Showing papers on "Terrane published in 2016"
TL;DR: The Qinling Orogenic Belt (QOB) as mentioned in this paper is a composite orogenic belt that witnessed four major episodes of accretion and collision between discrete continental blocks, such as the North China Block, North Qinling Block and the South China Block.
653 citations
TL;DR: In this article, the Bangong Ocean may have closed during the Late Jurassic-Early Cretaceous (most likely ca. 140-130 ǫ) through arc-arc "soft" collision rather than continent-continent "hard" collision.
391 citations
TL;DR: The Sanandaj-Sirjan zone of Iran is a northwest trending orogenic belt immediately north of the Zagros suture, which represents the former position of the Neotethys Ocean.
Abstract: The Sanandaj-Sirjan zone of Iran is a northwest trending orogenic belt immediately north of the Zagros suture, which represents the former position of the Neotethys Ocean. The zone contains the most extensive, best preserved record of key events in the formation and evolution of the Neotethys, from its birth in Late Paleozoic time through its demise during the mid-Tertiary collision of Arabia with Eurasia. The record includes rifting of continental fragments off of the northern margin of Gondwanaland, formation of facing passive continental margins, initiation of subduction along the northern margin, and progressive development of a continental magmatic arc. The latter two of these events are critical phases of the Wilson Cycle that, elsewhere in the world, are poorly preserved in the geologic record because of superimposed events. Our new synthesis reaffirms the similarity between this zone and various terranes to the north in Central Iran. Late Paleozoic rifting, preserved as A-type granites and accelerated subsidence, was followed by a phase of pronounced subsidence and shallow marine sedimentation in Permian through Triassic time, marking the formation and evolution of passive margins on both sides of the suture. Subduction and arc magmatism began in latest Triassic/Early Jurassic time, culminating at ~170 Ma. The extinction of arc magmatism in this zone, and its shift northeastward to form the subparallel Urumieh-Dokhtar arc, occurred diachronously along strike, in Late Cretaceous or Paleogene time. Post-Cretaceous uplift transformed the zone from a primarily marine borderland into a marine archipelago that persisted until mid-Tertiary time.
186 citations
TL;DR: In this article, the authors presented new geochronological and geochemical (whole-rock major and trace element and Sr-Nd and zircon Hf isotope) data for recently identified volcanic rocks exposed in Changguo area, southernmost part of the Lhasa terrane.
161 citations
TL;DR: In this paper, an integrated investigation involving U-Pb dating of igneous and detrital zircon, geochemical analysis of igniferous rocks, compositional analysis of sedimentary strata, and a synthesis of existing work across the Qilian Shan, Qaidam Basin, and the Eastern Kunlun Range of central and northern Tibet was conducted.
Abstract: In order to better constrain the evolution of the Tethyan orogenic system, we conducted an integrated investigation involving U-Pb dating of igneous and detrital zircon, geochemical analysis of igneous rocks, compositional analysis of sedimentary strata, and a synthesis of existing work across the Qilian Shan, Qaidam Basin, and the Eastern Kunlun Range of central and northern Tibet. This effort reveals five stages of arc magmatism at 1005–910 Ma, 790–720 Ma, 580–500 Ma, 490–375 Ma, and 290–195 Ma, respectively. Arc activities were interrupted by repeated continent-continent collision followed by ocean opening along the older suture zones first created in the Neoproterozoic. This suggests that Wilson cycles have played a controlling role in constructing the southern Asian continent. The magmatic history and regional geologic constraints allow us to construct a coherent tectonic model that has the following key features. (1) The linked South Qilian suture in the west and North Qinling suture in the east formed the northern boundary of the coherent Kunlun–Qaidam–North Qinling Terrane in the early Paleozoic. (2) The Songpan-Ganzi Terrane has been the western part of the Yangtze craton since the Neoproterozoic. (3) Development of the wide (>700 km) Permian–Triassic arc across the Kunlun-Qaidam Terrane was induced by flat subduction and rapid slab rollback, which also caused extreme extension of the Songpan-Ganzi Terrane. (4) The formation of the Anymaqen-Kunlun-Muztagh Ocean (= the Neo–Kunlun Ocean in this study) was created within Laurasia rather than being a preexisting ocean between Gondwana and Laurasia as postulated by most early studies.
140 citations
TL;DR: In this article, the authors presented a seismic reflection profile across the western Himalaya at 81.5°E, and showed that the Main Himalayan Thrust dips ∼20° to ∼60 km depth beneath the Yarlung Zangbo suture, approaching a continuous Moho reflection at ∼70-75 km depth.
Abstract: The fate of the Indian plate during continental collision with Asian terranes, and the proportion of the Indian crust that is underthrust or subducted beneath Tibet as opposed to transferred to the upper (Himalayan) plate, are much debated. The active geometry of low-angle underthrusting or subduction of the Indian plate beneath the Lesser and Greater Himalayan thrust sheets is well known from seismic imaging. Previously, only lower-resolution images of the Main Himalayan Thrust have been obtained beneath the Yarlung Zangbo suture that separates Indian and Asian rocks at the surface. It remains controversial whether the orogenic wedge between the Main Himalayan Thrust and the Yarlung Zangbo suture, formed of Indian crust transferred to the upper plate, is evolving by thrust-faulting in a critical-taper wedge or by southward extrusion of a ductile channel flow. Here we present a seismic reflection profile across the western Himalaya at 81.5° E, and show that the Main Himalayan Thrust dips ∼20° to ∼60 km depth beneath the Yarlung Zangbo suture, approaching a continuous Moho reflection at ∼70–75 km depth. The Indian crust being transported northwards beyond the Yarlung Zangbo suture is no more than ∼15 km thick, reduced from its original ∼40 km thickness by transfer of material from the lower plate to the upper plate through crustal-scale duplexing. The fate of the Indian plate during collision with Asia is debated. Seismic images of the western Himalaya reveal large-scale thrust faults that transfer Indian crust upwards, into the overriding Asian plate.
139 citations
TL;DR: In this article, a finite-frequency tomographic inversion was performed to image 3D velocity structures beneath southern and central Tibet using teleseismic body-wave data recorded by the TIBET-31N passive seismic array as well as waveforms from previous temporary seismic arrays.
138 citations
TL;DR: In this article, a contribution combining geological and Hf-isotopic data for igneous rocks from the Sanjiang Tethyan Orogen (SJTO), together with the salient features associated with mineralization to gain insights into the crustal architecture and metallogeny was made.
133 citations
TL;DR: In this paper, a detrital zircon U-Pb-Hf dataset from Neoproterozoic-Silurian sedimentary sequences in NW Iberia and Avalonia, in conjunction with the comprehensive existing datasets from potential source cratons, is presented.
120 citations
TL;DR: In this paper, the authors provide a new, high-quality, well-dated paleomagnetic pole from the ca. 180 Ma Sangri Group volcanic rocks of the Lhasa terrane that yields a paleolatitude of 3.7°S ± 3.4°.
Abstract: The Mesozoic plate tectonic history of Gondwana-derived crustal blocks of the Tibetan Plateau is hotly debated, but so far, paleomagnetic constraints quantifying their paleolatitude drift history remain sparse. Here, we compile existing data published mainly in Chinese literature and provide a new, high-quality, well-dated paleomagnetic pole from the ca. 180 Ma Sangri Group volcanic rocks of the Lhasa terrane that yields a paleolatitude of 3.7°S ± 3.4°. This new pole confirms a trend in the data that suggests that Lhasa drifted away from Gondwana in Late Triassic time, instead of Permian time as widely perceived. A total northward drift of ∼4500 km between ca. 220 and ca. 130 Ma yields an average south-north plate motion rate of 5 cm/yr. Our results are consistent with either an Indian or an Australian provenance of Lhasa.
116 citations
TL;DR: The Russian South East orogenic belt as discussed by the authors consists of folded terranes made up of Jurassic and Early Cretaceous accretionary prisms, turbidite basins, and island arc terranses that are overlapped unconformably by undeformed upper Cenomanian to Cenozoic volcanic deposits.
TL;DR: In this article, detrital zircons from sandstones in the North Tianshan belt have been used to study the evolution of the Junggar ocean during early Paleozoic to late Carboniferous time.
Abstract: The Junggar ocean, once situated north (present coordinate) of the Yili and Central Tianshan blocks during early Paleozoic to late Carboniferous time, was a major southern branch of the Paleo–Asian Ocean, the opening, expansion, and final closure of which led to the development of the Central Asian Orogenic Belt between Eastern Europe–Siberia and Tarim–North China. However, the detailed evolution of the Junggar ocean has not been well constrained. This paper reports U-Pb and Lu-Hf isotopic data of detrital zircons from sandstones in the North Tianshan belt, which can provide new insights into understanding the Paleozoic development of the Junggar ocean. Most detrital zircons exhibit oscillatory zoning and high Th/U ratios, typical of igneous origin. The predominant Paleozoic zircons yield major age populations at ca. 294, 313–327, 338–375, 440–455, and 474–502 Ma and are interpreted to have been derived from the long-lived volcanic- and island-arc systems formed by the southward subduction of the Junggar ocean and subsequent collisional and postcollisional magmatism. The minor Precambrian zircons yield ages scattering at ca. 550, 680–765, 890, 970–990, 1160–1250, 1500, 1690–1750, 1840–1970, 2440–2500, and 2615–2700 Ma, which are nearly, but not fully, congruent with those from the adjacent Beishan and Kuluketage Precambrian terranes. Therefore, our results indicate that the Central Tianshan block was once part of the Tarim block during Precambrian time. Most of the 541–440 Ma zircons possess low negative eHf(t) values, while the <440–300 Ma zircons exhibit dominantly positive eHf(t) values, which can be linked to the Junggar oceanic slab rollback since ca. 440 Ma. This event, subsequently, gave rise to the opening of the South Tianshan back-arc basin/ocean between the Central Tianshan and Tarim blocks, exhumation of high-pressure granulites, and formation of a series of island arcs in the Junggar ocean. Combined with previous studies, we suggest that the Junggar ocean was probably closed at ca. 300 Ma in association with arc-continent collision, followed by postcollisional magmatism. It deserves mentioning that the ca. 0.5 and 1.4–1.5 Ga (detrital) zircons and contemporaneous magmatic rocks only occur in the Central Tianshan block, not in the Tarim block. Therefore, more detailed investigations are needed to better elucidate the origin and Precambrian evolution of the Central Tianshan block.
TL;DR: Zhang et al. as mentioned in this paper proposed that the Tengchong terrane in SW Yunnan is most likely linked with the Lhasa Terrane in southern Tibet, both of which experienced similar tectonomagmatic histories since the Early Paleozoic.
TL;DR: In this article, detrital zircon age spectra from the Tethyan Himalaya Sequence (THS) and the Nieru Formation (Nieru-Langjiexue Formation) were used to infer the Mesozoic paleogeography of Neo-Tethyan Ocean basins.
TL;DR: The Neoproterozoic Tsagaan-Olom Group is exposed in the Zavkhan Terrane of southwestern Mongolia and hosts unique geochemical, paleoclimate, and paleontological records that have become central to our understanding of this pivotal interval of Earth history as discussed by the authors.
Abstract: The Neoproterozoic Tsagaan-Olom Group is exposed in the Zavkhan Terrane of southwestern Mongolia and hosts unique geochemical, paleoclimate, and paleontological records that have become central to our understanding of this pivotal interval of Earth history. New sedimentological, stratigraphic, geochronological, and geochemical data provide context for and further develop these records. Detrital zircon provenance indicates that Neoproterozoic strata of the Zavkhan Terrane were derived from basement with age peaks between 1950 to 2100 and 2400 to 2600 Ma. At ∼800 Ma, the Zavkhan Terrane transformed from an active arc and back-arc complex to a rifted ribbon continent with passive margins on both sides. Deposition was accommodated by extension, which is recorded with syn-sedimentary normal faulting and alluvial fan deposition in the Zavkhan and Khasagt formations. Passive margin sedimentation in the overlying Tsagaan-Olom Group begins with the glacigenic Maikhan-Uul Formation, which consists of two massive diamictite units separated by clast-poor graded beds of the middle member. Detrital zircon at the base of the middle member of the Maikhan-Uul Formation were dated with U-Pb chemical abrasion isotope-dilution thermal ionization mass spectrometry and constrained its age to
TL;DR: In this article, the late Neoarchean granitoid gneisses are well exposed in the Northern Liaoning Province, located north of the ancient Anshan-Benxi terrane along the northeastern margin of the Eastern Block (EB) of the NCC.
TL;DR: In this article, the authors investigated the Quxu batholith in the central domain of the Gangdese magmatic belt and reported the occurrence of hornblende gabbros for the first time.
TL;DR: In this article, the authors presented new zircon U-Pb (ICP-MS) data from 52 igneous and metamorphic rocks, which they combined with whole rock geochemical and Pb isotopic data to constrain the tectonic history of the Precambrian to Mesozoic basement of the Merida Andes and the Santander Massif.
TL;DR: Zhang et al. as discussed by the authors showed that the Darutso volcanic rocks (DVRs) within ophiolitic melange in the Beila area, central Tibet, crystallized at ∼164-162 Ma.
Abstract: In addition to fluids, the concept of sediment-derived melts infiltrating the fore-arc mantle during subduction initiation has been proposed based on studies of modern subduction zones and ophiolite melange. However, outcrops that contain the products of such melts are rare, especially in conjunction with boninite. New U–Pb zircon dating reveals that the Darutso volcanic rocks (DVRs) within ophiolitic melange in the Beila area, central Tibet, crystallized at ∼164–162 Ma. This is the first recognition of Jurassic volcanic rocks in the middle section of the Bangong–Nujiang Suture Zone. Geochemically, the DVRs are high-Mg andesites with moderate SiO2 (59.03–63.62 wt%) and high MgO (3.74–6.53 wt%), Cr (up to 395 ppm), and Mg# (50.3–67.9). They also have high Th contents, (La/Sm)N ratios, and (87Sr/86Sr)i values (0.7085–0.7147); low Ba/Th, U/Th, and Sr/Y ratios; and negative values of eNd(t) (−8.7 to −9.8) and zircon eHf(t) (−7.4 to −9.9). The eNd(t) values of the DVRs overlap those of regional sediments. Detailed analyses of these geochemical characteristics indicate that the DVRs were derived from partial melting of subducted sediments and subsequent interaction with overlying mantle peridotite in a shallow and hot setting. In combination with the regional geology, in particular adjacent ophiolites that contain MORB-like and boninite mafic lavas, these rocks collectively recorded the evolution of a fore-arc setting during the initiation of the northward subduction of the south branch of the Bangong–Nujiang Ocean. Therefore, the results provide direct evidence for sediment melting during subduction initiation and constrain the Jurassic tectonic evolution of the Lhasa terrane. This article is protected by copyright. All rights reserved.
01 Apr 2016
TL;DR: Zhang et al. as discussed by the authors proposed that the Tengchong terrane in SW Yunnan is most likely linked with the Lhasa Terrane in southern Tibet, both of which experienced similar tectonomagmatic histories since the Early Paleozoic.
Abstract: Abstract New zircon U–Pb data, along with the data reported in the literature, reveal five phases of magmatic activity in the Tengchong Terrane since the Early Paleozoic with spatial and temporal variations summarized as Cambrian–Ordovician (500–460 Ma) to the east, minor Triassic (245–206 Ma) in the east and west, abundant Early Cretaceous (131–114 Ma) in the east, extensive Late Cretaceous (77–65 Ma) in the central region, and Paleocene–Eocene (65–49 Ma) in the central and western Tengchong Terrane, in which the Cretaceous–Eocene magmatism migrated from east to west. The increased zircon eHf(t) of the Early Cretaceous granitoids from − 12.3 to − 1.4 at ca. 131–122 Ma to − 4.6 to + 7.1 at ca. 122–114 Ma, identified for the first time in this study, and the magmatic flare-up at ca. 53 Ma in the central and western Tengchong Terrane indicate increased contributions from mantle- or juvenile crust-derived components. The spatial and temporal variations and changing magmatic compositions over time in the Tengchong Terrane closely resemble those of the Lhasa Terrane in southern Tibet. Such similarities, together with the data of stratigraphy and paleobiogeography, enable us to propose that the Tengchong Terrane in SW Yunnan is most likely linked with the Lhasa Terrane in southern Tibet, both of which experienced similar tectonomagmatic histories since the Early Paleozoic.
TL;DR: In this paper, an integrated interpretation of the late Paleozoic structural and geochronological record of the Iberian Massif is presented and discussed under the perspective of a Gondwana-Laurussia collision giving way to the Variscan orogen.
TL;DR: In this article, the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent was compiled, and various explanatory models were analyzed in light of this updated dataset.
Abstract: We compiled the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent. We also analyzed the various explanatory models in light of this updated dataset. The following main conclusions are discussed in this study. (1) The Izanagi slab detachment beneath the East Asia margin around 60–55 Ma likely triggered the Oki-Daito plume occurrence, Mesozoic proto-PSP splitting, shortening and then failure across the paleo-transform boundary between the proto-PSP and the Pacific Plate, Izu-Bonin-Mariana subduction initiation and ultimately PSP inception. (2) The initial splitting phase of the composite proto-PSP under the plume influence at ∼54–48 Ma led to the formation of the long-lived West Philippine Basin and short-lived oceanic basins, part of whose crust has been ambiguously called “fore-arc basalts” (FABs). (3) Shortening across the paleo-transform boundary evolved into thrusting within the Pacific Plate at ∼52–50 Ma, allowing it to subduct beneath the newly formed PSP, which was composed of an alternance of thick Mesozoic terranes and thin oceanic lithosphere. (4) The first magmas rising from the shallow mantle corner, after being hydrated by the subducting Pacific crust beneath the young oceanic crust near the upper plate spreading centers at ∼49–48 Ma were boninites. Both the so-called FABs and the boninites formed at a significant distance from the incipient trench, not in a fore-arc position as previously claimed. The magmas erupted for 15 m.y. in some places, probably near the intersections between back-arc spreading centers and the arc. (5) As the Pacific crust reached greater depths and the oceanic basins cooled and thickened at ∼44–45 Ma, the composition of the lavas evolved into high-Mg andesites and then arc tholeiites and calc-alkaline andesites. (6) Tectonic erosion processes removed about 150–200 km of frontal margin during the Neogene, consuming most or all of the Pacific ophiolite initially accreted to the PSP. The result was exposure of the FABs, boninites, and early volcanics that are near the trench today. (7) Serpentinite mud volcanoes observed in the Mariana fore-arc may have formed above the remnants of the paleo-transform boundary between the proto-PSP and the Pacific Plate.
TL;DR: In this article, the allochthony of the Nico Perez Terrane and Piedra Alta Terrane was shown to be formed during Archean episodic crustal growth and this crust underwent significant Paleo- and Neoproterozoic crustal reworking at ca.2.2 −2.0, 1.7 and 0.6 ǫ.
TL;DR: In this paper, the authors used zircon U-Pb ages and whole-rock elemental and isotopic data to reveal two groups of intermediate to felsic plutons in the Alxa terrane.
TL;DR: In this paper, the authors report the U-Pb and Hf isotopes of detrital zircons from the Late Carboniferous bauxite layer and use these data to constrain the tectonic evolution of the margin of the North China Craton.
TL;DR: In this paper, the authors used a tectono-stratigraphic model to analyze the Triassic basin structures in the Central Atlantic and North Atlantic domains, showing that the initial strain was accommodated in a Central Segment by inherited faults during the Early and Middle Triassic.
TL;DR: The Mesozoic and Cenozoic geological history of NE Asia comprises alternating episodes of subduction or transform strike-slip movement of the oceanic plate along the continental margin of Eurasia as mentioned in this paper.
TL;DR: The Zavkhan terrane is a Proterozoic cratonic fragment in southwestern Mongolia that forms the core of the Central Asian orogenic belt as mentioned in this paper, and it has been shown that the majority of continental growth in Mongolia occurred through the trapping and oroclinal bending of ribbon continents rather than long-lived accretion on the margin of a major craton.
Abstract: The Zavkhan terrane is a Proterozoic cratonic fragment in southwestern Mongolia that forms the core of the Central Asian orogenic belt. We provide new geologic and U-Pb zircon geochronologic constraints on the Neoproterozoic and early Paleozoic tectonic evolution of the terrane. Orthogneisses dated as ca. 1967 and ca. 839 Ma form the basement and are intruded and overlain by ca. 811–787 Ma arc-volcanic and volcaniclastic rocks that lack a gneissic fabric, suggestive of a mid-Neoproterozoic metamorphic event. Rifting and formation of the Zavkhan ribbon continent occurred from ca. 770–717 Ma and was followed by passive margin sedimentation between 717 and 580 Ma. During the latest Ediacaran to Cambrian, the southern margin of the Zavkhan terrane was reactivated with the obduction of the Lake terrane, slab break-off and reversal, and ca. 509–507 Ma magmatism. Metamorphosed Proterozoic and Cambrian units are cut by undeformed ca. 496 Ma gabbro, providing a tight constraint on the age of Cambrian metamorphism. Late Ordovician to Silurian rifting is marked by bimodal magmatism and deposition in narrow fault-bound basins. Our data indicate that the Zavkhan terrane traveled alone in the Neoproterozoic, collided with the Lake terrane in the late Ediacaran to Cambrian, accreted an unknown crustal block during Cambrian Epoch 2–Epoch 3, and then rifted away in the Ordovician. We suggest the majority of continental growth in Mongolia occurred through the trapping and oroclinal bending of ribbon continents rather than long-lived accretion on the margin of a major craton.
TL;DR: In this article, sediment sources and dispersal patterns of the Triassic Yanchang Formation in the southwest Ordos Basin were investigated using net-sand ratio maps, sandstone modal analysis, and U-Pb detrital zircon geochronology.
TL;DR: In this paper, radiometric ages from the late Caledonian granites were used to calculate probability density functions (age spectra), with each pluton weighted by outcrop area as a proxy for its volume.