Global Tectonic Setting and Climate of the Late Neoproterozoic: A Climate-Geochemical Coupled Study

2013 ◽  
pp. 79-89 ◽  
Author(s):  
Yannick Donnadieu ◽  
Gilles Ramstein ◽  
Yves Goddéris ◽  
FréDéric Fluteau
Keyword(s):  
Tectonic Setting ◽  
Late Neoproterozoic

scholarly journals Zircon U–Pb geochronology and geochemistry of granitic rocks in central Mongolia

2020 ◽  
Vol 50 ◽  
pp. 23-44
Author(s):  
Boldbaatar Dolzodmaa ◽  
Yasuhito Osanai ◽  
Nobuhiko Nakano ◽  
Tatsuro Adachi
Keyword(s):  
Tectonic Setting ◽  
Granitic Rocks ◽  
Metamorphic Rocks ◽  
Calc Alkaline ◽  
Volcanic Arc ◽  
Central Mongolia ◽  
Central Asian ◽  
High K ◽  
Three Stages ◽  
Late Neoproterozoic

The Central Asian Orogenic Belt had been formed by amalgamation of voluminous subduction–accretionary complexes during the Late Neoproterozoic to the Mesozoic period. Mongolia is situated in the center of this belt. This study presents new zircon U–Pb geochronological, whole-rock major and trace element data for granitoids within central Mongolia and discusses the tectonic setting and evolution of these granitic magmas during their formation and emplacement. The zircon U–Pb ages indicate that the magmatism can be divided into three stages: the 564–532 Ma Baidrag granitoids, the 269–248 and 238–237 Ma Khangai granitoids. The 564–532 Ma Baidrag granitoids are adakitic, have an I-type affinity, and were emplaced into metamorphic rocks. In comparison, the 269–248 Ma granitoids have high-K, calc-alkaline, granodioritic compositions and are I-type granites, whereas the associated the 238–237 Ma granites have an A-type affinity. The 564–532 Ma Baidrag and 269–248 Ma Khangai granitoids also both have volcanic arc-type affinities, whereas the 238–237 Ma granites formed in a post-collisional tectonic setting. These geochronological and geochemical results suggest that arc magmatism occurred at the 564–532 Ma which might be the oldest magmatic activity in central Mongolia. Between the Baidrag and the Khangai, there might be paleo-ocean and the oceanic plate subducted beneath the Khangai and produced voluminous granite bodies during the 269–248 Ma. After the closure of the paleo-ocean, the post collisional granitoids were formed at the 238–237 Ma based on the result of later granitoids in the Khangai area.

Late Neoproterozoic to early Paleozoic paleogeographic position of the Yangtze block and the change of tectonic setting in its northwestern margin: Evidence from detrital zircon U-Pb ages and Hf isotopes of sedimentary rocks

2021 ◽  
Author(s):  
Bingshuang Zhao ◽  
Xiaoping Long ◽  
Jin Luo ◽  
Yunpeng Dong ◽  
Caiyun Lan ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Tectonic Setting ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Hf Isotopes ◽  
Early Paleozoic ◽  
Yangtze Block ◽  
Sedimentary Provenance ◽  
Northwestern Margin ◽  
Late Neoproterozoic

The crustal evolution of the Yangtze block and its tectonic affinity to other continents of Rodinia and subsequent Gondwana have not been well constrained. Here, we present new U-Pb ages and Hf isotopes of detrital zircons from the late Neoproterozoic to early Paleozoic sedimentary rocks in the northwestern margin of the Yangtze block to provide critical constraints on their provenance and tectonic settings. The detrital zircons of two late Neoproterozoic samples have a small range of ages (0.87−0.67 Ga) with a dominant age peak at 0.73 Ga, which were likely derived from the Hannan-Micangshan arc in the northwestern margin of the Yangtze block. In addition, the cumulative distribution curves from the difference between the depositional age and the crystalline age (CA−DA) together with the mostly positive εHf(t) values of these zircon crystals (−6.8 to +10.7, ∼90% zircon grains with εHf[t] > 0) suggest these samples were deposited in a convergent setting during the late Neoproterozoic. In contrast, the Cambrian−Silurian sediments share a similar detrital zircon age spectrum that is dominated by Grenvillian ages (1.11−0.72 Ga), with minor late Paleoproterozoic (ca. 2.31−1.71 Ga), Mesoarchean to Neoarchean (3.16−2.69 Ga), and latest Archean to early Paleoproterozoic (2.57−2.38 Ga) populations, suggesting a significant change in the sedimentary provenance and tectonic setting from a convergent setting after the breakup of Rodinia to an extensional setting during the assembly of Gondwana. However, the presence of abundant Grenvillian and Neoarchean ages, along with their moderately to highly rounded shapes, indicates a possible sedimentary provenance from exotic continental terrane(s). Considering the potential source areas around the Yangtze block when it was a part of Rodinia or Gondwana, we suggest that the source of these early Paleozoic sediments had typical Gondwana affinities, such as the Himalaya, north India, and Tarim, which is also supported by their stratigraphic similarity, newly published paleomagnetic data, and tectono-thermal events in the northern fragments of Gondwana. This implies that after prolonged subduction in the Neoproterozoic, the northwestern margin of the Yangtze block began to be incorporated into the assembly of Gondwana and then accept sediments from the northern margin of Gondwanaland in a passive continental margin setting.

A late Neoproterozoic magmatic core complex in the Eastern Desert of Egypt: emplacement of granitoids in a wrench-tectonic setting

2002 ◽  
Vol 118 (1-2) ◽  
pp. 59-82 ◽  
Author(s):  
M. Bregar ◽  
A. Bauernhofer ◽  
K. Pelz ◽  
U. Kloetzli ◽  
H. Fritz ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Eastern Desert ◽  
Core Complex ◽  
Late Neoproterozoic

scholarly journals Age and tectonic setting of granitoid plutons in the Chéticamp belt, western Cape Breton Island, Nova Scotia, Canada

2017 ◽  
Vol 54 (1) ◽  
pp. 88-109 ◽  
Author(s):  
L.R. Slaman ◽  
S.M. Barr ◽  
C.E. White ◽  
D. van Rooyen
Keyword(s):  
Inductively Coupled Plasma ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Geological Mapping ◽  
Western Cape ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Isotopic Analyses ◽  
Plutonic Belt ◽  
Late Neoproterozoic

Geological mapping in the Chéticamp granitoid belt in combination with petrographic and geochemical studies and U–Pb (zircon) dating by laser ablation inductively coupled plasma mass spectrometry have resulted in major reinterpretation of the geology in the western part of the Ganderian Aspy terrane of Cape Breton Island. Nine new U–Pb (zircon) ages show that the former “Chéticamp pluton” consists of 10 separate plutons of five different ages: late Neoproterozoic (ca. 567 Ma), Cambrian–Ordovician (490–482 Ma), Ordovician–Silurian (442–440 Ma), mid-Silurian (ca. 428 Ma), and late Devonian (366 Ma). The three late Neoproterozoic granodioritic to monzogranitic plutons are older than the adjacent metavolcanic and metasedimentary rocks of the Jumping Brook Metamorphic Suite, whereas the tonalitic to quartz dioritic Cambrian–Ordovician plutons intruded those metamorphic rocks. Petrographic characteristics and approximately 100 whole-rock chemical analyses show that with the exception of the mid-Silurian Grand Falaise alkali-feldspar granite, which has A-type within-plate characteristics, the plutonic units have calc-alkaline affinity and were emplaced in a volcanic-arc tectonic setting. These results are evidence that fragments of a long history of episodic subduction-related magmatism and terrane collision are preserved in this small part of Ganderia. Eight new Sm–Nd isotopic analyses are consistent with the Ganderian affinity of the Chéticamp plutonic belt. The ca. 490–482 Ma plutons are the first direct evidence in Cape Breton Island for the Penobscottian event recognized in the Exploits Subzone of central Newfoundland and in New Brunswick. However, the structural relationship of the Chéticamp plutonic belt to the rest of the Aspy and Bras d’Or terranes remains enigmatic, as is the apparent absence of effects of Devonian deformation and metamorphism in the older plutonic units.

scholarly journals Supplemental Material: Late Neoproterozoic to early Paleozoic paleogeographic position of the Yangtze block and the change of tectonic setting in its northwestern margin: Evidence from detrital zircon U-Pb ages and Hf isotopes of sedimentary rocks

2021 ◽  
Author(s):  
Bingshuang Zhao ◽  
Xiaoping Long ◽  
et al.
Keyword(s):  
Detrital Zircon ◽  
Tectonic Setting ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Early Paleozoic ◽  
Yangtze Block ◽  
Isotopic Data ◽  
Northwestern Margin ◽  
Late Neoproterozoic

Supplementary Figure S1: Representative cathodoluminescence images of zircons from the northwestern Yangtze block samples; Supplementary Table S1: U–Pb dating results and in situ Lu–Hf isotopic data for detrital zircons from the northwestern Yangtze block samples.

A late Neoproterozoic paleomagnetic pole for the Congo craton: Tectonic setting, paleomagnetism and geochronology of the Nola dike swarm (Central African Republic)

2008 ◽  
Vol 164 (3-4) ◽  
pp. 214-226 ◽  
Author(s):  
Gaétan R. Moloto-A-Kenguemba ◽  
Ricardo I.F. Trindade ◽  
Patrick Monié ◽  
Anne Nédélec ◽  
Roberto Siqueira
Keyword(s):  
Central African Republic ◽  
Tectonic Setting ◽  
Dike Swarm ◽  
Paleomagnetic Pole ◽  
Late Neoproterozoic
Sign in / Sign up

Export Citation Format

Share Document