The Sub-Boreal/Boreal ammonite succession at the Oxfordian/Kimmeridgian boundary at Flodigarry, Staffin Bay (Isle of Skye), Scotland

2005 ◽  
Vol 96 (4) ◽  
pp. 387-405 ◽  
Author(s):  
Bronisław A. Matyja ◽  
Andrzej Wierzbowski ◽  
John K. Wright
Keyword(s):  
Close Correlation ◽  
Current Standard ◽  
First Occurrence ◽  
Stratotype Section ◽  
Isle Of Skye ◽  
Zonal Boundary

ABSTRACTThis paper describes extensive new collections of ammonites made bed-by-bed across the Oxfordian/Kimmeridgian boundary sequence in the Flodigarry sections at Staffin Bay on the Isle of Skye. The ammonites belong to the Sub-Boreal family Aulacostephanidae and the Boreal family Cardioceratidae, enabling recognition of both the current standard Sub-Boreal and Boreal ammonite zonations. In consequence, it is possible to make a close correlation of these two zonal schemes through the interval studied in Skye. The research has provided new palaeontological data at levels of precision that justify the proposal of the section at Staffin as the site of a potential Global Boundary Stratotype Section and Point (GSSP) for the Oxfordian/Kimmeridgian boundary.The traditional Oxfordian/Kimmeridgian boundary placed at the Pseudocordata/Baylei zonal boundary of the Sub-Boreal zonal scheme corresponds precisely to the Rosenkrantzi/Bauhini zonal boundary of the Boreal zonal scheme. This level is characterised by the appearance of the first Pictonia (Pictonia flodigarriensis sp. nov.) together with first Prorasenia, replacing an older assemblage of Ringsteadia–Microbiplices (Sub-Boreal). It is also characterised by the first occurrence of small-sized Amoeboceras (Plasmatites) spp., as well as large Amoeboceras schulginae Mesezhnikov (Boreal). An alternative level that may be considered as a potential GSSP is the boundary between the Bauhini Zone and the Kitchini Zone of the Boreal zonal scheme, characterised by first occurrence of Amoeboceras (Amoebites) of the A. bayi group. This level corresponds to the Planula/Galar subzonal boundary of the Sub-Mediterranean zonal scheme, and lies close to the currently accepted Oxfordian/Kimmeridgian boundary in the Sub-Mediterranean Province.

On the age of the Early/Middle Eocene boundary and other related events: cyclostratigraphic refinements from the Pyrenean Otsakar section and the Lutetian GSSP

2010 ◽  
Vol 148 (3) ◽  
pp. 442-460 ◽  
Author(s):  
A. PAYROS ◽  
J. DINARÈS-TURELL ◽  
G. BERNAOLA ◽  
X. ORUE-ETXEBARRIA ◽  
E. APELLANIZ ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Basque Country ◽  
Time Lapse ◽  
Early Eocene ◽  
Calcareous Nannofossil ◽  
Current Time ◽  
Correlation Criterion ◽  
First Occurrence ◽  
Stratotype Section ◽  
Zonal Boundary

AbstractAn integrated bio-, magneto- and cyclostratigraphic study of the Ypresian/Lutetian (Early/Middle Eocene) transition along the Otsakar section resulted in the identification of the C22n/C21r chron boundary and of the calcareous nannofossil CP12a/b zonal boundary; the latter is the main correlation criterion of the Lutetian Global Stratotype Section and Point (GSSP) recently defined at Gorrondatxe (Basque Country). By counting precession-related mudstone–marl couplets of 21 ka, the time lapse between both events was calculated to be 819 ka. This suggests that the age of the CP12a/b boundary, and hence that of the Early/Middle Eocene boundary, is 47.76 Ma, 250 ka younger than previously thought. This age agrees with, and is supported by, estimates from Gorrondatxe based on the time lapse between the Lutetian GSSP and the C21r/C21n boundary. The duration of Chron C21r is estimated at 1.326 Ma. Given that the base of the Eocene is dated at 55.8 Ma, the duration of the Early Eocene is 8 Ma, 0.8 Ma longer than in current time scales. The Otsakar results further show that the bases of planktonic foraminiferal zones E8 and P10 are younger than the CP12a/b boundary. The first occurrence ofTurborotalia frontosa, being approximately 550 ka older that the CP12a/b boundary, is the planktonic foraminiferal event that lies closest to the Early/Middle Eocene boundary. The larger foraminiferal SBZ12/13 boundary is located close to the CP12a/b boundary and correlates with Chron C21r, not with the C22n/C21r boundary.

Integrated stratigraphy at the Bartonian–Priabonian transition: Correlation between shallow benthic and calcareous plankton zones (Varignano section, northern Italy)

2019 ◽  
Vol 132 (3-4) ◽  
pp. 495-520
Author(s):  
Valeria Luciani ◽  
Eliana Fornaciari ◽  
Cesare A. Papazzoni ◽  
Edoardo Dallanave ◽  
Luca Giusberti ◽  
...  
Keyword(s):  
Late Eocene ◽  
Northern Italy ◽  
Critical Interval ◽  
Larger Foraminifera ◽  
Ne Italy ◽  
First Occurrence ◽  
Calcareous Plankton ◽  
Stratotype Section ◽  
Primary Base ◽  
Zonal Boundary

Abstract The Varignano section (Trento province, northern Italy) provides an exceptional opportunity for a direct correlation between shallow benthic (SB) zones and standard calcareous plankton zones at the Bartonian–Priabonian transition (middle–late Eocene). This transition has attracted great attention by biostratigraphers in the last decades in searching for a boundary stratotype section. The Alano di Piave section (NE Italy) is the leading candidate for the base Priabonian Global Stratotype Section and Point (GSSP). However, at Alano, larger foraminifera-bearing resedimented levels occur exclusively well below the critical interval. Conversely, the Varignano section, located ∼80 km west of the Alano section, preserves several coarse bioclastic levels rich in larger foraminifera throughout the section. These levels are intercalated with basinal marlstones, crystal tuff layers, and an organic-rich interval. The Varignano section spans planktic foraminiferal Zones E10 and E11 to lower E14, calcareous nannofossil Zones MNP16Bc to MNP18 and Chrons 18n to 17n.2n. The main calcareous plankton events recently proposed as primary base-Priabonian correlation tools, i.e., the last occurrence of the genus Morozovelloides and the Base common (= acme beginning) of Cribrocentrum erbae occur, respectively, within C17n.3n and C17n.2n. We correlate prominent crystal tuff layers exposed at Varignano with those outcropping at Alano, including the Tiziano bed, whose base has also been proposed as the GSSP level. The Varignano section spans the upper SB17 and the lower SB18 Zones, with the zonal boundary marked by the first occurrence of the genus Pellatispira. This event occurs in the lower part of Zones E13 and MNP17A within C18n, well below all the potential criteria to identify the GSSP that also includes Chron C17n.1n base. We point out that the usage of shallow-water biostratigraphers in placing the base of the Priabonian at the base of Zone SB19 is inconsistent with the proposed plankton events.

Correlation of calcareous nannofossil zones to the local first occurrence of Pachydiscus neubergicus (von Hauer, 1858) (Ammonoidea) in European Upper Cretaceous sections

2003 ◽  
Vol 82 (3) ◽  
pp. 283-288 ◽  
Author(s):  
M. Wagreich ◽  
T. Küchler ◽  
H. Summesberger
Keyword(s):  
Upper Cretaceous ◽  
Type Locality ◽  
Calcareous Nannofossil ◽  
Northern Spain ◽  
Northern Margin ◽  
First Occurrence ◽  
Stratotype Section ◽  
Sw France

AbstractThe first occurrence (FO) of the ammonite Pachydiscus neubergicus (von Hauer, 1858) has been correlated to calcareous nannofossil zonations in several European sections along the northern margin of the Tethyan palaeobiogeographic realm. Both the proposed stratotype section of Tercis (SW France) and complete, ammonite-bearing sections in northern Spain document the FO of P. neubergicus within standard nannofossil zone CC23a (UC16), below the LO of Broinsonia parca constricta. Other sections such as the type locality Neuberg (Austria), Nagoriani (the Ukraine) and Bjala (Bulgaria) indicate considerable diachroneity of local FOs and show P. neubergicus to range up to nannofossil zone CC25b/c (UC20; Late Maastrichtian).

The base of the Jurassic System: new data on the first appearance of Psiloceras planorbis in southwest Britain

1994 ◽  
Vol 131 (6) ◽  
pp. 841-844 ◽  
Author(s):  
Peter Hodges
Keyword(s):  
Jurassic System ◽  
First Occurrence ◽  
Facies Change ◽  
Stratotype Section ◽  
Definition Of

AbstractRecent collecting in the Lower Lias of localities at St Audrie's Bay, north Somerset, Sedbury Cliff, Gloucester and Lavernock Point, South Glamorgan has yielded Psiloceras planorbis (J. de C. Sowerby) in beds considered by some to be of Rhaetian, Triassic age. These are the earliest records of this ammonite to date in southwest Britain. Evidence is provided of a major facies change at the top of the pre-planorbis beds followed by the diachronous first occurrence of Psiloceras planorbis. These new data have implications for the use of earliest occurrence of Psiloceras planorbis as a chronostratigraphic marker in defining the base of the Jurassic System, and for the definition of the base of the Hettangian Stage in the recently proposed candidate Global Stratotype Section at St Audrie's Bay.

Streptognathodus (Conodonta) succession at the proposed Carboniferous-Permian boundary stratotype section, Aidaralash Creek, Northern Kazakhstan

1997 ◽  
Vol 71 (3) ◽  
pp. 459-474 ◽  
Author(s):  
Valery V. Chernykh ◽  
Scott M. Ritter
Keyword(s):  
New Species ◽  
River Section ◽  
Permian System ◽  
Northern Kazakhstan ◽  
First Occurrence ◽  
Stratotype Section

Streptognathodus Pa elements dominate conodont faunas from the proposed Carboniferous-Permian boundary stratotype at Aidaralash Creek, northern Kazakhstan. The phyletic development of this genus provides the means for subdividing the late Gzhelian to early Sakmarian prodeltaic section (Beds 9-37) into six zones. The preferred Global Stratotype Section and Point (GSSP) for the base of the Permian System is 27 m above the base of Bed 19 at the first occurrence of Streptognathodus isolatus Chernykh, Ritter, and Wardlaw, 1996. This arbitrarily chosen point in the evolutionary continuum of nodose streptognathodids is recognizable in basinal rocks elsewhere in the Ural trough (lower part of Bed 16 at Usolka) as well as the cyclic shelf succession of the American Midcontinent (Glenrock Limestone Member of the Red Eagle Limestone).Eight new species of Streptognathodus occur in the Aidaralash collections: S. bellus n. sp., S. costaeflabellus n. sp., S. flexuosus n. sp., S. glenisteri n. sp., S. longilatus n. sp., S. rectangularis n. sp., S. sigmoidalis n. sp., and S. tenuialveus n. sp. In addition, three morphotypes with limited occurrence (S. sp. A-C) are left in open nomenclature. New collections of topotype material from the nearby Tabantal River section permit clarification of S. barskovi (Kozur).

Clarification of Coccolithus crassus Bramlette and Sullivan, an index fossil of Coccolithophoridae

1993 ◽  
Vol 67 (1) ◽  
pp. 135-138 ◽  
Author(s):  
Wuchang Wei
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Species Concept ◽  
Lower Eocene ◽  
Considerable Confusion ◽  
First Occurrence ◽  
Upper Paleocene ◽  
Stratigraphic Range ◽  
Scanning Electron ◽  
Zonal Boundary

Coccolithus crassus was described by Bramlette and Sullivan (1961) from the Lodo Formation of California. This species has a short stratigraphic range within the lower Eocene and its first occurrence is a marker for the CP10/CP11 zonal boundary in the widely used nannofossil zonation of Okada and Bukry (1980). Most nannofossil workers, however, do not report this index fossil, and the CP10/CP11 zonal boundary is often not determined. This is in contrast to the work of D. Bukry, who used the first occurrence of C. crassus for the CP10/CP11 boundary in virtually all lower Eocene DSDP cores that he examined (Figure 1). Apparently, there is considerable confusion about C. crassus. For instance, Romein (1979) considered C. crassus a junior synonym of Coccolithus eopelagicus (Bramlette and Riedel) Bramlette and Sullivan; Steinmetz and Stradner (1984, p. 741, Pl. 42, figs. 1 and 2) figured a specimen of Ericsonia subpertusa Hay and Mohler from Zone CP7 (upper Paleocene) as C. crassus; Perch-Nielsen (1985, p. 433, figs. 3.46 and 3.47, p. 504, figs. 58.12 and 58.13) mistook Toweius callosus Perch-Nielsen as C. crassus, as did Varol (1989, p. 302, Pl. 4, figs. 37 and 38). The main problem that prevents most workers from using this index fossil is that the species concept is largely unclear. It appears to be difficult to distinguish C. crassus from C. pelagicus or T. callosus based on the light micrographs of Bramlette and Sullivan (1961, Pl. 1, figs. 4a and 4c), and scanning electron microscope (SEM) photographs of this species have never been published except one specimen of the species was illustrated in Matter et al. (1974, p. 914, Pl. 4, fig. 8) under the name Ericsonia ovalis Black.

scholarly journals Ammonites at the Cenomanian–Turonian boundary in the Sergipe Basin, Brazil

2005 ◽  
Vol 52 ◽  
pp. 167-191
Author(s):  
Andrew Gale ◽  
Peter Bengtson ◽  
William James Kennedy
Keyword(s):  
New Mexico ◽  
First Occurrence ◽  
Stratotype Section

Two distinctive ammonite faunas are described from the Cenomanian–Turonian boundary interval in the Sergipe Basin, Brazil. The Jardim 1 section assemblage comprises Euomphaloceras costatum Cobban, Hook & Kennedy, 1989, Burroceras transitorium Cobban, Hook & Kennedy, 1989, Pseudaspidoceras pseudonodosoides Choffat, 1898, and Vascoceras cf. gamai Choffat, 1898. This same association is found in New Mexico, where it occurs with the upper Cenomanian index fossil Neocardioceras juddii (Barrois & Guerne, 1898). On this basis the Sergipe assemblage is referred to the N. juddii Zone, and correlated with beds 79–84 of the Pueblo, Colorado section. These lie 1.14–0.63 m below the Global boundary Stratotype Section and Point (GSSP) for the base of the Turonian Stage, the base of bed 86, which corresponds to the first occurrence of the ammonite Watinoceras devonense Wright & Kennedy, 1981. The Japaratuba 16 locality in Sergipe yielded an assemblage of Pachydesmoceras kossmati Matsumoto, 1987, Watinoceras coloradoense (Henderson, 1908), Pseudaspidoceras flexuosum Powell, 1963, Pseudovascoceras nigeriense (Woods, 1911), Vascoceras globosum globosum (Reyment, 1954), V. simplex (Barber, 1957), and Pseudotissotia nigeriensis (Woods, 1911). The co-occurrence of W. coloradoense and P. flexuosum is also found in the Pueblo section, in bed 97, 1.65 m above the base of the Turonian. These ammonite records thus allow the placement of the Cenomanian–Turonian boundary in the Sergipe-Alagoas Basin, and correlation with the Global Boundary Stratotype Section and Point at Pueblo.

Clarification of an index nannofossil species for the Paleocene/Eocene boundary

1996 ◽  
Vol 70 (3) ◽  
pp. 526-529
Author(s):  
Wuchang Wei
Keyword(s):  
Calcareous Nannoplankton ◽  
Frequent Use ◽  
First Occurrence ◽  
Zonal Boundary

The first occurrence of Discoaster diastypus Bramlette and Sullivan is a marker for the CP8/CP9 zonal boundary in the widely used nannofossil zonation of Okada and Bukry (1980). This zonal boundary has commonly been used to approximate the Paleocene/Eocene boundary (e.g., Berggren et al., 1985; Perch-Nielsen, 1985). In spite of the frequent use and importance of D. diastypus in biostratigraphy, there has been some confusion about this species in the literature, including some of the most used references. For instance, Bramlette and Sullivan (1961), who first described the species, incorrectly defined D. diastypus in terms of its ray number and size (see Figure 1), and included a specimen of Discoaster falcatus Bramlette and Sullivan as an isotype of D. diastypus (Bramlette and Sullivan, 1961, pi. 11, fig. 6). Perch-Nielsen (1971, pi. 51, figs. 8 and 10) figured a specimen of Discoaster barbadiensis Tan and another specimen of Discoaster bifax Bukry as D. diastypus. These mistakes apparently have gone unnoticed and were adopted by Romein (1979, p. 168) and incorporated in the Handbook of Cenozoic Calcareous Nannoplankton (Aubry, 1984, p. 46, fig. 111; p. 48, figs. 114 and 115).

Biostratigraphy of the Vendian-Cambrian Sukharikha River section, northwestern Siberian Platform

1998 ◽  
Vol 35 (4) ◽  
pp. 339-352 ◽  
Author(s):  
Stephen M Rowland ◽  
Veronica A Luchinina ◽  
Igor V Korovnikov ◽  
Dmitri P Sipin ◽  
Alexander I Tarletskov ◽  
...  
Keyword(s):  
Lower Cambrian ◽  
Carbonate Rock ◽  
Early Cambrian ◽  
River Section ◽  
Isotopic Data ◽  
Apparent Absence ◽  
Small Shelly Fossils ◽  
First Occurrence ◽  
Stratotype Section ◽  
Definition Of

The Sukharikha River section contains more than 800 m of fossiliferous Vendian and Lower Cambrian carbonate rock deposited in ramp, shelf, and slope environments. A diverse fauna of small shelly fossils, calcibionts, brachiopods, trilobites, and archaeocyaths has allowed us to develop a multi-taxa biostratigraphic framework for this section. A dearth of distinctive fossils low in the Sukharikha Formation prevents us from determining the position of the Vendian-Cambrian boundary. Abundant small shelly fossils and archaeocyaths in the uppermost Sukharikha Formation and low in the Krasnoporog Formation provide ample biostratigraphic control near the base of the Tommotian Stage, but the Nemakit-Daldynian - Tommotian boundary, as defined at Ulakhan-Sulugur on the Aldan River, is temporally ambiguous. For this reason there is no precise definition of this boundary. In the Sukharikha River section we have provisionally placed the base of the Tommotian Stage at the first occurrence of Nochoroicyathus sunnaginicus Zone archaeocyaths, about 1.5 m below the top of the Sukharikha Formation. However, we suppose that this horizon actually predates the deposition of nominally basal Tommotian taxa in the Aldan region. A new global stratotype section for the Nemakit-Daldynian - Tommotian boundary should be selected, and this section may turn out to be a good candidate. The paleontological richness (especially small shelly fossils and archaeocyaths), the apparent absence of long depositional hiatuses, and the presence of well-preserved limestones suggest that the Sukharikha River section contains the combination of paleontological, sedimentological, and isotopic data to resolve some fundamental problems in Early Cambrian stratigraphy.

scholarly journals Carboniferous–Permian Boundary in Kansas, Midcontinent, U.S.A.

2006 ◽  
pp. 1-13
Author(s):  
Robert S. Sawin ◽  
Ronald R. West ◽  
Evan K. Franseen ◽  
W. Lynn Watney ◽  
James R. McCauley
Keyword(s):  
North American ◽  
Global Scale ◽  
Geological Survey ◽  
Ural Mountains ◽  
Permian System ◽  
First Occurrence ◽  
Stratigraphic Position ◽  
Stratotype Section ◽  
Rock Section

The placement of the Carboniferous (Pennsylvanian)-Permian boundary in Kansas has been debated since the rocks of this age were first described and named. With the ratification of the Global Stratotype Section and Point (GSSP) for the base of the Permian System in the southern Ural Mountains, the Carboniferous-Permian boundary in Kansas can now be confidently defined. Based on the identification of the first occurrence of the conodont Streptognathodus isolatus that definitively correlates the Kansas rock section to the basal Permian GSSP, the Carboniferous-Permian boundary in Kansas can be placed at the base of the Bennett Shale Member of the Red Eagle Limestone. The Kansas Geological Survey proposes that the Tuttle Creek Lake Spillway section, located in northeast Kansas, be considered for the Carboniferous-Permian boundary stratotype in Kansas. It is further suggested that the stratigraphic position of the Carboniferous-Permian boundary in the Tuttle Creek Lake Spillway section be considered as a potential North American stratotype. In addition to being a significant biostratigraphic boundary, the Carboniferous-Permian boundary and enclosing strata also have significance because they reflect important geologic events and changes that occurred on a regional and global scale.

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