A new locality bearing ichnofossils of the Cruziana Assemblage Zone-Ⅲ from the Mussoorie syncline,Lesser Himalaya,is located in rocks of Member-B of the Dhaulagiri Formation,Tal Group,exposed along the Maldewta-Chhim...A new locality bearing ichnofossils of the Cruziana Assemblage Zone-Ⅲ from the Mussoorie syncline,Lesser Himalaya,is located in rocks of Member-B of the Dhaulagiri Formation,Tal Group,exposed along the Maldewta-Chhimoli fresh road cut section.The site yielded ichnofossils Bergaueria perata,Cochlichnus anguineus,？Diplocraterion isp.,Dimorphichnus obliquus,diplichnitiform Cruziana bonariensis,Diplichnites gouldi,Glockeria isp.,Helminthopsis isp.,Monomorphichnus lineatus,Phycodes palmatum,Palaeophycus striatus,Planolites beverleyensis,Planolites montanus,Treptichnus cf.T.pedum,scratch marks and an undetermined worm impression.An Early Cambrian age （Cambrian Series 2） is assigned to the ichnofossil-bearing strata based on the stratigraphic position between the Drepanuroides and Palaeoolenus trilobite zones.A revised Cambrian ichnofossil zonation is presented for the Tal Group of the Mussoorie syncline.Together with their occurrence on rippled surfaces,and the lateral displacement of some trackways （due to current action）,a sub-aqueous shallow-marine depositional setting is proposed for the rocks of Member-B.展开更多
Sabellaria alveolata(Linnaeus 1767)is a polychaete able to build bioconstructions of different thickness,size and patchiness,in intertidal and subtidal environments.Its biological features have been the object of nume...Sabellaria alveolata(Linnaeus 1767)is a polychaete able to build bioconstructions of different thickness,size and patchiness,in intertidal and subtidal environments.Its biological features have been the object of numerous studies worldwide.The worm reefs are formed by millions of tubes built by sand and shells(whole or in fragments)bonded together with a strong glue produced by the worm itself.Hence,Sabellaria alveolata represents a sedimentological asset for the coastal protection,since it contributes to create natural barriers against storm waves and erosion,and supplies the beach with new sandy deposits.This work shows a multidisciplinary approach to studying a bioconstruction of Sabellaria alveolata along the Latium coast(Ostia,Tyrrhenian Sea,central Italy),proposing image analysis as a novel technique to investigate worm reefs,along with classical sedimentological/ecological tools.The Sabellaria bioconstructions have been analysed at different scales of observation,suggesting the more appropriate strategies to develop a reliable model illustrating the different growth steps of these bioconstructions.展开更多
基金The University Grants Commission (UGC, New Delhi) is acknowledged for providing UGC-BSR Grant (F.20-1/2012(BSR) 20-8(12)2012(BSR) to BPS for research work
文摘A new locality bearing ichnofossils of the Cruziana Assemblage Zone-Ⅲ from the Mussoorie syncline,Lesser Himalaya,is located in rocks of Member-B of the Dhaulagiri Formation,Tal Group,exposed along the Maldewta-Chhimoli fresh road cut section.The site yielded ichnofossils Bergaueria perata,Cochlichnus anguineus,？Diplocraterion isp.,Dimorphichnus obliquus,diplichnitiform Cruziana bonariensis,Diplichnites gouldi,Glockeria isp.,Helminthopsis isp.,Monomorphichnus lineatus,Phycodes palmatum,Palaeophycus striatus,Planolites beverleyensis,Planolites montanus,Treptichnus cf.T.pedum,scratch marks and an undetermined worm impression.An Early Cambrian age （Cambrian Series 2） is assigned to the ichnofossil-bearing strata based on the stratigraphic position between the Drepanuroides and Palaeoolenus trilobite zones.A revised Cambrian ichnofossil zonation is presented for the Tal Group of the Mussoorie syncline.Together with their occurrence on rippled surfaces,and the lateral displacement of some trackways （due to current action）,a sub-aqueous shallow-marine depositional setting is proposed for the rocks of Member-B.
文摘Sabellaria alveolata(Linnaeus 1767)is a polychaete able to build bioconstructions of different thickness,size and patchiness,in intertidal and subtidal environments.Its biological features have been the object of numerous studies worldwide.The worm reefs are formed by millions of tubes built by sand and shells(whole or in fragments)bonded together with a strong glue produced by the worm itself.Hence,Sabellaria alveolata represents a sedimentological asset for the coastal protection,since it contributes to create natural barriers against storm waves and erosion,and supplies the beach with new sandy deposits.This work shows a multidisciplinary approach to studying a bioconstruction of Sabellaria alveolata along the Latium coast(Ostia,Tyrrhenian Sea,central Italy),proposing image analysis as a novel technique to investigate worm reefs,along with classical sedimentological/ecological tools.The Sabellaria bioconstructions have been analysed at different scales of observation,suggesting the more appropriate strategies to develop a reliable model illustrating the different growth steps of these bioconstructions.
