7 research outputs found
New Bovid (Artiodactyla) Fossils from the Siwaliks of Pakistan: Reviving a Lost World
Get PDFThis research investigates new fossil specimens of bovids (Artiodactyla) from the Dhok-Pathan Formation in the Siwalik region of Pakistan, a crucial site for understanding South Asia\u27s paleoecology and evolutionary history. This study provides new insights into the taxonomy and diversity of Siwalik bovids, addressing gaps in the fossil record and contributing to a more comprehensive understanding of their evolutionary relationships. In this paper, new dental elements of bovids were recovered (seven specimens were collected) comprised of both upper and lower dentitions have been recovered from the most fossiliferous sites i.e., Dhok Pathan and Hasnot villages, in Potwar foreland basin of Himalayas in Pakistan. On the basis of comparative morphology and the precise measurements of these specimens refer to the mandible of Selenoportax vexillarius, rest of all are molars and premolars of Pachyportax latidens, Pachyportax nagrii and Kobus porrecticornis. All the new dental material is documented in this research belongs to Dhok Pathan Formation of upper Siwaliks Group. The stratigraphic layers, encompassing various depositional environments such as river channels and floodplains, provide insights into the chronological and environmental contexts of the fossil assemblages. Comparative analysis with fossils from other regions ensures the accuracy and relevance of the findings, contributing to a refined understanding of the evolutionary history and biogeographic patterns of these species. The study also documents the paleoecology of the region, indicating a grassland and woodland biome that supported diverse bovid species. These findings underscore the Siwalik region\u27s significance as a key site for studying the evolutionary history of Artiodactyla and provide valuable data for future paleontological and conservation studies. The examined fauna suggests a vast and an open landscape with intermittent dry and flood seasons, creating a mosaic of ecotonal habitats with numerous niches. This research enhances our knowledge of the Siwalik region\u27s past biodiversity and environmental changes, emphasizing the need for continued exploration and analysis of its fossil record
PETROGRAPHY OF UPPER NARI FORMATION, GANDRI JABAL, PAKISTAN
No full textThe petrographic study has been well carried out in order to understand the mineralogical and geochemical characteristics of the Nari Formation at “Gandri Jabal” section near Nooriabad, Jamshoro. The formations were found to be mainly composed of sandstone, limestone, shale and variegated clays in the studied section. Sandstones are compact to semi-compact, ferruginous, fine to coarse grained and range from pinkish, reddish, brownish to camel in color. It was unusual that one bed of camel colored limestone with maga fossils was observed in the upper part of the formation. Petrographic study of the Gandri Jabal Section, Upper part of Nari Formation on the texture of most of the samples is medium to coarse grained as well as the shape of the grains is angular to sub-angular. Dominant cementing material is calcite along iron oxide. It was further justified by geochemical analysis of major elements through automated Scanning Electron Microscopy Energy Dispersive Spectrometer (SEM-EDS), that the highest peak was silicon (Si), the second dominant peak was of calcium (Ca), and a third dominant peak was fermium(Fe). This mean that the major mineral constituent was quartz and within the sandstone the cementing material is calcite and iron oxide, and highly calcium (Ca) bed found means that major mineral constituent was Calcite within mega fossils limestone. These finding demonstrate that majority of the lithologic units of this formation are daltatic or beach and one bed is in Marine environment as considered by earlier workers. The samples having higher proportion of quartz grains belonging to quartz arenite category. Hence it is concluded based on the shape of detrial quartz grains, that the source of these sediments neither came from northern Himalayan nor from Indian shield, but very likely came from the western highlands and on the basis of the present rock fragments, we conjecture that source is igneous, sedimentary or metamorphic
New Bovid (Artiodactyla) Fossils from the Siwaliks of Pakistan: Reviving a Lost World
Get PDFThis research investigates new fossil specimens of bovids (Artiodactyla) from the Dhok-Pathan Formation in the Siwalik region of Pakistan, a crucial site for understanding South Asia\u27s paleoecology and evolutionary history. This study provides new insights into the taxonomy and diversity of Siwalik bovids, addressing gaps in the fossil record and contributing to a more comprehensive understanding of their evolutionary relationships. In this paper, new dental elements of bovids were recovered (seven specimens were collected) comprised of both upper and lower dentitions have been recovered from the most fossiliferous sites i.e., Dhok Pathan and Hasnot villages, in Potwar foreland basin of Himalayas in Pakistan. On the basis of comparative morphology and the precise measurements of these specimens refer to the mandible of Selenoportax vexillarius, rest of all are molars and premolars of Pachyportax latidens, Pachyportax nagrii and Kobus porrecticornis. All the new dental material is documented in this research belongs to Dhok Pathan Formation of upper Siwaliks Group. The stratigraphic layers, encompassing various depositional environments such as river channels and floodplains, provide insights into the chronological and environmental contexts of the fossil assemblages. Comparative analysis with fossils from other regions ensures the accuracy and relevance of the findings, contributing to a refined understanding of the evolutionary history and biogeographic patterns of these species. The study also documents the paleoecology of the region, indicating a grassland and woodland biome that supported diverse bovid species. These findings underscore the Siwalik region\u27s significance as a key site for studying the evolutionary history of Artiodactyla and provide valuable data for future paleontological and conservation studies. The examined fauna suggests a vast and an open landscape with intermittent dry and flood seasons, creating a mosaic of ecotonal habitats with numerous niches. This research enhances our knowledge of the Siwalik region\u27s past biodiversity and environmental changes, emphasizing the need for continued exploration and analysis of its fossil record
Structural and stratigraphic studies of Hazara-Kashmir Syntaxis, northwestern Himalaya, Pakistan
No full textThe study area lies in the southern part of the Hazara Kashmir syntaxis, which is an antiformal structure, located in the Northwestern part of the Himalaya. It is a major tectonic feature controlling the tectonic setting at the western termination of Himalaya. The Tertiary molasse sequence lies in the core of the syntaxis, and the erosional processes of Himalaya feds the detritus in the adjoining Foreland Basin. This molasses sequence is further divided into Chinji, Nagri, Dhok Pathan and, Soan formations, and Mirpur conglomerate.
The molasse sequence is folded and imbricated being a part of an active fold and thrust belt in the sub-Himalaya of Pakistan. The folds are northeast-southwest trending, northwest-southeast vergent, close fold geometry and northeast or southwest plunge. The Chinji Formation lies in the core and Nagri Formation on the south-eastern limb, whereas, Malikpur-Diljaba fault truncates the northwestern limb of Tamliahn anticline.
The Malikpur-Diljaba, Tanyam and Makhlot faults are reverse faults, whereas, Jhelum fault is a left-lateral strike-slip fault, are major structures in the study area. The Jhelum fault is the youngest and an active tectonic feature in the syntaxial zone. The tectonic history reveals a north-south compressional related deformation.
Keywords: Structure and stratigraphy, Hazara-Kashmir Syntaxis, Northwestern Himalaya, Jhelum Fault, Himalayan Foreland Basi
Petrographic and geochemical evidence for determining the provenance of the Nari Formation, Pakistan
Get PDFThe geochemical and petrographic characteristics of the Nari Formation (NF) have been thoroughly examined at the Haji Haroon section in the Lower Indus Basin (LIB), located in the Northern Laki Range, approximately 20 kilometres south of Therhi village, Sehwan Sharif. The NF is predominantly composed of sandstone, multicoloured clays, shale and limestone in the Haji Haroon section. The geochemical analysis of major elements using the automated Scanning Electron Microscopy Energy Dispersive Spectrometer (automated SEM-EDS) reveals that quartz is the dominant mineral in all the studied sandstones, typically comprising over 75% and reaching up to 90% and the second dominant phase mineral is calcite which varies from sample to sample. In the basal part of the NF sample, labelled HHS-02, consists of calcitic limestone, with calcite making up more than 85% of the weight (%). The previous studies in Lower Indus Basin shows that the basal part and upper part of the Nari Formation are formed in fluvial environments. However, our study contradicted the existing paradigms and revealed novel insights into the depositional environment of the NF. The current petrography, SEM-EDS, and field observations suggest that the NF at the Haji Haroon section in the Northern Laki range does not solely originate from fluvial processes. Instead, the basal part of the formation is marine in origin, while the upper part is fluvial. The basal part is characterized by transitional environments, which may be deltaic or beach deposits due to the presence of significant amounts of both quartz and calcite. The samples bear an elevated amount of quartz, classifying them as quartz arenite. Therefore, it is determined from the shape of clastic quartz grains that the sediments presumably originated in the western highlands rather than the northern Himalayas or the Indian shield, and based on the existing rock fragments
