Slab break-off and syncollisional origin of the Late Cretaceous magmatism in the Central Anatolian crystalline complex, Turkey

Author(s):  
Yusuf K. Kadıoğlu ◽  
Yildirim Dilek ◽  
Kenneth A. Foland
Geology ◽  
2001 ◽  
Vol 29 (8) ◽  
pp. 723 ◽  
Author(s):  
David R. Lageson ◽  
James G. Schmitt ◽  
Brian K. Horton ◽  
Thomas J. Kalakay ◽  
Bradford R. Burton

2021 ◽  
pp. jgs2021-109
Author(s):  
Igor V. Kemkin ◽  
Andrei V. Grebennikov ◽  
Xing-Hua Ma ◽  
Ke-Ke Sun

We present new U–Pb age data for granitoids in the Central Sikhote–Alin orogenic belt in SE Russia, which refute the established opinion about the absence of the Late Cretaceous magmatism at the eastern margin of the Paleo-Asian continent. It was previously thought that a period of magmatic quiescence occurred from 88 to 50 Ma, related to subduction of the Paleo-Pacific Plate under the eastern margin of the Paleo-Asian continent, although this is inconsistent with evidence from the Sikhote–Alin, Sakhalin, and Japan regions. Three suites of plutonic rocks with different ages were identified in this study. The first suite has ages of 105–92 Ma and formed in a syn-orogenic setting. The second (86–83 Ma) and third (ca. 73 Ma) suites formed during the post-orogenic stage of the Sikhote–Alin orogenic belt. The second and third suites were coeval with Late Cretaceous granitoids that formed in a suprasubduction continental arc known as the Eastern Sikhote–Alin volcanic–plutonic belt (ESAVPB). However, the studied rocks are located far inland from the ESAVPB. The ages of the studied granitoids coincide with the timing of a change in the angle of convergence between the Paleo-Pacific Plate and eastern margin of the Paleo-Asian continent. This change in motion of the oceanic plate with respect to the continental plate was probably caused by a rupture in the subducted slab (i.e., a slab tear), followed by asthenospheric upwelling and partial melting of the overlying crust, which ultimately generated post-orogenic intrusive magmatism.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5738616


Lithos ◽  
2016 ◽  
Vol 245 ◽  
pp. 258-273 ◽  
Author(s):  
Li-Qiang Yang ◽  
Jun Deng ◽  
Yildirim Dilek ◽  
Jian-Yin Meng ◽  
Xue Gao ◽  
...  

1998 ◽  
Vol 164 (1-2) ◽  
pp. 221-232 ◽  
Author(s):  
T.H Torsvik ◽  
R.D Tucker ◽  
L.D Ashwal ◽  
E.A Eide ◽  
N.A Rakotosolofo ◽  
...  

2020 ◽  
Vol 157 (8) ◽  
pp. 1316-1332
Author(s):  
Zhuanrong Sun ◽  
Guochen Dong ◽  
M Santosh ◽  
Xuanxue Mo ◽  
Pengsheng Dong ◽  
...  

AbstractThe Tengchong Block within the Sanjiang Tethys belt in the southeastern part of the Tibetan plateau experienced a widespread intrusion of a felsic magmatic suite of granites in its central domain during Late Cretaceous times. Here, we investigate the Guyong and Xiaolonghe plutons from this suite in terms of their petrological, geochemical, and Sr–Nd, zircon U–Pb and Lu–Hf–O isotopic features to gain insights into the evolution of the Neo-Tethys. The Guyong pluton (76 Ma) is composed of metaluminous monzogranites, and the Xiaolonghe pluton (76 Ma) is composed of metaluminous to peraluminous medium- and fine-grained syenogranite. A systematic decrease in Eu, Ba, Sr, P and Ti concentrations; a decrease in Zr/Hf and LREE/HREE ratios; and an increase in the Rb/Ba and Ta/Nb ratios from the Guyong to Xiaolonghe plutons suggest fractional crystallization of biotite, plagioclase, K-feldspar, apatite, ilmenite and titanite. They also show the characteristics of I-type granites. The negative zircon εHf(t) isotopic values (−10.04 to −5.22) and high δ18O values (6.69 to 8.58 ‰) and the negative whole-rock εNd(t) isotopic values (−9.7 to −10.1) and high initial 87Sr/86Sr ratios (0.7098–0.7099) of the Guyong monzogranite suggest that these rocks were generated by partial melting of the Precambrian basement without mantle input. The zircon εHf(t) isotopic values (−10.63 to −3.04) and δ18O values (6.54 to 8.69 ‰) of the Xiaolonghe syenogranite are similar to the features of the Guyong monzogranite, and this similarity suggests a cogenetic nature and magma derivation from the lower crust that is composed of both metasedimentary and meta-igneous rocks. The Xiaolonghe fine-grained syenogranite shows an obvious rare earth element tetrad effect and lower Nb/Ta ratios, which indicate its productive nature with respect to ore formation. In fact, we discuss that the Sn mineralization in the region was possible due to Sn being scavenged from these rocks by exsolved hydrothermal fluids. We correlate the Late Cretaceous magmatism in the central Tengchong Block with the northward subduction of the Neo-Tethys beneath the Burma–Tengchong Block.


2021 ◽  
Vol 82 (3) ◽  
pp. 274-276
Author(s):  
Svetoslav Georgiev

We present new Hf isotopic data of magmatic zircons from the Eastern Srednogorie zone. The data outline two clear temporal trends: rising initial εHf from the initiation of the magmatism at ~95 Ma to 81 Ma, followed by a rapid decline in the initial εHf in the 81–78 Ma time period. The first trend highlights the increasing participation of mantle melts in the formation of magmatic products in the East Balkan and Strandzha regions, which is likely dictated by the southward retreat of the subducting slab. This trend is also evident in published Hf isotopic data on zircons from Central Srednogorie zone. The second trend of rapidly decreasing initial εHf of zircons is interpreted to reflect increased proportion of lower crustal melts in an intra-arc rift extensional environment (the Yambol-Burgas region) between 81 and 78 Ma; this trend is not observed in the Central Srednogorie zone.


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