The study provides the first comprehensive record of the plant megafossils mainly Glossopteris flora from the Barakar Formation, Rajmahal Open Cast Mine, Rajmahal Basin, Jharkhand. The assemblage is composed of pterid...The study provides the first comprehensive record of the plant megafossils mainly Glossopteris flora from the Barakar Formation, Rajmahal Open Cast Mine, Rajmahal Basin, Jharkhand. The assemblage is composed of pteridophytes and gymnosperms. The pteridophytes comprise Equisetalean axes (order Equisetales), whereas, gymnosperms include nine species of Glossopteris including Glossopteris communis, G. damudica, G. gigas, G. indica, G. lanceolatus, G. longicaulis, G. oldhamii, G. taenioides, G. tenuifolia along with Vertebraria indica and Noeggerathiopsis hislopi. The present investigation adds to the knowledge of the Glossopteris flora of India, especially that of the Rajmahal Basin from where the plant fossil records are sporadic. The area is a treasure for palaeobotanical studies as evinced by different fossil localities. However, the localities are degraded by mining activities performed by private companies and hence systematic investigation for such vegetation is vital to create a palaeobotanical database before their complete degradation. The floral assemblage compares with earlier known assemblages, recorded from the Barakar Formation of other Lower Gondwana basins of peninsular India. .展开更多
This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to ...This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to establish the chronology of sedimentation and to propose palaeobotanical as well as geochemical evidence for the occurrence of wildfires in these sediments. The palynological investigation suggests a Scheuringipollenites barakarensis palynoassemblage from the lower Barakar Formation, dated as Artinskian(Early Permian) in age. This assemblage reveals the dominance of Glossopteridales and sub-dominance of taxa belonging to Cordaitales and Coniferales.Fossil charcoal in sediments is usually recognized as a direct indicator for the occurrence of palaeo-wildfires. More data involving the anatomical features of fossil charcoal analyzed by Field Emission Scanning Electronic Microscope broaden our knowledge on Early Permian wildfires from the peninsula of India. The studied macroscopic charcoal fragments exhibit anatomical details such as homogenized cell walls, uniseriate simple and biseriate alternate pitting on tracheid walls and rays of varying heights pointing to a gymnospermous wood affinitity. The excellent preservation of charcoal fragments, shown by their large sizes and almost unabraded edges, suggests a parautochthonous origin. The embedded biomarker study performed for charcoal sediments and its characterization demonstrate the presence of n-alkanes, isoprenoids, terpenoids and aromatic compounds. A bimodal distribution pattern of n-alkanes with a Cmaxat n-C25 is identified. Diterpenoids and pentacyclic terpenoids are identified, indicating the input of an early conifer vegetation and bacterial activity, respectively. The identified polyaromatic hydrocarbon(PAH) compounds, together with the charcoal fragments, clearly suggest that repeated wildfire events occurred during the deposition of these Artinskian sediments in the Rajmahal Basin.展开更多
文摘The study provides the first comprehensive record of the plant megafossils mainly Glossopteris flora from the Barakar Formation, Rajmahal Open Cast Mine, Rajmahal Basin, Jharkhand. The assemblage is composed of pteridophytes and gymnosperms. The pteridophytes comprise Equisetalean axes (order Equisetales), whereas, gymnosperms include nine species of Glossopteris including Glossopteris communis, G. damudica, G. gigas, G. indica, G. lanceolatus, G. longicaulis, G. oldhamii, G. taenioides, G. tenuifolia along with Vertebraria indica and Noeggerathiopsis hislopi. The present investigation adds to the knowledge of the Glossopteris flora of India, especially that of the Rajmahal Basin from where the plant fossil records are sporadic. The area is a treasure for palaeobotanical studies as evinced by different fossil localities. However, the localities are degraded by mining activities performed by private companies and hence systematic investigation for such vegetation is vital to create a palaeobotanical database before their complete degradation. The floral assemblage compares with earlier known assemblages, recorded from the Barakar Formation of other Lower Gondwana basins of peninsular India. .
基金This study was funded by the Birbal Sahni Institute of Palaeosciences,Department of Science and Technology,Lucknow,India Research Development and Coordination Committee(RDCC,Permission Number 10/2020–2021)。
文摘This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to establish the chronology of sedimentation and to propose palaeobotanical as well as geochemical evidence for the occurrence of wildfires in these sediments. The palynological investigation suggests a Scheuringipollenites barakarensis palynoassemblage from the lower Barakar Formation, dated as Artinskian(Early Permian) in age. This assemblage reveals the dominance of Glossopteridales and sub-dominance of taxa belonging to Cordaitales and Coniferales.Fossil charcoal in sediments is usually recognized as a direct indicator for the occurrence of palaeo-wildfires. More data involving the anatomical features of fossil charcoal analyzed by Field Emission Scanning Electronic Microscope broaden our knowledge on Early Permian wildfires from the peninsula of India. The studied macroscopic charcoal fragments exhibit anatomical details such as homogenized cell walls, uniseriate simple and biseriate alternate pitting on tracheid walls and rays of varying heights pointing to a gymnospermous wood affinitity. The excellent preservation of charcoal fragments, shown by their large sizes and almost unabraded edges, suggests a parautochthonous origin. The embedded biomarker study performed for charcoal sediments and its characterization demonstrate the presence of n-alkanes, isoprenoids, terpenoids and aromatic compounds. A bimodal distribution pattern of n-alkanes with a Cmaxat n-C25 is identified. Diterpenoids and pentacyclic terpenoids are identified, indicating the input of an early conifer vegetation and bacterial activity, respectively. The identified polyaromatic hydrocarbon(PAH) compounds, together with the charcoal fragments, clearly suggest that repeated wildfire events occurred during the deposition of these Artinskian sediments in the Rajmahal Basin.
