Isotopic evidence for Late Jurassic–Early Cretaceous climate change

2003 ◽  
Vol 202 (1-2) ◽  
pp. 97-118 ◽  
Author(s):  
Darren R Gröcke ◽  
Gregory D Price ◽  
Alastair H Ruffell ◽  
Jörg Mutterlose ◽  
Evgenij Baraboshkin
Keyword(s):  
Climate Change ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Isotopic Evidence

Petrogenesis and tectonic implications of Late Jurassic – Early Cretaceous granitic magmatism in the Xing’an Block, Northeast China: geochronological, geochemical, and Hf isotopic evidence

2018 ◽  
Vol 55 (6) ◽  
pp. 571-588 ◽  
Author(s):  
Yue He ◽  
Zhong-Hua He ◽  
Wen-Chun Ge ◽  
Hao Yang ◽  
Zhi-Hui Wang ◽  
...  
Keyword(s):  
Partial Melting ◽  
Early Cretaceous ◽  
Northeast China ◽  
Late Jurassic ◽  
Granitic Rocks ◽  
Geochemical Data ◽  
Magma Source ◽  
Isotopic Evidence ◽  
Depleted Mantle ◽  
Microgranular Enclaves

This study presents new geochronological, whole-rock geochemical, and zircon Hf isotopic evidence for the age, petrogenesis, and source of Mesozoic granitic rocks of the Xing’an Block, Northeast China. This evidence reveals the Late Mesozoic tectonic evolution of the eastern section of the Central Asian Orogenic Belt. Laser-ablation inductively coupled plasma – mass spectrometryzircon U–Pb age data indicate that the syenogranite, monzogranite, and alkali feldspar granite units, as well as their associated diorite microgranular enclaves, were emplaced between 150–142 Ma, providing evidence of Late Jurassic to Early Cretaceous magmatic events within the Xing’an Block. The granites contain high concentrations of SiO2 (65.24%–75.73 wt.%) and K2O (3.94%–5.30 wt.%), low concentrations of MgO (0.10%–1.30 wt.%), and A/CNK values of 0.92–1.06. In addition, Hf isotopic analysis of zircons from the 150–142 Ma granites yields εHf(t) values of +4.54 to +12.16 and two-stage Hf model aged from 906 to 423 Ma, indicating that they formed from magmas generated by partial melting of a juvenile Neoproterozoic–Phanerozoic accreted crustal source. The basic magma source for the diorite microgranular enclaves most likely formed from partial melting of a depleted mantle that had been metasomatized by subduction-related fluids. Combining these new geochemical data with the geology of this region, Late Jurassic to Early Cretaceous magmatism in the Xing’an Block most likely occurred in an extensional environment associated with closure of the Mongol–Okhotsk Ocean.

AGE MODEL FOR LATE JURASSIC THROUGH EARLY CRETACEOUS USED IN THE GEOLOGIC TIMESCALE 2012/2016 REFERENCE SCALES

2018 ◽  
Author(s):  
James G. Ogg ◽  
◽  
Chunju Huang ◽  
Chunju Huang ◽  
Linda A. Hinnov ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Age Model

CLIMATE CHANGE AND CARBON CYCLE PERTURBATIONS IN THE NORWEGIAN-GREENLAND SEAWAY DURING THE LATEST JURASSIC AND EARLY CRETACEOUS

2018 ◽  
Author(s):  
Holly E. Turner ◽  
◽  
Felix M. Gradstein ◽  
Sietske J. Batenburg ◽  
Andrew S. Gale ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Cycle ◽  
Early Cretaceous

Theropod teeth from the basalmost Cretaceous of Anoual (Morocco) and their palaeobiogeographical significance

2009 ◽  
Vol 146 (4) ◽  
pp. 602-616 ◽  
Author(s):  
F. KNOLL ◽  
J. I. RUIZ-OMEÑACA
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Dispersal Events ◽  
Early Occurrence

AbstractThe theropod teeth from the Berriasian (Early Cretaceous) site of Anoual (N Morocco) are described. The assemblage is important in that it comes from one of the very few dinosaur sites of this age globally and the only one for the whole of Gondwana. The theropod teeth from Anoual are morphologically diverse. Most of the material possibly belongs to the clade Dromaeosauridae, which would be an early occurrence for this taxon. The palaeogeographic position of Anoual enables it to provide data on the dispersal events that affected terrestrial faunas during Mesozoic times. A Laurasian influence is evidenced by the presence of Velociraptorinae and, on the whole, the theropod fauna from Anoual provides support for the existence of a trans-Tethyan passage allowing terrestrial faunal interchanges during Late Jurassic and/or earliest Cretaceous times. Additionally, Anoual records the existence of diminutive theropods. However, it cannot yet be determined whether the small size of the specimens is genetic or ontogenetic.

scholarly journals Late Jurassic-Early Cretaceous palynostratigraphy and palaeoclimate in the Andigama Basin, Sri Lanka

2021 ◽  
pp. 100067
Author(s):  
Panchala Weerakoon ◽  
Harinam Joshi ◽  
Neha Aggarwal ◽  
Neerja Jha ◽  
Hetti Arachchige Hemachandra Jayasena ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Early Cretaceous ◽  
Late Jurassic

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

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