Paleo- to Mesoproterozoic magmatic and tectonic evolution of the southwestern Yangtze Block, south China: New constraints from ca. 1.7–1.5 Ga mafic rocks in the Huili-Dongchuan area
Graphical abstract
Introduction
The Yangtze Block is one of the largest ancient continental crust blocks in eastern Asia. Recent studies highlight Archean basement evolution of the Yangtze Block (e.g., Li et al., 2014; Hui et al., 2017; Wang et al., 2018; and references therein). The subsequent Paleo- to Mesoproterozoic history of the Yangtze Block has attracted increasing research attention because of its possible involvement in the assembly and breakup of the Paleo- to Mesoproterozoic supercontinent Nuna (also known as Columbia; e.g., Rogers and Santosh, 2002; Zhao et al., 2002; Ernst et al., 2008; Evans and Mitchell, 2011; Meert, 2012; Wang et al., 2012; Fan et al., 2013; Chen et al., 2013; Wang and Zhou, 2014; Zhou et al., 2014; Meert and Santosh, 2017; Lu et al., 2019; Cui et al., 2019) as well as the presence of large Fe–Cu–rare earth element (REE) deposits (e.g., the Dahongshan, Lala, Yinachang, Xikuangshan and Sin Quyen deposits; Zhou et al., 2014; and references therein) and Fe-Ti-V oxide ore deposits (such as the Zhuqing deposit; Fan et al., 2013, Fan et al., 2014) in the late Paleoproterozoic to early Mesoproterozoic rocks of the southwestern part of the block.
Nevertheless, outcrops of Paleo- to Mesoproterozoic rock units (e.g. the Tianli schists and the Dahongshan, Hekou, Dongchuan and Tong'an groups) (e.g., Greentree et al., 2006; Li et al., 2007, Li et al., 2014; Greentree and Li, 2008; Zhao et al., 2010; Peng et al., 2012; Fan et al., 2013; Zhou et al., 2014) and 1.7–1.5 Ga intrusive and metavolcanic rocks (e.g., Zhao et al., 2010; Fan et al., 2013; Chen et al., 2013; Lu et al., 2019; Zhu et al., 2016a, Zhu et al., 2017, Zhu et al., 2019) are extremely sparse, and have been identified mostly in the Kangdian region of southwestern Yangtze Block (Fig. 1). As a consequence, the stratigraphy of these Paleo- to Mesoproterozoic rock units has been long debated due to few constraints on the ages of them (e.g., Zhao et al., 2010; Fan et al., 2013; Zhou et al., 2014). Moreover, the lack of systematic geochronological, geochemical, and isotope studies of the intrusive and metavolcanic rocks has prevented a comprehensive understanding of the Paleo- to Mesoproterozoic evolution of the Yangtze Block.
In this contribution, we report the results of a detailed study of several recently discovered mafic intrusions that intrude the Paleoproterozoic Dongchuan and Tong'an groups in the Huili–Dongchuan area (Fig. 1). On the basis of precise ages and distinguishable geochemical compositions, the studied mafic rocks can be subdivided into three groups: a 1.72–1.71 Ga group of gabbros and diabases with ages of 1716–1714 Ma, a 1.70 Ga group of gabbros and a diabase-porphyrite with ages of 1705–1700 Ma, and a 1.52–1.50 Ga group of a gabbro and a diabase with ages of 1519–1504 Ma. Taking into account preciously reported geochemical and isotopic data for some of these intrusions (Fan et al., 2013; Chen et al., 2013; Zhu et al., 2016a, Zhu et al., 2017, Zhu et al., 2019; Lu et al., 2019), we use our new data to assess the origin of these rocks and to discuss the implications for regional stratigraphic correlation and tectonic evolution of the southwestern Yangtze Block during the late Paleo- to Mesoproterozoic.
Section snippets
Regional geology
The Yangtze Block and the Cathaysia Block was joined by the late-Mesoproterozoic to earliest Neoproterozoic Sibao Orogen to form the South China Block (Li et al., 2007) (Fig. 1a). In the Yangtze Block, Archaean–Palaeoproterozoic basement rocks crop out mainly in the northern part, whereas late Palaeoproterozoic basement rocks are found in the southwestern part of the block, known as the Kangdian region (Fig. 1b). The oldest supracrustal in this area are the late Paleoproterozoic Dahongshan,
Sampling and analytical methods
More than one hundred and fifty samples were collected from the best-exposed and least-altered outcrops of four diabase dikes, six gabbroic plutons and a diabase-porphyrite pluton in the Huili–Dongchuan area (Figs. 2c and 3). Thin sections were prepared for all samples and seventy-nine least altered samples were chosen for whole rock analysis, among which, ten representative samples were selected for zircon and baddeleyite U-Pb dating, and thirty-two samples were used for Nd isotopic analysis.
1.72–1.71 Ga intrusions
Zircons from sample TST1305 (diabase intruding the Tong'an Group) and BK1102 (gabbro intruding the Dongchuan Group) gave ages of >1.71 Ga (Supplementary Table S1). The zircons are simple prismatic crystals 50–120 μm in length, have aspect ratios of 1:1 to 2:1, and show obvious zoning under CL (Fig. 5a and b). Eleven analyses that were conducted on 12 zircon grains from sample TST1305 yielded a discordia line with an upper intercept age of 1714 ± 16 Ma and a lower intercept age of 277 ± 41 Ma
Chronological and stratigraphic differences between the Huili and Tong'an groups
Zircons from mafic rocks in the Huili-Dongchuan area are clearly magmatic, as judged from their CL images and Th/U ratios (Fig. 5, Fig. 6, Fig. 7; Supplementary Table S1), and together with baddeleyites, which have a very stable U-Pb isotopic system in mafic–ultramafic rocks (e.g., Li et al., 2010), the age data for these minerals suggest that these gabbroic intrusions and dikes formed in three time intervals of 1.72–1.71, 1.70, and 1.52–1.50 Ga (Figs. 2c and Fig. 5, Fig. 6, Fig. 7;
Conclusions
We report results of detailed geochronological and geochemical analyses on newly discovered Paleo- to early Mesoproterozoic diabase dikes and gabbroic and diabase-porphyrite plutons in southwestern Yangtze Block, South China. Precise SIMS zircon and baddeleyite U-Pb dating provide first evidence for three episodes of mafic rocks between 1.72 and 1.50 Ga in southwestern Yangtze Block. These ages constraint the initial depositional age of the previously poorly dated Tong'an and Dongchuan groups
CRediT authorship contribution statement
Hong-Peng Fan: Data curation, Writing - original draft. Wei-Guang Zhu: Supervision, Project administration, Writing - review & editing. Zheng-Xiang Li: Supervision, Writing - review & editing.
Declaration of competing interest
We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work. There is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in or the review of the manuscript entitled.
Acknowledgements
We appreciate Q.L. Li, G.Q Tang, and X.X. Lin for their assistances in SIMS dating, J. Hu, G.P. Bao and Y. Huang for trace element analyses by ICP-MS, Z.Y. Chu, F. Xiao, and X.B. Li for Nd isotope analyses by TIMS, and Z.Y. Chu, C.F. Li and W.J. Hu for Nd isotope analyses by MAT262. The paper has benefited from constructive comments of the Editor Prof. Y.P. Dong and two anonymous reviewers. This work is supported by the NSFC (Grants 41572074, 41403044, and 41273049). This is contribution 1524
References (60)
- et al.
Petrogenetic evolution of late Cenozoic, post-collision volcanism in western Anatolia, Turkey
J. Volcanol. Geotherm. Res.
(2000) - et al.
Late Paleoproterozoic sedimentary and mafic rocks in the Hekou area, SW China: Implication for the reconstruction of the Yangtze Block in Columbia
Precambrian Res.
(2013) - et al.
“Grenvillian” intra-plate mafic magmatism in the southwestern Yangtze Block, SW China
Precambrian Res.
(2014) - et al.
Early Paleoproterozoic (ca. 2.36 Ga) post-collisional granitoids in Yunnan, SW China: Implications for linkage between Yangtze and Laurentia in the Columbia supercontinent
J. Asian Earth Sci.
(2019) - et al.
Global record of 1600–700 Ma large Igneous Provinces (LIPs): Implications for the reconstruction of the proposed Nuna (Columbia) and Rodinia supercontinents
Precambrian Res.
(2008) - et al.
Ca. 1.5 Ga mafic magmatism in South China during the break-up of the supercontinent Nuna/Columbia: the Zhuqing Fe–Ti–V oxide ore-bearing mafic intrusions in western Yangtze Block
Lithos
(2013) - et al.
The oldest known rocks in south-western China: SHRIMP U-Pb magmatic crystallization age and detrital provenance analysis of the Paleoproterozoic Dahongshan Group
J. Asian Earth Sci.
(2008) - et al.
Late Mesoproterozoic to earliest Neoproterozoic basin record of the Sibao orogenesis in western South China and relationship to the assembly of Rodinia
Precambrian Res.
(2006) Heterogeneous mantle domains: signatures, genesis and mixing chronologies
Earth Planet. Sci. Lett.
(1988)- et al.
Mantle plumes from ancient oceanic crust
Earth Planet. Sci. Lett.
(1982)
Zircon U-Pb chronology, Hf isotope analysis and whole-rock geochemistry for the Neoarchean-Paleoproterozoic Yudongzi complex, northwestern margin of the Yangtze craton, China
Precambrian Res.
Revisiting the “Yanbian Terrane”: implications for Neoproterozoic tectonic evolution of the western Yangtze Block, South China
Precambrian Res.
Petrogenesis of Paleo-Mesoproterozoic mafic rocks in the southwestern Yangtze Block of South China: Implications for tectonic evolution and paleogeographic reconstruction
Precambrian Res.
What’s in a name? The Columbia (Paleopangaea/Columbia) supercontinent
Precambrian Res.
The Columbia supercontinent revisited
Gondwana Res.
Geochemistry of near-EPR seamounts: importance of source vs. process and the origin of enriched mantle component
Earth Planet. Sci. Lett.
Dynamical geochemistry of the Hawaiian plume
Earth Planet. Sci. Lett.
A mantle plume below the Eifil volcanic fields, Germany
Earth Planet. Sci. Lett.
Configuration of Columbia, a Mesoproterozoic supercontinent
Gondwana Res.
Detrital zircon U-Pb geochronological and Lu-Hf isotopic constraints on the Precambrian magmatic and crustal evolution of the western Yangtze block, SW China
Precambrian Res.
Early crustal evolution of the Yangtze Craton, South China: New constraints from zircon U-Pb-Hf isotopes and geochemistry of ca. 2.9–2.6 Ga granitic rocks in the Zhongxiang complex
Precambrian Res.
Early crustal evolution in the western Yangtze Block: evidence from U-Pb and Lu-Hf isotopes on detrital zircons from sedimentary rocks
Precambrian Res.
Provenance and tectonic setting of the Paleo- to Mesoproterozoic Dongchuan Group in the southwestern Yangtze Block, South China: implication for the breakup of the supercontinent Columbia
Tectonophysics
Late Paleoproterozoic to Mesoproterozoic rift successions in SW China: Implication for the Yangtze Block-North Australia-Northwest Laurentia connection in the Columbia supercontinent
Sediment. Geol.
Petrologic and geochemical constraints on the petrogenesis of Permian-Triassic Emeishan flood basalts in southwestern China
Lithos
Review of global 2.1–1.8 Ga orogens: Implications for a pre-Rodinia supercontinent
Earth Sci. Rev.
Late Paleoproterozoic to early Mesoproterozoic Dongchuan Group in Yunnan, SW China: implications for tectonic evolution of the Yangtze Block
Precambrian Res.
Proterozoic Fe-Cu metallogeny and supercontinental cycles of the southwestern Yangtze Block, southern China and northern Vietnam
Earth Sci. Rev.
The Yinachang Fe-Cu-Au-U-REE deposit and its relationship with intermediate to mafic intrusions, SW China: Implications for ore genesis and geodynamic setting
Ore Geol. Rev.
SIMS zircon U-Pb ages, geochemistry and Nd–Hf isotopes of ca. 1.0 Ga mafic dykes and volcanic rocks in the Huili area, SW China: Origin and tectonic significance
Precambrian Res.
Cited by (18)
Positioning the Yangtze Block within Nuna: Constraints from Paleoproterozoic granitoids in North Vietnam
2023, Precambrian Research