نتایج جستجو برای: barremian aptian

تعداد نتایج: 602  

Journal: :Geology 2021

Abstract The age of the beginning magnetic polarity Chron M0r, a proposed marker for base Aptian Stage, is disputed due to divergence published radioisotopic dates and ambiguities in stratigraphic correlation sections. Our magnetostratigraphy core DH1 from Svalbard, Norway, calibrates bentonite bed, dated by U-Pb methods 123.1 ± 0.3 Ma, uppermost part magnetozone M1r, which ∼1.9 m.y. before M0r...

Journal: :Journal of Asian Earth Sciences 2021

Lower Cretaceous carbonate successions outcrop extensively along the northern Tethyan margin in Kopet-Dagh (NE Iran) and Yazd Block (Central Iran). These units are not well constraint terms of stratigraphic, sedimentological, geochemical, paleobiogeographic view point. To improve our knowledge, a detailed multidisciplinary study has been presented on two roughly coeval stratigraphic different a...

Journal: :Basin Research 2021

The rift phase of the Campos Basin developed during Early Cretaceous on a heterogeneous crust comprising structures inherited from Brasiliano-Pan African tectonic events, mostly generated Neoproterozoic-Cambrian amalgamation western Gondwana blocks. main rifting episode took place Hauterivian to Barremian, then was succeeded by transition and post-rift (SAG) phases Aptian. Rift faults as result...

Journal: :Basin Research 2022

Abstract The structure and tectonic evolution of the Cretaceous rift basins southern Egypt are poorly understood. In this study, tectonostratigraphy Komombo Basin has been determined using seismic, well biostratigraphic data. basin is compared to Kharit, Nuqra Beni Suef in as Muglad Sudan. a 58 km long, 28 wide NW–SE trending half‐graben infilled with 2200 m Berriasian‐Maastrichtian sediments o...

Journal: :Geological Society of America Bulletin 2022

Alternative depositional models for the Early Cretaceous McMurray Formation between a dominantly continental and marginal marine settings remain controversial topic. The source-to-sink model can be inverted to reconstruct ancient sediment-routing systems by utilizing methods estimate drainage basins, which contribute understanding of sediment routing testing alternative models. New detrital zir...

Journal: :Journal of Sedimentary Research 2021

ABSTRACT Submarine slopes prograde via accretion of sediment to clinoform foresets and degrade in response channel or canyon incision mass-wasting processes. The timescales over which progradation degradation occur, the large-scale stratigraphic record these processes, remain unclear due poor age constraints subsurface-based studies areally limited exposures exhumed systems. We here integrate 3...

Journal: :نشریه دانشکده فنی 0
کاظم سید امامی

at the boundary between jurassic and cretaceous, because of late kimmerian movements, the sea ragressed from many areas of north and cantral iran, and many continental areas rose, which included a number of differentiated basins. the boundary between jurassic and cretaceous in these parts of iran is usually marked by a big diastem or by red, clastic and evaporitic sediments. the whole or part o...

2013
Wu-Bin Yang He-Cai Niu Wei-Dong Sun Qiang Shan Yong-Fei Zheng Ning-Bo Li Cong-Ying Li Nicholas T. Arndt Xing Xu Yu-Hang Jiang Xue-Yuan Yu

Cretaceous represents one of the hottest greenhouse periods in the Earth's history, but some recent studies suggest that small ice caps might be present in non-polar regions during certain periods in the Early Cretaceous. Here we report extremely negative δ(18)O values of -18.12‰ to -13.19‰ for early Aptian hydrothermal zircon from an A-type granite at Baerzhe in northeastern China. Given that ...

2017
Maria Edenilce Peixoto Batista Delmira da Costa Silva Marcos A. F. Sales Artur A. Sá Antônio A. F. Saraiva Maria Iracema Bezerra Loiola

Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf...

Journal: :Geology 2021

Abstract The early to mid-Aptian was punctuated by episodic phases of organic-carbon burial in various oceanographic settings, which are possibly related massive volcanism associated with the emplacement Ontong Java, Manihiki, and Hikurangi oceanic plateaus southwestern Pacific Ocean, inferred have formed a single plateau called Java Nui. Sedimentary osmium (Os) isotopic compositions one best p...

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