scholarly journals Was the Precambrian Basement of Western Troms and Lofoten-Vesterålen in Northern Norway Linked to the Lewisian of Scotland? A Comparison of Crustal Components, Tectonic Evolution and Amalgamation History"

10.5772/48257 ◽  
2012 ◽  
Author(s):  
Steffen G. ◽  
Fernando Corfu ◽  
Per Inge ◽  
Kre Kullerud ◽  
Paul E.B. ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Precambrian Basement ◽  
Northern Norway

scholarly journals Precambrian Basement and Late Paleoproterozoic to Mesoproterozoic Tectonic Evolution of the SW Yangtze Block, South China: Constraints from Zircon U–Pb Dating and Hf Isotopes

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 333 ◽  
Author(s):  
Wei Liu ◽  
Xiaoyong Yang ◽  
Shengyuan Shu ◽  
Lei Liu ◽  
Sihua Yuan
Keyword(s):  
South China ◽  
Tectonic Evolution ◽  
Detrital Zircons ◽  
Geochemical Data ◽  
Precambrian Basement ◽  
Yangtze Block ◽  
Two Stage ◽  
Clastic Rocks ◽  
Columbia Supercontinent ◽  
Isotopic Analyses

Zircon U–Pb dating and Hf isotopic analyses are performed on clastic rocks, sedimentary tuff of the Dongchuan Group (DCG), and a diabase, which is an intrusive body from the base of DCG in the SW Yangtze Block. The results provide new constraints on the Precambrian basement and the Late Paleoproterozoic to Mesoproterozoic tectonic evolution of the SW Yangtze Block, South China. DCG has been divided into four formations from the bottom to the top: Yinmin, Luoxue, Heishan, and Qinglongshan. The Yinmin Formation, which represents the oldest rock unit of DCG, was intruded by a diabase dyke. The oldest zircon age of the clastic rocks from the Yinmin Formation is 3654 Ma, with εHf(t) of −3.1 and a two-stage modeled age of 4081 Ma. Another zircon exhibits an age of 2406 Ma, with εHf(t) of −20.1 and a two-stage modeled age of 4152 Ma. These data provide indirect evidence for the residues of the Hadean crustal nuclei in the Yangtze Block. In combination with the published data, the ages of detrital zircons from the Yinmin Formation yielded three peak ages: 1.84, 2.30 and 2.71 Ga. The peaks of 1.84 and 2.71 Ga are global in distribution, and they are best correlated to the collisional accretion of cratons in North America. Moreover, the peak of 1.84 Ga coincides with the convergence of the global Columbia supercontinent. The youngest age of the detrital zircon from the Yinmin Formation was 1710 Ma; the age of the intrusive diabase was 1689 ± 34 Ma, whereas the weighted average age of the sedimentary tuff from the Heishan Formation was 1414 ± 25 Ma. It was presumed that the depositional age for DCG was 1.71–1.41 Ga, which was in accordance with the timing of the breakup of the Columbia supercontinent. At ~1.7 Ga, the geochemical data of the diabase were characterized by E-MORB and the region developed the same period A-type granites. Thus, 1.7 Ga should represent the time of the initial breakup of the Yangtze Block. Furthermore, the Yangtze Block continues to stretch and breakup until ~1.4 Ga, which is characterized by the emergence of oceanic island, deep-sea siliceous rock and flysch, representing the final breakup. In brief, the tectonic evolution of the Yangtze Block during the Late Paleoproterozoic to Mesoproterozoic coincided with the events caused by the convergence and breakup of the Columbia supercontinent, because of which, the Yangtze Block experienced extensive magmatic activity and sedimentary basin development during this period.

Precambrian basement, provenance implication, and tectonic evolution of the Gargan block of the Tuva-Mongolia terranes, Central Asian Orogenic Belt

2019 ◽  
Vol 75 ◽  
pp. 172-183 ◽  
Author(s):  
Uyanga Bold ◽  
Yukio Isozaki ◽  
Shogo Aoki ◽  
Shuhei Sakata ◽  
Akira Ishikawa ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Precambrian Basement ◽  
Central Asian

Possible forced folding in the Taurus–Zagros Belt of northern Iraq

1991 ◽  
Vol 128 (6) ◽  
pp. 561-584 ◽  
Author(s):  
M. S. Ameen
Keyword(s):  
Remote Sensing ◽  
Rocky Mountains ◽  
Tectonic Evolution ◽  
Sedimentary Cover ◽  
Convincing Evidence ◽  
Precambrian Basement ◽  
Substantial Evidence ◽  
Northern Iraq ◽  
Forced Folding

AbstractThe folds in the Taurus–Zagros Belt of northern Iraq have generally been considered to be decollement buckle folds. This implies the presence of a decollement horizon at or near the base of the sedimentary cover, the ‘Infra-Cambrian Hormuz Salt’ and a passive role of the Precambrian basement in the tectonic evolution of the folded belt. Structural, stratigraphic, geophysical and remote sensing evidence suggests that forced folding, due to faulting in the basement, has played a significant role in the development of many of the folds in this region. This is clear from the substantial evidence of basement faulting, the lack of any convincing evidence for the presence of an extensive and regional decollement horizon (i.e. the Hormuz Salt) between the basement and the cover rocks, and the geometries of the folds and related mesostructures. The study shows that in the Taurus Foothills Zone, the folds are short, oval in plan shape, and arranged in an en echelon pattern along two sets of dislocation zones in the basement. However, the folds in the Zagros Foothills Zone are longer, linear and arcuate in plan shape. Many of the studied folds show similar features to those observed in the Rocky Mountains, U.S.A.

Paleozoic crustal evolution and tectonic switching in the Northeastern Tianshan: insights from zircon Hf isotopes of granitoids

2020 ◽  
pp. jgs2020-035
Author(s):  
Long Du ◽  
Hongli Zhu ◽  
Chao Yuan ◽  
Yunying Zhang ◽  
Zongying Huang ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Crustal Growth ◽  
Precambrian Basement ◽  
Content Type ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Juvenile Crust ◽  
Supplementary Material ◽  
Last Stage

Decoding the crustal and tectonic evolution of ancient accretionary orogens is not always straightforward. Here, four episodes of Paleozoic granitoids have been identified with distinct zircon–Hf isotopic characteristics from the Northeastern Tianshan. The first stage granitoids in the Dananhu–Harlik arc system are characterized by highly positive zircon εHf(t) values and short crustal incubation times with a rising event signature, suggesting a northward trench advance for the Kangguer Ocean. During the second stage, granitoids in the Dananhu and Kangguer belts have high zircon εHf(t) values and short crustal incubation times, but with a decreasing event signature for the Dananhu granitoids, implying a reworking of the juvenile arc crust. However, the near-zero εHf(t) values and the longest crustal incubation times of the Yamansu granitoids in this stage elucidate an origin from a Precambrian basement. These variations suggest that the northern trench of the Kangguer Ocean retreated southward while the southern trench advanced southward. During the third stage, the enlarged ranges of zircon εHf(t) values and crustal residence ages as well as crustal incubation times for the Dananhu and Kangguer granitoids show an interaction of juvenile material and the pre-existing crust, whereas the highly positive zircon εHf(t) values with a sharp rising event signature of the Yamansu granitoids suggest an significant crustal growth, indicating that a northward trench advance and a southern trench retreat for the Kangguer Ocean. However, the last stage granitoids in the Northeastern Tianshan entirely exhibit decreasing zircon εHf(t) values and long crustal incubation times, demonstrating a reworking of the pre-existing juvenile crust with minor input of ancient crustal materials in a post-collisional setting.Supplementary material: Table S1 and S2 and analytical methods are available at https://doi.org/10.6084/m9.figshare.c.5197889

scholarly journals Geology and gold mineralisation in the Mauken Precambrian basement window, Målselv, Troms, northern Norway

2016 ◽  
Author(s):  
Terje Bjerkgård ◽  
Trond Slagstad ◽  
Iain H.C. Henderson ◽  
Jan Sverre Sandstad ◽  
Johannes Schönenberger
Keyword(s):  
Precambrian Basement ◽  
Northern Norway

Tectonic evolution of Precambrian basement massifs and an adjoining fold-and-thrust belt (Gyeonggi Marginal Belt), Korea: An overview

2017 ◽  
Vol 21 (6) ◽  
pp. 845-865 ◽  
Author(s):  
Moonsup Cho ◽  
Yuyoung Lee ◽  
Taehwan Kim ◽  
Wonseok Cheong ◽  
Yoonsup Kim ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Precambrian Basement ◽  
Thrust Belt ◽  
Fold And Thrust Belt
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