{"id":{"repo_id":"regina","oai_identifier":"oai:uregina.scholaris.ca:10294/15560"},"canonical_url":"https://search.dev.ndltd.org/etd/regina/oai:uregina.scholaris.ca:10294/15560","repository":{"repo_id":"regina","name":"University of Regina","base_url":"https://uregina.scholaris.ca/server/oai/request"},"display":{"title":"Sedimentology and Biostratigraphy of the Chorgali Formation, Potwar and Hazara Sub-Basins, Upper Indus Basin of Pakistan: Implications for the Closing Stage of the Eastern Neo-Tethys Ocean","abstract":"The Chorgali Formation is a hydrocarbon-producing lithostratigraphic unit that occurs in different sub-basins of the Indus Basin in northern Pakistan, such as Potwar and Hazara sub- basins. The formation is part of a very thick carbonate succession deposited in the eastern Neo- Tethys Ocean shelf. It conformably overlies on early Eocene Sakesar Formation in southern Potwar sub-basin and lies on Margala Hill Limestone in the northern Potwar sub-basin and Hazara sub-basin. The Chorgali Formation is either covered by Miocene continental deposits of Murree Formation (Himalayan molasse deposits) or middle Eocene mixed clastic-carbonate succession of marine to continental beds of the Kuldana Formation. This study addresses the Chorgali Formation of the Potwar and Hazara sub-basins. This study intends to explore the spatial and temporal evolution of the Chorgali Formation as preserved in the Hazara and Potwar sub-basins and analyze it within the regional tectono-eustatic context. Six sections in the Potwar sub-basin and two sections in the Hazara sub-basin were studied; they give an average thickness of 32.5 m for the formation. Field observations and petrographic analyses of the studied sections allowed the recognition of nine lithofacies units (LF1-LF9) for the Chorgali Formation. These lithofacies include Calcareous Sandstone (LF1), Intraclastic Dolomitic Packstone (LF2), Algal-miliolid Mudstone (LF3), Coralline Algae Mudstone (LF4), Assilina-Nummulites Floatstone (LF5), Mixed Benthic-Planktonic Foraminifera Wackestone (LF6), Benthic Foraminifera Rudstone (LF7), Shale Lithofacies (LF8), and Planktonic Mudstone (LF9). The sedimentary features and fossil associations of the formation suggest that deposition of the formation took place in a homoclinal carbonate ramp characterized by low to moderate energy hydrodynamic conditions. The LF1 to LF5 association represents inner ramp, whereas the LF6 to LF9 association represents mid-ramp accumulations. Biostratigraphically important Larger Benthic Foraminifera (LBF) in the formation include, Assilina spinosa, A. sub-spinosa, A. laminosa, A. granulosa, A. placentula, Nummulites atacicus, N. globulus, N. mamillatus, Lockhartia conditi, L. tipperi and Alveolina indicatrix. These LBFs indicate an age range of late Paleocene to middle Eocene. By considering the age ranges of these index fossils and formation’s stratigraphic position (i.e., between middle Ilerdian Sakesar Formation/ Margala Hill Limestone, and upper Cuisian Kuldana Formation), the Chorgali Formation can be regarded as late Ilerdian to lower Cuisian (53 - 51.5 Ma) in age. The stratigraphic position and age of the formation indicate that it evolved in a time in which the eastern Neo-Tethys Ocean was getting more restricted as the Indo-Pakistan Plate moved farther to the north and got closer to collide with the Eurasian Plate. The collision event was diachronous (~ 55 Ma to 41 Ma, from east to west). Thus, the deposition of the formation took place at the stage of the initial collision, basin closure and latest stage that heralded the demise of the carbonate platform. Sedimentologic properties that potentially indicate signatures of basin closure and relative sea level drop are present in the uppermost part of the Chorgali Formation. These features include, 1) localized sandy facies (LF1), 2) localized supratidal intraclastic dolomitic packstone (LF2), and 3) localized pedogenic features such as, karstified surface, dolomitized algal mats, evaporite nodules and flat pebble breccia that collectively underscore exposed to restricted marine conditions, were recognized in the uppermost part of the formation in other parts of the Potwar sub-basin by previous researchers. Previous work has also indicated that Oxygen and Carbon isotopic signatures of the dolomitic unit indicate mixed marine-meteoric origin. The Kuldana Formation that conformably overlies the Chorgali Formation, is dominated by shallow marine siliciclastic succession with subordinate carbonate interbeds in its lower part. However, in other places, the Kuldana Formation contains continental clastic lithology with freshwater vertebrate fossils (e.g., crocodilia fossils). These evidences clearly indicate that the Chorgali Formation represents deposition during the latest stage of the closure of the eastern Neo-Tethys Ocean and consequently, the demise of the carbonate platform.","abstract_html":"The Chorgali Formation is a hydrocarbon-producing lithostratigraphic unit that occurs in different sub-basins of the Indus Basin in northern Pakistan, such as Potwar and Hazara sub- basins. The formation is part of a very thick carbonate succession deposited in the eastern Neo- Tethys Ocean shelf. It conformably overlies on early Eocene Sakesar Formation in southern Potwar sub-basin and lies on Margala Hill Limestone in the northern Potwar sub-basin and Hazara sub-basin. The Chorgali Formation is either covered by Miocene continental deposits of Murree Formation (Himalayan molasse deposits) or middle Eocene mixed clastic-carbonate succession of marine to continental beds of the Kuldana Formation. This study addresses the Chorgali Formation of the Potwar and Hazara sub-basins. This study intends to explore the spatial and temporal evolution of the Chorgali Formation as preserved in the Hazara and Potwar sub-basins and analyze it within the regional tectono-eustatic context. Six sections in the Potwar sub-basin and two sections in the Hazara sub-basin were studied; they give an average thickness of 32.5 m for the formation. Field observations and petrographic analyses of the studied sections allowed the recognition of nine lithofacies units (LF1-LF9) for the Chorgali Formation. These lithofacies include Calcareous Sandstone (LF1), Intraclastic Dolomitic Packstone (LF2), Algal-miliolid Mudstone (LF3), Coralline Algae Mudstone (LF4), Assilina-Nummulites Floatstone (LF5), Mixed Benthic-Planktonic Foraminifera Wackestone (LF6), Benthic Foraminifera Rudstone (LF7), Shale Lithofacies (LF8), and Planktonic Mudstone (LF9). The sedimentary features and fossil associations of the formation suggest that deposition of the formation took place in a homoclinal carbonate ramp characterized by low to moderate energy hydrodynamic conditions. The LF1 to LF5 association represents inner ramp, whereas the LF6 to LF9 association represents mid-ramp accumulations. Biostratigraphically important Larger Benthic Foraminifera (LBF) in the formation include, Assilina spinosa, A. sub-spinosa, A. laminosa, A. granulosa, A. placentula, Nummulites atacicus, N. globulus, N. mamillatus, Lockhartia conditi, L. tipperi and Alveolina indicatrix. These LBFs indicate an age range of late Paleocene to middle Eocene. By considering the age ranges of these index fossils and formation’s stratigraphic position (i.e., between middle Ilerdian Sakesar Formation/ Margala Hill Limestone, and upper Cuisian Kuldana Formation), the Chorgali Formation can be regarded as late Ilerdian to lower Cuisian (53 - 51.5 Ma) in age. The stratigraphic position and age of the formation indicate that it evolved in a time in which the eastern Neo-Tethys Ocean was getting more restricted as the Indo-Pakistan Plate moved farther to the north and got closer to collide with the Eurasian Plate. The collision event was diachronous (~ 55 Ma to 41 Ma, from east to west). Thus, the deposition of the formation took place at the stage of the initial collision, basin closure and latest stage that heralded the demise of the carbonate platform. Sedimentologic properties that potentially indicate signatures of basin closure and relative sea level drop are present in the uppermost part of the Chorgali Formation. These features include, 1) localized sandy facies (LF1), 2) localized supratidal intraclastic dolomitic packstone (LF2), and 3) localized pedogenic features such as, karstified surface, dolomitized algal mats, evaporite nodules and flat pebble breccia that collectively underscore exposed to restricted marine conditions, were recognized in the uppermost part of the formation in other parts of the Potwar sub-basin by previous researchers. Previous work has also indicated that Oxygen and Carbon isotopic signatures of the dolomitic unit indicate mixed marine-meteoric origin. The Kuldana Formation that conformably overlies the Chorgali Formation, is dominated by shallow marine siliciclastic succession with subordinate carbonate interbeds in its lower part. However, in other places, the Kuldana Formation contains continental clastic lithology with freshwater vertebrate fossils (e.g., crocodilia fossils). These evidences clearly indicate that the Chorgali Formation represents deposition during the latest stage of the closure of the eastern Neo-Tethys Ocean and consequently, the demise of the carbonate platform.","abstract_has_math":false,"creators":["Khan, Muhammad Tufail"],"institution":"Faculty of Graduate Studies and Research, University of Regina","degree_name":"Master of Science (MSc)","degree_level":"Master's","degree_discipline":"Geology","degree_department":null,"school":null,"contributors":[],"advisors":["Salad Hersi, Osman"],"committee_chairs":[],"committee_members":["Qing, Hairuo"],"year":2022,"date_issued":"2022-03","date_published":"2022-03","updated_at":"2026-07-24T04:03:43Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.82465/4671"],"render_values":[{"text":"https://doi.org/10.82465/4671","href":"https://doi.org/10.82465/4671","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10294/15560","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Salad Hersi, Osman"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Qing, Hairuo"]},{"key":"dc:creator","label":"Author","values":["Khan, Muhammad Tufail"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-12-09T21:21:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-12-09T21:21:21Z"]},{"key":"dc:date.issued","label":"Date","values":["2022-03"]},{"key":"dc:publisher","label":"Institution","values":["Faculty of Graduate Studies and Research, University of Regina"]},{"key":"dc:type","label":"Dc Type","values":["master thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Master's"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MSc)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Faculty of Graduate Studies and Research, University of Regina"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.82465/4671"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10294/15560"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Geology, University of Regina. ix, 120 p."]},{"key":"dc:description.abstract","label":"Abstract","values":["The Chorgali Formation is a hydrocarbon-producing lithostratigraphic unit that occurs in different sub-basins of the Indus Basin in northern Pakistan, such as Potwar and Hazara sub- basins. The formation is part of a very thick carbonate succession deposited in the eastern Neo- Tethys Ocean shelf. It conformably overlies on early Eocene Sakesar Formation in southern Potwar sub-basin and lies on Margala Hill Limestone in the northern Potwar sub-basin and Hazara sub-basin. The Chorgali Formation is either covered by Miocene continental deposits of Murree Formation (Himalayan molasse deposits) or middle Eocene mixed clastic-carbonate succession of marine to continental beds of the Kuldana Formation. This study addresses the Chorgali Formation of the Potwar and Hazara sub-basins. This study intends to explore the spatial and temporal evolution of the Chorgali Formation as preserved in the Hazara and Potwar sub-basins and analyze it within the regional tectono-eustatic context. Six sections in the Potwar sub-basin and two sections in the Hazara sub-basin were studied; they give an average thickness of 32.5 m for the formation. Field observations and petrographic analyses of the studied sections allowed the recognition of nine lithofacies units (LF1-LF9) for the Chorgali Formation. These lithofacies include Calcareous Sandstone (LF1), Intraclastic Dolomitic Packstone (LF2), Algal-miliolid Mudstone (LF3), Coralline Algae Mudstone (LF4), Assilina-Nummulites Floatstone (LF5), Mixed Benthic-Planktonic Foraminifera Wackestone (LF6), Benthic Foraminifera Rudstone (LF7), Shale Lithofacies (LF8), and Planktonic Mudstone (LF9). The sedimentary features and fossil associations of the formation suggest that deposition of the formation took place in a homoclinal carbonate ramp characterized by low to moderate energy hydrodynamic conditions. The LF1 to LF5 association represents inner ramp, whereas the LF6 to LF9 association represents mid-ramp accumulations. Biostratigraphically important Larger Benthic Foraminifera (LBF) in the formation include, Assilina spinosa, A. sub-spinosa, A. laminosa, A. granulosa, A. placentula, Nummulites atacicus, N. globulus, N. mamillatus, Lockhartia conditi, L. tipperi and Alveolina indicatrix. These LBFs indicate an age range of late Paleocene to middle Eocene. By considering the age ranges of these index fossils and formation’s stratigraphic position (i.e., between middle Ilerdian Sakesar Formation/ Margala Hill Limestone, and upper Cuisian Kuldana Formation), the Chorgali Formation can be regarded as late Ilerdian to lower Cuisian (53 - 51.5 Ma) in age. The stratigraphic position and age of the formation indicate that it evolved in a time in which the eastern Neo-Tethys Ocean was getting more restricted as the Indo-Pakistan Plate moved farther to the north and got closer to collide with the Eurasian Plate. The collision event was diachronous (~ 55 Ma to 41 Ma, from east to west). Thus, the deposition of the formation took place at the stage of the initial collision, basin closure and latest stage that heralded the demise of the carbonate platform. Sedimentologic properties that potentially indicate signatures of basin closure and relative sea level drop are present in the uppermost part of the Chorgali Formation. These features include, 1) localized sandy facies (LF1), 2) localized supratidal intraclastic dolomitic packstone (LF2), and 3) localized pedogenic features such as, karstified surface, dolomitized algal mats, evaporite nodules and flat pebble breccia that collectively underscore exposed to restricted marine conditions, were recognized in the uppermost part of the formation in other parts of the Potwar sub-basin by previous researchers. Previous work has also indicated that Oxygen and Carbon isotopic signatures of the dolomitic unit indicate mixed marine-meteoric origin. The Kuldana Formation that conformably overlies the Chorgali Formation, is dominated by shallow marine siliciclastic succession with subordinate carbonate interbeds in its lower part. However, in other places, the Kuldana Formation contains continental clastic lithology with freshwater vertebrate fossils (e.g., crocodilia fossils). These evidences clearly indicate that the Chorgali Formation represents deposition during the latest stage of the closure of the eastern Neo-Tethys Ocean and consequently, the demise of the carbonate platform."]},{"key":"dc:title","label":"Title","values":["Sedimentology and Biostratigraphy of the Chorgali Formation, Potwar and Hazara Sub-Basins, Upper Indus Basin of Pakistan: Implications for the Closing Stage of the Eastern Neo-Tethys Ocean"]}]}],"canonical_facts":{"dc:contributor.advisor":["Salad Hersi, Osman"],"dc:contributor.committeemember":["Qing, Hairuo"],"dc:creator":["Khan, Muhammad Tufail"],"dc:date.accessioned":["2022-12-09T21:21:21Z"],"dc:date.available":["2022-12-09T21:21:21Z"],"dc:date.issued":["2022-03"],"dc:description":["A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Science in Geology, University of Regina. ix, 120 p."],"dc:description.abstract":["The Chorgali Formation is a hydrocarbon-producing lithostratigraphic unit that occurs in different sub-basins of the Indus Basin in northern Pakistan, such as Potwar and Hazara sub- basins. The formation is part of a very thick carbonate succession deposited in the eastern Neo- Tethys Ocean shelf. It conformably overlies on early Eocene Sakesar Formation in southern Potwar sub-basin and lies on Margala Hill Limestone in the northern Potwar sub-basin and Hazara sub-basin. The Chorgali Formation is either covered by Miocene continental deposits of Murree Formation (Himalayan molasse deposits) or middle Eocene mixed clastic-carbonate succession of marine to continental beds of the Kuldana Formation. This study addresses the Chorgali Formation of the Potwar and Hazara sub-basins. This study intends to explore the spatial and temporal evolution of the Chorgali Formation as preserved in the Hazara and Potwar sub-basins and analyze it within the regional tectono-eustatic context. Six sections in the Potwar sub-basin and two sections in the Hazara sub-basin were studied; they give an average thickness of 32.5 m for the formation. Field observations and petrographic analyses of the studied sections allowed the recognition of nine lithofacies units (LF1-LF9) for the Chorgali Formation. These lithofacies include Calcareous Sandstone (LF1), Intraclastic Dolomitic Packstone (LF2), Algal-miliolid Mudstone (LF3), Coralline Algae Mudstone (LF4), Assilina-Nummulites Floatstone (LF5), Mixed Benthic-Planktonic Foraminifera Wackestone (LF6), Benthic Foraminifera Rudstone (LF7), Shale Lithofacies (LF8), and Planktonic Mudstone (LF9). The sedimentary features and fossil associations of the formation suggest that deposition of the formation took place in a homoclinal carbonate ramp characterized by low to moderate energy hydrodynamic conditions. The LF1 to LF5 association represents inner ramp, whereas the LF6 to LF9 association represents mid-ramp accumulations. Biostratigraphically important Larger Benthic Foraminifera (LBF) in the formation include, Assilina spinosa, A. sub-spinosa, A. laminosa, A. granulosa, A. placentula, Nummulites atacicus, N. globulus, N. mamillatus, Lockhartia conditi, L. tipperi and Alveolina indicatrix. These LBFs indicate an age range of late Paleocene to middle Eocene. By considering the age ranges of these index fossils and formation’s stratigraphic position (i.e., between middle Ilerdian Sakesar Formation/ Margala Hill Limestone, and upper Cuisian Kuldana Formation), the Chorgali Formation can be regarded as late Ilerdian to lower Cuisian (53 - 51.5 Ma) in age. The stratigraphic position and age of the formation indicate that it evolved in a time in which the eastern Neo-Tethys Ocean was getting more restricted as the Indo-Pakistan Plate moved farther to the north and got closer to collide with the Eurasian Plate. The collision event was diachronous (~ 55 Ma to 41 Ma, from east to west). Thus, the deposition of the formation took place at the stage of the initial collision, basin closure and latest stage that heralded the demise of the carbonate platform. Sedimentologic properties that potentially indicate signatures of basin closure and relative sea level drop are present in the uppermost part of the Chorgali Formation. These features include, 1) localized sandy facies (LF1), 2) localized supratidal intraclastic dolomitic packstone (LF2), and 3) localized pedogenic features such as, karstified surface, dolomitized algal mats, evaporite nodules and flat pebble breccia that collectively underscore exposed to restricted marine conditions, were recognized in the uppermost part of the formation in other parts of the Potwar sub-basin by previous researchers. Previous work has also indicated that Oxygen and Carbon isotopic signatures of the dolomitic unit indicate mixed marine-meteoric origin. The Kuldana Formation that conformably overlies the Chorgali Formation, is dominated by shallow marine siliciclastic succession with subordinate carbonate interbeds in its lower part. However, in other places, the Kuldana Formation contains continental clastic lithology with freshwater vertebrate fossils (e.g., crocodilia fossils). These evidences clearly indicate that the Chorgali Formation represents deposition during the latest stage of the closure of the eastern Neo-Tethys Ocean and consequently, the demise of the carbonate platform."],"dc:identifier.doi":["https://doi.org/10.82465/4671"],"dc:identifier.uri":["https://hdl.handle.net/10294/15560"],"dc:language.iso":["en"],"dc:publisher":["Faculty of Graduate Studies and Research, University of Regina"],"dc:title":["Sedimentology and Biostratigraphy of the Chorgali Formation, Potwar and Hazara Sub-Basins, Upper Indus Basin of Pakistan: Implications for the Closing Stage of the Eastern Neo-Tethys Ocean"],"dc:type":["master thesis"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["Master's"],"thesis:degree_name":["Master of Science (MSc)"],"thesis:institution_name":["Faculty of Graduate Studies and Research, University of Regina"]},"updated_at":"2026-07-24T04:03:43Z"}