing literature with multiscale data. Additionally, carbonate production laws, contingent on water depth, play a pivotal role in the meticulous modeling process. This work illustrates the efficacy of geological process modelling as a transformative approach for unraveling the complexities of carbonate systems, particularly in regions with prolific hydrocarbon reservoirs like Central Luconia. The incorporation of literature-derived parameters and multiscale data serves as evidence of the model's ability to offer nuanced understandings of the dynamic evolution of carbonate platforms, thereby advancing our understanding of reservoir prediction and future management strategies.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107117"},"PeriodicalIF":3.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.marpetgeo.2024.107112
Shaoyun Chen , Yongqiang Yang , Zaixing Jiang , Longwei Qiu , Xiaojuan Wang
Chlorite is a widely distributed clay mineral in sandstone reservoirs, attracting significant attention due to its complex physicochemical properties and unique reservoir significance. The Shaximiao Formation in the Sichuan Basin, SW China, features abundant diagenetic chlorite, offering valuable insights into chlorite growth theories. Petrographic observations and electron probe analyses reveal that the formation of authigenic chlorite resembles a continuous, staged growth process, akin to tree growth. This process encompasses stages from depositional smectite clay (seeding) to inner-layer chlorite formation (germination), outer-layer chlorite development (branching), and pore-filling chlorite precipitation (blooming). During the initial burial, depositional smectite (seeds) transforms into low-Fe, low-Mg inner-layer chlorite (germination) under the influence of Fe and Mg ions in the original formation water. In the early diagenetic stage, volcanic detritus and biotite alteration release substantial Fe2+ and Mg2+, fostering the growth of outer-layer chlorite (branching) on the inner-layer chlorite. In the middle diagenetic stage, volcanic detritus releases Ca2+, Fe2+, and Mg2+ under the influence of organic acids, leading to supersaturation of Si4+, Al3+, Fe2+, and Mg2+ in pore water, which directly crystallizes into highly euhedral pore-filling chlorite (blooming). The presence of precursor smectite is fundamental to this process, while sufficient Fe and Mg sources are crucial for chlorite formation.
{"title":"Insights into the formation and growth of authigenic chlorite in sandstone: Analysis of mineralogical and geochemical characteristics from Shaximiao Formation, Sichuan Basin, SW China","authors":"Shaoyun Chen , Yongqiang Yang , Zaixing Jiang , Longwei Qiu , Xiaojuan Wang","doi":"10.1016/j.marpetgeo.2024.107112","DOIUrl":"10.1016/j.marpetgeo.2024.107112","url":null,"abstract":"<div><div>Chlorite is a widely distributed clay mineral in sandstone reservoirs, attracting significant attention due to its complex physicochemical properties and unique reservoir significance. The Shaximiao Formation in the Sichuan Basin, SW China, features abundant diagenetic chlorite, offering valuable insights into chlorite growth theories. Petrographic observations and electron probe analyses reveal that the formation of authigenic chlorite resembles a continuous, staged growth process, akin to tree growth. This process encompasses stages from depositional smectite clay (seeding) to inner-layer chlorite formation (germination), outer-layer chlorite development (branching), and pore-filling chlorite precipitation (blooming). During the initial burial, depositional smectite (seeds) transforms into low-Fe, low-Mg inner-layer chlorite (germination) under the influence of Fe and Mg ions in the original formation water. In the early diagenetic stage, volcanic detritus and biotite alteration release substantial Fe<sup>2+</sup> and Mg<sup>2+</sup>, fostering the growth of outer-layer chlorite (branching) on the inner-layer chlorite. In the middle diagenetic stage, volcanic detritus releases Ca<sup>2+</sup>, Fe<sup>2+</sup>, and Mg<sup>2+</sup> under the influence of organic acids, leading to supersaturation of Si<sup>4+</sup>, Al<sup>3+</sup>, Fe<sup>2+</sup>, and Mg<sup>2+</sup> in pore water, which directly crystallizes into highly euhedral pore-filling chlorite (blooming). The presence of precursor smectite is fundamental to this process, while sufficient Fe and Mg sources are crucial for chlorite formation.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107112"},"PeriodicalIF":3.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines the influence of tectonics and paleoclimate on the diagenetic evolution of Upper Cretaceous carbonate reservoirs (Sarvak Formation) in the Abadan Plain, Zagros Basin, Iran. Through petrographic analysis and scanning electron microscopy, the sedimentary facies, diagenetic processes, and pore system within the Sarvak Formation were analyzed. Facies analysis identified eight microfacies, which were deposited in shallow to deep settings of a carbonate ramp. Among these, the grain-dominated facies (packstone and grainstone) of shoal complexes and reef-talus settings were identified as the most important reservoir facies. The formation's complex diagenetic history includes marine, meteoric, and burial diagenetic processes, with meteoric diagenesis playing a significant role beneath paleoexposure surfaces. The Sarvak Formation was categorized into eight flow units, seven pore size classes, eleven electrofacies, eight velocity deviation zones, and thirteen Lorenz zones. The study's findings indicate that the most favorable reservoir units are located beneath the Cenomanian–Turonian exposure surface, characterized by significant dissolution of rudist-dominated facies due to meteoric processes and karstification. Tectonic uplift, along with weathering and erosion within a warm and humid (tropical) paleoclimate, significantly impacts the diagenetic evolution, pore types, and petrophysical properties of the Sarvak Formation. This research underscores the complex interplay between tectonics, paleoclimate, and petrophysical properties in the Abadan Plain, enhancing our understanding of carbonate systems in tectonically active and paleoclimatically dynamic regions.
{"title":"Controls of tectonics and paleoclimate on depositional–diagenetic evolution and pore types of Upper Cretaceous successions (Sarvak Formation) in the Abadan plain, Iran","authors":"Hamzeh Mehrabi , Nafiseh Fakhar-Shahreza , Fatemeh Karami , Javad Honarmand","doi":"10.1016/j.marpetgeo.2024.107118","DOIUrl":"10.1016/j.marpetgeo.2024.107118","url":null,"abstract":"<div><div>This study examines the influence of tectonics and paleoclimate on the diagenetic evolution of Upper Cretaceous carbonate reservoirs (Sarvak Formation) in the Abadan Plain, Zagros Basin, Iran. Through petrographic analysis and scanning electron microscopy, the sedimentary facies, diagenetic processes, and pore system within the Sarvak Formation were analyzed. Facies analysis identified eight microfacies, which were deposited in shallow to deep settings of a carbonate ramp. Among these, the grain-dominated facies (packstone and grainstone) of shoal complexes and reef-talus settings were identified as the most important reservoir facies. The formation's complex diagenetic history includes marine, meteoric, and burial diagenetic processes, with meteoric diagenesis playing a significant role beneath paleoexposure surfaces. The Sarvak Formation was categorized into eight flow units, seven pore size classes, eleven electrofacies, eight velocity deviation zones, and thirteen Lorenz zones. The study's findings indicate that the most favorable reservoir units are located beneath the Cenomanian–Turonian exposure surface, characterized by significant dissolution of rudist-dominated facies due to meteoric processes and karstification. Tectonic uplift, along with weathering and erosion within a warm and humid (tropical) paleoclimate, significantly impacts the diagenetic evolution, pore types, and petrophysical properties of the Sarvak Formation. This research underscores the complex interplay between tectonics, paleoclimate, and petrophysical properties in the Abadan Plain, enhancing our understanding of carbonate systems in tectonically active and paleoclimatically dynamic regions.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107118"},"PeriodicalIF":3.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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