The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary se...The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary section at Tieqiao have been permanently flooded since 2020.We herein designate an excavated section at Penglaitan as the new GSSP and the Fengshan section as a new Standard Auxiliary Boundary Stratotype(SABS).In addition,we revised the original definition based on a detailed restudy of the conodont succession from the two sections.We define the GSSP of the base-Wuchiapingian by the First Appearance Datum(FAD)of Clarkina postbitteri within the lineage Jinogondolella granti→Clarkina postbitteri→C.dukouensis.It represents a major evolutionary turnover in conodonts from Jinogondolella to Clarkina and marks the end-Guadalupian extinction event.The U-Pb date of 259.51±0.21 Ma from the uppermost part of the Emeishan basalt is adopted for the GLB age.δ13Ccarb chemostratigraphy at the SABS exhibits several excursions between 3‰and 5‰across the GLB interval.Carbonate 87Sr/86Sr ratio is 0.707244 at the GLB.Remarkably,the SABS contains six normal and six reverse geomagnetic polarity zones in the uppermost Capitanian and three in the lowest Wuchiapingian.展开更多
Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geologic...Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geological Sciences unanimously approved in March 2023 the Global Stratotype Section and Point(GSSP)for the Barremian Stage(Lower Cretaceous).The base of the Barremian Stage is defined at the base of bed 171 of the Río Argos section,near Caravaca(SE Spain)and correlated by the first appearance of the ammonite species Taveraidiscus hugii.This event falls within the NC5C calcareous nannofossil Subzone,the Lilliputianella semielongata planktonic foraminiferal Zone,and the Dorothia ouachensis benthic foraminiferal Zone.It roughly coincides with the beginning of a slightly negative trend interval in theδ^(13)C curve.Indirect calibration to the magnetostratigraphic scale suggests that the boundary falls in the lowermost part of polarity chron M3r.According to the astrochronological analysis,a time interval of 0.74 myr separates the beginning of the late Hauterivian Faraoni Episode from the base of the Barremian,which is dated at 125.77 MA.展开更多
The Global Stratotype Section and Point(GSSP)of the base of Langhian Stage(base of the Middle Miocene Subseries)is defined at a level of 17.84 m in the“Lower La Vedova Beach”section in central Italy.This level marks...The Global Stratotype Section and Point(GSSP)of the base of Langhian Stage(base of the Middle Miocene Subseries)is defined at a level of 17.84 m in the“Lower La Vedova Beach”section in central Italy.This level marks the mid-point of the darker marly interval above“Megabed IV”which has been astronomically calibrated to the most prominent~100-kyr eccentricity maximum,with an astronomical age of 15.981 Ma according to La2004 nominal solution,and of 15.978 Ma according to the La2011,in the 405-kyr maximum around 16.0 Ma.The GSSP level in the Lower La Vedova Beach section corresponds closely to the top of Chron C5Cn(at 15.795 m),which is considered the principal event for recognizing the boundary globally.This magnetic reversal with an astronomical age of 16.017 Ma(Turco et al.,2017)(15.97 Ma in Hilgen et al.,2012 ATNTS,2012;15.994 Ma in Raffi et al.,2020 in GTS2020)is preferred to the historical guiding criterion,the Praeorbulina datum,which has been complicated by taxonomic confusion and revision(Turco et al.,2011a),and hence is considered less suitable for recognizing the boundary.The Lower La Vedova Beach section is preferred to the St.Peter’s Pool section(in Malta)as it has an independent astronomical tuning and a better paleomagnetic signal.展开更多
The Huanghuachang section near Yichang,southern China was successively approved by ISOS,recognized by ICS and then officially ratified as being the Global Stratotype Section and point(GSSP)for the base of the Middle O...The Huanghuachang section near Yichang,southern China was successively approved by ISOS,recognized by ICS and then officially ratified as being the Global Stratotype Section and point(GSSP)for the base of the Middle Ordovician Series and the Third Stage,named as Dapingian,of the Ordovician System.The conodont succession at the section is complete across the Lower to Middle Ordovician series boundary and several excellent phylogenetic lineages of Baltoniodus,Gothodus,Microzarkodina and Periodon are represented.The base of the Middle Ordovician Series and the Daping Stage is defined at a point 10.57 m above the base of the Dawan Formation at the base of Bed SHod-16 of the Huanghuachang section,22km NE of Yichang City,Hubei Province,South China.It coincides with the first appearance datum(FAD)of the conodont species Baltoniodus triangularis within the Baltoniodus lineage starting from Baltoniodus cf.B.triangularis to Baltoniodus navis.It is associated with the FAD of Periodon sp.A and followed closely by the FAD of Microzarkodina flabellum,which is taken as a reasonable proxy for the boundary.This level approxi-mates the boundary between the lower and upper Azygograptus suecicus graptolite Biozone,and nearly coincides with the base of the Belonechitina cf.henryi chitinozoan Biozone.The same faunal succession is also recorded from the Chenjiahe section,near Daping village,5 km to the north of the Huanghuachang section.展开更多
The Global boundary Stratotype Section and Point(GSSP)for the base of the Guzhangian Stage(Cambrian Series 3)is defined at the base of a limestone(calcisiltite)layer 121.3 m above the base of the Huaqiao Formation in ...The Global boundary Stratotype Section and Point(GSSP)for the base of the Guzhangian Stage(Cambrian Series 3)is defined at the base of a limestone(calcisiltite)layer 121.3 m above the base of the Huaqiao Formation in the Louyixi section along the Youshui River(Fengtan Reservoir),about 4 km northwest of Luoyixi(4 km southeast of Wangcun),in northwestern Hunan,China.The GSSP is exposed in a road cut at a position of 28°43.20'N and 109°57.88'E.The GSSP level contains the lowest occurrence of the cosmopolitan agnostoid trilobite Lejopyge laevigata(base of the L.laevigata Zone).Secondary global markers near the base of the stage include the appearance of either L.calva or L.armata just below the base of the stage,the appearance of conodonts associated with the base of the Laiwugnathus laiwuensis Zone,and the transgressive phase of a small eustatic event.Faunal turnovers close to the base of the Guzhangian Stage are recognized as near the base of the Boomerangian Stage in Australia,the base of the Aldanaspis Zone(polymerid trilobites)in Siberia,and the base of the Paradoxides forchhammeri Zone in western Avalonia.The horizon corresponding to the first appearance of L.laevigata is near the peak of a rather long negativeδ13C excursion of up to 0.58‰.展开更多
The Global Stratotype Section and Point(GSSP)for the Base of the Serravallian Stage(Middle Miocene)is defined in the Ras il Pellegrin section located in the coastal cliffs along the Fomm Ir-Rih Bay on the west coast o...The Global Stratotype Section and Point(GSSP)for the Base of the Serravallian Stage(Middle Miocene)is defined in the Ras il Pellegrin section located in the coastal cliffs along the Fomm Ir-Rih Bay on the west coast of Malta(35°54'50"N,14°20'10"E).The GSSP is at the base of the Blue Clay Formation(i.e.,top of the transitional bed of the uppermost Globigerina Limestone).This boundary between the Langhian and Serravallian stages coincides with the end of the major Mi-3b global cooling step in the oxygen isotopes and reflects a major increase in Antarctic ice volume,marking the end of the Middle Miocene climate transition and the Earth’s transformation into an“Icehouse”climate state.展开更多
The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in th...The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country,northern Spain.In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation,ca.49 m above the Cretaceous/Paleogene boundary.At the base of the Selandian,marls replace the succession of Danian red limestone and limestone-marl couplets.The best marine,global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group.展开更多
The Global Stratotype Section and Point(GSSP)defining the base of the Jurassic System Lower Jurassic Epoch and Hettangian Stage is situated at the Kuhjoch pass,Karwendel Mountains,Northern Calcareous Alps,Austria(47&#...The Global Stratotype Section and Point(GSSP)defining the base of the Jurassic System Lower Jurassic Epoch and Hettangian Stage is situated at the Kuhjoch pass,Karwendel Mountains,Northern Calcareous Alps,Austria(47°29'02"N/11°31'50"E).The Triassic-Jurassic(T-J)boundary is exposed at Kuhjoch West and at Kuhjoch East,and corresponds to the first occurrence(FO)of the ammonite Psiloceras spelae tirolicum.The“Golden Spike”was fixed at Kuhjoch East.The section displays a high and continuous sedimentation rate with a constant facies trend across the boundary level.展开更多
This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting o...This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting of the section are briefly introduced. Changhsingian to ＂Griesbachian＂ conodont and ammonoid zonations, the most perfect Permo-Triassic zonations over the world, are presented, with a short discussion on the age of Otoceras, The Changhsingian to ＂Griesbachian＂ strata are subdivided into three 3rd order sequences, and the sedimentary structure of each sequence is indicated. The paper presents a correlation of the Changhsingian to ＂Griesbachian＂ magneetostratigraphy of the Meishan section with the general scale, and informed the negation of a short magnetic reversal at the PTB suggested by Zhu and Liu （1999）. Recent developments of chemostratigraphy of δ^13C and δ^34S are introduced, especially the discovery of more than one negative δ^13C excursions across the PTB. Two important molecular researches reveal the profound changes at the base of eco-system, the microbial catastrophy, and the euxinic conditions in the photic zone during the Permian-Triassic superanoxic event. The paper reports the changes in dating the age of PTB since 2001. According to recent achievements, the age of volcanogenic claybed 25, 14 cm below the PTB, is now set at 252.4±0.3 Ma. A discussion on the eventostratigraphy concludes that, although there is a major event episode at beds 25-26, the events across the PTB at Meishan are multi-episodic and commenced prior to the Event Beds 25-26, thus the possibility that the mass extinction was mainly induced by an exterrestrial impact is largely excluded.展开更多
This paper gives the detail description of Meishucun section , Yunnan , China . By studying biotic characteristics , analyzing isotopic age and comparing with the main Precambrian - Cambrian boundary sections in the w...This paper gives the detail description of Meishucun section , Yunnan , China . By studying biotic characteristics , analyzing isotopic age and comparing with the main Precambrian - Cambrian boundary sections in the world , we construct a global stratotype section and a point for the Precambrian-Cambrian boundary at Meishucun , which are of the convenient assessibility , abundant fossils of diverse groups , continuous sedimentation . perfect outcropping , lock of tectonic and metamorphic alteration , and have been deep studied in all related disciplines of sciences .展开更多
The Meishucun secton has been recommended as an international candidate stratotype secton of thePrecambrian-Cambrian boundary. The paper deals with the palaeomagnetic study on the section. A total of159 palaeomagnetic...The Meishucun secton has been recommended as an international candidate stratotype secton of thePrecambrian-Cambrian boundary. The paper deals with the palaeomagnetic study on the section. A total of159 palaeomagnetic samples were successively collected from the platform-facies sequence of carbonates andphosphates at the section. Thermal demagnetization results indicate a great majority of the rocks at the sectionhave been strongly overprinted by recent magnetic field, but 57 samples have preserved remanentmagnetization with antipodal directions (mean D/I=4.2°/ 7.1°, K=9, α_(95) = 6.6°). Baaed on calculation,the location of the palaeomagnetic pole was at 68.8°N and 270.7°E, which is different from any palaeopolesobtained from younger Phanerozoic rocks in South China. The results reveal a polarity zonation which in-cludes at least 9 reversal events. A comparison of China's magnetostratigraphic records with those fromSiberia, Australia and the western U.S.A. shows that all the sections are characterized by frequent polarity re-versals.展开更多
The Global Stratotype Section and Point(GSSP)for the base of Toarcian Stage,Lower Jurassic,is placed at the base of micritic limestone bed 15e at Ponta do Trovão(Peniche,Lusitanian Basin,Portugal;coordinates:39&#...The Global Stratotype Section and Point(GSSP)for the base of Toarcian Stage,Lower Jurassic,is placed at the base of micritic limestone bed 15e at Ponta do Trovão(Peniche,Lusitanian Basin,Portugal;coordinates:39°22′15″N,9°23′07″W),80km north of Lisbon,and coincides with the mass occurrence of the ammonite Dactylioceras(Eodactylites).The Pliensbachian/Toarcian boundary(PLB/TOA)is contained in a continuous section forming over 450m of carbonate-rich sediments.Tectonics,syn-sedimentary disturbance,metamorphism or significant diagenesis do not significantly affect this area.At the PLB/TOA,no vertical facies changes,stratigraphical gaps or hiatuses have been recorded.The base of the Toarcian Stage is marked in the bed 15e by the first occurrence of D.(E.)simplex,co-occurring with D.(E.)pseudocommune and D.(E.)polymorphum.The ammonite association of D.(Eodactylites)ssp.and other species e.g.Protogrammoceras(Paltarpites)cf.展开更多
The Global boundary Stratotype Section and Point(GSSP)for the base of the Carnian Stage(Late Triassic)is defined on the north flank of the Cordevole Valley,on the southern slopes of the crest separating the Badia/Abte...The Global boundary Stratotype Section and Point(GSSP)for the base of the Carnian Stage(Late Triassic)is defined on the north flank of the Cordevole Valley,on the southern slopes of the crest separating the Badia/Abtei and the Cordevole valleys(46°31'37"N,11°55'49"E)at an elevation of 1980 m,approximately 4.7 km south of San Cassiano/St.Kassian in the Dolomites(Southern Alps).The Prati di Stuores/Stuores Wiesen section(Province of Belluno,Veneto Region,Italy)is located a few hundred meters east of Pralongià,a locality northeast of Arabba(Belluno).The section consists of hemipelagites and thin turbidite beds(both siliciclastic and carbonate intraclastic),deposited below storm wave-base with a high but variable sediment accumulation rate(San Cassiano Fm.).The GSSP boundary is located at the base of bed SW4,45 m above the base of the San Cassiano Fm.Bed SW4 yielded ammonoids including Daxatina canadensis(Whiteaves),which is the primary global marker for identifying the base of the Carnian Stage.The secondary marker for the Carnian Stage,the conodont Paragondolella polygnathiformis(Budurov and Stefanov),appears 70 cm above the first occurrence of Daxatina canadensis and at the base of a long normal-polarity magnetic zone(S2n)in close proximity to the boundary.Furthermore,the GSSP is located one ammonite subzone just above a level dated at 237.77±0.14 Ma.展开更多
Following the unanimous approval of the Executive Committee on the International Union of Geological Sciences as notified on April 8,2016,the Global boundary Stratotype Section and Point for the base of the Albian Sta...Following the unanimous approval of the Executive Committee on the International Union of Geological Sciences as notified on April 8,2016,the Global boundary Stratotype Section and Point for the base of the Albian Stage of the Cretaceous is defined at the first occurrence datum of the planktonic foraminiferan Microhedbergella renilaevis Huber and Leckie,2011 at a level 37.4 meters above the base of the Marnes Bleues Formation and 40 cm above the base of the Niveau Kilian marker bed in the section SSE of the Col de Pré-Guittard,Arnayon,Drôme,France.The first occurrence of Microhedbergella renilaevis is placed within a 100-m section of argillaceous sediments with 28 secondary markers including calcareous nannofossils,planktonic foraminifera,an inoceramid bivalve,ammonites,stable carbon isotopes,and local marker beds.展开更多
The Global Stratotype Section and Point(GSSP)for the Cretaceous/Paleogene(K/Pg)boundary was defined at the base of the boundary clay at a section near El Kef,Tunisia,but the outcrop became quite deteriorated.In order ...The Global Stratotype Section and Point(GSSP)for the Cretaceous/Paleogene(K/Pg)boundary was defined at the base of the boundary clay at a section near El Kef,Tunisia,but the outcrop became quite deteriorated.In order to better characterize the boundary and to solve problems of correlation,several auxiliary sections are designed and described in detail including:Aïn Settara and Ellès in Tunisia,Caravaca and Zumaya in Spain,Bidart in France and El Mulato and Bochil in Mexico.These sections are the most continuous,expanded and representative of marine sedimentation in areas proximal and distal to the Chicxulub meteorite impact site.展开更多
The Kyrshabakty section in the Malyi Karatau Range,southern Kazakhstan,has been approved as the Auxiliary boundary Stratotype Section and Point(ASSP)for the base of the Jiangshanian Stage of the Furongian Series(Cambr...The Kyrshabakty section in the Malyi Karatau Range,southern Kazakhstan,has been approved as the Auxiliary boundary Stratotype Section and Point(ASSP)for the base of the Jiangshanian Stage of the Furongian Series(Cambrian System).The first appearance datum(FAD)of the agnostoid trilobite Agnostotes orientalis coincides with the horizon marking the base of the Jiangshanian Stage,and the FAD of A.orientalis occurs at 259.0 m in the measured section,61.2 m above the base of Unit 8 in the Zhumabai Formation.The boundary interval in the Kyshabakty section shows a relatively monotonous succession of carbonate deposits.The section contains an abundance of Cambrian fossils including diverse trilobites,brachiopods,molluscs,bradoriids,protoconodonts and paraconodonts.展开更多
The GSSP for the base of the Lutetian Stage(early/middle Eocene boundary)is defined at 167.85 metres in the Gorrondatxe sea-cliff section(NW of Bilbao city,Basque Country,northern Spain;43°22'46.47"N,3&#...The GSSP for the base of the Lutetian Stage(early/middle Eocene boundary)is defined at 167.85 metres in the Gorrondatxe sea-cliff section(NW of Bilbao city,Basque Country,northern Spain;43°22'46.47"N,3°00'51.61"W).This dark marly level coincides with the lowest occurrence of the calcareous nannofossil Blackites inflatus(CP12a/b boundary),is in the middle of polarity Chron C21r,and has been interpreted as the maximumflooding surface of a depositional sequence that may be global in extent.The GSSP age is approximately 800 kyr(39 precession cycles)younger than the beginning of polarity Chron C21r,or~47.8 Ma in the GTS04 time scale.The proposal was approved by the International Subcommission on Paleogene Stratigraphy in February 2010,approved by the International Commission of Stratigraphy in January 2011,and ratified by the International Union of Geological Sciences in April 2011.展开更多
The Bathonian GSSP is defined at the base of limestone bed RB071 in the Ravin du Bès Section,Bas-Auran area,southern Subalpine Chains(France).This section satisfies most of the requirements recommended by the Int...The Bathonian GSSP is defined at the base of limestone bed RB071 in the Ravin du Bès Section,Bas-Auran area,southern Subalpine Chains(France).This section satisfies most of the requirements recommended by the International Commission on Stratigraphy.The exposure extends over 13 m in thickness.展开更多
The GSSP for the base of the Chattian Stage(Paleogene System,Oligocene Series)is defined at meter level 197 in the Monte Cagnero section,which belongs to the pelagic succession of the Umbria–Marche basin(Urbania,cent...The GSSP for the base of the Chattian Stage(Paleogene System,Oligocene Series)is defined at meter level 197 in the Monte Cagnero section,which belongs to the pelagic succession of the Umbria–Marche basin(Urbania,central Italy:43°38′47.81″N–12°28′03.83″E).This level with an astronomical age of 27.82 Ma coincides with the highest common occurrence of the planktonic foraminifer Chiloguembelina cubensis at the base of planktonic foraminiferal O5 Zone and falls in the upper part of calcareous nannofossil NP24 Zone,in the lower part of dinocyst Dbi Zone,and in the lower Chron C9n.The proposal was approved by the International Subcommission of Paleogene Stratigraphy in July 2015,approved by the International Commission of Stratigraphy in August 2016,and ratified by the International Union of Geological Sciences in September 2016.展开更多
The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoc...The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.展开更多
基金supported by the National Natural Science Foundation of China(42293280,42272031,42250104,42261144668)Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB26000000).
文摘The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary section at Tieqiao have been permanently flooded since 2020.We herein designate an excavated section at Penglaitan as the new GSSP and the Fengshan section as a new Standard Auxiliary Boundary Stratotype(SABS).In addition,we revised the original definition based on a detailed restudy of the conodont succession from the two sections.We define the GSSP of the base-Wuchiapingian by the First Appearance Datum(FAD)of Clarkina postbitteri within the lineage Jinogondolella granti→Clarkina postbitteri→C.dukouensis.It represents a major evolutionary turnover in conodonts from Jinogondolella to Clarkina and marks the end-Guadalupian extinction event.The U-Pb date of 259.51±0.21 Ma from the uppermost part of the Emeishan basalt is adopted for the GLB age.δ13Ccarb chemostratigraphy at the SABS exhibits several excursions between 3‰and 5‰across the GLB interval.Carbonate 87Sr/86Sr ratio is 0.707244 at the GLB.Remarkably,the SABS contains six normal and six reverse geomagnetic polarity zones in the uppermost Capitanian and three in the lowest Wuchiapingian.
文摘Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geological Sciences unanimously approved in March 2023 the Global Stratotype Section and Point(GSSP)for the Barremian Stage(Lower Cretaceous).The base of the Barremian Stage is defined at the base of bed 171 of the Río Argos section,near Caravaca(SE Spain)and correlated by the first appearance of the ammonite species Taveraidiscus hugii.This event falls within the NC5C calcareous nannofossil Subzone,the Lilliputianella semielongata planktonic foraminiferal Zone,and the Dorothia ouachensis benthic foraminiferal Zone.It roughly coincides with the beginning of a slightly negative trend interval in theδ^(13)C curve.Indirect calibration to the magnetostratigraphic scale suggests that the boundary falls in the lowermost part of polarity chron M3r.According to the astrochronological analysis,a time interval of 0.74 myr separates the beginning of the late Hauterivian Faraoni Episode from the base of the Barremian,which is dated at 125.77 MA.
文摘The Global Stratotype Section and Point(GSSP)of the base of Langhian Stage(base of the Middle Miocene Subseries)is defined at a level of 17.84 m in the“Lower La Vedova Beach”section in central Italy.This level marks the mid-point of the darker marly interval above“Megabed IV”which has been astronomically calibrated to the most prominent~100-kyr eccentricity maximum,with an astronomical age of 15.981 Ma according to La2004 nominal solution,and of 15.978 Ma according to the La2011,in the 405-kyr maximum around 16.0 Ma.The GSSP level in the Lower La Vedova Beach section corresponds closely to the top of Chron C5Cn(at 15.795 m),which is considered the principal event for recognizing the boundary globally.This magnetic reversal with an astronomical age of 16.017 Ma(Turco et al.,2017)(15.97 Ma in Hilgen et al.,2012 ATNTS,2012;15.994 Ma in Raffi et al.,2020 in GTS2020)is preferred to the historical guiding criterion,the Praeorbulina datum,which has been complicated by taxonomic confusion and revision(Turco et al.,2011a),and hence is considered less suitable for recognizing the boundary.The Lower La Vedova Beach section is preferred to the St.Peter’s Pool section(in Malta)as it has an independent astronomical tuning and a better paleomagnetic signal.
基金Research on the Huanghuachang GSSP and preparation of this proposal was financially supported by the China Geological Survey(NO:200113900072)National Natural Science Foundation of China(NO:40272020)the Germany Academic exchange Centre(DAAD),Chinese Commission of Stratigraphy and Yichang Institute of Geology and Mineral Resources(YIGMR).
文摘The Huanghuachang section near Yichang,southern China was successively approved by ISOS,recognized by ICS and then officially ratified as being the Global Stratotype Section and point(GSSP)for the base of the Middle Ordovician Series and the Third Stage,named as Dapingian,of the Ordovician System.The conodont succession at the section is complete across the Lower to Middle Ordovician series boundary and several excellent phylogenetic lineages of Baltoniodus,Gothodus,Microzarkodina and Periodon are represented.The base of the Middle Ordovician Series and the Daping Stage is defined at a point 10.57 m above the base of the Dawan Formation at the base of Bed SHod-16 of the Huanghuachang section,22km NE of Yichang City,Hubei Province,South China.It coincides with the first appearance datum(FAD)of the conodont species Baltoniodus triangularis within the Baltoniodus lineage starting from Baltoniodus cf.B.triangularis to Baltoniodus navis.It is associated with the FAD of Periodon sp.A and followed closely by the FAD of Microzarkodina flabellum,which is taken as a reasonable proxy for the boundary.This level approxi-mates the boundary between the lower and upper Azygograptus suecicus graptolite Biozone,and nearly coincides with the base of the Belonechitina cf.henryi chitinozoan Biozone.The same faunal succession is also recorded from the Chenjiahe section,near Daping village,5 km to the north of the Huanghuachang section.
基金supported in part by grants from the Chinese Academy of Sciences(KZCX2-YW-122)the Ministry of Science and Technology of China(2006FY120300)+2 种基金National Natural Science Foundation of China(40332018)to Pengby a grant from the U.S.National Science Foundation(EAR-0106883)to Babcockby a grant from National Natural Science Foundation of China(40672023)to Zuo.
文摘The Global boundary Stratotype Section and Point(GSSP)for the base of the Guzhangian Stage(Cambrian Series 3)is defined at the base of a limestone(calcisiltite)layer 121.3 m above the base of the Huaqiao Formation in the Louyixi section along the Youshui River(Fengtan Reservoir),about 4 km northwest of Luoyixi(4 km southeast of Wangcun),in northwestern Hunan,China.The GSSP is exposed in a road cut at a position of 28°43.20'N and 109°57.88'E.The GSSP level contains the lowest occurrence of the cosmopolitan agnostoid trilobite Lejopyge laevigata(base of the L.laevigata Zone).Secondary global markers near the base of the stage include the appearance of either L.calva or L.armata just below the base of the stage,the appearance of conodonts associated with the base of the Laiwugnathus laiwuensis Zone,and the transgressive phase of a small eustatic event.Faunal turnovers close to the base of the Guzhangian Stage are recognized as near the base of the Boomerangian Stage in Australia,the base of the Aldanaspis Zone(polymerid trilobites)in Siberia,and the base of the Paradoxides forchhammeri Zone in western Avalonia.The horizon corresponding to the first appearance of L.laevigata is near the peak of a rather long negativeδ13C excursion of up to 0.58‰.
文摘The Global Stratotype Section and Point(GSSP)for the Base of the Serravallian Stage(Middle Miocene)is defined in the Ras il Pellegrin section located in the coastal cliffs along the Fomm Ir-Rih Bay on the west coast of Malta(35°54'50"N,14°20'10"E).The GSSP is at the base of the Blue Clay Formation(i.e.,top of the transitional bed of the uppermost Globigerina Limestone).This boundary between the Langhian and Serravallian stages coincides with the end of the major Mi-3b global cooling step in the oxygen isotopes and reflects a major increase in Antarctic ice volume,marking the end of the Middle Miocene climate transition and the Earth’s transformation into an“Icehouse”climate state.
文摘The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country,northern Spain.In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation,ca.49 m above the Cretaceous/Paleogene boundary.At the base of the Selandian,marls replace the succession of Danian red limestone and limestone-marl couplets.The best marine,global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group.
基金sponsored by the Austrian National Committee(Austrian Academy of Sciences)for IGCPfinancial support from the HP program of Utrecht University(The Netherlands)partial support from the US National Science Foundation(Grant EAR 0518605).
文摘The Global Stratotype Section and Point(GSSP)defining the base of the Jurassic System Lower Jurassic Epoch and Hettangian Stage is situated at the Kuhjoch pass,Karwendel Mountains,Northern Calcareous Alps,Austria(47°29'02"N/11°31'50"E).The Triassic-Jurassic(T-J)boundary is exposed at Kuhjoch West and at Kuhjoch East,and corresponds to the first occurrence(FO)of the ammonite Psiloceras spelae tirolicum.The“Golden Spike”was fixed at Kuhjoch East.The section displays a high and continuous sedimentation rate with a constant facies trend across the boundary level.
基金The work was supported by the National Natural Science Foundation of China(project no.40232025).
文摘This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting of the section are briefly introduced. Changhsingian to ＂Griesbachian＂ conodont and ammonoid zonations, the most perfect Permo-Triassic zonations over the world, are presented, with a short discussion on the age of Otoceras, The Changhsingian to ＂Griesbachian＂ strata are subdivided into three 3rd order sequences, and the sedimentary structure of each sequence is indicated. The paper presents a correlation of the Changhsingian to ＂Griesbachian＂ magneetostratigraphy of the Meishan section with the general scale, and informed the negation of a short magnetic reversal at the PTB suggested by Zhu and Liu （1999）. Recent developments of chemostratigraphy of δ^13C and δ^34S are introduced, especially the discovery of more than one negative δ^13C excursions across the PTB. Two important molecular researches reveal the profound changes at the base of eco-system, the microbial catastrophy, and the euxinic conditions in the photic zone during the Permian-Triassic superanoxic event. The paper reports the changes in dating the age of PTB since 2001. According to recent achievements, the age of volcanogenic claybed 25, 14 cm below the PTB, is now set at 252.4±0.3 Ma. A discussion on the eventostratigraphy concludes that, although there is a major event episode at beds 25-26, the events across the PTB at Meishan are multi-episodic and commenced prior to the Event Beds 25-26, thus the possibility that the mass extinction was mainly induced by an exterrestrial impact is largely excluded.
文摘This paper gives the detail description of Meishucun section , Yunnan , China . By studying biotic characteristics , analyzing isotopic age and comparing with the main Precambrian - Cambrian boundary sections in the world , we construct a global stratotype section and a point for the Precambrian-Cambrian boundary at Meishucun , which are of the convenient assessibility , abundant fossils of diverse groups , continuous sedimentation . perfect outcropping , lock of tectonic and metamorphic alteration , and have been deep studied in all related disciplines of sciences .
文摘The Meishucun secton has been recommended as an international candidate stratotype secton of thePrecambrian-Cambrian boundary. The paper deals with the palaeomagnetic study on the section. A total of159 palaeomagnetic samples were successively collected from the platform-facies sequence of carbonates andphosphates at the section. Thermal demagnetization results indicate a great majority of the rocks at the sectionhave been strongly overprinted by recent magnetic field, but 57 samples have preserved remanentmagnetization with antipodal directions (mean D/I=4.2°/ 7.1°, K=9, α_(95) = 6.6°). Baaed on calculation,the location of the palaeomagnetic pole was at 68.8°N and 270.7°E, which is different from any palaeopolesobtained from younger Phanerozoic rocks in South China. The results reveal a polarity zonation which in-cludes at least 9 reversal events. A comparison of China's magnetostratigraphic records with those fromSiberia, Australia and the western U.S.A. shows that all the sections are characterized by frequent polarity re-versals.
基金supported by the BIOSCALES Project(POCTI/36438/PAL/2000)coordinated by the Universidade NOVA de Lisboa+1 种基金R.B.Rocha thanks the support of A.F.Soares,J.C.Kullberg,P.S.Caetano and P.H.VerdialFinancial support was provided to L.V.Duarte,S.Pinto and M.C.Cabral by Projects PDCTE/CTA/44907/2002 and PTDC/CTE-GIX/098968/2008.
文摘The Global Stratotype Section and Point(GSSP)for the base of Toarcian Stage,Lower Jurassic,is placed at the base of micritic limestone bed 15e at Ponta do Trovão(Peniche,Lusitanian Basin,Portugal;coordinates:39°22′15″N,9°23′07″W),80km north of Lisbon,and coincides with the mass occurrence of the ammonite Dactylioceras(Eodactylites).The Pliensbachian/Toarcian boundary(PLB/TOA)is contained in a continuous section forming over 450m of carbonate-rich sediments.Tectonics,syn-sedimentary disturbance,metamorphism or significant diagenesis do not significantly affect this area.At the PLB/TOA,no vertical facies changes,stratigraphical gaps or hiatuses have been recorded.The base of the Toarcian Stage is marked in the bed 15e by the first occurrence of D.(E.)simplex,co-occurring with D.(E.)pseudocommune and D.(E.)polymorphum.The ammonite association of D.(Eodactylites)ssp.and other species e.g.Protogrammoceras(Paltarpites)cf.
文摘The Global boundary Stratotype Section and Point(GSSP)for the base of the Carnian Stage(Late Triassic)is defined on the north flank of the Cordevole Valley,on the southern slopes of the crest separating the Badia/Abtei and the Cordevole valleys(46°31'37"N,11°55'49"E)at an elevation of 1980 m,approximately 4.7 km south of San Cassiano/St.Kassian in the Dolomites(Southern Alps).The Prati di Stuores/Stuores Wiesen section(Province of Belluno,Veneto Region,Italy)is located a few hundred meters east of Pralongià,a locality northeast of Arabba(Belluno).The section consists of hemipelagites and thin turbidite beds(both siliciclastic and carbonate intraclastic),deposited below storm wave-base with a high but variable sediment accumulation rate(San Cassiano Fm.).The GSSP boundary is located at the base of bed SW4,45 m above the base of the San Cassiano Fm.Bed SW4 yielded ammonoids including Daxatina canadensis(Whiteaves),which is the primary global marker for identifying the base of the Carnian Stage.The secondary marker for the Carnian Stage,the conodont Paragondolella polygnathiformis(Budurov and Stefanov),appears 70 cm above the first occurrence of Daxatina canadensis and at the base of a long normal-polarity magnetic zone(S2n)in close proximity to the boundary.Furthermore,the GSSP is located one ammonite subzone just above a level dated at 237.77±0.14 Ma.
文摘Following the unanimous approval of the Executive Committee on the International Union of Geological Sciences as notified on April 8,2016,the Global boundary Stratotype Section and Point for the base of the Albian Stage of the Cretaceous is defined at the first occurrence datum of the planktonic foraminiferan Microhedbergella renilaevis Huber and Leckie,2011 at a level 37.4 meters above the base of the Marnes Bleues Formation and 40 cm above the base of the Niveau Kilian marker bed in the section SSE of the Col de Pré-Guittard,Arnayon,Drôme,France.The first occurrence of Microhedbergella renilaevis is placed within a 100-m section of argillaceous sediments with 28 secondary markers including calcareous nannofossils,planktonic foraminifera,an inoceramid bivalve,ammonites,stable carbon isotopes,and local marker beds.
基金funded by the IUGS,the Spanish Ministerio de Educación y Ciencia(Consolider project CGL2007-63724 and AECI project A/4845/06)the Aragonian Departamento de Educación y Ciencia(DGA group E05)L.Alegret acknowledges support from a Ramon y Cajal research contract from the Spanish Ministry of Science and Technology.
文摘The Global Stratotype Section and Point(GSSP)for the Cretaceous/Paleogene(K/Pg)boundary was defined at the base of the boundary clay at a section near El Kef,Tunisia,but the outcrop became quite deteriorated.In order to better characterize the boundary and to solve problems of correlation,several auxiliary sections are designed and described in detail including:Aïn Settara and Ellès in Tunisia,Caravaca and Zumaya in Spain,Bidart in France and El Mulato and Bochil in Mexico.These sections are the most continuous,expanded and representative of marine sedimentation in areas proximal and distal to the Chicxulub meteorite impact site.
文摘The Kyrshabakty section in the Malyi Karatau Range,southern Kazakhstan,has been approved as the Auxiliary boundary Stratotype Section and Point(ASSP)for the base of the Jiangshanian Stage of the Furongian Series(Cambrian System).The first appearance datum(FAD)of the agnostoid trilobite Agnostotes orientalis coincides with the horizon marking the base of the Jiangshanian Stage,and the FAD of A.orientalis occurs at 259.0 m in the measured section,61.2 m above the base of Unit 8 in the Zhumabai Formation.The boundary interval in the Kyshabakty section shows a relatively monotonous succession of carbonate deposits.The section contains an abundance of Cambrian fossils including diverse trilobites,brachiopods,molluscs,bradoriids,protoconodonts and paraconodonts.
基金Financial support was mainly provided by different projects of the Ministry of Science and Innovation of Spain,the Town Council of Getxo and the Basque Government.
文摘The GSSP for the base of the Lutetian Stage(early/middle Eocene boundary)is defined at 167.85 metres in the Gorrondatxe sea-cliff section(NW of Bilbao city,Basque Country,northern Spain;43°22'46.47"N,3°00'51.61"W).This dark marly level coincides with the lowest occurrence of the calcareous nannofossil Blackites inflatus(CP12a/b boundary),is in the middle of polarity Chron C21r,and has been interpreted as the maximumflooding surface of a depositional sequence that may be global in extent.The GSSP age is approximately 800 kyr(39 precession cycles)younger than the beginning of polarity Chron C21r,or~47.8 Ma in the GTS04 time scale.The proposal was approved by the International Subcommission on Paleogene Stratigraphy in February 2010,approved by the International Commission of Stratigraphy in January 2011,and ratified by the International Union of Geological Sciences in April 2011.
基金supported by the CGL2004-0694/BTE(MEC-CSIC)and CGL2008-01273/BTE(MICINN)projectsgrants from the 2006 and 2007 Geoconservation Projects,respectively coordinated at the Madrid and Torino universities.
文摘The Bathonian GSSP is defined at the base of limestone bed RB071 in the Ravin du Bès Section,Bas-Auran area,southern Subalpine Chains(France).This section satisfies most of the requirements recommended by the International Commission on Stratigraphy.The exposure extends over 13 m in thickness.
文摘The GSSP for the base of the Chattian Stage(Paleogene System,Oligocene Series)is defined at meter level 197 in the Monte Cagnero section,which belongs to the pelagic succession of the Umbria–Marche basin(Urbania,central Italy:43°38′47.81″N–12°28′03.83″E).This level with an astronomical age of 27.82 Ma coincides with the highest common occurrence of the planktonic foraminifer Chiloguembelina cubensis at the base of planktonic foraminiferal O5 Zone and falls in the upper part of calcareous nannofossil NP24 Zone,in the lower part of dinocyst Dbi Zone,and in the lower Chron C9n.The proposal was approved by the International Subcommission of Paleogene Stratigraphy in July 2015,approved by the International Commission of Stratigraphy in August 2016,and ratified by the International Union of Geological Sciences in September 2016.
文摘The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.
