Journal articles: 'Biostratigraphic constraint'

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Wang, Yaquiong, Jingeng Sha, Yanhong Pan, and Xiaolin Zhang. "Early Cretaceous nonmarine ostracod biostratigraphy of western Liaoning area, NE China." Micropaleontology 61, no. 1-2 (2015): 135–45. http://dx.doi.org/10.47894/mpal.61.1.10.

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The Early Cretaceous ostracod fauna in western Liaoning is divided into eight successive ostracod assemblages. These assemblages have provided information about age constraint of relevant nonmarine Early Cretaceous strata: Yixian Formation – Hauterivian to Barremian, probably up to Aptian; Jiufotang Formation – Barremian to Aptian; Fuxin Formation – Aptian; Sunjiawan Formation – Albian. According to the revised age for the upper part of the Yixian Formation in the Kazuo – Chaoyang Basin, which is Hauterivian – Barremian, Ziziphocypris linchengensis is the earliest record of the genus Ziziphocypris. This work demonstrates that the supra-regionally distributed ostracod species, including species of Cypridea, are useful for biostratigraphic correlation and age determination of lacustrine deposits. In contrast, the endemic Cypridea species are helpful for regional biostratigraphic correlation of scattered basins within western Liaoning.

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Over, D. Jeffrey. "Conodont biostratigraphy of the Chattanooga Shale, Middle and Upper Devonian, southern Appalachian basin, eastern United States." Journal of Paleontology 81, no. 6 (November 2007): 1194–217. http://dx.doi.org/10.1666/06-056r.1.

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The Chattanooga Shale of the southern Appalachian Basin contains a diverse conodont fauna of the high Givetian, Frasnian, and Famennian. The predominantly fine-grained strata were deposited in an offshore setting where depositional packages are separated by unconformities. Conodonts allow regional and global correlation of these strata, recognition of the Frasnian-Famennian boundary, and narrow biostratigraphic constraint of two Frasnian ash beds, MN Zone 8 for the Belpre Ash and upper MN Zone 13 for the Center Hill Ash. Three new Frasnian palmatolepid conodonts are described in open nomenclature, and the holotype ofPalmatolepis regularisCooper is reillustrated.

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Ritter, Scott M. "Improved conodont biostratigraphic constraint of the Carboniferous/Permian boundary in south-central New Mexico, USA." Stratigraphy 17, no. 1 (2020): 39–56. http://dx.doi.org/10.29041/strat.17.1.39-56.

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Fang, Peiyue, Bo Xu, Brian T. Huber, Shijia Liu, Youhua Zhu, and Hui Luo. "Late Campanian to early Maastrichtian planktonic foraminiferal assemblages from Cretaceous oceanic red beds (CORBs) in the Yongla section, Gyangze, southern Tibet." Micropaleontology 66, no. 2 (2020): 85–102. http://dx.doi.org/10.47894/mpal.66.2.01.

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Well-preserved and abundant planktonic foraminifera have been recovered from limestones of the Cretaceous oceanic red beds (CORBs) from the Yongla section in Gyangze, southern Tibet. This foraminiferal assemblage is dominated by species of Contusotruncana, Globotruncana, and Globotruncanita. The assemblage contains 21 species belonging to 7 genera and suggests a late Campanian to early Maastrichtian age, which permits amore precise age constraint for CORBs in the Gyangze area. This planktonic assemblage provides an important biostratigraphic datum for the correlations of theCORBs in theHimalayan region of the northern Tethys. The interval yielding foraminifers in the Yongla section may be the youngest known CORB in the Gyangze area.

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Wang, Yuan, Jianghai Yang, Dong-Xun Yuan, Jia Liu, and Rui Ma. "Conodont Biostratigraphic Constraint on the Lower Taiyuan Formation in Southern North China and Its Paleogeographic Implications." Journal of Earth Science 33, no. 6 (December 2022): 1480–93. http://dx.doi.org/10.1007/s12583-021-1526-8.

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Schofield, David I., John W. F. Waldron, Chris E. White, and Sandra M. Barr. "Discussion of the reply by R.L. Romer and U. Kroner on “Geochemical signature of Ordovician Mn-rich sedimentary rocks on the Avalonian shelf” 1Appears in Canadian Journal of Earth Sciences, 49(6): 775–780, 10.1139/e2012-006." Canadian Journal of Earth Sciences 49, no. 11 (November 2012): 1372–77. http://dx.doi.org/10.1139/e2012-049.

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In their article ‘Reply to the discussion by J.W.F. Waldron and C.E. White on “Geochemical signature of Ordovician Mn-rich sedimentary rocks on the Avalonian shelf”’, R.L. Romer and U. Kroner reinterpret geochronological data presented by J.W.F. Waldron, D.I. Schofield, C.E. White, and S.M. Barr to imply an Ordovician, not a Cambrian, depositional age for the succession of the Harlech Dome, North Wales, and Meguma Supergroup, Nova Scotia. However, an extensive history of biostratigraphic and geological survey data refutes this interpretation and shows that the rocks are unequivocally Cambrian. Waldron et al. used the U–Pb zircon laser-ablation – multicollector – inductively coupled plasma – mass spectrometry technique primarily to provide information on sediment provenance and not depositional age. Investigation of anomalously young 206Pb/238U ages showed evidence of Pb loss. These data provide little constraint on depositional age and cannot be used to infer that the Harlech Grits Group is Ordovician.

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Jaff, Rawand B. N., Mark Williams, Ian P. Wilkinson, Fadhil Lawa, Sarah Lee, and Jan Zalasiewicz. "A refined foraminiferal biostratigraphy for the Late Campanian–Early Maastrichtian succession of northeast Iraq." GeoArabia 19, no. 1 (January 1, 2014): 161–80. http://dx.doi.org/10.2113/geoarabia1901161.

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ABSTRACT Species of the benthonic foraminiferal genus Bolivinoides provide a refined biostratigraphic biozonation for the Late Campanian to Early Maastrichtian (Late Cretaceous) Shiranish Formation in NE Iraq. Three biozones and two subzones are identified: the Bolivinoides decoratus Biozone (Late Campanian) subdivided into a lower B. decoratus Subzone and upper B. laevigatus Subzone; the B. miliaris Biozone (Earliest Maastrichtian); and the B. draco Biozone (late Early Maastrichtian). These zones can be related to the biostratigraphical interval of the Globotruncana aegyptiaca (Late Campanian), Gansserina gansseri (latest Campanian–Early Maastrichtian) and Contusotruncana contusa (late Early Maastrichtian) planktonic foraminiferal biozones. Combined, the benthonic and planktonic foraminiferal biostratigraphy enables the informal recognition of lower and upper intervals within both the Globotruncana aegyptiaca and Gansserina gansseri biozones that may be important for more refined inter-regional correlation in the Middle East and North Africa. The new Bolivinoides biozonation precisely locates the Campanian–Maastrichtian boundary in NE Iraq. The foraminiferal assemblages also constrain the timing of a shallowing marine trend in the Shiranish Formation beginning from the latest Campanian that is consistent with shallowing facies noted globally at this time.

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Zhong, Yuting, Roland Mundil, Jun Chen, Dongxun Yuan, Steven W. Denyszyn, Adam B. Jost, Jonathan L. Payne, Bin He, Shuzhong Shen, and Yigang Xu. "Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province." GSA Bulletin 132, no. 9-10 (February 3, 2020): 1969–86. http://dx.doi.org/10.1130/b35464.1.

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Abstract The initiation and peak magmatic periods of the Emeishan Large Igneous Province (LIP) are well constrained by both biostratigraphic and radioisotopic dating methods; however, the age of cessation of volcanism is poorly constrained and continues to be debated. Marine carbonates interbedded with volcanic ashes across the Guadalupian–Lopingian boundary (GLB) are widespread in south China, and these ashes provide an opportunity to study its timing, origin, and potential relationship with the Emeishan LIP. Here we present biostratigraphic constraints, mineralogical and geochemical characteristics, and high-resolution geochronology of ash layers from the Maoershan and Chaotian sections. Stratigraphic correlation, especially conodont biostratigraphy, confines these ashes to the early Wuchiapingian. Those altered ashes are geochemically akin to alkali tonsteins from the coal seams of the lower Xuanwei/Lungtan Formation in southwest China. The ashes postdating the GLB yield a coherent cluster of zircon U-Pb ages with weighted mean 206Pb/238U ages of 258.82 ± 0.61 Ma to 257.39 ± 0.68 Ma, in agreement with the ages of intrusive rocks (259.6 ± 0.5 Ma to 257.6 ± 0.5 Ma) in the central Emeishan LIP. Moreover, the ɛHf(t) values of zircons from the ashes vary from +2.5 to +10.6, a range consistent with that of the Emeishan LIP. The results collectively suggest that the early Wuchiapingian volcanic ashes are a product of extrusive alkaline magmatism and most likely mark the waning stage of the Emeishan volcanism, which may have continued until ca. 257.4 Ma in the early Wuchiapingian.

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Crippa, Gaia, Michele Azzarone, Cinzia Bottini, Stefania Crespi, Fabrizio Felletti, Mattia Marini, Maria Rose Petrizzo, Daniele Scarponi, Sergio Raffi, and Gianluca Raineri. "Bio- and lithostratigraphy of lower Pleistocene marine successions in western Emilia (Italy) and their implications for the first occurrence of Arctica islandica in the Mediterranean Sea." Quaternary Research 92, no. 2 (May 14, 2019): 549–69. http://dx.doi.org/10.1017/qua.2019.20.

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AbstractThe Arda and Stirone marine successions (Italy) represent key sections for the early Pleistocene; they were deposited continuously within a frame of climate change, recording the Calabrian cooling as testified by the occurrence of the “northern guests,” such as the bivalve Arctica islandica. In addition, although the first occurrence of A. islandica in the Mediterranean Sea was used as the main criterion to mark the former Pliocene-Pleistocene boundary, the age of this bioevent was never well constrained. Here, we describe the Stirone depositional environment and constrain for the first time the section age using calcareous nannofossil and foraminifera biostratigraphy. We also correlate the Arda and Stirone sections using complementary biostratigraphic and magnetostratigraphic data. Our results indicate that A. islandica first occurred in both the successions slightly below the top of the CNPL7 biozone (dated at 1.71 Ma). Comparisons with other lower Pleistocene Mediterranean marine successions indicate that the stratigraphically lowest level where A. islandica first occurred in the Mediterranean Sea is in the Arda and Stirone sections; these environments satisfied the ecological requirements for the establishment and the proliferation of the species, which only subsequently (late Calabrian) has been retrieved in southern Italy and other areas of the Mediterranean Sea.

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De Lira Mota, Marcelo Augusto, Guy Harrington, and Tom Dunkley Jones. "Organic-walled dinoflagellate cyst biostratigraphy of the upper Eocene to lower Oligocene Yazoo Formation, US Gulf Coast." Journal of Micropalaeontology 39, no. 1 (January 3, 2020): 1–26. http://dx.doi.org/10.5194/jm-39-1-2020.

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Abstract. New data from a continuously cored succession, the Mossy Grove core, near Jackson, central Mississippi, recovered ∼137 m of marine clays (Yazoo Formation), spanning ∼5 Ma and including the critical Eocene–Oligocene transition (EOT) event. These clay-rich sediments yield well-preserved calcareous microfossil and palynomorph assemblages. Here, we present a new organic-walled dinoflagellate cyst (dinocyst) biostratigraphic framework, including the recognition of 23 dinocyst bioevents. These are integrated with new age constraints based on calcareous nannofossil biostratigraphy and a reassessment of the existing radiometric dates and planktonic foraminiferal biostratigraphy, permitting the establishment of a robust and significantly refined age model for the core. According to this new age model, a major increase in sedimentation rate – from ∼2.1 to ∼4.7 cm kyr−1 – is observed at a core depth of ∼89.1 m (∼34.4 Ma). In the new age model the section is significantly older than previously thought, by up to 1 Ma, with the Eocene-Oligocene boundary (∼33.89 Ma) placed ∼34 m below the level previously identified. With these more accurate age estimates, future isotopic and palaeoecological work on this core can be more precisely integrated with other, globally distributed records of the EOT.

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Pyle, Leanne J., and Christopher R. Barnes. "Lower Paleozoic stratigraphic and biostratigraphic correlations in the Canadian Cordillera: implications for the tectonic evolution of the Laurentian margin." Canadian Journal of Earth Sciences 40, no. 12 (December 1, 2003): 1739–53. http://dx.doi.org/10.1139/e03-049.

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The ancient Laurentian margin rifted in the latest Neoproterozoic to early Cambrian but appears not to have developed as a simple passive margin through a long, post-rift, drift phase. Stratigraphic and conodont biostratigraphic information from four platform-to-basin transects across the margin has advanced our knowledge of the early Paleozoic evolution of the margin. In northeastern British Columbia, two northern transects span the Macdonald Platform to Kechika Trough and Ospika Embayment, and a third transect spans the parautochthonous Cassiar Terrane. In the southern Rocky Mountains, new conodont biostratigraphic data for the Ordovician succession of the Bow Platform is correlated to coeval basinal facies of the White River Trough. In total, from 26 stratigraphic sections, over 25 km of strata were measured and > 1200 conodont samples were collected that yielded over 100 000 conodont elements. Key zonal species were used for regional correlation of uppermost Cambrian to Middle Devonian strata along the Cordillera. The biostratigraphy temporally constrains at least two periods of renewed extension along the margin, in the latest Cambrian and late Early Ordovician. Alkalic volcanics associated with abrupt facies changes across the ancient shelf break, intervals of slope debris breccia deposits, and distal turbidite flows suggest the margin was characterized by intervals of volcanism, basin foundering, and platform flooding. Siliciclastics in the succession were sourced by a reactivation of tectonic highs, such as the Peace River Arch. Prominent hiatuses punctuate the succession, including unconformities of early Late Ordovician, sub-Llandovery, possibly Early to Middle Silurian and Early Devonian ages.

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Corral, Isaac, David Gómez-Gras, Albert Griera, Mercè Corbella, and Esteve Cardellach. "Sedimentation and volcanism in the Panamanian Cretaceous intra-oceanic arc and fore-arc: New insights from the Azuero peninsula (SW Panama)." Bulletin de la Société Géologique de France 184, no. 1-2 (January 1, 2013): 35–45. http://dx.doi.org/10.2113/gssgfbull.184.1-2.35.

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Abstract The Azuero Peninsula, located in SW Panama, is a region characterized by a long-lived intra-oceanic subduction zone. Volcanism began in Late Cretaceous time, as the result of subduction of the Farallon plate beneath the Caribbean plate. Usually, ancient volcanic arcs related to intra-oceanic subduction zones are not preserved, because they are in areas with difficult access or covered by modern volcanic arc material. However, on the Azuero peninsula, a complete section of the volcanic arc together with arc basement rocks provides the opportunity to study the sedimentation and volcanism in the initial stages of volcanic arc development. The lithostratigraphic unit which records fore-arc evolution is the “Río Quema” Formation (RQF), a volcanic apron composed of volcanic and volcaniclastic sedimentary rocks interbedded with hemipelagic limestones, submarine dacite lava domes, and intruded by basaltic-andesitic dikes. The “Río Quema” Formation, interpreted as a fore-arc basin infilling sequence, lies discordantly on top of arc basement rocks. The exceptionally well exposed arc basement, fore-arc basin, volcanic arc rocks and arc-related intrusive rocks provide an unusual opportunity to study the relationship between volcanism, sedimentation and magmatism during the arc development, with the objective to reconstruct its evolution. The “Río Quema” Formation can be divided into three groups: 1) proximal apron, a sequence dominated by lava flows, interbedded with breccias, mass flows and channel fill, all intruded by basaltic dikes. The rocks represent the nearest materials to the volcanic source, reflecting a coarse sediment supply. This depositional environment is similar to gravel-rich fan deltas and submarine ramps; 2) medial apron, characterized by a volcanosedimentary succession dominated by andesitic lava flows, polymictic volcanic conglomerates and crystal-rich sandstones with minor pelagic sediments and turbidites. These rocks were deposited from high-density turbidity currents and debris flows, directly derived from erupted material and gravitational collapse of an unstable volcanic edifice or volcaniclastic apron; 3) distal apron, a thick succession of sandy to muddy volcaniclastic rocks, interbedded with pelagic limestones and minor andesitic lavas, intruded by dacite domes and by basaltic to andesitic dikes. Bedforms and fossils suggest a quiet, relatively deep-water environment characterized by settling of clay and silt (claystone, siltstone) and by dilute turbidity currents of reworked volcaniclastic detritus. The timing of the initial stages of the volcanic arc has been constrained through a biostratigraphic study, using planktonic foraminifera and radiolarian species. The fossil assemblage indicates that the age of the “Río Quema” Formation ranges from Late Campanian to Maastrichtian, providing a good constraint for the development of the volcanic arc and volcaniclastic apron, during the initial stages of an intra-oceanic subduction zone.

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Krizmanić, Krešimir, Krisztina Sebe, and Imre Magyar. "Dinoflagellate cysts from the Pannonian (late Miocene) "white marls" in Pécs-Danitzpuszta, southern Hungary." Földtani Közlöny 151, no. 3 (December 4, 2021): 267–74. http://dx.doi.org/10.23928/foldt.kozl.2021.151.3.267.

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Dinoflagellate-cyst based biostratigraphy is an important tool in the stratigraphical subdivision and correlation of the Neogene Lake Pannon deposits. A total of 66 palynological samples were investigated from the Pannonian (upper Miocene) marl succession exposed in the Pécs-Danitzpuszta sand pit in order to evaluate the biostratigraphical assignment and constrain the age of the strata. Earlier attempts to recover dinoflagellate cysts from this important reference section had failed. In our material, six samples contained well-preserved palynomorphs. One sample from the lower part of the succession (D25) contained a probably reworked middle Miocene assemblage. Samples from the middle segment of the succession (D3, D2, D1) indicate the Pontiadinium pecsvaradensis Zone (ca. 10.8 to 10.6 Ma). Samples from the top of the marl (D219, D221) did not give additional stratigraphic information (P. pecsvaradensis Zone or younger). The palynofacies of samples D3 to D221 indicates a relatively distal, calm, occasionally oxygen-deficient, probably deep depositional environment.

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Whitelaw, Michael John. "Age Constraints on the Duck Ponds and Limeburner's Point Mammalian Faunas Based on Magnetic Polarity Stratigraphy in the Geelong Area (Victoria), Australia." Quaternary Research 39, no. 1 (January 1993): 120–24. http://dx.doi.org/10.1006/qres.1993.1014.

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AbstractNew magnetostratigraphic results may be used to determine the age of two locally important fossil vertebrate faunas near Geelong (Victoria), Australia. Paleomagnetic samples collected from sections located at Limeburner's Point and Limeburner's Bay, together with previously suggested stratigraphic correlations, now constrain the age of the Duck Ponds Local Fauna to be younger than 1.66 myr (and probably greater than 0.98 myr) and the age of the Limeburner's Point Local Fauna to be younger than 0.98 myr. These age determinations enhance the biostratigraphic importance of both local faunas on a continent characterized by a chronic lack of chronologically well-constrained fossil vertebrate localities.

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Parker, William G., and Jeffrey W. Martz. "The Late Triassic (Norian) Adamanian–Revueltian tetrapod faunal transition in the Chinle Formation of Petrified Forest National Park, Arizona." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 101, no. 3-4 (September 2010): 231–60. http://dx.doi.org/10.1017/s1755691011020020.

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ABSTRACTRecent stratigraphic revisions of the Upper Triassic Chinle Formation of Petrified Forest National Park, in conjunction with precise and accurate documentation of fossil tetrapod occurrences, clarified the local biostratigraphy, with regional and global implications. A significant overlap between Adamanian and Revueltian faunas is rejected, as is the validity of the Lamyan sub-land vertebrate faunachron. The Adamanian–Revueltian boundary can be precisely placed within the lower Jim Camp Wash beds of the Sonsela Member and thus does not occur at the hypothesised Tr-4 unconformity. This mid-Norian faunal turnover, may coincide with a floral turnover, based on palynology studies and also on sedimentological evidence of increasing aridity. Available age constraints bracketing the turnover horizon are consistent with the age of the Manicouagan impact event. The rise of dinosaurs in western North America did not correspond to the Adamanian–Revueltian transition, and overall dinosauromorph diversity seems to have remained at a constant level across it. The paucity of detailed Late Triassic vertebrate biostratigraphic data and radioisotopic dates makes it currently impossible to either support or reject the existence of globally synchronous Late Triassic extinctions for tetrapods.

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Grotzinger, J. P., S. A. Bowring, B. Z. Saylor, and A. J. Kaufman. "Biostratigraphic and Geochronologic Constraints on Early Animal Evolution." Science 270, no. 5236 (October 27, 1995): 598–604. http://dx.doi.org/10.1126/science.270.5236.598.

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Day, Michael O., Jahandar Ramezani, Samuel A. Bowring, Peter M. Sadler, Douglas H. Erwin, Fernando Abdala, and Bruce S. Rubidge. "When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa." Proceedings of the Royal Society B: Biological Sciences 282, no. 1811 (July 22, 2015): 20150834. http://dx.doi.org/10.1098/rspb.2015.0834.

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A mid-Permian (Guadalupian epoch) extinction event at approximately 260 Ma has been mooted for two decades. This is based primarily on invertebrate biostratigraphy of Guadalupian–Lopingian marine carbonate platforms in southern China, which are temporally constrained by correlation to the associated Emeishan Large Igneous Province (LIP). Despite attempts to identify a similar biodiversity crisis in the terrestrial realm, the low resolution of mid-Permian tetrapod biostratigraphy and a lack of robust geochronological constraints have until now hampered both the correlation and quantification of terrestrial extinctions. Here we present an extensive compilation of tetrapod-stratigraphic data analysed by the constrained optimization (CONOP) algorithm that reveals a significant extinction event among tetrapods within the lower Beaufort Group of the Karoo Basin, South Africa, in the latest Capitanian. Our fossil dataset reveals a 74–80% loss of generic richness between the upper Tapinocephalus Assemblage Zone (AZ) and the mid- Pristerognathus AZ that is temporally constrained by a U–Pb zircon date (CA-TIMS method) of 260.259 ± 0.081 Ma from a tuff near the top of the Tapinocephalus AZ. This strengthens the biochronology of the Permian Beaufort Group and supports the existence of a mid-Permian mass extinction event on land near the end of the Guadalupian. Our results permit a temporal association between the extinction of dinocephalian therapsids and the LIP volcanism at Emeishan, as well as the marine end-Guadalupian extinctions.

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MCCAY, GILLIAN A., ALASTAIR H. F. ROBERTSON, DICK KROON, ISABELLA RAFFI, ROBERT M. ELLAM, and MEHMET NECDET. "Stratigraphy of Cretaceous to Lower Pliocene sediments in the northern part of Cyprus based on comparative 87Sr/86Sr isotopic, nannofossil and planktonic foraminiferal dating." Geological Magazine 150, no. 2 (October 29, 2012): 333–59. http://dx.doi.org/10.1017/s0016756812000465.

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AbstractNew age data from Sr isotope analysis and both planktonic foraminifera and nannofossils are presented and discussed here for the Upper Eocene–Upper Miocene sedimentary rocks of the Değirmenlik (Kythrea) Group. New dating is also given of some Cretaceous and Pliocene sediments. In a revised stratigraphy the Değirmenlik (Kythrea) Group is divided into ten formations. Different Upper Miocene formations are developed to the north and south of a regionally important, E–W-trending syn-sedimentary fault. The samples were dated wherever possible by three independent methods, namely utilizing Sr isotopes, calcareous nannofossils and planktonic foraminifera. Some of the Sr isotopic dates are incompatible with the nannofossil and/or the planktonic foraminiferal dates. This is mainly due to reworking within gravity-deposited or current-affected sediments. When combined, the reliable age data allow an overall biostratigraphy and chronology to be erected. Several of the boundaries of previously defined formations are revised. Sr data that are incompatible with well-constrained biostratigraphical ages are commonly of Early Miocene age. This is attributed to a regional uplift event located to the east of Cyprus, specifically the collision of the Anatolian (Eurasian) and Arabian (African) plates during Early Miocene time. This study, therefore, demonstrates that analytically sound Sr isotopic ages can yield geologically misleading ages, particularly where extensive sediment reworking has occurred. Convincing ages are obtained when isotopic dating is combined with as many forms of biostratigraphical dating as possible, and this may also reveal previously unsuspected geological events (e.g. tectonic uplift or current activity).

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Fåhræus, Lars E. "Spectres of biostratigraphic resolution and precision: Rock accumulation rates, processes of speciation and paleoecological constraints." Newsletters on Stratigraphy 15, no. 3 (February 3, 1986): 150–62. http://dx.doi.org/10.1127/nos/15/1986/150.

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Wang, Xin, Xingliang Zhang, and Wei Liu. "Biostratigraphic constraints on the age of Neoproterozoic glaciation in North China." Journal of Asian Earth Sciences 219 (October 2021): 104894. http://dx.doi.org/10.1016/j.jseaes.2021.104894.

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Buczek, Alexandra J., Austin J. W. Hendy, Melanie J. Hopkins, and Jocelyn A. Sessa. "On the reconciliation of biostratigraphy and strontium isotope stratigraphy of three southern Californian Plio-Pleistocene formations." GSA Bulletin 133, no. 1-2 (May 6, 2020): 100–114. http://dx.doi.org/10.1130/b35488.1.

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Abstract The San Diego Formation, Pico Formation, Careaga Sandstone, and Foxen Mudstone of southern California are thought to be late Pliocene to early Pleistocene; however, numerical ages have not been determined. Following assessment of diagenetic alteration via multiple methods including scanning electron microscopy (SEM), X-ray diffraction (XRD), and minor elemental concentrations, we attempted to use strontium isotope stratigraphy to assign numerical ages. Using aragonitic fossils, we obtained ages of 2.0–1.85 Ma for the Careaga Sandstone and 2.0–1.75 Ma for the uppermost Foxen Mudstone, consistent with biostratigraphic work suggesting a Gelasian age for the Careaga Sandstone. Isotope ratios for aragonitic and calcitic fossils from the Pico Formation were poorly constrained, with the exception of one bed yielding ages of 5.1–4.3 Ma. Isotope ratios from the San Diego Formation were also inconsistent within beds, with the exception of two isolated outcrops that yielded ages of 5.0–4.5 Ma and 4.5–2.8 Ma, respectively. The age estimates for the Pico and San Diego Formations are older than most ages inferred from biostratigraphy. Noting that some aragonitic specimens from the San Diego Formation yielded isotope ratios indicative of ages as old as 19.4 Ma, we propose that some outcrops have been affected by diagenesis caused by groundwater flow through proximal granitic rocks and input from detrital sediment. Although we recommend that strontium isotope results for the Pico and San Diego Formations be interpreted with caution, the ages of the uppermost Foxen Mudstone and Careaga Sandstone can be confidently placed within the early Pleistocene.

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Maron, Matteo, Giovanni Muttoni, Mark J. Dekkers, Michele Mazza, Guido Roghi, Anna Breda, Wout Krijgsman, and Manuel Rigo. "Contribution to the magnetostratigraphy of the Carnian: new magneto-biostratigraphic constraints from Pignola-2 and Dibona marine sections, Italy." Newsletters on Stratigraphy 50, no. 2 (April 1, 2017): 187–203. http://dx.doi.org/10.1127/nos/2017/0291.

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Jordan, Leslie M., James V. Browning, Kenneth G. Miller, and W. John Schmelz. "Quantitative Biostratigraphic Analysis and Age Estimates of Middle Cretaceous Sequences in The Baltimore Canyon Trough, Offshore Mid-Atlantic U.S. Margin." Journal of Foraminiferal Research 52, no. 4 (October 1, 2022): 229–47. http://dx.doi.org/10.2113/gsjfr.52.4.229.

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ABSTRACT We applied quantitative methods to previously published biostratigraphic data from the Baltimore Canyon Trough (offshore of the Mid-Atlantic U.S.A.) to provide an improved chronostratigraphic framework for Cretaceous sequences. Here, we successfully used graphic correlation of 228 planktonic foraminifera, nannofossil, and palynological events spanning 22 wells to define assemblage and interval zones as well as major paleoenvironmental changes in the Dawson Canyon, Logan Canyon (three sequences), and Missisauga Formations (two sequences, undifferentiated here). Ranking and scaling techniques were not successful because of the of the limited number of usable biostratigraphic markers. The ages of the sequences previously identified using well logs and seismic profiles were temporally constrained based on chronostratigraphically significant biostratigraphic markers that we identified: the late Cenomanian to Turonian DCx sequence (Rotalipora cushmani and Thalmanninella greenhornensis); the early Cenomanian LC1 sequence; the middle and late Albian LC2 sequence (Braarudosphaera africana, Planomalina buxtorfi, and Spinidinium vestitum); the late Aptian LC3 sequence (Cyclonephelium tabulatum); and the early Aptian to Barremian Missisauga sequences (Aptea anaphrissa, Pseudoceratium pelliferum, and Muderongia simplex). These five biostratigraphic associations are correlated with six prominent seismic reflectors and sequence boundaries that can be traced across the basin. Duration of hiatuses associated with these sequence boundaries are uncertain, though our Monte Carlo analysis allows extraction of age estimates from broad and sometimes contradictory ranges and suggests correlation of hiatuses with global sea-level falls. Together, these seismic and biostratigraphic interpretations can be applied (1) to evaluate reservoir continuity and the viability of offshore carbon storage reservoirs in the Baltimore Canyon Trough, (2) to better define the tectonostratigraphic evolution of the basin, and (3) to contribute to the understanding of regional and global variations in Cretaceous sea level.

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Wellman, Charles H. "Palynology of the ‘Lower Old Red Sandstone’ at Glen Coe, Scotland." Geological Magazine 131, no. 4 (July 1994): 563–66. http://dx.doi.org/10.1017/s0016756800012176.

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Abstract‘Lower Old Red Sandstone’ deposits preserved by cauldron subsidence at Glen Coe, Scotland have hitherto lacked secure biostratigraphical age constraint. A sporomorph assemblage recovered from basal sediments of these deposits permits age determination, despite being highly carbonized. The sporomorph assemblage is correlated with the micrornatus-newportensis Sporomorph Assemblage Biozone, indicating a late early-early late Lochkovian age (early Devonian). Sporomorph assemblages from basal sediments of the ‘Lower Old Red Sandstone’ sequence at nearby Lorne, a suggested correlative of the Glen Coe deposits, are older (latest Pridoli-earliest Lochkovian age). However, the new biostratigraphical data do not preclude the possibility that the Glen Coe and Lorne deposits are lithological correlatives and the basal sediments are diachronous.

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25

Pallikarakis, Aggelos, Ioannis Papanikolaou, Klaus Reicherter, Maria Triantaphyllou, Margarita Dimiza, and Olga Koukousioura. "Constraining the regional uplift rate of the Corinth Isthmus area (Greece), through biostratigraphic and tectonic data." Zeitschrift für Geomorphologie, Supplementary Issues 62, no. 2 (October 1, 2019): 127–42. http://dx.doi.org/10.1127/zfg_suppl/2019/0609.

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The eastern Corinth Gulf is constantly uplifted at least since Middle Pleistocene. This uplift is the combined result of the regional uplift and the activity of major active faults which influence the area. These tectonic movements which control the sedimentation processes of the study area resulted in a complex stratigraphy, paleogeography and paleoenvironment of the Corinth Isthmus. Stratigraphy supported with nannofossil biozonation data, demonstrates that marine sedimentation processes occurred during MIS 7 and MIS 5, providing some important constraints regarding the uplift rate of the area. An 0.22 ± 0.12 mm/yr uplift rate is extracted through nannofossils biozonation which is in agreement with published data from U/Th coral dating in a neighboring setting, adding confidence to the measured uplift rates. In order to constrain the regional uplift of the area, the influence of the surrounding active faults has been extracted. The latter has been implemented by extracting the influence of each individual active fault to the study site (using the fault geometry, fault slip-rates, the fault dip and the fault footwall uplift/ hangingwall subsidence ratio), in order to calculate the regional uplift rate. By considering the stratigra- phy and the biostratigraphy of the eastern part of the Corinth Isthmus and by extracting the influence of the active faults, a~0.34 ± 0.04 mm/yr regional uplift is calculated.

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Tolotti, R., C. Salvi, G. Salvi, and M. C. Bonci. "Late Quaternary climate variability as recorded by micropalaeontological diatom data and geochemical data in the western Ross Sea, Antarctica." Antarctic Science 25, no. 6 (March 28, 2013): 804–20. http://dx.doi.org/10.1017/s0954102013000199.

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AbstractCores acquired from the Ross Sea continental shelf and continental slope during the XXX Italian Programma Nazionale di Ricerche in Antartide (PNRA) were analysed and yielded interesting micropalaeontological, biostratigraphic diatom results and palaeoceanographic implications. These multi-proxy analyses enabled us to reconstruct the glacial/deglacial history of this sector of the Ross embayment over the last 40 000 years, advancing our understanding of the Last Glacial Maximum (LGM) environmental and sedimentological processes linked to the Ross Sea ice sheet/ice shelf fluctuations in a basin and continental-slope environment, and allowed us to measure some of the palaeoceanographic dynamics. The central sector of the Ross Sea and part of its coast (south of the Drygalski Ice Tongue) enjoyed open marine conditions in the pre-LGM era (27 500–24 000 years bp). The retreat of the ice sheet could have been influenced by a southward shift of a branch of the Ross gyre, which triggered early deglaciation at c. 18 600 cal bp with a significant Modified Circumpolar Deep Water inflow over the continental slope at c. 14 380 cal BP. We assume that a lack of depositional material in each core, although at different times, represents a hiatus. Other than problems in core collection, this could be due to the onset of modern oceanographic conditions, with strong gravity currents and strong High Salinity Shelf Water exportation. Moreover, we presume that improvements in biostratigraphy, study of reworked diatom taxa, and lithological and geochemical analyses will provide important constraints for the reconstruction of the LGM grounding line, ice-flow lines and ice-flow paths and an interesting tool for reconstructing palaeo-sub-bottom currents in this sector of the Ross embayment.

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Archibald, J. David. "The importance of phylogenetic analysis for the assessment of species turnover: a case history of Paleocene mammals in North America." Paleobiology 19, no. 1 (1993): 1–27. http://dx.doi.org/10.1017/s0094837300012288.

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During the latest Cretaceous and the Paleocene in western North America, disappearance rates for mammalian genera track appearance rates, both reaching their peak in the early Paleocene (Puercan) following the extinction of non-avian dinosaurs. Some of the disappearances during this time were pseudoextinctions that resulted when ancestral species disappeared during speciation.Species-level cladistic analyses and a well-constrained biostratigraphic framework are required to study this form of pseudoextinction. Cladistic analyses show that monophyly cannot be established or rejected for some species because these species lack autapomorphies (uniquely derived character states) that unite their constituent members. Such taxa, termed metaspecies, are potential ancestors to species and higher clades with which they share a node in the cladogram.A hypothetical species-level cladistic analysis coupled with three different hypothetical biostratigraphies shows how different models of speciation (bifurcation, budding, or anagenesis) result in very different patterns of true versus pseudoextinction. Depending on the speciation model, true extinction can be overestimated by as much as a factor of four, raising the specter of mass extinction. Species-level studies for three early Tertiary mammalian taxa—taeniodont eutherians, taeniolabidid multituberculates, and periptychid ungulates—use the same procedures. They show that almost 25% of disappearances during the early Paleocene (Puercan) for species in the analysis were pseudoextinctions of metaspecies. Budding and anagenetic-like peripatric speciation, but not bifurcation, are seen in the three examples.Equating disappearance to true extinction can profoundly affect interpretations of faunal turnover, especially during mass extinctions or major faunal reorganizations. Some authors use pseudoextinction to describe the taxonomic rather than evolutionary disappearance of nonmonophyletic groups. Pseudoextinction, as used here refers only to the evolutionary disappearance of metaspecies via speciation. Both usages seem appropriate but should not be confounded.

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Uhl, Dieter, and André Jasper. "New data on the macroflora of the basal Rotliegend group (Remigiusberg Formation; Gzhelian) in the Saar-Nahe basin (SW-Germany)." Fossil Imprint 72, no. 3-4 (December 30, 2016): 239–50. http://dx.doi.org/10.14446/fi.2016.239.

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New discoveries of fossil plant macroremains from the Remigiusberg Formation (lowermost Rotliegend group) considerably enlarge our knowledge about the flora of the basal-most part of the lithostratigraphically defined Rotliegend group within the Saar-Nahe Basin in SW-Germany. Most taxa are plants that grew in relatively humid habitats near rivers, or around margins of the lake in whose sediments the plant macroremains were found. This, together with previously reported palynological data, suggests that the wetlands in which these plants grew were large enough to act as taphonomical barriers against the deposition of plant macroremains from dryer habitats. Based on some of the new taxa, it is also possible to constrain the base of the biostratigraphic Autunia conferta zone in this basin, a task that was not possible before, due to the scarcity of macrofloristic data from the basal Rotliegend group. The new data provide evidence that the upper part of the Remigiusberg Formation is probably not older than late Gzhelian. This corresponds to earlier biostratigraphic interpretations based on palaeozoological remains.

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Dewing, Keith, and W. G. E. Caldwell. "Biostratigraphy of Late Ordovician-Early Silurian strophomenoid brachiopods from Anticosti Island, Quebec." Paleontological Society Special Publications 6 (1992): 84. http://dx.doi.org/10.1017/s2475262200006444.

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A combination of shape and form, mode of preservation, and degree of variation makes the strophomenoids one of the more difficult groups of brachiopods to study taxonomically. In turn, taxonomic confusion may explain why the strophomenoids have not been used to the same extent as other groups of brachiopods as a basis for biostratigraphic classification and correlation, and for elucidating biogeographic provincialism. Such conclusions certainly seem warranted following a detailed investigation of the strophomenoids present in the Late Ordovician-Early Silurian carbonate sequence of Anticosti Island, Quebec.The abundance and superb preservation of Anticosti strophomenoids permit a thorough analysis of external and internal features and the high degree of variation that some of these exhibit. Serial sections are critical to reconstructing the interiors of articulated specimens, establishing taxonomic relationships among discrete valves, and exposing developmental changes in shell structure. When subject to such detailed treatment, at least seventeen genera and twenty-seven species of strophomenoids can be securely identified. Variation among these taxa is such that some features - shape, convexity, ornamentation, and outline of muscle field - hitherto depended upon for taxonomic purposes, have little value in this respect. Other features - pattern of pseudopuncta, form of foramen, pseudodeltidium, chilidium, cardinal process, teeth, dental plates, and socket plates, and presence of ridges and septa bounding and dividing the muscle field - are demonstrably more reliable.The Ordovician-Silurian boundary in the Anticosti sequence is broadly characterized by change from a plectambonitid-rafinesquinid-strophomenid fauna in the Vaureal Formation (Ashgill), through a plectambonitid-leptaenid-stropheodontid-Fardenia fauna in the Ellis Bay Formation (uppermost Ashgill), to a leptaenid-stropheodontid-Fardenia fauna in the Becscie to Chicotte formations (Llandovery). Considerable overlap occurs between Ordovician and Silurian taxa. The oldest known chonetid and the oldest stropheodontid on Anticosti Island occur in the Vaureal Formation. Plectambonitids and strophomenids are rare in the late Llandovery Jupiter Formation.Taking a more rigorous biostratigraphical approach, however, distribution of the twenty-seven well-constrained species allows numerous sequential biozones of different type (assemblage, range, overlapping range) to be recognized, up to six of them in the Ashgill section alone. Some zones are distinguished by cosmopolitan species, others by species known from basins well removed from the Anticosti Basin, others again by species seemingly endemic to the Anticosti Basin. These replacements point to a changing pattern of faunal provincialism as Late Ordovician gave way to Early Silurian time. In the Ordovician portion of the section in particular, the biostratigraphic refinement of the potential strophomenoid zones exceeds that of such other brachiopod groups as rhynchonellids or of conodonts.

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Smith, E. F., L. L. Nelson, S. M. Tweedt, H. Zeng, and J. B. Workman. "A cosmopolitan late Ediacaran biotic assemblage: new fossils from Nevada and Namibia support a global biostratigraphic link." Proceedings of the Royal Society B: Biological Sciences 284, no. 1858 (July 12, 2017): 20170934. http://dx.doi.org/10.1098/rspb.2017.0934.

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Owing to the lack of temporally well-constrained Ediacaran fossil localities containing overlapping biotic assemblages, it has remained uncertain if the latest Ediacaran ( ca 550–541 Ma) assemblages reflect systematic biological turnover or environmental, taphonomic or biogeographic biases. Here, we report new latest Ediacaran fossil discoveries from the lower member of the Wood Canyon Formation in Nye County, Nevada, including the first figured reports of erniettomorphs, Gaojiashania , Conotubus and other problematic fossils. The fossils are spectacularly preserved in three taphonomic windows and occur in greater than 11 stratigraphic horizons, all of which are below the first appearance of Treptichnus pedum and the nadir of a large negative δ 13 C excursion that is a chemostratigraphic marker of the Ediacaran–Cambrian boundary. The co-occurrence of morphologically diverse tubular fossils and erniettomorphs in Nevada provides a biostratigraphic link among latest Ediacaran fossil localities globally. Integrated with a new report of Gaojiashania from Namibia, previous fossil reports and existing age constraints, these finds demonstrate a distinctive late Ediacaran fossil assemblage comprising at least two groups of macroscopic organisms with dissimilar body plans that ecologically and temporally overlapped for at least 6 Myr at the close of the Ediacaran Period. This cosmopolitan biotic assemblage disappeared from the fossil record at the end of the Ediacaran Period, prior to the Cambrian radiation.

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Hull, J. N. F., S. A. Smith, and H. C. Young. "SEQUENCE STRATIGRAPHIC INTERPRETATION OF CARBONATE WIRELINE LOG MOTIFS: AN EXAMPLE FROM THE NORTH WEST SHELF OF AUSTRALIA." APPEA Journal 38, no. 1 (1998): 188. http://dx.doi.org/10.1071/aj97010.

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An integrated biostratigraphic, wireline and seismic sequence stratigraphic study has been conducted to constrain the timing and evolution of Late Cretaceous to Tertiary depocentres along the North West Shelf of Australia. During this study a model for the sequence stratigraphic interpretation of wireline logs in this carbonate-dominated regime has been developed.A series of readily identifiable, lowstand clastic deposits interspersed within the predominantly carbonate passive margin section of the North West Shelf provide well-defined correctable events with which to divide the section. Biostratigraphic data have indicated the presence of missing section at the base of these clastic deposits and their shelfal equivalents. These events have been correlated to define sequence boundaries that are represented on wireline log data by a sharp increase in the gamma signature. Lowstand systems tracts exhibit an irregular sonic and upwardly increasing gamma signature. Transgressive systems tracts show characteristically upward-decreasing gamma and sonic profiles. Maximum flooding surfaces have been identified as the point of cleanest carbonate sedimentation represented by gamma minima on wireline logs. Log motifs exhibiting little character have been interpreted as highstand systems tracts. On seismic these sequence stratigraphic events are represented by stratal geometries that would be expected for these systems tracts.The model has enabled the definition of a higher resolution chronostratigraphic framework for the Mid Cretaceous to Recent section of the North West Shelf than has previously been possible. Forty basin-wide events have been identified from the biostratigraphic and wireline log analysis, thirty of which can be tied throughout the Barrow, Dampier and Roebuck basins.

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Schneider, David A., Jan Backman, William B. Curry, and Göran Possnert. "Paleomagnetic Constraints on Sedimentation Rates in the Eastern Arctic Ocean." Quaternary Research 46, no. 1 (July 1996): 62–71. http://dx.doi.org/10.1006/qres.1996.0044.

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Deep-sea sediments recovered from six sites visited during the International Arctic Ocean Expedition of 1991 were examined to determine sedimentation rates in the eastern Arctic Ocean basin. The dearth of age-diagnostic biogenic material in these sediments precludes the application of biostratigraphic methods, but ages can be deduced using paleomagnetism, in conjunction with measurements of radiocarbon and carbonate concentration. Although no one of these techniques gives an unambiguous determination of age, the interpretation most consistent with these diverse data implies that sedimentation rates in the eastern Arctic are, in general, a few centimeters per thousand years. Such estimates of sedimentation rate are an order of magnitude greater than those previously determined from many sediment cores taken from the Canada Basin. However, one site examined on the Morris Jesup Rise shows a relatively low rate of sediment accumulation (less than 0.6 cm/103 yr) suggesting that, although higher than in the Canada Basin, sedimentation rates in the eastern Arctic can be highly variable.

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33

Dallanave, Edoardo, Claudia Agnini, Kristina M. Pascher, Pierre Maurizot, Valerian Bachtadse, Christopher J. Hollis, Gerald R. Dickens, Julien Collot, and Edoardo Monesi. "Magneto-biostratigraphic constraints of the Eocene micrite–calciturbidite transition in New Caledonia: tectonic implications." New Zealand Journal of Geology and Geophysics 61, no. 2 (March 15, 2018): 145–63. http://dx.doi.org/10.1080/00288306.2018.1443946.

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34

Toffanin, Federica, Claudia Agnini, Domenico Rio, Gary Acton, and Thomas Westerhold. "Middle Eocene to early Oligocene calcareous nannofossil biostratigraphy at IODP Site U1333 (equatorial Pacific)." Micropaleontology 59, no. 1 (2013): 69–82. http://dx.doi.org/10.47894/mpal.59.1.04.

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We present a biostratigraphic and biochronologic study of calcareous nannofossils of middle Eocene - early Oligocene age recovered during IODP Expedition 320, at Hole U1333C in the equatorial Pacific Ocean. The study succession encompasses nannofossil Zones NP16–NP21 (equivalent to CP13–CP16) and Chrons C20r–C12r (middle Eocene-early Oligocene). The distribution patterns of calcareous nannofossil taxa are studied by means of relative abundance and semiquantitative counts with the final aim to test the reliability of biohorizons used in the Paleogene standard biozonations (Martini 1971; Okada and Bukry 1980) and check alternative bioevents included in a more recent mid-latitudes biostratigraphic scheme (Fornaciari et al. 2010). Calibration ages are estimated based on the ranges of the biozones relative to a detailed magnetostratigraphy constructed for the site. Of particular biostratigraphic significance, our study shows that the Top of Sphenolithus furcatolithoides, the Base of common and continuous occurrence (Bc) of Dictyococcites bisectus and the total range of Sphenolithus obtusus can be used to better constrain the middle Eocene interval. The studied sediments cover the crucial time period that followed maximum Cenozoic warmth and led up to the initial major glaciation on Antarctica, including two important climatic events, the Middle Eocene Climatic Optimum (MECO), a transient episode of global warming during a long-term cooling trend, and the Oi-1 event. The peculiar regime in sedimentation observed in the equatorial Pacific, which roughly consists of alternating phases of Carbonate Accumulation Events (CAE) and crashes in carbonate content, are correlated with increases and decreases in calcareous nannofossil abundances. A more detailed comparison indicates that the MECO corresponds to an interval with very low carbonate in between CAE3 and CAE4. This event is correlative with the Top of S. furcatolithoides, the Bc of D. bisectus and a prominent increase in the relative abundance of heavy calcified nannofossils (e.g., discoasters).

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35

Kováč, Michal, Eva Halásová, Natália Hudáčková, Katarína Holcová, Matúš Hyžný, Michal Jamrich, and Andrej Ruman. "Towards better correlation of the Central Paratethys regional time scale with the standard geological time scale of the Miocene Epoch." Geologica Carpathica 69, no. 3 (June 1, 2018): 283–300. http://dx.doi.org/10.1515/geoca-2018-0017.

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AbstractDepositional sequences originating in semi-enclosed basins with endemic biota, partly or completely isolated from the open ocean, frequently do not allow biostratigraphic correlations with the standard geological time scale (GTS). The Miocene stages of the Central Paratethys represent regional chronostratigraphic units that were defined in type sections mostly on the basis of biostratigraphic criteria. The lack of accurate dating makes correlation within and between basins of this area and at global scales difficult. Although new geochronological estimates increasingly constrain the age of stage boundaries in the Paratethys, such estimates can be misleading if they do not account for diachronous boundaries between lithostratigraphic formations and for forward smearing of first appearances of index species (Signor-Lipps effect), and if they are extrapolated to whole basins. Here, we argue that (1) geochronological estimates of stage boundaries need to be based on sections with high completeness and high sediment accumulation rates, and (2) that the boundaries should preferentially correspond to conditions with sufficient marine connectivity between the Paratethys and the open ocean. The differences between the timing of origination of a given species in the source area and timing of its immigration to the Paratethys basins should be minimized during such intervals. Here, we draw attention to the definition of the Central Paratethys regional time scale, its modifications, and its present-day validity. We suggest that the regional time scale should be adjusted so that stage boundaries reflect local and regional geodynamic processes as well as the opening and closing of marine gateways. The role of eustatic sea level changes and geodynamic processes in determining the gateway formation needs to be rigorously evaluated with geochronological data and spatially-explicit biostratigraphic data so that their effects can be disentangled.

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Voldman, Gustavo G., Juan L. Alonso, Luis P. Fernández, Gladys Ortega, Guillermo L. Albanesi, Aldo L. Banchig, and Raúl Cardó. "Tips on the SW-Gondwana margin: Ordovician conodont-graptolite biostratigraphy of allochthonous blocks in the Rinconada mélange, Argentine Precordillera." Andean Geology 45, no. 3 (June 6, 2018): 399. http://dx.doi.org/10.5027/andgeov45n3-3095.

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The Rinconada Formation is a mélange that crops out in the eastern margin of the Argentine Precordillera, an exotic terrane accreted to Gondwana in Ordovician times. Its gravity-driven deposits have been studied by means of conodont and graptolite biostratigraphy, and complemented with stratigraphic analyses. 46 rock samples (85 kg total weight) were obtained from blocks of limestones and of carbonate-cemented quartz-arenites, and from limestone clasts included in conglomerate blocks and debrites. 16 of these samples were productive after standard laboratory acid procedures, yielding 561 conodont elements. The specimens occur in variable number per sample and are frequently fragmented, but they reveal the occurrence of phantom stratigraphic units in the Darriwilian of the Precordillera. Lithological and fossil evidence from the Rinconada Formation provide new constraints on the biostratigraphy, palaebiogeography and tectonostratigraphic history of the southwestern margin of Gondwana during the Ordovician to Lower Devonian times.

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Muttoni, Giovanni, Dennis V. Kent, Flavio Jadoul, Paul E. Olsen, Manuel Rigo, Maria Teresa Galli, and Alda Nicora. "Rhaetian magneto-biostratigraphy from the Southern Alps (Italy): Constraints on Triassic chronology." Palaeogeography, Palaeoclimatology, Palaeoecology 285, no. 1-2 (January 2010): 1–16. http://dx.doi.org/10.1016/j.palaeo.2009.10.014.

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38

Zulauf, Gernold, Joachim Blau, Wolfgang Dörr, Thomas Klein, Jochen Krahl, Evelyn Kustatscher, Rainer Petschick, and Bas van de Schootbrugge. "New U-Pb zircon and biostratigraphic data of the Tyros Unit, eastern Crete: constraints on Triassic palaeogeography and depositional environment of the eastern Mediterranean." Zeitschrift der Deutschen Gesellschaft für Geowissenschaften 164, no. 2 (June 1, 2013): 337–52. http://dx.doi.org/10.1127/1860-1804/2013/0009.

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39

Moczydłowska, Małgorzata, and Gonzalo Vidal. "Phytoplankton from the Lower Cambrian Læså formation on Bornholm, Denmark: biostratigraphy and palaeoenvironmental constraints." Geological Magazine 129, no. 1 (January 1992): 17–40. http://dx.doi.org/10.1017/s0016756800008104.

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AbstractAcritarchs from the Lower Cambrian Læsså formation on Bornholm, Denmark, are taxonomically diverse. Their state of preservation, including thermal, mechanical and chemical alteration, is discussed. Different states of thermal maturation of acritarchs in shales and phosphorites of the Broens Odde member could be explained in terms of possible irradiation from natural radioactive decay. The microfossils form two age-diagnostic assemblages that allow recognition of the Skiagia ornata–Fimbriaglomerella membranacea and Heliosphaeridium dissimilare–Skiagia ciliosa Assemblage Zones within the Broens Odde member of the Laeså formation. Acritarch-based biostratigraphy indicates that the Lower Cambrian Balka Formation and Læså formation correspond to the Schmidliellus mickwitzi Zone and Holmia kjerulfi Assemblage Zone recognized in Baltoscandia and the East European Platform. Acritarch distribution within three different depositional settings indicates that comparable spectra of morphotypes occurred in different depositional environments. This suggests the absence of facies control. During early Cambrian times palaeoenvironmental barriers in shallow, epicontinental shelf basins constituted a minor obstacle for widespread distribution of acritarch taxa. Formerly proposed early Palaeozoic acritarch provincialism appears insufficiently documented in the fossil record and no evidence could be extracted from the Cambrian record. Following a rapid radiation at the onset of the Phanerozoic, Cambrian phytoplankton populations underwent dispersion following oxygenic and nutrient-rich bodies of water within epicontinental and presumably basinal environments. Lower Cambrian acritarch taxa were largely cosmopolitan and little affected by lithofacies associations. A continuous flow of data is contributing to the emergence of acritarch-based biostratigraphy. Its apparent consistency suggests great usefulness for interregional and detailed event correlation.

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Xiao, Shuhai, Bing Shen, Qing Tang, Alan J. Kaufman, Xunlai Yuan, Jianhua Li, and Maiping Qian. "Biostratigraphic and chemostratigraphic constraints on the age of early Neoproterozoic carbonate successions in North China." Precambrian Research 246 (June 2014): 208–25. http://dx.doi.org/10.1016/j.precamres.2014.03.004.

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Lehrmann, Daniel J., Jahandar Ramezani, Samuel A. Bowring, Mark W. Martin, Paul Montgomery, Paul Enos, Jonathan L. Payne, Michael J. Orchard, Wang Hongmei, and Wei Jiayong. "Timing of recovery from the end-Permian extinction: Geochronologic and biostratigraphic constraints from south China." Geology 34, no. 12 (2006): 1053. http://dx.doi.org/10.1130/g22827a.1.

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Sennikov, N. V., N. V. Novozhilova, O. T. Obut, and R. A. Khabibulina. "The Pridoli (Silurian) Lithostratigraphy and Biostratigraphy of Gorny Altai." Russian Geology and Geophysics 62, no. 11 (November 1, 2021): 1269–84. http://dx.doi.org/10.2113/rgg20204232.

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Abstract —The paper presents new data on the upper Silurian litho- and biostratigraphy of the Gorny Altai area. Sediments within this interval store a succession of taxonomically representative middle–upper Ludfordian, lower Pridoli, and Lower Devonian (Lochkovian–Pragian) conodont assemblages. The new fauna constraints made a basis for updated correlations of the local and regional stratigraphic units at the Silurian/Devonian boundary of Gorny Altai with the stages of the International Stratigraphic Chart. The correlation results reveal a mismatch between the boundaries of the local and regional Silurian units and the respective boundaries of stages in the International Stratigraphic Chart.

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Sweet, Dustin E., Corbin R. Carsrud, and Aaron J. Watters. "Proposing an Entirely Pennsylvanian Age for the Fountain Formation through New Lithostratigraphic Correlation along the Front Range." Mountain Geologist 52, no. 2 (April 1, 2015): 43–70. http://dx.doi.org/10.31582/rmag.mg.52.2.43.

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The Fountain Formation is an important unit recording ancestral Rocky Mountain tectonics and paleogeography along the Front Range urban corridor. The age of the formation constrains timing of uplift of the ancestral Front Range and Ute Pass uplift and subsidence of adjacent basins. Yet, age models for the Fountain Formation are crude and varied. Specifically, available biostratigraphic data suggest an entirely Pennsylvanian age for the Fountain Formation, however historical lithostratigraphic assignment of the Lyons Formation atop the Fountain Formation south of Lyons, Colorado allows for a significant early Permian component of deposition. New stratigraphic and sedimentologic data recorded from the Ingleside Formation and the Lower Permian unit at Manitou Springs, Colorado demonstrate: 1) a conformable contact between the upper Fountain Formation and Lower Permian strata at both localities and 2) close grain size and framework mineralogy comparisons at both localities. These data suggest that the Lower Permian at Manitou Springs, Colorado best correlates to the Ingleside Formation, rather than the previously mapped Lyons Formation. This newly proposed lithostratigraphic correlation aligns with the available biostratigraphic data that the Fountain Formation is a Pennsylvanian unit with little to no Lower Permian component. An entirely Pennsylvanian age for the Fountain Formation indicates that active uplift of the ancestral Front Range and delivery of first-cycle arkose had ceased by the latest Pennsylvanian.

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Lidz, Barbara H., and Timothy J. Bralower. "Microfossil biostratigraphy of prograding Neogene platform-margin carbonates, Bahamas: Age constraints and alternatives." Marine Micropaleontology 23, no. 4 (May 1994): 265–344. http://dx.doi.org/10.1016/0377-8398(94)90022-1.

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Webster, Mark, and Steven J. Hageman. "Buenellus chilhoweensisn. sp. from the Murray Shale (lower Cambrian Chilhowee Group) of Tennessee, the oldest known trilobite from the Iapetan margin of Laurentia." Journal of Paleontology 92, no. 3 (March 26, 2018): 442–58. http://dx.doi.org/10.1017/jpa.2017.155.

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AbstractThe Ediacaran to lower Cambrian Chilhowee Group of the southern and central Appalachians records the rift-to-drift transition of the newly formed Iapetan margin of Laurentia. Body fossils are rare within the Chilhowee Group, and correlations are based almost exclusively on lithological similarities. A critical review of previous work highlights the relatively weak biostratigraphic and radiometric age constraints on the various units within the succession. Herein, we document a newly discovered fossil-bearing locality within the Murray Shale (upper Chilhowee Group) on Chilhowee Mountain, eastern Tennessee, and formally describe a nevadioid trilobite,Buenellus chilhoweensisn. sp., from that site. This trilobite indicates that the Murray Shale is of Montezuman age (provisional Cambrian Stage 3), which is older than the Dyeran (provisional late Stage 3 to early Stage 4) age suggested by the historical (mis)identification of “Olenellussp.” from within the unit as reported by workers more than a century ago.Buenellus chilhoweensisn. sp. represents only the second known species ofBuenellus, and demonstrates that the genus occupied both the Innuitian and Iapetan margins of Laurentia during the Montezuman. It is the oldest known trilobite from the Iapetan margin, and proves that the hitherto apparent absence of trilobites from that margin during the Montezuman was an artifact of inadequate sampling rather than a paleobiogeographic curiosity. The species offers a valuable biostratigraphic calibration point within a rock succession that has otherwise proven recalcitrant to refined dating.UUID:http://zoobank.org/30af790b-e7b1-44c3-b1d5-55cdf579bde2

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Kasuya, Masao. "Fission-Track Ages of Tuff Layers Related to the Pliocene-Pleistocene Boundary on the Boso Peninsula, Japan." Quaternary Research 33, no. 1 (January 1990): 86–93. http://dx.doi.org/10.1016/0033-5894(90)90086-z.

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AbstractFission-track ages of zircon crystals from four tuff layers in the late Cenozoic sediment sequence of the Boso Peninsula,.Japan, are 1.6 ± 0.2 myr (the Kurotaki Formation), 5.5 ± 0.6 and 5.2 ± 0.5 myr (the uppermost part of the Amatsu Formation), and 11.5 ± 0.8 myr (the middle part of the Amatsu Formation). These ages provide numerical age constraints on magneto-biostratigraphy. The normal polarity interval in the lower part of the Kiwada Formation corresponds to the Olduvai polarity subzone. The boundary between the Pliocene and Pleistocene lies slightly above the Olduvai polarity subzone.

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Orchard, M. J., F. Cordey, L. Rui, E. W. Bamber, B. Mamet, L. C. Struik, H. Sano, and H. J. Taylor. "Biostratigraphic and biogeographic constraints on the Carboniferous to Jurassic Cache Creek Terrane in central British Columbia." Canadian Journal of Earth Sciences 38, no. 4 (April 1, 2001): 551–78. http://dx.doi.org/10.1139/e00-120.

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Conodonts, radiolarians, foraminiferids, and corals provide constraints on the geology and tectonics of the Nechako region. They also support the notion that the Cache Creek Terrane is allochthonous with respect to the North American craton. The 177 conodont collections, assigned to 20 faunas, range in age from Bashkirian (Late Carboniferous) to Norian (Late Triassic); 70 radiolarian collections representing 12 zones range from Gzhelian (Late Carboniferous) to Toarcian (Early Jurassic); 335 collections assigned to 11 fusulinacean assemblages (with associated foram-algal associations) range from Bashkirian to Wordian (Middle Permian); and two coral faunas are of Bashkirian and Wordian age. The fossils document a long but sporadic history of sedimentary events within the Cache Creek Complex that included two major carbonate buildups in the Late Carboniferous (Pope limestone) and Middle Permian (Copley limestone), punctuated by intervening Early Permian deepening; basaltic eruptions during the mid Carboniferous and mid Permian; the onset of oceanic chert sedimentation close to the CarboniferousPermian boundary and its persistence through the Late Triassic (Sowchea succession); latest Permian and Early Triassic mixed clastics and volcanics (Kloch Lake succession); Middle and Late Triassic reworking of carbonates (Whitefish limestone), including cavity fill in older limestones (Necoslie breccia), and fine-grained clastic sedimentation extending into the Early Jurassic (Tezzeron succession). Tethyan, eastern Pacific, and (or) low-latitude biogeographic attributes of the faunas are noted in the Gzhelian (fusulines), Artinskian (conodonts, fusulines), Wordian (fusulines, corals, conodonts), and Ladinian (conodonts, radiolarians). The Cache Creek Terrane lay far to the west of the North American continent during these times.

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Schnabl, Petr, Petr Pruner, and William A. P. Wimbledon. "A review of magnetostratigraphic results from the Tithonian–Berriasian of Nordvik (Siberia) and possible biostratigraphic constraints." Geologica Carpathica 66, no. 6 (December 1, 2015): 489–98. http://dx.doi.org/10.1515/geoca-2015-0040.

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Abstract In this contribution we examine and discuss recently published magnetostratigraphic data from the Nordvik section (north Siberia) around the Tithonian–Berriasian (J/K) boundary, with a special emphasis on calibration with biostratigraphy and the reliability of both the fossil and magnetic records, as well as sedimentation rates. Specifically, we discuss original new interpretations by Bragin et al. (2013) and the commentary on that work by Guzhikov (2013). We consider some limitations of the Nordvik section, and conclude that the base of M18r, because it is in a condensed part of the sequence, makes a poor contender for precise long-range correlation. We discuss the lack of ammonites at several magnetozone boundaries, and whether the bases of the local zones of Craspedites taimyrensis and Arctoteuthis tehamaensis can be used to bracket the correlative horizon of Calpionella alpina, a widespread marker in the middle of M19n.2n in Tethys.

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Benedetti, Andrea. "Benthic foraminiferal turnover at the Eocene-Oligocene transition in the Caltavuturo Formation cropping out near Santa Cristina Gela (Sicily)." Micropaleontology 65, no. 5 (2019): 425–34. http://dx.doi.org/10.47894/mpal.65.5.03.

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A qualitative and quantitative study was carried out on the benthic foraminiferal assemblages from the upper Eocene to lower Oligocene of a section of the Caltavuturo Formation exposed near Piana degli Albanesi (northwestern Sicily). The recognized taxa are evaluated in terms of their ecology and bathymetric interpretation. Biostratigraphic constraints are defined combining both nannofossils and planktic foraminifers biozonations. The planktic-benthic foraminiferal ratio allowed the reconstruction of water depth variations. Atotal of 48 benthic foraminiferal taxawere extracted from the samples. The benthic assemblages and the P/(P+B) ratio indicate a lower to middle bathyal depositional depth, although an abrupt drop of sea level of about 140 m is recorded across the suspected Eocene-Oligocene transition. Calcium carbonate content decreases upsection, suggesting an increase in terrigenous supply in the lowermost Oligocene.

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Szakács, Alexandru, Zoltán Pécskay, Lóránd Silye, Kadosa Balogh, Daniela Vlad, and Alexandrina Fülöp. "On the age of the Dej Tuff, Transylvanian Basin (Romania)." Geologica Carpathica 63, no. 2 (April 1, 2012): 139–48. http://dx.doi.org/10.2478/v10096-012-0011-9.

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On the age of the Dej Tuff, Transylvanian Basin (Romania)The Dej Tuff is an important stratigraphic marker in the Transylvanian Basin. However, its Early Badenian age is known only on biostratigraphical grounds so far. A number of radiometric dating techniques including K-Ar, Ar-Ar and fission-track have been used in order to constrain more precisely its age, allowing the calibration of the Transylvanian Basin's evolutionary models. Although individual dating methods could not provide a unique, reliable and accurate radiometric age, comparison and evaluation of multiple methods gives 14.8-15.1 Ma as the most likely formation age of the Dej Tuff.

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Journal articles on the topic 'Biostratigraphic constraint'

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