U–Pb geochronology and Hf isotope geochemistry of detrital zircons from the Zhongtiao Complex: Constraints on the tectonic evolution of the Trans-North China Orogen (original) (raw)
Related papers
Precambrian Research, 2001
An examination of lithological, geochemical, geochronological, structural and metamorphic P-T path data suggests that the basement of the North China Craton can be divided into Eastern and Western Blocks, separated by major crustal boundaries that roughly correspond with the limits of a 300 km wide zone, called the Trans-North China Orogen. The Eastern Block consists predominantly of Late Archean domiform tonalitic-trondhjemitic-granodioritic (TTG) batholiths surrounded by anastomosing networks and linear belts of open to tight synforms of minor volcanic and sedimentary rocks metamorphosed from greenschist to granulite facies at 2.5 Ga, with anticlockwise P-T paths. Some Early to Middle Archean rocks are locally present in the Eastern Block, but their tectonic history is unclear due to reworking by the 2.5 Ga tectonothermal event. The Western Block has a Late Archean assemblage, structural style and metamorphic history similar to that of the Eastern Block, but it differs in the absence of early to middle Archean assemblages and in being overlain by and interleaved with Paleoproterozoic khondalites, which were affected by a 1.8 Ga metamorphic event involving clockwise P-T paths. A mantle plume model is proposed for the formation and evolution of Late Archean basement rocks in the Eastern and Western Blocks based on a combination of extensive exposure of TTG gneisses, affinities of mafic rocks to continental tholeiitic basalts, presence of voluminous komatiitic rocks, dominant diaprism-related domiform structures, anticlockwise P -T paths, and a short time span from the primary emplacement of TTG and ultramafic to mafic rocks until the onset of regional metamorphism. Between the two blocks is the Trans-North China Orogen which is bounded by two major fault systems and is composed of Late Archean to Paleoproterozoic TTG gneisses and granitoids, interleaved with abundant sedimentary and volcanic rocks that are geochemically interpreted as having developed in magmatic arc and intra-arc basin environments. These rocks underwent multiple phases of compressional deformation and peak high-pressure metamorphism followed by rapid exhumation during the Late Paleoproterozoic at 1.8 Ga as a result of collision between the Eastern and Western Blocks, resulting in the amalgamation of the North China Craton. : S 0 3 0 1 -9 2 6 8 ( 0 0 ) 0 0 1 5 4 -6 G. Zhao et al. / Precambrian Research 107 (2001) 45-73 46
Paleoproterozoic tectonic evolution of the Trans-North China Orogen: Toward a comprehensive model
Precambrian Research
In this contribution we present a reconstruction of the overall lithotectonic architecture, from inner zones to external ones, of the Paleoproterozoic Trans-North China Orogen, within the North China Craton. Moreover, forward thermobarometrical modelling on a kyanite-bearing gneiss yields a reliable prograde P-T-t-D path. In addition, 40 Ar/ 39 Ar dating on rocks from distinct litho-tectonic units helps us to distinguish several tectono-metamorphic events during the orogenic development. Considering these results, we propose a geodynamic model involving three cratonic blocks, namely the Western, Fuping and Eastern Blocks, separated by two oceans, the Lüliang and Taihang Oceans. The opening of oceanic basins occurred around 2.2-2.3 Ga. After the westward subductions of oceanic lithosphere, the Trans-North China Orogen was built up through a polyphase tectonic evolution within the period 1900-1800 Ma. The first event (D1) corresponded to the emplacement of lower and upper nappes herein called the Orthogneiss-and-Volcanite Unit (OVU) and the Low-Grade-and-Mafic Unit (LGMU), respectively. The syn-metamorphic D1 deformation (1880 ± 10 Ma) is characterized by a NW-SE stretching and mineral lineation with a top-to-the SE sense of shear. During ongoing compression of the thickening orogenic crust, a second deformation event D2 (1850 ± 10 Ma) was responsible for (1) syn-anatectic lateral flow and exhumation of the orogenic root and (2) folding of the middle and upper parts of the orogenic wedge that consequently acquired a fan-type geometry. The late D3 (1830 ± 10 Ma) and D4 (1810 ± 10 Ma) events are related to late-orogenic normal and strike-slip shearing, respectively. In our present state of knowledge, the Paleoproterozoic Trans-North China Orogen might be regarded as the assemblage of two continent-continent collisional belts, both of which are characterized by nappe stacking accommodated by top-to-the E/SE ductile shearing. Continental subduction, crustal thickening, partial melting of overthickened crust, exhumation of HP rocks and deposition of syn-orogenic detrital basins are typical features of modern collisional-type orogens.
Earth Science Reviews, 2016
Craton (NCC) consists of several distinctly different tectonic units, but the delineation and understanding of the significance of individual sutures and the rocks between them has been controversial. We present an actualistic tectonic division and evolution of the North China Craton based on Wilson Cycle and comparative tectonic analysis that uses a multi-disciplinary approach in order to define sutures, their ages, and the nature of the rocks between them, to determine their mode of formation and means of accretion or exhumation, and propose appropriatemodern analogues. The eastern unit of the craton consists of several different small blocks assembled between 2.6 and 2.7 Ga ago, that resemble fragments of accreted arcs from an assembled archipelago similar to those in the extant SW Pacific. A thick Atlantic-type passive margin developed on the western side of the newly assembled Eastern Block by 2.6–2.5 Ga. A N1300 km-long arc and accretionary prism collidedwith the margin of the Eastern Block at 2.5 Ga, obducting ophiolites and ophiolitic mélanges onto the block, and depositing a thick clastic wedge in a foreland basin farther into the Eastern Block. This was followed by an arc-polarity reversal, which led to a short-lived injection of mantle wedge-derived melts to the base of the crust that led to the intrusion ofmafic dikes and arc-type granitoid (TTG) plutons with associated metamorphism. By 2.43 Ga, the remaining open ocean west of the accreted arc closed with the collision of an oceanic plateau now preserved as the Western Block with the collision-modified margin of the Eastern Block, causing further deformation in the Central Orogenic Belt. 2.4–2.35 Ga rifting of the newly amalgamated continental block formed a rift along its center, and new oceans within the other two rift arms, which removed a still-unknown continental fragment from its northern margin. By 2.3 Ga an arc collided with a new Atlantic-type margin developed over the rift sequence along the northern margin of the craton, and thus was converted to an Andean margin through arc-polarity reversal. Andean margin tectonics affected much of the continental block from 2.3 to 1.9 Ga, giving rise to a broad E-W swath of continental margin magmas, and retro-arc sedimentary basins including a foreland basin superimposed on the passive northern margin. The horizontal extent of these tectonic components is similar to that across the present-day Andes in South America. From 1.88 to 1.79 Ga a granulite facies metamorphic event was superimposed across the entire continental block with high-pressure granulites and eclogites in the north, and medium-pressure granulites across the whole craton to the south. The scale and duration of this post-collisional event is similar to that in Central Asia that resulted from the Cenozoic India-Asia collision. The deep crustal granulites and volcanic rocks on the surface today, interpreted to be anatectic melts from deep crustal granulites, are similar to high-grade metamorphic rocks and partial melts presently forming at mid-crustal levels beneath Tibet. Structural fabrics in lower-crustal migmatites related to this event reveal that they flowed laterally parallel to the collision boundary, in a way comparable to what is speculated to be happening in the deep crust of the Himalayan/ Tibetan foreland. We relate this continent-continent collision to the collision of the North China Craton with the postulated Columbia (Nuna) Continent. The NCC broke out of the Columbia Continent between 1753– 1673Ma, as shown by the formation of a suite of anorthosite, mangerite, charnockite, and alkali-feldspar granites in an ENE-striking belt along the northern margin of the craton, whose intrusion was followed by the development of rifts and graben, mafic dike swarms, and eventually an Atlantic-type passive margin that signaled the beginning of a long period of tectonic quiescence and carbonate deposition for the NCC during Sinian times, which persisted into the Paleozoic. The style of tectonic accretion in the NCC changed at circa 2.5 Ga, from an earlier phase of accretion of arcs that are presently preserved in horizontal lengths of several hundred kilometers, to the accretion and preservation of linear arcs several thousand kilometers long with associated oceanic plateaus, microcontinents, and accretionary prisms. The style of progressively younger andwestward outward accretion of different tectonic components is reminiscent of the style of accretion in the Superior Craton, and may signal the formation of progressively larger landmasses at the end of the Archean (perhaps like the Kenorland Continent), then into the Paleoproterozoic, culminating in the assembly of the Columbia (Nuna) Continent at 1.9–1.8 Ga.
Tectonic evolution of the North China Block: from orogen to craton to orogen
Geological Society, London, Special Publications, 2007
The North China Craton contains one of the longest, most complex records of magmatism, sedimentation, and deformation on Earth, with deformation spanning the interval from the Early Archaean (3.8 Ga) to the present. The Early to Middle Archaean record preserves remnants of generally gneissic meta-igneous and metasedimentary rock terranes bounded by anastomosing shear zones.
Gondwana Research, 2013
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 lowto 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 granitegreenstone 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;
Late Archean to Paleoproterozoic evolution of the North China Craton: key issues revisited
2005
A recently proposed model for the evolution of the North China Craton envisages discrete Eastern and Western Blocks that developed independently during the Archean and collided along the Trans-North China Orogen during a Paleoproterozoic orogenic event. This model has been further refined and modified by new structural, petrological and geochronological data obtained over the past few years. These new data indicate that the Western Block formed by amalgamation of the Ordos Block in the south and the Yinshan Block in the north along the east-west-trending Khondalite
Precambrian Research, 2014
In order to understand how Late Mesoproterozoic to Early Neoproterozoic orogenic belts evolved during the assembly and rifting of the supercontinent Rodinia, we have carried out detailed studies on the geochemical compositions of Early Neoproterozoic crust across the Jiangnan orogen (JO) which connects the Yangtze and Cathaysia blocks on the northwestern margin of Rodinia. A gradual geochemical variation is recognized from east to west, based on comparisons of whole-rock Nd isotopes, U-Pb age spectra of detrital zircons, and Hf isotopes in magmatic zircons and detrital zircons from the Neoproterozoic granitoids and metasedimentary basement sequences in the JO. LA-ICP-MS U-Pb dating of detrital zircons from the sediments and magmatic zircons from interlayered volcanic rocks suggests that the folded basement sequences formed within the span 860-825 Ma, implying the final amalgamation of the Yangtze and Cathaysia blocks occurred no older than ca 825 Ma. The 950-820 Ma detrital zircons strongly dominate in the eastern basement sequences, and most of them show moderately to highly positive ε Hf (t). In contrast, many of the Early Neoproterozoic detrital zircons in the western JO have moderately negative ε Hf (t) and more older (>1.0 Ga) detrital zircons were found in this area. We suggest that the metasedimentary basement sequences in the JO were deposited in retro-arc foreland basins which originally evolved from back-arc basins, and the change of provenance controlled the variation in crustal geochemistry of crust across the JO. Sediments in the eastern basement sequences have been sourced mainly from the juvenile subduction-related igneous rocks to the east, with a few from the central Yangtze Block, whereas those in the western JO may have been located far from arc terranes to the east and thus received more older recycled detritus from the southern part of the South China Block. Moreover, the Hf isotopes of the detrital zircons imply episodic crustal growth in the provenance of the JO metasedimentary basement sequences, with age peaks at 1.0-0.8 Ga, 1.75-1.50 Ga and 2.60-2.45 Ga. The early crust in South China may have been formed mainly at around 3.8 Ga ago, and contains some Hadean components (ca 4.1 Ga).