The Age and Sources of Protoliths of Metasedimentary Rocks in the Eastern Tukuringra Terrane of the Mongol–Okhotsk Fold Belt: Results of U–Th–Pb, Lu–Hf, and Sm–Nd Isotope Studies

2021 ◽  
Vol 15 (3) ◽  
pp. 188-198
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin
Keyword(s):  
Fold Belt ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
Isotope Studies

scholarly journals Age and sources of the Lower Mesozoic metasedimentary rocks of the Un'ja-Bom terrane in the Mongol-Okhotsk fold belt: results of the U–Th–Pb geohronological (LA–ICP–MS) AND Sm–Nd isotope studies

2019 ◽  
Vol 484 (4) ◽  
pp. 455-459
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin ◽  
V. P. Kovach ◽  
A. P. Sorokin ◽  
A. B. Kotov
Keyword(s):  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Fold Belt ◽  
Relative Probability ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
Icp Ms ◽  
Isotope Studies ◽  
Geochemical Studies ◽  
Age Estimates

The results of the U—Th—Pb geochronological studies indicate that in the Un’ja-Bom terrane the youngest peaks on the relative probability curves of ages are 207 and 212 Ma for zircons from the metasiltstone of the Kurnal formation and from the metasiltstone of the Amkan formation. Similar age estimates for the youngest peaks were obtained for the detrital zircons from the metasedimentary rocks of the Tukuringra terrain of the eastern part of the Mongol-Okhotsk belt, which indicates that the Lower Mesozoic flyschoid complexes in the structure of this belt are developed much wider than is currently believed. The results obtained in our U—Th—Pb geochronological and Sm—Nd isotope geochemical studies suggest’s that the sedimentary rocks material was carried to the sedimentation basin mainly from the continental massifs of the Amur superterrane.

scholarly journals AGE AND SOURCES OF PROTOLITHS OF METASEDIMENTARY ROCKS IN THE EASTERN TUKURINGRA TERRANE OF THE MONGOL-OKHOTSK FOLD BELT: RESULTS OF U-TH-PB, LU-HF, AND SM-ND ISOTOPE STUDIES

2021 ◽  
Vol 40 (3) ◽  
pp. 16-27
Author(s):  
V.A. Zaika ◽  
◽  
A.A. Sorokin ◽  
Keyword(s):  
Early Jurassic ◽  
Late Triassic ◽  
Fold Belt ◽  
North Asian Craton ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
Isotope Data ◽  
The North ◽  
Early Mesozoic ◽  
Isotope Studies

The article presents detrital zircon U-Th-Pb and Lu-Hf isotope data for metasedimentary rocks from the eastern Tukuringra Terrane, as well as whole-rock Sm-Nd isotope data. Our analyses show that the zircons in metasedimentary rocks are mostly early Mesozoic in age. Early Paleozoic and Neoproterozoic zircons are also common, whereas early Precambrian zircons are virtually absent. The age of the youngest zircon population places a lower age limit on the age of the Tungalin Formation at 204 Ma (Late Triassic, Rhaetian), the Dugda Formation at 181 Ma (Early Jurassic, Toarcian), and the Tangomen Formation at 189 Ma (Early Jurassic, Pliensbachian). Essentially all Mesozoic, Paleozoic and Neoproterozoic zircons are characterized by Neo- and Mesoproterozoic Hf-model ages (tHf(DM) = 1.41–0.46 Ga, tHf(C) = 1.55–0.49) and Mesoproterozoic Nd-model ages (tNd(DM) = 1.25–1.10 Ga, tNd(С) = 1.31–1.14). Our results suggest that sediments for deposition were sourced mainly from the continental Amuria Superterrane, but not from the southern margin of the North Asian Craton.

scholarly journals Age and sources of the metasedimrntary rocks of the Tokur terrane in the Mongol-Okhotsk fold belt: results of the U–Pb geoсhronological and Lu–Hf isotope studies

2019 ◽  
Vol 486 (4) ◽  
pp. 446-450
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin ◽  
A. P. Sorokin
Keyword(s):  
Detrital Zircons ◽  
Hf Isotope ◽  
Fold Belt ◽  
Metasedimentary Rocks ◽  
The North ◽  
Icp Ms ◽  
North Asia ◽  
Southeastern Margin ◽  
Isotope Studies ◽  
Metamorphic Complexes

This paper presents the results of U–Pb (LA–ICP–MS) and Lu–Hf ­isotope studies of detrital zircons from metasedimentary rocks of the Tokur Terrane. It has been shown that metasedimentary rocks of the Tokur and Ekimchan formations are characterized by similar age peaks of detrital zircons, which indicates a close (or same) age of these formations. The lower age of the sedimentation is determined by the age of the youngest zircons of 326–323 Ma. The upper age boundary is determined of 254–251 Ma, based on the intruded of the Late Permian granitoids. The main sources of zircons in the metasedimentary rocks of the Tokur Terrane are the igneous and metamorphic complexes of the southeast framing of the North Asia Craton. The Tokur Terrane can be considered as a fragment of the Paleozoic accretionary complex, the formation in front of the southeastern margin of the North Asia Craton.

scholarly journals Sources and source areas of the Upper Paleozoic metasedimentary rocks of the Dzhagda terrane of the Mongol-Okhotsk fold belt: the results of Sm-Nd isotope geochemical studies

2018 ◽  
Vol 9 (4) ◽  
pp. 1331-1338 ◽  
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin ◽  
V. P. Kovach
Keyword(s):  
Fold Belt ◽  
North Asian Craton ◽  
Nd Isotope ◽  
Source Areas ◽  
Metasedimentary Rocks ◽  
The North ◽  
Upper Paleozoic ◽  
Geochemical Studies ◽  
Nd Model Age ◽  
Metaterrigenous Rocks

The article presents the results of Sm-Nd isotope geochemical studies of the Upper Paleozoic metasedimentary rocks of the Dzheskogon, Nektera and Bochagor suites of the Dzhagda terrane. These rocks are characterized by slightly varying values of the Nd model age tNd(DM)=1.5–1.0 Gyr, which gives evidence that the main sources of protoliths were the rocks of the Mesoproterozoic Nd model age (in average). This Nd model age is similar to the ages of the metaterrigenous rocks of the Teply Klyuch, Garmakan and Alga suites of the Tukuringra terrane of the Mongol-Okhotsk Belt. The results obtained in our studies suggest that the sedimentary rocks of the Dzhagda and Tukuringra terranes developed from the material that was mainly sourced from the Amur superterrane (from the south in modern coordinates). A supply of the material from the southern margin of the North Asian craton (from the north in modern coordinates) was either absent or minimal.

Conditions for emerald formation at Davdar, China: fluid inclusion, trace element and stable isotope studies

2012 ◽  
Vol 76 (1) ◽  
pp. 213-226 ◽  
Author(s):  
D. Marshall ◽  
V. Pardieu ◽  
L. Loughrey ◽  
P. Jones ◽  
G. Xue
Keyword(s):  
Stable Isotope ◽  
Fluid Inclusion ◽  
Trace Element ◽  
Metasedimentary Rocks ◽  
Quartz Veins ◽  
Trace Element Chemistry ◽  
Stable Isotope Signatures ◽  
Swat Valley ◽  
Isotope Studies ◽  
Geological Work

AbstractPreliminary geological work on samples from Davdar in China indicate that emerald occurs in quartz veins hosted within upper greenschist grade Permian metasedimentary rocks including quartzite, marble, phyllite and schist. Fluid inclusion studies indicate highly saline fluids ranging from approximately 34 to 41 wt.% NaCl equivalent, with minimal amounts of CO2 estimated at a mole fraction of 0.003. Fluid inclusion, stable isotope and petrographic studies indicate the Davdar emeralds crystallized from highly saline brines in greenschist facies conditions at a temperature of ∼350°C and a pressure of up to 160 MPa. The highly saline fluid inclusions in the emeralds, the trace-element chemistry and stable isotope signatures indicate that the Davdar emeralds have some similarities to the Khaltaro and Swat Valley emerald deposits in Pakistan, but they show the greatest similarity to neighbouring deposits at Panjshir in Afghanistan.

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
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