Members Highlights: authored by Guochun Zhao
- Article: Lithotectonic elements of Precambrian basement in the North China Craton: Review and tectonic implications
- Source Information
- Original Title: Lithotectonic elements of Precambrian basement in the North China Craton: Review and tectonic implications
- Authors: Guochun Zhao, Mingguo Zhai
- Affiliations: Department of Earth Sciences, The University of Hong Kong; Institute of Geology & Geophysics, Chinese Academy of Science
- Keywords:Archean; North China Craton; Mantle plume; Paleoproterozoic; Continent–continent collision
- Source Link:https://www.sciencedirect.com/science/article/pii/S1342937X12002936?via%3Dihub
- Editor’s Comments
This seminal paper by Zhao represents a landmark contribution to Precambrian geology that has fundamentally reshaped understanding of the North China Craton’s tectonic evolution. The authors’ comprehensive synthesis of structural, metamorphic, geochemical and geochronological data provides a unifying framework that resolves long-standing controversies about the craton’s assembly history. What makes this work particularly remarkable is how it bridges the gap between Archean and Proterozoic research paradigms, demonstrating that the NCC’s formation involved both mantle plume and subduction-collision processes operating at different times. The paper’s meticulous documentation of high-pressure and ultrahigh-temperature metamorphism sets new standards for identifying ancient suture zones, while its systematic age compilation establishes crucial temporal constraints that have become foundational for subsequent studies. Perhaps most importantly, the proposed “Three Orogenic Belts” model has proven exceptionally durable, serving as the reference framework for all modern investigations of NCC evolution and influencing global perspectives on Precambrian craton formation.
- Original text summary
The paper presents a groundbreaking synthesis of the North China Craton’s Precambrian basement, integrating decades of research into a coherent tectonic model. At its core is the identification of three distinct Paleoproterozoic orogenic belts – the Khondalite Belt, Trans-North China Orogen, and Jiao-Liao-Ji Belt – each recording separate collisional events between 1.95-1.85 Ga. The authors provide compelling evidence that these belts developed through different mechanisms, from continental collision to intracontinental rifting and closure. Their analysis of Neoarchean crustal growth reveals two major pulses at 2.8-2.7 Ga and 2.6-2.5 Ga, with the eastern and western blocks showing mantle plume signatures while the central region exhibits arc characteristics. The work is particularly notable for its detailed documentation of metamorphic evolution, including high-pressure granulites and ultrahigh-temperature rocks that constrain the thermal-tectonic history.
An extensive geochronological compilation establishes precise timing for key events, confirming 1.85 Ga as the final cratonization age while distinguishing earlier 2.5 Ga stabilization. The paper’s methodological innovations, particularly in combining zircon Hf isotopes with metamorphic petrology, created new approaches for studying ancient orogens. By reconciling previously conflicting models and providing definitive evidence for both vertical (plume) and horizontal (plate tectonic) processes in craton formation, this work has become the standard reference for NCC research and a benchmark for Precambrian studies globally. Its influence extends beyond the North China Craton, informing our broader understanding of how Archean and Paleoproterozoic crust evolved through complex interactions between mantle dynamics and plate tectonic processes.
Fig. 1. Tectonic subdivision of the North China Craton proposed (a) by Wu et al. (1998) and (b) by Zhai et al. (2000).
Fig. 2. Tectonic subdivision of the North China Craton proposed by Zhang et al. (1998).
Fig. 3. Updated subdivision of the North China Craton proposed by Zhai and Santosh(2011).
Fig. 4. Tectonic subdivision of the North China Craton proposed by Zhao et al., 1998, Zhao et al., 2001a, Zhao et al., 2005.
Fig. 5. Three Paleoproterozoic orogenic/mobile belts of the North China Craton recognized by Zhai and Peng (2007).
Fig. 6. Tectonic subdivision of the North China Craton proposed by Faure et al. (2007).
Fig. 7. Double-side subduction model for the assembly of the NCC proposed by Santosh (2010).
Fig. 8. (a) Tectonic subdivision of the North China Craton and (b) schematic sections showing for the formation and evolution of the craton proposed by Kusky and Li (2003).
Fig. 9. Schematic sections showing the formation and evolution of the North China Craton recently updated by Kusky, 2011a, Kusky, 2011b.
Fig. 10. Regional distribution of Eoarchean to Neoarchean basement rocks in the Anshan area (after Wu et al., 1998).
Fig. 11. Regional distribution of Early to Late Archaean basement rocks in the Caozhuang area, Eastern Hebei (after Wu et al., 1998).
Fig. 12. Geological map of Western Shandong (after Wan et al., 2010, Wan et al., 2011a).
Fig. 13. Geological map of the Qixia area, Jiaodong Terrane (Jahn et al., 2008). The map sheet is about 19 × 23 km.
Fig. 14. Simplified tectonic map showing the distribution of metamorphic complexes in the Trans-North China Orogen (after Zhao et al., 2000a).
Fig. 15. P–T paths of metamorphic rocks in the (a) Eastern Block, (b) Western Block and (c) Trans-North China Orogen. (a) Eastern Block: 1, Western Shandong domain; 2, Eastern Hebei; 3, Western Liaoning; 4, Northern Liaoning; 5, Eastern Shandong; 6, Miyun–Chengde; 7, Southern Jilin. (b) Western Block: 1, Guyang–Wuchuan; 2, Sheerteng; 3, Daqingshan-Wuchuan. (c) Trans-North China Orogen: 1, Hengshan; 2, Wutai; 3, Fuping; 4, Lüliang domain (Zhao et al., 2000a); 5, Zhongtiao; 6, Huaian, 7, High-pressure granulite. References for P–T paths of the Eastern Block, Western Block and Trans-North China Orogen are given in Zhao et al. (1998), Zhao et al. (1999a) and Zhao et al. (2000a), respectively.
Fig. 16. (a) Structural map showing the distribution of domiform structures in Eastern Hebei (after He et al., 1991); (b) structural map showing the distribution of domiform structures in Northern Liaoning and southern Jilin (after Sun et al., 1993a).
Fig. 17. Geological map showing the spatial distribution of the Jiao-Liao-Ji (Liaoji) Belt (after Zhao et al.,2005), which can be further subdivided into the northern and southern zones; the former comprises the Laoling, North Liaohe and Fenzishan Groups, whereas the latter consists of the Ji’an, South Liaohe and Jingshan Groups.
Fig. 18. A map showing the distribution of the Khondalite Belt which divides the Western Block into the Yinshan Block in the north and the Ordos Block in the south. The map also shows the localities of the high-pressure (HP) pelitic granulites and ultrahigh temperature (UHT) rocks in the belt (after Zhao et al.,2005).
Fig. 19. Metamorphic P–T paths of high- and medium-pressure pelitic granulites in the Khondalite Belt: (1) medium-pressure pelitic granulites from the Helanshan Complex (Zhao et al., 1999a); (2) medium-pressure pelitic granulites from the Daqingshan–Wulashan Complex (Jin et al., 1991); (3) high-pressure pelitic granulites from the Helanshan Complex (Yin et al., submitted for publication); (4) medium-pressure pelitic granulites from the Jining Complex (Wang et al., 2011); (5) medium-pressure pelitic granulites from the Datong Complex (Liu et al., 1997a).
Fig. 20. P–T paths of the UHT rocks from (a) Tuguiwula in the Jining area (Santosh et al., 2007a) and (b) Dongpo in the Daqingshan area (Guo et al., 2006, Guo et al., 2012).
Fig. 21. A field photograph showing the close relationship between the 1.92 Ga UHT rocks and ~ 1.92 Ga gabbroic dyke.
Fig. 22. Tectonic evolution for the Neoarchean–Paleoproterozoic evolution of the North China Craton proposed by Zhai et al. (2010).
Fig. 23. Tectonic evolution for the Paleoproterozoic assembly of the North China Craton proposed by Zhao et al.
- Original text information
ABSTRACT
The North China Craton (NCC) consists of Archean to Paleoproterozoic basement overlain by Mesoproterozoic to Cenozoic cover. Minor Eoarchean to Mesoarchean basement rocks are locally present in the eastern part of the NCC, but little is known about their extent, nature and tectonic evolution due to widespread reworking by later events. The Neoarchean basement in the NCC was formed during two distinct periods: 2.8–2.7 Ga and 2.6–2.5 Ga, of which the former is considered as a major period of juvenile crustal growth in the NCC as evidenced by Nd and zircon Hf isotopic data, though the 2.8–2.7 Ga rocks are not widely exposed. The 2.6–2.5 Ga rocks make up ~ 80% of the Precambrian basement of the NCC and can be divided into high-grade gneiss complexes and low- to medium-grade granite-greenstone belts that are widespread over the whole NCC, seeming to support a notion that the cratonization of the NCC occurred at ~ 2.5 Ga. However, the 2.6–2.5 Ga rocks in the eastern and western parts of the NCC (Eastern and Western Blocks) are different from those similar-aged rocks in the central part (Trans-North China Orogen), with the former dominated by gneiss domes and metamorphosed at ~ 2.5 Ga, characterized by anticlockwise P–T paths involving isobaric cooling, reflecting an origin related to the underplating of mantle-derived magmas, whereas the latter, which are defined by strike-slip ductile shear zones, large-scale thrusting and folding, and transcurrent tectonics locally with sheath folds, were metamorphosed at ~ 1.85 Ga, characterized by clockwise P–T paths involving isothermal decompression, consistent with subduction and continent-continent collision settings. In addition, komatiites/komatiitic rocks are present in the granite-greenstone belts in the eastern and western parts of the NCC, but generally are absent in the central part. These differences imply that the 2.6–2.5 Ga basement rocks in the eastern and western parts of the NCC formed under different tectonic settings from those in the central part. Although both magmatic arc and mantle plume models can be used to explain the tectonic setting of the 2.6–2.5 Ga basement rocks in the eastern part of the NCC, a mantle plume model is favored as it can reasonably interpret: (1) the exceptionally large exposure of granitoid intrusions that formed over a short time period (2.55–2.50 Ga), without systematic age progression across a ~ 800 km wide block; (2) generation of komatiitic magmas with eruption temperatures as high as ~ 1650 °C; (3) dominant domal structures; (4) bimodal volcanic assemblages in the greenstone sequences; (5) affinities of mafic rocks to continental tholeiitic basalts; and (6) metamorphism with anticlockwise P–T paths involving isobaric cooling. In contrast, the 2.6–2.5 Ga high-grade gneiss terranes and low-grade granite-greenstone belts in the central part of the NCC exhibit the same structural and metamorphic characteristics as those of Paleoproterozoic lithological elements that typify active continental margin arcs and continent–continent collisional belts.
Paleoproterozoic lithological assemblages in the NCC are mainly restricted to three Paleoproterozoic linear tectonic belts in the western, central and eastern parts of the NCC, which were, respectively, named the “Khondalite Belt (Fengzhen Belt/Inner Mongolia Suture Zone)”, “Trans-North China Orogen (Central Orogen Belt)” and “Jiao-Liao-Ji (Liaoji) Belt”. The three belts display some of the following lithotectonic elements that are classical indicators of subduction and collision tectonics in plate tectonic regimes: (1) arc-related juvenile crust; (2) linear structural belts defined by strike-slip ductile shear zones, large-scale thrusting and folding, and sheath folds and mineral lineations; (3) high-pressure (HP) mafic and pelitic granulites, retrograde eclogites and ultrahigh temperature (UHT) rocks; (4) clockwise metamorphic P–T paths involving near-isothermal decompression; (5) possible ancient oceanic fragments and mélange; and (6) back-arc or foreland basins. These lithotectonic elements indicate that subduction- and collision-related orogenic processes must have been involved in the development of the three Paleoproterozoic belts in the NCC. Different models have been proposed for the formation and evolution of these three Paleoproterozoic orogenic belts, and one of the models suggests that the Khondalite Belt was a continent–continent collisional belt along which the Yinshan and Ordos Blocks amalgamated to form the Western Block at ~ 1.95 Ga, which then collided with the exotic Eastern Block along the Trans-North China Orogen at ~ 1.85 Ga, whereas the Jiao-Liao-Ji Belt represents a rifting-and-collision belt within the Eastern Block which underwent rifting to form an incipient oceanic basin that was closed upon itself through subduction and collision at ~ 1.9 Ga. An alternative model proposes that all of the three Paleoproterozoic orogenic belts in the NCC were initialized from continental rifting on a single continent, which was cratonized through fusing Achaean microcontinental blocks at ~ 2.5 Ga, followed by the development of incipient oceanic basins which themselves were closed in the Paleoproterozoic through subduction and collision.
- This issue’s editor
Mr Yidong Zhu, Doctoral candidate at Institute of Geographic Science and Natural Resources Research (IGSNRR), the Chinese Academy of Sciences (CAS), focuses on the research of natural resources economics.