scholarly journals Petrogenesis and Tectonic Setting of Early Cretaceous Intrusive Rocks in the Northern Ulanhot Area, Central and Southern Great Xing’an Range, NE China

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1414
Author(s):  
Baoqiang Tai ◽  
Wentian Mi ◽  
Genhou Wang ◽  
Yingjie Li ◽  
Xu Kong
Keyword(s):  
Early Cretaceous ◽  
Tectonic Setting ◽  
Granite Porphyry ◽  
Granitic Rocks ◽  
Magma Source ◽  
Isotopic Data ◽  
Quartz Porphyry ◽  
Intrusive Rocks ◽  
Quartz Monzonite ◽  
Great Xing’An Range

Abundant Early Cretaceous magmatism is conserved in the central and southern Great Xing’an Range (GXR) and has significant geodynamic implications for the study of the Late Mesozoic tectonic framework of northeast China. In this study, we provide new high-precision U–Pb zircon geochronology, whole-rock geochemistry, and zircon Hf isotopic data for representative intrusive rocks from the northern part of the Ulanhot area to illustrate the petrogenesis types and magma source of these rocks and evaluate the tectonic setting of the central-southern GXR. Laser ablation inductively coupled plasma–mass spectrometry (LA-ICP-MS) zircon U–Pb dating showed that magmatism in the Ulanhot area (monzonite porphyry: 128.07 ± 0.62 Ma, quartz monzonite porphyry: 127.47 ± 0.36, quartz porphyry: 124.85 ± 0.34, and granite porphyry: 124.15 ± 0.31 Ma) occurred during the Early Cretaceous. Geochemically, monzonite porphyry belongs to the metaluminous and alkaline series rocks and is characterized by high Al2O3 (average 17.74 wt.%) and TiO2 (average 0.88 wt.%) and low Ni (average 4.63 ppm), Cr (average 6.69 ppm), Mg# (average 31.11), Y (average 15.16 ppm), and Yb (average 1.62 ppm) content with enrichment in Ba, K, Pb, Sr, Zr, and Hf and depletion in Ti, Nb, and Ta. The granitic rocks (e.g., quartz monzonite porphyry, quartz porphyry, and granite porphyry) pertain to the category of high-K calc-alkaline rocks and are characterized by high SiO2 content (>66 wt.%) and low MgO (average 0.69 wt.%), Mg# (average 31.49 ppm), Ni (average 2.78 ppm), and Cr (average 8.10 ppm) content, showing an affinity to I-type granite accompanied by Nb, Ta, P, and Ti depletion and negative Eu anomalies (δEu = 0.57–0.96; average 0.82). The Hf isotopic data suggest that these rocks were the product of the partial melting of juvenile crustal rocks. Notably, fractionation crystallization plays a crucial role in the process of magma emplacement. Combining our study with published ones, we proposed that the Early Cretaceous intrusive rocks in the Ulanhot area were formed in an extensional tectonic background and compactly related to the subduction of the Paleo-Pacific Ocean plate.

scholarly journals Geology, Geochronology and Geochemistry of Weilasituo Sn-Polymetallic Deposit in Inner Mongolia, China

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 104 ◽  
Author(s):  
Fan Yang ◽  
Jinggui Sun ◽  
Yan Wang ◽  
Junyu Fu ◽  
Fuchao Na ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Lower Crust ◽  
Structural Evolution ◽  
Magma Source ◽  
Crustal Material ◽  
Quartz Porphyry ◽  
Polymetallic Deposit ◽  
High Concentrations ◽  
Great Xing’An Range ◽  
Lower Crustal

The recently discovered Weilasituo Sn-polymetallic deposit in the Great Xing’an Range is an ultralarge porphyry-type deposit. The mineralization is closely associated with an Early Cretaceous quartz porphyry. Analysis of quartz porphyry samples, including zircon U-Pb dating and Hf isotopies, geochemical and molybdenite Re-Os isotopic testing, reveals a zircon U-Pb age of 138.6 ± 1.1 Ma and a molybdenite Re-Os isotopic age of 135 ± 7 Ma, suggesting the concurrence of the petrogenetic and metallogenic processes. The quartz porphyry has high concentrations of SiO2 (71.57 wt %–78.60 wt %), Al2O3 (12.69 wt %–16.32 wt %), and K2O + Na2O (8.85 wt %–10.44 wt %) and A/CNK ratios from 0.94–1.21, is mainly peraluminous, high-K calc-alkaline I-type granite and is relatively rich in LILEs (large ion lithophile elements, e.g., Th, Rb, U and K) and HFSEs (high field strength elements, e.g., Hf and Zr) and relatively poor in Sr, Ba, P, Ti and Nb. The zircon εHf(t) values range from 1.90 to 6.90, indicating that the magma source materials were mainly derived from the juvenile lower crust and experienced mixing with mantle materials. Given the regional structural evolution history, we conclude that the ore-forming magma originated from lower crust that had thickened and delaminated is the result of the subduction of the Paleo–Pacific Ocean. Following delamination, the lower crustal material entered the underlying mantle, where it was partially melted and reacted with mantle during ascent. The deposit formed at a time of transition from post-orogenic compression to extension following the subduction of the Paleo–Pacific Ocean.

Geochemistry, geochronology and Sr–Nd–Hf isotopes of two types of Early Cretaceous granite porphyry dykes in the Sulu orogenic belt, eastern China

2020 ◽  
Vol 57 (2) ◽  
pp. 249-266 ◽  
Author(s):  
Song-Jie Wang ◽  
Hans-Peter Schertl ◽  
Yu-Mao Pang
Keyword(s):  
Early Cretaceous ◽  
Eastern China ◽  
Orogenic Belt ◽  
Granite Porphyry ◽  
Granitic Rocks ◽  
Geodynamic Setting ◽  
Type I ◽  
Yangtze Craton ◽  
T Values ◽  
Sulu Orogenic Belt

Late Mesozoic granitic rocks are widely distributed in the Sulu orogenic belt, but the source, tectonic affinity, and associated geodynamic setting that produced the respective magmas remain controversial. To provide insights into these issues, we present field-based petrological, whole-rock major and trace element and Sr–Nd isotope geochemical, zircon U–Pb dating, and Lu–Hf isotope studies on two types of granite porphyry dykes that are newly recognized from the central Sulu belt. U–Pb dating of magmatic zircons from both types yields consistent ages that vary between 124 ± 2 and 118 ± 2 Ma, constraining the timing of intrusion as Early Cretaceous. The granitic rocks have high-K calc-alkaline peraluminous compositions with low Mg# values and are characterized by fractionated rare earth element patterns with strong depletion in high field strength elements. Compared with type I of the granite porphyry dykes, type II exhibits higher SiO2 but slightly lower Na2O and K2O abundances, contains higher Rb/Sr and 87Sr/86Sr ratios, and shows more pronounced negative Eu, Sr, and Ba anomalies. Both types I and II have high initial 87Sr/86Sr ratios of 0.709–0.711 and negative εNd(t) values of −19.8 to −18.4. The magmatic zircons possess negative εHf(t) values of −29.1 to −20.8, with mostly Neoarchean Hf model ages of 3001–2478 Ma. These features, together with the presence of Neoproterozoic inherited zircons, indicate that the two types of granite porphyries successively crystallized from a joint granite magma that derived from partial melting of the continental crust of the Yangtze Craton. Therefore, an interrelationship between the granite porphyry dykes and massive magmatic granitoids from adjacent regions in the Sulu belt may be documented, recording evidence of a joint ancient crustal reworking and recycling in a fossilized continental subduction zone during the Early Cretaceous.

Lower Cretaceous alkali feldspar granites in the central part of the Great Xing’an Range, northeastern China: chronology, geochemistry and tectonic implications

2014 ◽  
Vol 152 (3) ◽  
pp. 383-399 ◽  
Author(s):  
DEXIN TIAN ◽  
WENCHUN GE ◽  
HAO YANG ◽  
GUOCHUN ZHAO ◽  
YANLONG ZHANG
Keyword(s):  
Lower Cretaceous ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Pacific Plate ◽  
Northeastern China ◽  
Formation Time ◽  
Granitic Rocks ◽  
Geochemical Data ◽  
Regional Geology ◽  
Great Xing’An Range

AbstractThe Mingshui–Jilasitai–Suolun area, located in the central part of the Great Xing’an Range, is characterized by large volumes of alkali feldspar granites. However, the formation time and tectonic setting of these rocks remains controversial owing to a lack of precise geochronological and detailed geochemical data. In this paper, we report new SIMS U–Pb zircon ages and mineralogical, petrographical and geochemical data for Lower Cretaceous alkali feldspar granites from the Mingshui–Jilasitai–Suolun area. The SIMS zircon dating results indicate that these granites formed at 133.6–135.9 Ma. The mineralogical, petrographical and geochemical data show that these granitic rocks belong to highly fractionated I-type granites. Combined with the regional geology data, we propose that the formation of the Lower Cretaceous alkali feldspar granitic rocks was related to an extension induced by delamination of the lithosphere that arose from subduction of the Palaeo-Pacific plate.

Petrogenesis of high Ba–Sr plutons with high Sr/Y ratios in an intracontinental setting: evidence from Early Cretaceous Fushan monzonites, central North China Craton

2019 ◽  
Vol 156 (12) ◽  
pp. 1965-1981 ◽  
Author(s):  
Xi-Yao Li ◽  
San-Zhong Li ◽  
Feng Huang ◽  
Yong-Ming Wang ◽  
Sheng-Yao Yu ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
North China Craton ◽  
North China ◽  
Mantle Wedge ◽  
Magma Source ◽  
Magmatic Evolution ◽  
Calc Alkaline ◽  
Isotopic Data ◽  
Lree Enrichment ◽  
Roll Back

AbstractGeochronological, major and trace element, and Sr–Nd–Hf isotopic data are reported for the monzonitic rocks of the Fushan pluton in the Taihang Mountains, central North China Craton, in order to investigate their sources, petrogenesis and tectonic implications. Zircon U–Pb dating results reveal that the Fushan pluton was emplaced during the Early Cretaceous (∼126–124 Ma). The monzonites and quartz monzonites are mainly characterized by calc-alkaline and magnesian features and display light rare earth element (LREE) enrichment and flat heavy REE (HREE) patterns with slightly positive Eu anomalies. They have similar whole-rock initial 87Sr/86Sr ratios (0.70653–0.70819), εNd(t) values (−13.6 to −18.6) and zircon εHf(t) values (−21.8 to −17.3). The primary magma of the Fushan pluton was derived from the partial melting of a spinel-facies amphibole-bearing ancient enriched lithospheric mantle. The monzonitic rocks also have high Ba–Sr and low Y and Yb contents, with high Sr/Y and La/Yb ratios. These geochemical features of monzonitic rocks are not only inherited from the magma source but also significantly enhanced by crystal fractionation during magmatic evolution; e.g. hornblende fractionation increased the Ba–Sr concentrations and Sr/Y ratios. During the Early Cretaceous, the slab sinking and roll-back of the Palaeo-Pacific Plate could have created an ancient big mantle wedge beneath East Asia and induced a lithospheric extensional process in the central North China Craton within an intracontinental setting.

Petrogenesis and tectonic implications of Late Jurassic – Early Cretaceous granitic magmatism in the Xing’an Block, Northeast China: geochronological, geochemical, and Hf isotopic evidence

2018 ◽  
Vol 55 (6) ◽  
pp. 571-588 ◽  
Author(s):  
Yue He ◽  
Zhong-Hua He ◽  
Wen-Chun Ge ◽  
Hao Yang ◽  
Zhi-Hui Wang ◽  
...  
Keyword(s):  
Partial Melting ◽  
Early Cretaceous ◽  
Northeast China ◽  
Late Jurassic ◽  
Granitic Rocks ◽  
Geochemical Data ◽  
Magma Source ◽  
Isotopic Evidence ◽  
Depleted Mantle ◽  
Microgranular Enclaves

This study presents new geochronological, whole-rock geochemical, and zircon Hf isotopic evidence for the age, petrogenesis, and source of Mesozoic granitic rocks of the Xing’an Block, Northeast China. This evidence reveals the Late Mesozoic tectonic evolution of the eastern section of the Central Asian Orogenic Belt. Laser-ablation inductively coupled plasma – mass spectrometryzircon U–Pb age data indicate that the syenogranite, monzogranite, and alkali feldspar granite units, as well as their associated diorite microgranular enclaves, were emplaced between 150–142 Ma, providing evidence of Late Jurassic to Early Cretaceous magmatic events within the Xing’an Block. The granites contain high concentrations of SiO2 (65.24%–75.73 wt.%) and K2O (3.94%–5.30 wt.%), low concentrations of MgO (0.10%–1.30 wt.%), and A/CNK values of 0.92–1.06. In addition, Hf isotopic analysis of zircons from the 150–142 Ma granites yields εHf(t) values of +4.54 to +12.16 and two-stage Hf model aged from 906 to 423 Ma, indicating that they formed from magmas generated by partial melting of a juvenile Neoproterozoic–Phanerozoic accreted crustal source. The basic magma source for the diorite microgranular enclaves most likely formed from partial melting of a depleted mantle that had been metasomatized by subduction-related fluids. Combining these new geochemical data with the geology of this region, Late Jurassic to Early Cretaceous magmatism in the Xing’an Block most likely occurred in an extensional environment associated with closure of the Mongol–Okhotsk Ocean.

scholarly journals SHRIMP U–Pb Zircon Ages, Geochemistry and Sr–Nd–Hf Isotope Systematics of the Zalute Intrusive Suite in the Southern Great Xing’an Range, NE China: Petrogenesis and Geodynamical Implications

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 927
Author(s):  
Huanan Liu ◽  
Feng Yuan ◽  
Shengjin Zhao ◽  
Mingjing Fan ◽  
Xiangguo Guo
Keyword(s):  
Early Cretaceous ◽  
Parental Magma ◽  
Source Rocks ◽  
Granitic Rocks ◽  
Common Source ◽  
Published Data ◽  
Ne China ◽  
Granite Porphyries ◽  
Intrusive Suite ◽  
Great Xing’An Range

An integrated zircon geochronological, elemental geochemical, and Sr–Nd–Hf isotopic investigation was carried out on a suite of dioritic–granitic rocks at Zalute in the southern Great Xing’an Range (SGXR), NE China, in order to probe the source and petrogenesis of these granitoid rocks and further constrain the geodynamical setting of early Early Cretaceous magmatism. The results of Sensitive High-Resolution Ion Micro Probe (SHRIMP) zircon U–Pb dating reveal that the Zalute dioritic–granitic rocks have a consistent crystallization age of ca. 137–136 Ma, consisting of quartz diorite (136 ± 1.4 Ma), monzogranite (136 ± 0.8 Ma), and granite porphyry (137 ± 1.3 Ma), which record an early Early Cretaceous magmatic intrusion. Geochemically, the quartz diorites, monzogranites, and granite porphyries are mostly high-K calc-alkaline and show features of typical I-type affinity. They possess uniform and depleted Sr–Nd–Hf isotopic compositions (e.g., initial 87Sr/86Sr ratios of 0.7035 to 0.7049, εNd(t) of −0.02 to +2.61, and εHf(t) of +6.8 to +9.6), reflecting a common source, whose parental magma is best explained as resulting from the partial melting of juvenile source rocks in the lower crust produced by underplating of mantle-derived mafic magma, with minor involvement of ancient crustal components. Evidence from their close spatio–temporal relationship, common source, and the compositional trend is consistent with a magmatic differentiation model of the intermediate-felsic intrusive suite, with continued fractional crystallization from quartz diorites, towards monzogranites, then to granite porphyries. Combined with previously published data in the SGXR, our new results indicate that the Zalute intermediate-felsic intrusive suite was formed during the post-collisional extension related to the closure of the Mongol–Okhotsk Ocean and subsequent slab break-off.

scholarly journals Petrogenesis and tectonic setting of the Early Cretaceous granitoids in the eastern Tengchong terrane, SW China: Constraint on the evolution of Meso-Tethys

Lithosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 150-165
Author(s):  
Xiaohu He ◽  
Zheng Liu ◽  
Guochang Wang ◽  
Nicole Leonard ◽  
Wang Tao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Partial Melting ◽  
Early Cretaceous ◽  
Lower Crust ◽  
Tectonic Setting ◽  
Igneous Rocks ◽  
Source Rocks ◽  
Granitic Rocks ◽  
The Tibetan Plateau ◽  
Sw China

Abstract As a result of the evolution of Meso-Tethys, Early Cretaceous granitoids are widespread in the eastern Tengchong terrane, SW China, which is considered as the southern extension of the Tibetan Plateau. These igneous rocks are therefore very important for understanding the tectonic setting of Meso-Tethys and the formation of the Tibetan Plateau. In this paper, we present new zircon U-Pb dating, whole-rock elemental, and Nd isotopic data of granitoids obtained from the eastern Tengchong terrane. Our results show that these granitoids are composed of monzogranites and granodiorites and formed at ca. 124 Ma in the Early Cretaceous. Mineralogically and geochemically, these granitoids display metaluminous nature and affinity to I-type granites, which are derived from preexisting intracrustal igneous source rocks. The predominantly negative whole-rock εNd(t) values (−10.86 to −8.64) for all samples indicate that they are derived mainly from the partial melting of the Mesoproterozoic metabasic rocks in the lower crust. Integrating previous studies with the data presented in this contribution, we propose that the Early Cretaceous granitic rocks (135–110 Ma) also belong to I-type granites with minor high fractionation. Furthermore, in discriminant diagrams for source, granitoids are mainly derived from the partial melting of metaigneous rocks with minor sediments in the lower crust. The new identification of the Myitkyina Meso-Tethys ophiolitic suite in eastern Myanmar and mafic enclaves indicate that these Cretaceous igneous rocks were the products of the tectonic evolution of the Myitkyina Tethys Ocean, which was related to post-collisional slab rollback. Moreover, the Tengchong terrane is probably the southern extension of the South Qiangtang terrane.

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