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Jurassic Forum » JURASSIC references & paper reviews » Jurassic around the world » New issue of the Volumina Jurassica is available! (Vol.VII, 2009)
New issue of the Volumina Jurassica is available!
mhornДата: Monday, 08.03.2010, 18:17 | Сообщение # 1
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Volumina Jurassica. 2009. Vol.VII is available online: http://voluminajurassica.org/en/index-7
it is includes the following artiucles:

Fazzuoli S, Orti L. Remarks on the supposed bolid impacts at the T/J boundary in the Corfino Section (Northern Apennines, Italy). P.3-8
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_3-8.pdf
In 1991, American scientists found “shocked” quartz grains, indicating extraterrestrial bolide impacts,near Corfino (Northern Tuscany) in shaly beds at the boundary between the Rhaetian Calcare a Rhaetavicula and the inferred Lower Jurassic (Hettangian) Calcare Massiccio. According to our observations of the same section, the top interval of the Calcare a Rhaetavicula consists of beds of oolitic grainstone, interlayered with thin levels of marls where the shocked quartz grains were found. In the overlying Calcare Massiccio the rock consists mostly of dolomitised and recrystallised mudstone up to about 30 m, where abundant Rhaetian benthic foraminifers occur. The occurrence of shocked quartz in the upper part of the Calcare a Rhaetavicula suggests that one or more impact events took place at this time; however, Triassic fossils occur well above the shocked quartz levels and any impact events therefore occurred within the Rhaetian.

Meister C., Schirolli P., Dommergues J.-L. Sinemurian to lowermost Toarcian ammonites of the Brescian Prealps (Southern Alps, Italy): preliminary biostratigraphical framework and correlations. P.9-18.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_9-18.pdf
A set of 28 ammonite biohorizons or faunal assemblages is proposed for the Sinemurian, the Pliensbachian and the lowermost Toarcian of the Brescian Prealps, in part based on the published data of the authors of this contribution and partly on new results, derived both from recent field investigations and from the study of the historical collection of Lower Jurassic ammonites preserved in the Museum of Natural Sciences of Brescia (Northern Italy). The biohorizons are present in the Liassic carbonate succession of the Brescian Prealps, cropping out between the eastern surroundings of Brescia (Botticino), to the east, and Lake Iseo, to the west. Since the Hettangian this region was subjected to Jurassic rifting. The area of study was located on the eastern border of the wide Lombardian Basin, a part of the southern continental passive margin of Tethys. An articulated fault-system, trending from Brescia to the North, separated the western subsiding area of the Val Trompia-Sebino Basin from the eastern Botticino structural high. After the drowning of the Rhetian-Hettangian Corna Platform, the very thick synrift succession of the Medolo Group accumulated in the Val Trompia-Sebino Basin, whereas the coeval reduced sequence of the Rezzato Encrinite and the overlying Botticino Corso Rosso covered the Botticino High, subsequent to the Early Sinemurian. The ammonite biohorizons and assemblages recognised are quite well integrated and correlable with either the NW European standard zonation or the different zonations proposed for the Tethyan Realm.

Page K.N. High resolution ammonite stratigraphy of the Charmouth Mudstone Formation (Lower Jurassic: Sinemurian-Lower Pliensbachian)in south-west England, UK. P.19-29.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_19-29.pdf
The “Lower Lias” mudrocks of the Charmouth Mudstone Formation in West Dorset coast are world famous for their ammonite faunas, which range from mid Lower Sinemurian (Semicostatum Chronozone) to Lower Pliensbachian (topmost Davoei Chronozone) in age. The succession includes significant non-sequences, however, and as certain other intervals yield only crushed and relatively poorly preserved material, much of the sequence of ammonite faunas of this interval in south-west England has remained poorly understood. Inland, however, although it has been realised for many years that some of the missing horizons reappear, the Formation is very poorly exposed and as a consequence little has been known about its detailed stratigraphy and palaeontology. The systematic recording over 40 years by Mr H.C. Prudden (Montacute) of temporary excavations in East Somerset (around 20 km north of the Dorset coast), combined with material collected by others from similar exposures has now, however, revealed a virtually complete sequence of ammonite faunas through the interval represented by the Formation including from many of the which are missing on the Dorset coast. In particular, only one subchronozone remains to be conclusively proven in the region, the terminal Sinemurian, Aplanatum Subchronozone (Raricostatum Chronozone). This faunal succession is correlated with that on the coast to provide a detailed synthesis of the sequence of ammonite biohorizons in the region, which is correlated with a contemporary Standard Zonation and high-resolution biohorizonal/ zonule scheme for interval in North-West Europe. The significance for regional and international correlations of the Lower Lias is also discussed.

Meister C., Blau J., Dommergues J.-L., Schlatter R., Schmidt-Effing R. The Upper Sinemurian ammonite succession in the Sierra Madre Oriental (Mexico). P.31-36.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_31-36.pdf
In the Sierra Madre Oriental (Mexico), the biostratigraphic subdivision of the Upper Sinemurian can be refined. It has been possible to differentiate 11 horizons from the upper Obtusum Zone to the top of the Raricostatum Zone which are correlated with the NW European standard zonation. The index species of each horizon is figured

Elmi S., Marok A., Sebane A., Almeras Y. Importance of the Mellala section (Traras Mountains, northwestern Algeria) for the correlation of the Pliensbachian-Toarcian boundary. P.37-45.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_37-45.pdf
In the Mellala profile, located in the Traras Mountains (Tlemcen Domain, NW Algeria), the hemipelagic Bayada Fm. includes the transition from the Pliensbachian to the Toarcian within a continuous succession of alternating marls and marly limestones, whose thickness reaches approximatively 50 m. The Bayada Fm. begins in the Upper Domerian. The Solare Subzone of the Emaciatum Zone is proved by the occurence of several Pleuroceras solare (Phillips) in the lower part, associated with Emaciaticeras upwards. The Elisa Subzone is characterized by Tauromeniceras elisa (Fucini), Canavaria finitima (Fucini), Paltarpites bettonii (Fucini) associated with numerous Phymatothyris kerkyreae (Renz) and rare Lobothyris punctata (Sowerby). Leioceratoides gr. serotinus (Bettoni) has been found in the upper part of the subzone. The base of the lowermost Toarcian (Mirabile Horizon, Paltus Subzone) is marked by a decimetric bed (no. 38) with Paltarpites paltus (Buckman) but which has not yielded Eodactylites in the present state of the research. The following calcareous bed (no. 40) has yielded several Dactylioceras (Eodactylites) polymorphum (Fucini), D. (E.) mirabile (Fucini) and D. (E.) pseudocommune (Fucini). Upwards, Eodactylites is abundant over 10 to12 m, especially in Bed no. 44. At 3.50 m below the top, a marker-bed corresponds to a lenticular level of bioclastic quartz-rich limestones that marks the limit between the two members of the formation. The overlying 15 m are attributed to the Semicelatum Subzone (Tethyan nomenclature). At the base a level with D. (Orthodactylites) crosbeyi (Simpson) allows a good correlation with the Clevelandicum Subzone (or Horizon) of Northwestern Europe. The topmost 5 m of the outcrop are dated to the Levisoni Zone with Eleganticeras sp. The anoxic event of the beginning of this Zone is indicated only by an abnormal variability of the foraminifera. The presence of Lenticulina obonensis Ruget indicates stressing conditions. The occurrence, from the Upper Domerian to the Polymorphum Zone, of a fauna comprising the brachiopod Koninckella is important because it confirms that the environment was restricted within a deep, strongly subsiding basin (the “umbilicus”).


Middle Jurassic - Lower Cretaceous ammonites & aptychi
 
mhornДата: Monday, 08.03.2010, 18:17 | Сообщение # 2
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Nakada K., Matsuoka A. On the Pliensbachian/Toarcian boundary in the Lower Jurassic Toyora Group in southwest Japan. P.47-54.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_47-54.pdf
The Toyora Group, consisting of continental shelf sediments, is exposed in southwest Japan. It is divided into three formations, the Higashinagano, the Nishinakayama, and the Utano formations in ascending order. The Nm Member, the lower part of the Nishinakayama Formation, has yielded abundant ammonites, indicating successive ages of Early Toarcian. The ammonite zonation was established on these materials, but the Pliensbachian/Toarcian (P/T) boundary was not defined clearly in previous studies. A total of 99 ammonite specimens including 11 genera and 16 species were collected along the Sakuraguchi-dani Valley. The first occurrence of Dactylioceras helianthoides is the most suitable candidate for drawing the P/T boundary in the Toyora Group, the boundary being drawn at least 35.5 m lower than the previously indicated.

Perilli N., Rodrigues R., Veiga de Oliveira L.C., Catanzariti R. Lower Toarcian organic-rich sediments from the Tuscan Succession (Northern Apennines, Italy): preliminary results. P.55-65.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_55-65.pdf
For the first time is here documented the presence of Lower Toarcian black shales in the lower portion of the Calcari e marne a Posidonia (Posidonia Marls auctt.) belonging to the Tuscan Nappe. It consists of alternations of 30 cm to 5 m thick black laminated marlstone and marly claystone, with TOC values ranging from 0.43% to 2.49%. Based on calcareous nannofossils, the basal portion of the Calcari e marne a Posidonia spans the Lotharingius hauffii to Carinolithus superbus zones, and the organic-rich interval lies within the Carinolithus superbus Zone.

Pavia G., Martire L. Indirect biostratigraphy in condensed successions: a case history from the Bajocian of Normandy (NW France). P.67-76.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_67-76.pdf
The fossil assemblages of the Bajocian of Normandy are affected by taphonomic condensation, and the use of these assemblages for biostratigraphy must be carried out with great care because of the taphonomic reworking (reelaboration) of most of them. Nevertheless such beautiful fossils, ammonites in particular, retain their value at least as taxonomic references if their relative stratigraphic position is recognized. Such a goal has been achieved in the Bretteville section, where the “Oolithe Ferrugineuse de Bayeux” Formation (OFB), consisting of 14 beds contained within 170 cm of strata, is exposed. Each bed contains a condensed ammonite assemblage in which the overall chronologic interval represented by fossils is longer than the time of sedimentation of the bed, and no ammonites can be defined as contemporaneous with the enclosing matrix, except for the topmost two beds. The timing of biologic and sedimentary events in this Fe-oolitic succession must thus be established in an indirect way, through a stratigraphy of fossils based on their taphonomically delayed first occurrence. In particular, we can only define the maximum age of each layer, constrained by the youngest recorded fossil. On the basis of this approach, the lower part of the OFB is shown to fall within the middle to upper part of the Bajocian Stage (Humphriesianum to Parkinsoni chrons), whereas the uppermost OFB can be referred to as the uppermost Bajocian (latest Parkinsoni Chron). We conclude that, at Bretteville and in general for the Fe-oolites of Normandy, fossiliferous horizons with condensed assemblages have no value for definition of the biostratigraphic standard scale, and that indirect biostratigraphy is useful to assign minimal chronologic values to taxa when (1) their stratigraphical range has not yet been established in expanded successions, (2) they are new taxa, and (3) they are present only in a condensed succession that suffered from the same taphonomic constraints as the Bajocian of Normandy.


Middle Jurassic - Lower Cretaceous ammonites & aptychi
 
mhornДата: Monday, 08.03.2010, 18:17 | Сообщение # 3
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Fernández-López S.R. Candidate sections for the GSSP of the base of the Bathonian Stage (Middle Jurassic). P.77-88.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_77-88.pdf
In accordance with the recommendations of the International Commission on Stratigraphy (ICS), the leading candidate for the Global Boundary Stratotype Section and Point (GSSP) of the base of the Bathonian Stage is located in the Ravin du Bas (Bas Auran area, SE France). This section was formally proposed as candidate nineteen years ago. A second potential candidate section is located in the Cabo Mondego area (Portugal). This Portuguese section, however, has not been formally proposed as a candidate for the Bathonian basal boundary stratotype. The formal selection and proposal of a GSSP for the Bathonian Stage is the responsibility of the Bathonian Working Group (BtWG) and is expected by September 2007. In accordance with the procedures to ratify GSSPs, a formal ballot on the selection and proposal of a GSSP for the Bathonian Stage, by post or email, by all members of the BtWG is the responsibility of the convenor and the International Subcommission on Jurassic Stratigraphy Executive, and will be carried out within this time scale.

Page K.N., Meléndez G., Wright J.K. The ammonite faunas of the Callovian-Oxfordian boundary interval in Europe and their relevance to the establishment of an Oxfordian GSSP. P.89-99.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_89-99.pdf
The latest Callovian and Early Oxfordian are characterised by one of the highest levels of mixing of Boreal, Submediterranean and even Mediterranean faunas. In particular the massive expansion of Boreal Cardioceratidae from their original “home” in Arctic areas as far south as south-east France, brings them into contact with Mediterranean style faunas rich in Phylloceratidae. This so-called “Boreal Spread” provides the framework within which high resolution inter-bioprovincial correlations are possible and hence the context for a successful GSSP designation for the base of the Oxfordian Stage within Europe (and hence the beginning of the Upper Jurassic). Associated with the Cardioceratidae, especially in more Tethyan areas is a great variety of Perisphinctoidea, including Aspidoceratidae, Periphinctinae, Grossouvrinae and rarer Pachyceratidae as well as frequent Hecticoceratinae and rarer Phylloceratidae. As several of these persist beyond Europe they therefore provide tantalising indications that a truly global correlation of any GSSP established in Europe will ultimately be possible. The stratigraphical, taxonomic and palaeobiogeographical context and significance of the trans Callovian-Oxfordian boundary faunas within Europe is here reviewed and the faunas of the candidate GSSP at Redcliff Point, Weymouth, SW England are described, including the basal Oxfordian species Cardioceras (Pavloviceras) redcliffense sp. nov.

Page K.N., Meléndez G., Hart M.B., Price G.D., Wright J.K., Bown P., Bello J. Integrated stratigraphical study of the candidate Oxfordian Global Stratotype Section and Point (GSSP) at Redcliff Point, Weymouth, Dorset, UK. P.101-111.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_101-111.pdf
Ham Cliff near Redcliff Point, Weymouth, Dorset (SW England) exposes one of Europe’s most complete Callovian-Oxfordian boundary sequences and has consequently been identified as a potential candidate GSSP for the base of the Oxfordian Stage. The boundary sequence lies within the thick mudrock facies of the Oxford Clay Formation and is abundantly fossiliferous, cardioceratid ammonites in particular being conspicuous. By convention, the stage boundary is drawn at the first occurrence of the genus Cardioceras here represented by C. redcliffense Page, Meléndez and Wright at the base of the Scarburgense Subchronozone of the Mariae Chronozone. Associated Perisphinctoidea (including Peltoceras, Alligaticeras and Euaspidoceras) provide additional biostratigraphical information. Other macrofossil groups show less discernible changes, although frequent belemnites (Hibolithes) provide new highresolution carbon and strontium isotope data which are consistent with global curves and continuous sedimentation across the boundary interval. Magnetostratigraphic information is also available. Foraminiferal assemblages are dominated by epistominids but include a flood of early planktonic forms, including ?Globuligerina oxfordiana (Grigelis) immediately above the boundary. Well-preserved nannofloras are dominated by Watznaueria with conspicuous Zeugrhabdotus, podorhabdids and Stephanolithion indicating the NJ14 Biozone. Ostracoda and holothurian spicules are also recorded. These results are synthesised to provide a multidisciplinary, integrated review of the suitability of Redcliff Point for the definition of an Oxfordian GSSP. Correlations with the French candidate site in Haute-Provence are discussed and proposals made for formally establishing a GSSP for the base of the Oxfordian Stage in Europe.

Meléndez G., Atrops F., Bello J., Brochwicz-Lewiński W., d’Apra C., Fözy I., Pérez-Urresti I., Ramajo J., Sequeiros L. The Oxfordian ammonite genus Passendorferia Brochwicz Lewiński and the Tethyan subfamily Passendorferiinae Meléndez: origin and palaeobiogeography. P.113-134.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_113-134.pdf
The Oxfordian ammonite group Passendorferiinae (known as “Mediterranean perisphinctids”) forms a group of perisphinctids characterized by strongly evolute serpenticone coiling and subcircular to subquadrate whorl section, and forms a lateral divergent branch of the main stem Perisphinctidae. They originated probably from Late Callovian Grossouvriinae (Alligaticeras) and spread mainly in the Mediterranean (Tethyan) Province along the southern margin of Tethys, occasionally reaching the outer areas of epicontinental platforms. Their particular morphological features make them somewhat homoeomorphic with Tethyan Kimmeridgian Nebrodites. The phyletic link might be represented by the genus Geyssantia Meléndez, known from the Late Oxfordian Planula Chronozone. Separate biogeographic distribution in relation to the Perisphinctinae might reflect a progressive differentiation of western Tethyan faunas at the Callovian-Oxfordian boundary and at the onset of the Middle Oxfordian Transversarium Chronozone. Their rapid evolution gives them a biostratigraphic value similar to that of the Perisphinctinae. At the turn of the Middle-Late Oxfordian they gave rise to early Ataxioceratinae (Orthosphinctes), which replaced the Perisphinctinae in epicontinental areas, and colonised the marginal epicontinental blocks of northern Tethys. The taxonomy of this group is based upon the recognition of sexual dimorphism, using a single generic and specific name for both (M) and (m), and hence rejecting the use of former subgeneric names for both dimorphs. A new species within this line: Passendorferia nodicostata sp. nov . from the Plicatilis Biozone (Paturattensis Subbiozone) is defined and described for the first time.

Fazzuoli M., Morelli M., Pavia J., Al-Thour K.A., Chiocchini M., Reale V., Taddei E. The Jurassic succession of Ras Sharwayn, South-eastern Yemen. P.135-145.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_135-145.pdf
Four Jurassic stratigraphic units have been recognised at Ras Sharwayn, about 300 km east of Al-Mukalla along coast of the Gulf of Aden. The Kohlan Formation (60 m) unconformably overlies the crystalline basement. Its lower and middle part consist of fluviatile sandstone and conglomerate. The upper part is made up of transitional coarse- and fine-grained sandstones and siltstones. The sequence ends with shallow marine fine-grained sandstones. The Shuqra Formation (71 m) can be divided into two members. The lower Calcareous-marly Member (45 m) consists of grey bioclastic limestone and subordinate nodular marl (inner to mid ramp). Its age is Late Oxfordian. The upper Carbonate Member (26 m) changes from basal reddish marly limestones (mid ramp) to thick beds of red-brown, coarsely crystalline limestones and dolomites (inner ramp). The topmost beds contain fossils of colonial organisms, essentially stromatoporoids. Its age is Late Oxfordian, and possibly earliest Kimmeridgian. The Madbi Formation (>30 m) consists of yellowish marl alternating with marly limestone and bioclastic limestone (coquinas) corresponding to storm layers (mid to outer ramp). With regard to its age, a specimen of Orthosphinctes sp., collected a few metres from the base, possibly refers to the Early Kimmeridgian. The Madbi Formation ends with an unconformity surface. The informal Clastic unit (56 m) (including the Naifa Formation) consists, from bottom upwards, of: red-brown dolomite; grey detrital limestone with quartz grains; massive, white conglomerate with well rounded limestone clasts, quartz and bioclasts (e.g. colonial organisms). The last lithotypes are gravity flow deposits, accumulated at the base of a scarp possibly tectonic in origin, approximately at the Jurassic-Cretaceous boundary. This detailed lithological, sedimentological and biostratigraphical study has provided revised litostratigraphical subdivision and nomenclature and improved the stratigraphic control.

Rogov M., Wierzbowski A. The succession of ammonites of the genus Amoeboceras in the Upper Oxfordian – Kimmeridgian of the Nordvik section in northern Siberia. P.147-156.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_147-156.pdf
A collection of ammonites of the genus Amoeboceras located carefully in the section of Nordvik Peninsula in northern Siberia has enabled recognition of the standard Boreal ammonite zones of the Upper Oxfordian and Kimmeridgian. The recognition of the standard Amoeboceras zones, well known in NW Europe and the Barents Sea area, in northern Siberia indicates the uniform character of the Late Oxfordian and Kimmeridgian ammonite faunas across the whole Boreal Province. Some comments on the occurrence of Boreal oppeliids of the genus Suboxydiscites in the studied section are also given.

Podobina V., Gabysheva E., Tatyanin G. The foraminiferal assemblages of the uppermost Kimmeridgian-Volgian succession of Western Siberia and their correlation potential. P.157-172.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_157-172.pdf
The present study summarizes the data on the continuous stratigraphic sequence of foraminiferal assemblages from the Volgian deposits of the south-east of Western Siberia. Microfaunal analyses of 650 core samples from 18 boreholes of Volgian deposits were performed. Eighty two foraminiferal species, identified from the samples, were combined into the Volgian assemblages. On the basis of these assemblages, four biostratigraphic units were established in the range of foraminiferal zones and foraminiferal beds with characteristic species. These biostratigraphic units correspond to the upper part of the Kimmeridgian/ lower part of the Volgian, the Middle Volgian (lowermost and uppermost beds), and the Upper Volgian. A detailed biostratigraphic analysis of the Volgian beds was carried out, which enabled a correlation scheme to be developed for major regions of Russia. West-Siberian foraminiferal assemblages were correlated with those of Europe and North America within the Panboreal Superrealm. The species composition of foraminiferal assemblages was analyzed, and correlatable species were established. This provided an opportunity to correlate coeval strata from Western Siberia, East European (Russian) Platform, northern territories of Siberia and Arctic Islands, Canada, Spitsbergen and England. The possibility was established for correlating Volgian-Tithonian deposits of the Panboreal and Tethys-Panthalassa Superrealms through the Dnieper-Donets Basin where faunas of both southern and Boreal-Arctic types are met.

Ogg J., Przybylski P. Jurassic Chronostratigraphic Database and the TimeScale Creator Visualization System. P.175-179.
Pdf: http://voluminajurassica.org/en/pdf/Vol_VII_175-179.pdf
A joint project of the International Commission on Stratigraphy (ICS) and CHRONOS database program is to provide detailed global and regional “reference” scales of Earth history . Such scales integrate biostratigraphy (zones, datums for marine and terrestrial realms), sea-level (curves, sequences), geochemistry (trends, events), magnetic polarity chrons and astronomical cycles. The current Jurassic scale contains over 1000 events and zones correlated to Tethyan and Boreal ammonite zones with approximate numerical ages from Geologic Time Scale 2004 (Gradstein et al. 2004). This public database will be progressively enhanced through the efforts of the Jurassic Subcommission of the ICS and by other stratigraphic and regional experts. On-screen display and production of user-tailored time-scale charts is provided by the TimeScale Creator , a Java package freely available from the ICS Subcommission for Stratigraphic Information or the TS-Creator websites (http://stratigraphy.science.purdue.edu or www.tscreator .org). After specifying the time interval and vertical scale, a user selects a subset of stratigraphic columns and trends. In addition to screen views and a scalable-vector graphics (SVG) file for importation into popular graphics programs, the on-screen display also has “hot-curser-points” to open windows providing additional information on events, zones and boundaries. The database and visualization package are envisioned as a convenient reference tool, chart-production assistant, and a window into the geologic history of our planet


Middle Jurassic - Lower Cretaceous ammonites & aptychi
 
Jurassic Forum » JURASSIC references & paper reviews » Jurassic around the world » New issue of the Volumina Jurassica is available! (Vol.VII, 2009)
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