scholarly journals Contribution to the structural study of the Rhodiani ophiolites, Vourinos massif

2001 ◽  
Vol 34 (1) ◽  
pp. 111 ◽  
Author(s):  
A. PHOTIADES ◽  
F. ΡΟΜΟΝΙ-ΡΑΡΑΙΟΑΝΝΟΥ
Keyword(s):  
Structural Study ◽  
Upper Cretaceous ◽  
Upper Jurassic ◽  
Tectonic Structure ◽  
Two Stage ◽  
Thrust Sheets ◽  
Ultramafic Unit ◽  
Upper Maastrichtian

The Rhodiani area geologically is comprised of a sequence of Mesozoic and Tertiary thrust sheets, including the Jurassic ophiolite and sedimentary covers; they composed of an ultramafic unit overlain by an Albian to Cenomanian redeposited limestone cover, and at the top a volcanic unit that is overlain by neritic to pelagic Upper Jurassic to Upper Cretaceous age limestone and Upper Maastrichtian flysch deposits. These thrust sheets were emplaced over the Pelagonian platform. Therefore the Rhodiani "ophiolite" is not a single thrust unit, but it is an imbricated ophiolite tectonic structure resulting from a two-stage emplacement process; the ultramafic unit was overthrust on the melange of the Pelagonian platform during the initial emplacement (Jurassic) and the volcanic unit was re-thrust on the former during subsequent post-Eocene tectonic phase

Neritoptyx hogansoninew species (Gastropoda, Mollusca) from the Upper Cretaceous Fox Hills Formation on the Dakota Isthmus, western United States

2018 ◽  
Vol 93 (2) ◽  
pp. 278-290
Author(s):  
J. Mark Erickson
Keyword(s):  
Heat Transfer ◽  
United States ◽  
New Species ◽  
North America ◽  
Upper Cretaceous ◽  
Gulf Coast ◽  
Western United States ◽  
Western Interior Seaway ◽  
Decapod Crustaceans ◽  
Upper Maastrichtian

AbstractIn midcontinent North America, the Fox Hills Formation (Upper Cretaceous, upper Maastrichtian) preserves the last marine faunas in the central Western Interior Seaway (WIS).Neritoptyx hogansoninew species, a small littoral snail, exhibited allometric change from smooth to corded ornament and rounded to shouldered shape during growth. Specimens preserve a zig-zag pigment pattern that changes to an axial pattern during growth.Neritoptyx hogansoninew species was preyed on by decapod crustaceans, and spent shells were occupied by pagurid crabs. Dead mollusk shells, particularly those ofCrassostrea subtrigonalis(Evans and Shumard, 1857), provided a hard substrate to which they adhered on the Fox Hills tidal flats. This new neritimorph gastropod establishes a paleogeographic and chronostratigraphic proxy for intertidal conditions on the Dakota Isthmus during the late Maastrichtian. Presence of a neritid extends the marine tropical/temperate boundary in the WIS northward to ~44° late Maastrichtian paleolatitude. Late Maastrichtian closure of the isthmus subsequently altered marine heat transfer by interrupting northward flow of tropical currents from the Gulf Coast by as much as 1 to 1.5 million years before the Cretaceous ended.UUID:http://zoobank.org/3ba56c07-fcca-4925-a2f0-df663fc3a06b

scholarly journals BROECKINELLA HENSONI N. SP., A NEW LARGER BENTHIC FORAMINIFERA FROM THE UPPER MAASTRICHTIAN OF IRAN AND A REVISION OF THE GENUS BROECKINELLA HENSON, 1948

2020 ◽  
pp. 57-67
Author(s):  
Felix Schlagintweit ◽  
Koorosh Rashidi
Keyword(s):  
Benthic Foraminifera ◽  
Upper Cretaceous ◽  
Test Chamber ◽  
First Record ◽  
Generic Diagnosis ◽  
Larger Benthic Foraminifera ◽  
Zagros Zone ◽  
Sw Iran ◽  
Tarbur Formation ◽  
Upper Maastrichtian

new larger benthic foraminifera is described as Broeckinella hensoni from the upper Maastrichtian Tar-bur Formation of SW Iran (Zagros Zone). In comparison to the type species of the genus, Broeckinella arabica Henson, which also occurs in the Tarbur Formation, the new species has distinctly larger dimensions (e.g., size and thickness of test, chamber height). The first record of a microspheric specimen of B. arabica shows previously unrecorded annular chambers in the final test stage. Therefore, the generic diagnosis is herein emended. In the Tarbur Formation, both B. hensoni n. sp. and B. arabica occur in foraminiferal-algal wackestones. However, B. arabica occurs in a wider range of microfacies, including packstones and grainstones. It is assumed that Broeckinella originated in the Upper Cretaceous with Broeckinella neumannae Gendrot. The upper Albian Broeckinella aragonensis Peybernès is herein transferred to the porcellaneous genus Peneroplis Montfort.

scholarly journals First record of Calappoidea and Dromioidea from the Upper Cretaceous (Upper Maastrichtian) of NW Madagascar

2003 ◽  
Vol 72 (2-3) ◽  
pp. 135-136
Author(s):  
Alessandro Garassino ◽  
Giovanni Pasini
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
First Record ◽  
Upper Maastrichtian

The crustaceans from the marine Berivotra Formation, dated as late Cretaceous, from 50 km south of Mahajanga, Madagascar contains macrurans, brachyurans and thalassinideans. Two brachyuran families, Raninidae and Dynomenidae, were previously identified with the genera Notopocorystes, Caloxanthus, Titanocarcinus, Xanthosia, and Dromiopsis. Fragmentary material now also allows the recognition of Dromioidea, Calappoidea and Xanthoidea.

An Early Cretaceous (Berriasian) fossil-bearing locality from the Rocky Mountains of Alberta, yielding the oldest dinosaur skeletal remains from western Canada

2020 ◽  
Vol 57 (4) ◽  
pp. 542-552 ◽  
Author(s):  
Ramon S. Nagesan ◽  
James A. Campbell ◽  
Jason D. Pardo ◽  
Kendra I. Lennie ◽  
Matthew J. Vavrek ◽  
...  
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
Depositional Environment ◽  
Upper Cretaceous ◽  
Upper Jurassic ◽  
High Energy ◽  
Western Canada ◽  
Western North America ◽  
Terrestrial Vertebrate ◽  
Overlying Strata

Western North America preserves iconic dinosaur faunas from the Upper Jurassic and Upper Cretaceous, but this record is interrupted by an approximately 20 Myr gap with essentially no terrestrial vertebrate fossil localities. This poorly sampled interval is nonetheless important because it is thought to include a possible mass extinction, the origin of orogenic controls on dinosaur spatial distribution, and the origin of important Upper Cretaceous dinosaur taxa. Therefore, dinosaur-bearing rocks from this interval are of particular interest to vertebrate palaeontologists. In this study, we report on one such locality from Highwood Pass, Alberta. This locality has yielded a multitaxic assemblage, with the most diagnostic material identified so far including ankylosaurian osteoderms and a turtle plastron element. The fossil horizon lies within the upper part of the Pocaterra Creek Member of the Cadomin Formation (Blairmore Group). The fossils are assigned as Berriasian (earliest Cretaceous) in age, based on previous palynomorph analyses of the Pocaterra Creek Member and underlying and overlying strata. The fossils lie within numerous cross-bedded sandstone beds separated by pebble lenses. These sediments are indicative of a relatively high-energy depositional environment, and the distribution of these fossils over multiple beds indicates that they accumulated over multiple events, possibly flash floods. The fossils exhibit a range of surface weathering, having intact to heavily weathered cortices. The presence of definitive dinosaur material from near the Jurassic–Cretaceous boundary of Alberta establishes the oldest record of dinosaur body fossils in western Canada and provides a unique opportunity to study the Early Cretaceous dinosaur faunas of western North America.

Mesozoic and Cenozoic History of the Grand Banks of Newfoundland

1971 ◽  
Vol 8 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Grant A. Bartlett ◽  
Leigh Smith
Keyword(s):  
Upper Cretaceous ◽  
Fine Sand ◽  
Upper Jurassic ◽  
Oceanic Circulation ◽  
Silty Mudstone ◽  
Grand Banks ◽  
History Of ◽  
Depositional Age ◽  
Sea Floor Spreading ◽  
Lime Muds

Two wells drilled by Pan American in the Grand Banks of Newfoundland gave the first stratigraphic section of Cretaceous and Cenozoic age northeast of Long Island and the only Jurassic and possible Permian sections in the Atlantic Continental Margin of North America.Integrated analysis of lithic and faunal data showed a minimum of seven sequences present. These are Pleistocene, Middle and Upper Miocene, Intra-Eocene, Paleocene and lowest Eocene, Upper Cretaceous, Middle Cretaceous, and Neocomian in age.The rocks range from halite and anhydrite, of possible Permian depositional age, to limestones, in the Upper Jurassic, lower Upper Cretaceous, mid-Eocene and mid-Miocene, and sandstones, which dominate the Neocomian, Upper Eocene, and Middle Miocene. Variable proportions of shale and silty mudstone occur throughout.The microfaunas contain both Tethyan and Boreal elements, and suggest oceanic circulation changes, sea-floor spreading, or both.Depositional environments ranged from subaerial, for the quartz arenites, through very low-land, for stream and swamp deposits, to estuarine, lagoonal, bank and open-shelf warm-marine environments, in which were deposited fine sand to clay-size terrigenous sediment, or, in its absence, skeletal carbonates or lime muds. The first dominant cooling trend appeared in the Late Miocene.All erosional environments of the hiatal episodes appear to have been subaerial and humid.A salt dome intruded the Tors Cove well section, its last movement being in mid-Early Eocene.Periodic interregional tectonic oscillations produced the erosional and depositional episodes of the major baselevel transit cycles. Their total effect is a sedimentary wedge, thickening by preservation toward the continent's edge, and representing one-half or less of Upper Mesozoic and Cenozoic time.

Ostracodes and chronostratigraphic position of the Upper Cretaceous Arkadelphia Formation of Arkansas

1994 ◽  
Vol 68 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Kasana Pitakpaivan ◽  
Joseph E. Hazel
Keyword(s):  
Coastal Plain ◽  
Upper Cretaceous ◽  
Gulf Coastal Plain ◽  
Number Of Species ◽  
Sublittoral Zone ◽  
Upper Maastrichtian

The ostracode assemblage of the Arkadelphia Formation, upper Maastrichtian, of southwestern Arkansas is characterized by a well-preserved, relatively diverse, and abundant fauna representing 36 podocopid species and an undetermined number of species of the platycopid genus Cytherella. Thirteen of these account for 85 percent of the fauna. The dominant forms are Cytherella spp., Brachycythere rhomboidalis (Berry, 1925), Haplocytheridea renfroensis Crane, 1965, Haplocytheridea bruceclarki (Israelsky, 1929), and Brachycythere ovata (Berry, 1925), which account for about 57 percent of the specimens found. Other species that are less common, but are characteristic of the Arkadelphia, are Antibythocypris macropora (Alexander, 1929), Ascetoleberis hazardi (Israelsky, 1929), Aversovalva fossata (Skinner, 1956), Brachycythere ledaforma (Israelsky, 1929), Curfsina communis (Israelsky, 1929), Cytheromorpha arbenzi (Skinner, 1956), Escharacytheridea micropunctata (Alexander, 1929), and Veenia arachoides (Berry, 1925). The ostracode assemblage indicates that the Arkadelphia was deposited in the inner sublittoral zone.The species Veenia parallelopora (Alexander, 1929) and Brachycythere foraminosa Alexander, 1934, are restricted to the Arkadelphia Formation and allow correlation with other Gulf Coastal Plain Upper Cretaceous units. A new ostracode interval zone, the Veenia parallelopora Zone, is proposed. This zone divides the Platycosta lixula Zone.Calcareous planktic microfossils reported from the Arkadelphia and its correlatives in the Veenia parallelopora Zone indicate that these deposits are late Maastrichtian in age, not middle Maastrichtian as some authors have thought.

The final closure of the Vardar Ocean: paleomagnetic, AMS and structural results

2020 ◽  
Author(s):  
Emö Márton ◽  
Marinko Toljić ◽  
Vesna Lesić ◽  
Vesna Cvetkov
Keyword(s):  
Upper Cretaceous ◽  
National Development ◽  
Upper Jurassic ◽  
Igneous Rocks ◽  
Magmatic Activity ◽  
Ministry Of Education ◽  
Bedding Planes ◽  
The Republic ◽  
Final Closure ◽  
Oceanic Domain

<p>The Vardar zone divides units of African affinity from units of the European margin. It is characterized by extensional opening of an oceanic domain during the Triassic and Jurassic followed by divergent simultaneous obduction of the oceanic litoshphere over the continental units in the Upper Jurassic. However, a stripe of the oceanic domain persisted till the Cretaceous and Paleogene convergence. The remnants of the last closing part of the Vardar ocean are found in the Sava zone.</p><p>In this paper recently published and new paleomagnetic, AMS results in combination with structural observations will be presented from Upper Cretaceous sediments and Oligocene –Lower Miocene igneous rocks representing the areas bordering the Sava zone from the western and eastern sides, respectively and from the upper Cretaceous flysch deposited in the Sava zone.</p><p>In the areas W and E of the Sava zone, respectively, the primary remanences of the igneous rocks point to post-Oligocene CW rotation of about 30°. The sediments carry secondary magnetizations, imprinted during magmatic activity. Compared to the areas flanking it, the sediments of the Sava zone were intensively folded during the Upper Cretaceous and Paleogene and the paleomagnetic signals, which exhibit smeared distribution close to the present N, are of post-folding age. The AMS foliation and bedding planes are sub-parallel, thus the deformation must have been weak. Fold axes and AMS lineations are roughly N-S oriented, pointing to the deformational origin of the AMS lineations. These observations form the Sava zone will be discussed in the context of the post-Oligocene CW rotation of the flanking areas and the general NE-SW orientation of the compressional stress field outside of the zone.</p><p>Acknowledgement. This work was financially supported by the National Development and Innovation Office of Hungary, project K 128625 and by the Ministry of Education and Science of the Republic of Serbia, project 176015.</p>

scholarly journals Calcareous nannofossils from the upper Campanian–Maastrichtian (Upper Cretaceous) in the Kladorub Formation (Kula tectonic zone, NW Bulgaria)

2019 ◽  
Vol 48 (1) ◽  
pp. 73-101
Author(s):  
Georgi Granchovski
Keyword(s):  
Upper Cretaceous ◽  
Calcareous Nannofossils ◽  
Tectonic Zone ◽  
Lower Upper ◽  
Upper Maastrichtian ◽  
Stratigraphic Interval ◽  
Upper Campanian

A detailed investigation into the calcareous nannofossils from the upper Campanian–Maastrichtian deposits of the Kladorub Formation (NW Bulgaria) has been carried out in order to examine their taxonomic content and test the applicability of cosmopolitan zonation schemes for this stratigraphic interval in the country. The Kladorub Formation is composed of silty to fine-sandy marlstones and rare marly limestones, occasionally interbedded with sandstone layers. The recovered nannofloras are abundant, taxonomically diverse and exhibit predominantly moderate preservation, which allowed precise taxonomic identifications and biostratigraphic analysis to be made. As a result, the presence of two previously undocumented, biostratigraphically significant taxa has been recorded (i.e., Eiffellithus parallelus and Ceratolithoides kamptneri). Consequently, the studied Upper Cretaceous sediments have been assigned to subzone UC15dTP (pars.)–subzone UC20dTP; in the uppermost 2 m of the section, the presence of zone NP1 has also been indicated, which is in concordance with previous authors’ data. Due to the lack of proper chronostratigraphic framework for the Kladorub Formation, top Uniplanarius trifidus and base Lithraphidites quadratus have, respectively, been used to approximate the Campanian/Maastrichtian and lower/upper Maastrichtian boundaries. The Cretaceous/Palaeogene boundary, however, could not be drawn with precision, because it falls within a 6.5-m interval of non-exposure. The resulting biostratigraphic framework offers higher stratigraphic resolution than previously used local zonation schemes and allows correlation with coeval sedimentary successions from other parts of the Tethyan and Boreal realms.

Jagtia kunradensis, a new genus and species of clawed lobster (Decapoda: Nephropidae) from the Upper Cretaceous (Upper Maastrichtian) Maastricht Formation, The Netherlands

2000 ◽  
Vol 74 (2) ◽  
pp. 224-229 ◽  
Author(s):  
Dale Tshudy ◽  
Ulf Sorhannus
Keyword(s):  
The Netherlands ◽  
Deep Water ◽  
Phylogenetic Relationships ◽  
Upper Cretaceous ◽  
New Genus ◽  
New Genus And Species ◽  
Type Area ◽  
Fossil Form ◽  
Upper Maastrichtian

A new genus and species of clawed lobster, Jagtia kunradensis, is described from the Upper Cretaceous (Upper Maastrichtian) Kunrade Limestone facies of the Maastricht Formation, The Netherlands. Three nephropid lobster genera and at least three species (Oncopareia bredai Bosquet, 1854, sensu Tshudy, 1993, Oncopareia sp. Tshudy, 1993, Hoploparia beyrichi Schlüter, 1862, and Jagtia kunradensis) have now been collected from limestones of the Maastrichtian type area (southeastern Netherlands and northeastern Belgium). Cladistic methods were employed in re-evaluating the phylogenetic relationships of the nephropid lobsters, including Jagtia. These analyses indicate that Jagtia is part of a clade that includes the recent Thymops and Thymopsis. The new genus is the first fossil form to be closely allied with these deep-water genera.

Sign in / Sign up

Export Citation Format

Share Document