Newsletters on Stratigraphy最新文献

{"title":"Tephrochronology and chronostratigraphy of the Miocene Chilcatay and Pisco formations (East Pisco Basin, Peru)","authors":"G. Bosio, E. Malinverno, I. Villa, C. D. Celma, K. Gariboldi, A. Gioncada, V. Barberini, M. Urbina, G. Bianucci","doi":"10.1127/NOS/2019/0525","DOIUrl":"https://doi.org/10.1127/NOS/2019/0525","url":null,"abstract":"Strata of Chilcatay and Pisco formations exposed in the Ica Desert (East Pisco Basin, southern Peru) preserve one of the most complete and rich records of Miocene marine vertebrates of the world. Despite its exceptional importance, the chronostratigraphy of these fossil-bearing deposits has been only sporadically studied in the literature until recently. This work presents a detailed reconstruction of the chronostratigraphic framework, achieved by mapping and measuring of seven sections (totaling a height of almost 1000 m) of the Miocene Chilcatay and Pisco formations along the western side of the Ica River. The Chilcatay Formation consists of two allomembers, namely Ct1 and Ct2, bounded at the base by unconformities CE0.1 and CE0.2, respectively. Similarly, the immediately overlying Pisco Formation is divided into allomembers P0, P1, and P2, bounded at the base by unconformities PE0.0, PE0.1 and PE0.2, respectively. The new 39Ar–40Ar results presented here, combined with ages of previous work, provide precise constraints on the age of several stratigraphically referenced volcanic ash layers intercalated in the studied fossil-bearing succession, placing its vertebrate fossil fauna within a refined temporal framework and laying the solid ground for its detailed regional and global comparison. The ages of the allomembers, and thus their associated faunas, can be reliably estimated by the combination of 39Ar–40Ar dating on tephra layers with diatom biostratigraphy. In the study area, two methods are mutually consistent and constrain the deposition of the Chilcatay Formation between 19.2 and 18.0 Ma, that of P1 between 9.5 and 8.6 Ma, and that of P2 between 8.4 and 6.7 Ma. In the absence of direct dating of the P0 allomember, which lacks both preserved tephra suitable for 39Ar–40Ar dating and microfossils, its age can be constrained to the temporal gap between the youngest age available from the underlying Chilcatay strata (18.0 Ma) and the oldest age available from the overlying P1 strata (9.5 Ma).","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":"53 1","pages":"213-247"},"PeriodicalIF":2.2,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/NOS/2019/0525","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63663337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The onset of Oceanic Anoxic Event 2 on the Arabian Shelf – mechanisms between organic matter deposition, sea-level, and palaeoceanography (Shilaif Basin, United Arab Emirates)","authors":"Dominik Hennhoefer, A. A. Suwaidi, T. Steuber","doi":"10.1127/NOS/2019/0504","DOIUrl":"https://doi.org/10.1127/NOS/2019/0504","url":null,"abstract":"","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":"53 1","pages":"121-139"},"PeriodicalIF":2.2,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/NOS/2019/0504","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42993341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palynological, geochemical, and mineralogical characteristics of the Early Jurassic Liasidium Event in the Cleveland Basin, Yorkshire, UK","authors":"S. Hesselbo, Alexander J.L. Hudson, J. Huggett, M. Leng, J. Riding, C. Ullmann","doi":"10.1127/NOS/2019/0536","DOIUrl":"https://doi.org/10.1127/NOS/2019/0536","url":null,"abstract":"! \" # $ \" # % & # '() * + , ) + & # + & , ) # & & + ) . / # 0 # # ) $ & 0 # ) . ! \" # + # 1 + # # + )","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/NOS/2019/0536","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41779820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleogene carbonate systems of Saint Barthélemy, Lesser Antilles: stratigraphy and general organization","authors":"J. Cornée, M. BouDagher-Fadel, M. Philippon, J. Léticée, L. Legendre, G. Maincent, J. Lebrun, P. Münch","doi":"10.1127/nos/2020/0587","DOIUrl":"https://doi.org/10.1127/nos/2020/0587","url":null,"abstract":"Saint Barthelemy is the only island of the northern Lesser Antilles where it is possible to investigate in the detail the chronostratigraphy of the mixed carbonate-volcaniclastic deposits of the Paleogene Caribbean volcanic arc. Based on field mapping and new biostratigraphical and sedimentological data, we study the limestone units interbedded in the Paleogene volcaniclastic deposits. We find that four main carbonate units occur instead of previously believed six ones. Based on the ages given by the foraminifera assemblages, and taking into account the recently published 40Ar/39Ar ages of magmatic rocks, the Lower Limestone unit dates Lutetian, the Intermediate Limestone unit late (?) Bartonian-late Priabonian, the Upper Limestone late Priabonian and the Top Limestone unit early Miocene. The Paleogene carbonate beds were deposited on gently dipping submarine volcaniclastic deposits issued from emergent volcanoes, in muddy, unrimmed inner to mid-ramp setting dominated by bottom communities. A major subaerial unconformity is evidenced during the Oligocene, most probably corresponding to uplift affecting Saint Barthelemy. Our work offers a revised lithostratigraphic succession of Saint Barthelemy as a first key-point for further studies of the Paleogene Caribbean arc deposits which were dismembered following the entrance of the Bahamas Bank in the Lesser Antilles subduction zone.","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2020-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45132504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Should Unit-Stratotypes and Astrochronozones be formally defined? A dual proposal (including postscriptum)","authors":"F. Hilgen, L. Lourens, H. Pälike","doi":"10.1127/nos/2019/0514","DOIUrl":"https://doi.org/10.1127/nos/2019/0514","url":null,"abstract":"","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":"1 1","pages":"19-39"},"PeriodicalIF":2.2,"publicationDate":"2020-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44105953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon-isotope events during the Pliensbachian (Lower Jurassic) on the African and European margins of the NW Tethyan Realm","authors":"Mathilde Mercuzot, P. Pellenard, C. Durlet, C. Bougeault, C. Meister, J. Dommergues, N. Thibault, F. Baudin, O. Mathieu, Ludovic Bruneau, E. Huret, K. Hmidi","doi":"10.1127/nos/2019/0502","DOIUrl":"https://doi.org/10.1127/nos/2019/0502","url":null,"abstract":"Early Jurassic palaeoenvironments and palaeoclimates, based on chemostratigraphy, have been extensively studied for the northern Tethyan margin. For the first time, high-resolution chemostratigraphy for the entire Pliensbachian is proposed for the African Tethyan margin (Morocco), and compared with new sections from the European Tethyan margin (France). Precise ammonite determinations, completed by calcareous nannofossil distribution, provide an accurate biostratigraphic framework from the Upper Sinemurian to the Upper Pliensbachian. Bulk inorganic carbon (δ13Ccarb) and organic carbon (δ13Corg) isotope signals are used to characterise and compare carbon-cycle trends in the Central High Atlas Basin (Amellago-Ikis section, Morocco), the Paris Basin (Montcornet borehole, France), and the Subalpine Basin (Serre-Poncon section, France). Comparison of this new dataset with previously published geochemical data from European basins confirms the existence of five distinct carbon-isotope events, synchronous at the scale of the NW Tethyan Realm: (1) a clear –2‰ negative excursion of δ13Ccarb and δ13Corg, corresponding to the Sinemurian–Pliensbachian Boundary Event (SPBE), probably associated with a massive release of light carbon by volcanism and hydrothermalism during the breakup of Pangea; (2) a positive excursion (+1 to +1.5‰) in the Valdani and Luridum subzones (Ibex Zone), reflecting increased organic matter storage under warm climate conditions; (3) a broadly negative event from the Davoei Zone to the lower part of the Margaritatus Zone, associated with major oceanographic reorganisation in a transgressive context, and possible enhanced hydrothermalism related to the opening of the Hispanic corridor; (4) a positive carbon excursion (+2‰) during the Subnodosus and Gibbosus subzones (Margaritatus Zone), corresponding to the Late Pliensbachian Event (LPE), associated with organic matter storage; (5) an end-Margaritatus–Spinatum negative excursion, associated with sea-level fall, probably driven by glacio-eustasy. This new high-resolution carbon-isotope dataset highlights the synchroneity of carbon-cycle trends throughout the NW Tethyan Realm. Several major isotopic events, prior to those of the Toarcian, must therefore have occurred at a supra-regional to global scale during the Pliensbachian, involving significant internal and external geodynamic mechanisms.","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":"53 1","pages":"41-69"},"PeriodicalIF":2.2,"publicationDate":"2020-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46607166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leonardo da Vinci (1452–1519) and the birth of stratigraphy","authors":"A. Ferretti, Francesco Vezzani, M. Balini","doi":"10.1127/nos/2019/0564","DOIUrl":"https://doi.org/10.1127/nos/2019/0564","url":null,"abstract":"","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41822419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new high northern latitude dinocyst-based magneto-biostratigraphic calibration for the Norwegian-Greenland Sea","authors":"J. Eldrett, I. Harding, R. Wilshaw, C. Xuan","doi":"10.1127/NOS/2019/0496","DOIUrl":"https://doi.org/10.1127/NOS/2019/0496","url":null,"abstract":"","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":"8 4","pages":""},"PeriodicalIF":2.2,"publicationDate":"2019-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41307546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of total organic carbon-δ13C signatures in the Triassic–Jurassic transitional beds of the Central European Basin and western Tethys shelf seas","authors":"Martin Schobben, Julia Gravendyck, Franziska Mangels, U. Struck, R. Bussert, Wolfram M Kürschner, D. Korn, P. Sander, M. Aberhan","doi":"10.1127/NOS/2019/0499","DOIUrl":"https://doi.org/10.1127/NOS/2019/0499","url":null,"abstract":"Stratigraphic studies are an integral component in understanding the chronology of events that led to the end-Triassic mass extinction, by resolving causal relationships between environmental upheavals and biotic response. Successful correlation of Triassic–Jurassic (Tr–J) successions is complicated by the disappearance of macro-fossils that are otherwise central components in stratigraphic studies. This problem is exacerbated in multiple Tr–J sections situated in Europe, where the so-called “Event Beds” – assumed to demarcate the extinction interval – are virtually devoid of fossils. An alternative stratigraphic approach entails the reconstruction of carbon isotope records, where stratigraphic fluctuations in carbon isotope composition are considered to track changes in the global biogeochemical carbon cycle. The predominance of carbonate-lean sections has prompted the reconstruction of total organic carbon (TOC)-based carbon isotope records. However, bulk rock derived TOC is the diagenetically stabilized remnant of organic components that accumulated on the sea floor, and which can originate from multiple sources. In this study, we assess long-term TOC-based carbon isotope trends at two sites: Bonenburg (Central European Basin) and Kuhjoch (the Tr–J Global Stratotype Section and Point; western Tethys shelf seas). We focus on the TOC 13C-enrichment of the Event Beds with the aim of deciphering stratigraphic fluctuations in relation to their main driver (the exogenic carbon pool versus organic matter source changes). By studying the systematic co-variance of several sedimentary parameters (TOC, total nitrogen [TN], and the palynomorph composition), we infer that the TOC composition is possibly characterized by insignificant organic matter source changes in terms of the marine and terrestrial organic carbon contributions. By contrast, a clay mineralogical shift to more K-depleted minerals as well as the elevated occurrence of wood fragments in the Event Beds suggest a terrestrial organic matter source shift from immature substrates to substrates predominated by “pre-aged” or “fossil organic matter” under a changing continental weathering regime. This outcome urges for reservations when interpreting TOC-based carbon isotope records in terms of global C-cycle perturbations, especially when coinciding with lithological and mineralogical changes. On a more positive note, the shift towards positive carbon isotope values appears to be a recurring feature, possibly testifying to a globally significant climate-controlled weathering regime shift.","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2019-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1127/NOS/2019/0499","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41449981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Cretaceous tectonic inversion processes deciphered by micropalaeontology – a case study from northern Germany","authors":"L. Wulff, J. Mutterlose","doi":"10.1127/NOS/2019/0479","DOIUrl":"https://doi.org/10.1127/NOS/2019/0479","url":null,"abstract":"","PeriodicalId":49750,"journal":{"name":"Newsletters on Stratigraphy","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2019-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41667521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}