Petrogenesis and Sr-Nd isotope data of the Chadegan metabasites, Sanandaj-Sirjan Zone, Iran

2016 ◽  
Vol 279 (3) ◽  
pp. 311-322
Author(s):  
K. Akbari ◽  
S.M. Tabatabaei Manesh ◽  
J.F. Santos
Keyword(s):  
Nd Isotope ◽  
Isotope Data ◽  
Sanandaj Sirjan Zone

Geochemistry, Sr-Nd isotope data and petrogenesis of the Marziyan granitoid, Sanandaj–Sirjan Zone, western Iran

2015 ◽  
Vol 192 (2) ◽  
pp. 195-210
Author(s):  
E. Darvishi ◽  
M. Khalili ◽  
F. Toksoy-Köksal ◽  
S. Köksal ◽  
R. Beavers
Keyword(s):  
Nd Isotope ◽  
Western Iran ◽  
Isotope Data ◽  
Sanandaj Sirjan Zone

Origin of the Ordovician Mansehra granite in the NW Himalaya, Pakistan: constraints from Sr–Nd isotopic data, zircon U–Pb age and Hf isotopes

2018 ◽  
Vol 481 (1) ◽  
pp. 277-298 ◽  
Author(s):  
Masatsugu Ogasawara ◽  
Mayuko Fukuyama ◽  
Rehanul Haq Siddiqui ◽  
Ye Zhao
Keyword(s):  
Granitic Magma ◽  
Geochemical Data ◽  
Large Contribution ◽  
Crustal Material ◽  
Sr Isotope ◽  
Nw Himalaya ◽  
Nd Isotope ◽  
Isotope Data ◽  
Late Neoproterozoic ◽  
T Values

AbstractThe Mansehra granite in the NW Himalaya is a typical Lesser Himalayan granite. We present here new whole-rock geochemistry, Rb–Sr and Sm–Nd isotope data, together with zircon U–Pb ages and Hf isotope data, for the Mansehra granite. Geochemical data for the granite show typical S-type characteristics. Zircon U–Pb dating yields 206Pb/238U crystallization ages of 483–476 Ma. The zircon grains contain abundant inherited cores and some of these show a clear detrital origin. The 206Pb/238U ages of the inherited cores in the granite cluster in the ranges 889–664, 1862–1595 and 2029 Ma. An age of 664 Ma is considered to be the maximum age of the sedimentary protoliths. Thus the Late Neoproterozoic to Cambrian sedimentary rocks must be the protolith of the Mansehra granitic magma. The initial Sr isotope ratios are high, ranging from 0.7324 to 0.7444, whereas the εNd(t) values range from −9.2 to −8.6, which strongly suggests a large contribution of old crustal material to the protoliths. The two-stage Nd model ages and zircon Hf model ages are Paleoproterozoic, indicating that the protolith sediments were derived from Paleoproterozoic crustal components.

Nd and Pb isotope mapping of crustal domains within the Makkovik Province, Labrador

2018 ◽  
Vol 156 (5) ◽  
pp. 833-848 ◽  
Author(s):  
R. M. MOUMBLOW ◽  
G. A. ARCURI ◽  
A. P. DICKIN ◽  
C. F. GOWER
Keyword(s):  
Early Stage ◽  
Foreland Basin ◽  
Mobile Belt ◽  
South American ◽  
Pb Isotope ◽  
Volcanic Arc ◽  
Nd Isotope ◽  
North American Cordillera ◽  
Tectonic Model ◽  
Isotope Data

AbstractThe Makkovik Province of eastern Labrador represents part of an accretionary orogen active during an early stage in the development of the Palaeoproterozoic southern Laurentian continental margin. New Nd isotope data for the eastern Makkovik Province suggest that accreted juvenile Makkovik crust was generated in the Cape Harrison domain during a single crust-forming event at c. 2.0 Ga. Pb isotope data support this model, and show a strong similarity to radiogenic crustal signatures in the juvenile Palaeoproterozoic crust of the Ketilidian mobile belt of southern Greenland. As previously proposed, an arc accretion event at c. 1.9 Ga triggered subduction-zone reversal and the development of an ensialic arc on the composite margin. After the subduction flip, a temporary release of compressive stress at c. 1.87 Ga led to the development of a retro-arc foreland basin on the downloaded Archean continental edge, forming the Aillik Group. Unlike previous models, a second arc is not envisaged. Instead, a compressive regime at c. 1.82 Ga is attributed to continued ensialic arc plutonism on the existing margin. The tectonic model for the Makkovikian orogeny proposed here is similar to that for the Ketilidian orogeny. Major- and trace-element analyses suggest that much of the magmatism in the Makkovik orogen results from post-accretionary ensialic arc activity, and that few vestiges remain of the original accreted volcanic arc. This pattern of arc accretion and intense post-accretion reworking is common to many accretionary orogens, such as the South American Andes and North American Cordillera.

Sources of Ore Substance of Carbonatite Complexes of the Ural Fold Belt: Rb–Sr and Sm–Nd Isotope Data

2018 ◽  
Vol 480 (2) ◽  
pp. 773-777 ◽  
Author(s):  
I. L. Nedosekova ◽  
V. A. Koroteev ◽  
T. B. Bayanova ◽  
B. V. Belyatsky
Keyword(s):  
Fold Belt ◽  
Nd Isotope ◽  
Isotope Data

scholarly journals Biologically recycled continental iron is a major component in banded iron formations

2015 ◽  
Vol 112 (27) ◽  
pp. 8193-8198 ◽  
Author(s):  
Weiqiang Li ◽  
Brian L. Beard ◽  
Clark M. Johnson
Keyword(s):  
Continental Margin ◽  
Iron Reduction ◽  
Banded Iron Formations ◽  
Nd Isotope ◽  
Isotope Data ◽  
Dissimilatory Iron Reduction ◽  
Wide Scale ◽  
First Time ◽  
Iron Formations ◽  
Marine Basin

Banded iron formations (BIFs) record a time of extensive Fe deposition in the Precambrian oceans, but the sources and pathways for metals in BIFs remain controversial. Here, we present Fe- and Nd-isotope data that indicate two sources of Fe for the large BIF units deposited 2.5 billion y ago. High-εNd and -δ56Fe signatures in some BIF samples record a hydrothermal component, but correlated decreases in εNd- and δ56Fe values reflect contributions from a continental component. The continental Fe source is best explained by Fe mobilization on the continental margin by microbial dissimilatory iron reduction (DIR) and confirms for the first time, to our knowledge, a microbially driven Fe shuttle for the largest BIFs on Earth. Detailed sampling at various scales shows that the proportions of hydrothermal and continental Fe sources were invariant over periods of 100–103 y, indicating that there was no seasonal control, although Fe sources varied on longer timescales of 105–106 y, suggesting a control by marine basin circulation. These results show that Fe sources and pathways for BIFs reflect the interplay between abiologic (hydrothermal) and biologic processes, where the latter reflects DIR that operated on a basin-wide scale in the Archean.

Age of source rocks of the Late Precambrian metaterrigenous sediments of the South Ulutau mountains, Central Kazakhstan: U-Pb and Sm-Nd isotope data

2015 ◽  
Vol 463 (1) ◽  
pp. 715-718 ◽  
Author(s):  
N. V. Dmitriev ◽  
E. F. Letnikova ◽  
K. E. Degtyarev ◽  
A. A. Trertyakov ◽  
H. Geng
Keyword(s):  
Source Rocks ◽  
The South ◽  
Nd Isotope ◽  
Late Precambrian ◽  
Isotope Data

scholarly journals Supplemental Material: Apatite fingerprints on the magmatic-hydrothermal evolution of the Daheishan giant porphyry Mo deposit, NE China

2021 ◽  
Author(s):  
Pan Qu ◽  
Wubin Yang
Keyword(s):  
Wall Rock ◽  
Major And Trace Elements ◽  
Primitive Mantle ◽  
Ne China ◽  
Pb Isotope ◽  
Nd Isotope ◽  
Isotope Data ◽  
Porphyry Mo Deposit ◽  
Spider Diagrams ◽  
Ree Patterns

Figure S1: Harker diagrams illustrating major elemental variations of the porphyry and wall rock. QGP—Qiancuoluo granodioritic porphyry; QBG—Qiancuoluo biotite granodiorite; Figure S2: (a) Chondrite-normalized REE patterns and (b) primitive mantle (PM)-normalized spider diagrams of the porphyry and wall rock. Normalizing values are taken from S. Sun and McDonough (1989); Table S1: Whole-rock major and trace element compositions of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG) granites; Table S2: Whole-rock Sr-Nd compositions of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S3: Apatite major and trace elements (ppm) of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S4: Apatite Sr and Nd isotope data of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG); Table S5: Apatite U-Pb isotope data of the Qiancuoluo granodioritic porphyry (QGP) and Qiancuoluo biotite granodiorite (QBG).

scholarly journals The role of island-arc oceanic, collisional and intraplate magmatism in the formation of continental crust in the Mongolia-Trasnbaikalia region: geostructural, geochronological and Sm-Nd isotope data

2021 ◽  
Vol 12 (1) ◽  
pp. 1-47
Author(s):  
I. V. Gordienko
Keyword(s):  
Continental Crust ◽  
Early Stage ◽  
Island Arc ◽  
Published Data ◽  
Crustal Material ◽  
Tectonic Structures ◽  
Nd Isotope ◽  
Isotope Data ◽  
Intraplate Magmatism

The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify the mechanisms of interactions between the crust and the mantle in the development of the Neoarchean, Proterozoic and Paleozoic magmatic and sedimentary complexes in the study area. Using the results of his own studies conducted for many years and other published data on this vast region of Central Asia, the author have analysed compositions, ages and conditions for the formation of Karelian, Baikalian, Caledonian and Hercynian structure-formational complexes in a variety of geodynamic settings. Based on the geostructural, petrological, geochemical, geochronological and Sm-Nd isotope data, he determines the crustal and mantle sources of magmatism, conducts the identification and mapping of isotopic provinces, and reveals the role of island-arc oceanic, accretion-collision and intraplate magmatism in the formation of continental crust. Considering the formation of the bulk continental crust, three main stages are distinguished: (1) Neoarchean and Paleoproterozoic (Karelian) (almost 30% of the crust volume), (2) Meso-Neoproterozoic (Baikalian) (50%), and (3) Paleozoic (Caledonian and Hercynian) (over 20%). This sequence of the evolution stages shows the predominance of the ancient crustal material in igneous rocks sources at the early stage. During the subsequent stages, tectonic structures created earlier were repeatedly reworked, and mixed crustal-mantle and juvenile sources were widely involved in the formation of the bulk continental crust in the study area.

scholarly journals Hafnium isotope constraints on the nature of the mantle beneath the Southern Lau basin (SW Pacific)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Quanshu Yan ◽  
Susanne Straub ◽  
Paterno Castillo ◽  
Haitao Zhang ◽  
Liyan Tian ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Isotopic Signature ◽  
Spreading Center ◽  
Nd Isotope ◽  
Lau Basin ◽  
Average Value ◽  
Isotope Data ◽  
Sw Pacific ◽  
The Pacific ◽  
Ocean Ridge

Abstract New Hf isotope data provide new insights into the nature of the mantle beneath the southern Lau basin, adding new constraints on the displacement process of the Pacific mid-ocean ridge basalt (MORB)-type mantle by the Indian MORB-type mantle. The Hf isotopic ratios (176Hf/177Hf) of submarine lavas from the eastern Lau spreading center (ELSC) range from 0.283194 (εHf = 14.92) to 0.283212 (εHf = 15.54), with an average value of 0.283199 (εHf = 15.11) whereas those from the Valu Fa ridge (VFR) vary from 0.283221 (εHf = 15.88) to 0.283200 (εHf = 15.14), with an average of 0.283214 (15.61), indicating that ELSC lavas have a slightly more radiogenic Hf isotopic composition than VFR lavas. In contrast to the results from previous studies, the new Hf analyses combined with previous Nd isotope data clearly show that both VFR and ELSC have the distinct Hf–Nd isotope composition of the so-called DUPAL isotopic anomaly in the Indian MORB-type mantle. The DUPAL isotopic signature at VFR demonstrates for the first time that the inflow of the Indian MORB-type mantle has reached the southern tip of tectonic propagation in the southern Lau basin.

Sign in / Sign up

Export Citation Format

Share Document