scholarly journals Kinematics of Late Cretaceous subduction initiation in the Neo-Tethys Ocean reconstructed from ophiolites of Turkey, Cyprus, and Syria

2017 ◽  
Vol 122 (5) ◽  
pp. 3953-3976 ◽  
Author(s):  
Marco Maffione ◽  
Douwe J. J. van Hinsbergen ◽  
Giovanni I. N. O. de Gelder ◽  
Freek C. van der Goes ◽  
Antony Morris
Keyword(s):  
Late Cretaceous ◽  
Subduction Initiation ◽  
Tethys Ocean ◽  
Cretaceous Subduction

scholarly journals Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran

2019 ◽  
Vol 132 (5-6) ◽  
pp. 1083-1105 ◽  
Author(s):  
Hadi Shafaii Moghadam ◽  
R.J. Stern ◽  
W.L. Griffin ◽  
M.Z. Khedr ◽  
M. Kirchenbaur ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Subduction Zones ◽  
Mantle Peridotite ◽  
Igneous Rocks ◽  
Subduction Initiation ◽  
The North ◽  
Depleted Mantle ◽  
Back Arc ◽  
Cretaceous Subduction ◽  
Ne Iran

Abstract How new subduction zones form is an ongoing scientific question with key implications for our understanding of how this process influences the behavior of the overriding plate. Here we focus on the effects of a Late Cretaceous subduction-initiation (SI) event in Iran and show how SI caused enough extension to open a back-arc basin in NE Iran. The Late Cretaceous Torbat-e-Heydarieh ophiolite (THO) is well exposed as part of the Sabzevar-Torbat-e-Heydarieh ophiolite belt. It is dominated by mantle peridotite, with a thin crustal sequence. The THO mantle sequence consists of harzburgite, clinopyroxene-harzburgite, plagioclase lherzolite, impregnated lherzolite, and dunite. Spinel in THO mantle peridotites show variable Cr# (10–63), similar to both abyssal and fore-arc peridotites. The igneous rocks (gabbros and dikes intruding mantle peridotite, pillowed and massive lavas, amphibole gabbros, plagiogranites and associated diorites, and diabase dikes) display rare earth element patterns similar to MORB, arc tholeiite and back-arc basin basalt. Zircons from six samples, including plagiogranites and dikes within mantle peridotite, yield U-Pb ages of ca. 99–92 Ma, indicating that the THO formed during the Late Cretaceous and was magmatically active for ∼7 m.y. THO igneous rocks have variable εNd(t) of +5.7 to +8.2 and εHf(t) ranging from +14.9 to +21.5; zircons have εHf(t) of +8.1 to +18.5. These isotopic compositions indicate that the THO rocks were derived from an isotopically depleted mantle source similar to that of the Indian Ocean, which was slightly affected by the recycling of subducted sediments. We conclude that the THO and other Sabzevar-Torbat-e-Heydarieh ophiolites formed in a back-arc basin well to the north of the Late Cretaceous fore-arc, now represented by the Zagros ophiolites, testifying that a broad region of Iran was affected by upper-plate extension accompanying Late Cretaceous subduction initiation.

Mesozoic Tectonic Setting of SE Sundaland After Magmatism and Suture Evidences in JS-1 Ridge Area

2021 ◽  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Tectonic Setting ◽  
Plate Boundary ◽  
Early Jurassic ◽  
The South ◽  
Magmatic Arc ◽  
Plate Convergence ◽  
Ridge Area ◽  
Cretaceous Subduction

Mesozoic plate convergence in SE Sundaland has been a source of debate for decades. A determination of plate convergence boundaries and timing have been explained in many publications, but not all boundaries were associated with magmatism. Through integration of both plate configurations and magmatic deposits, the basement can be accurately characterized over time and areal extents. This paper will discuss Cretaceous subductions and magmatic arc trends in SE Sundaland area with additional evidence found in JS-1 Ridge. At least three subduction trends are captured during the Mesozoic in the study area: 1) Early Jurassic – Early Cretaceous trend of Meratus, 2) Early Cretaceous trend of Bantimala and 3) Late Cretaceous trend in the southernmost study area. The Early Jurassic – Early Cretaceous subduction occurred along the South and East boundary of Sundaland (SW Borneo terrane) and passes through the Meratus area. The Early Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo and Paternoster terranes) and pass through the Bantimala area. The Late Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo, Paternoster and SE Java – South Sulawesi terranes), but is slightly shifted to the South approaching the Oligocene – Recent subduction zone. Magmatic arc trends can also be generally grouped into three periods, with each period corresponds to the subduction processes at the time. The first magmatic arc (Early Jurassic – Early Cretaceous) is present in core of SW Borneo terrane and partly produces the Schwaner Magmatism. The second Cretaceous magmatic arc (Early Cretaceous) trend is present in the SW Borneo terrane but is slightly shifted southeastward It is responsible for magmatism in North Java offshore, northern JS-1 Ridge and Meratus areas. The third magmatic arc trend is formed by Late Cretaceous volcanic rocks in Luk Ulo, the southern JS-1 Ridge and the eastern Makassar Strait areas. These all occur during the same time within the Cretaceous magmatic arc. Though a mélange rock sample has not been found in JS-1 Ridge area, there is evidence of an accretionary prism in the area as evidenced by the geometry observed on a new 3D seismic dataset. Based on the structural trend of Meratus (NNE-SSW) coupled with the regional plate boundary understanding, this suggests that both Meratus & JS-1 Ridge are part of the same suture zone between SW Borneo and Paternoster terranes. The gradual age transition observed in the JS-1 Ridge area suggests a southward shift of the magmatic arc during Early Cretaceous to Late Cretaceous times.

scholarly journals Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline?

PLoS ONE ◽  
2020 ◽  
Vol 15 (8) ◽  
pp. e0238040
Author(s):  
Eric Otto Walliser ◽  
Bernd R. Schöne
Keyword(s):  
Late Cretaceous ◽  
Tethys Ocean

Timing of subduction initiation in the Proto-Tethys Ocean: Evidence from the Cambrian gabbros from the NE Pamir Plateau

Lithos ◽  
2018 ◽  
Vol 314-315 ◽  
pp. 40-51 ◽  
Author(s):  
Chuan-Lin Zhang ◽  
Hai-Bo Zou ◽  
Xian-Tao Ye ◽  
Xiang-Yan Chen
Keyword(s):  
Subduction Initiation ◽  
Tethys Ocean

Late Cretaceous subduction-related magmatism on the southern edge of Sabzevar basin, NE Iran

2019 ◽  
Vol 176 (3) ◽  
pp. 530-552 ◽  
Author(s):  
Zakie Kazemi ◽  
Habibollah Ghasemi ◽  
Romain Tilhac ◽  
William Griffin ◽  
Hadi Shafaii Moghadam ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Cretaceous Subduction ◽  
Ne Iran

scholarly journals Boninitic blueschists record subduction initiation and subsequent accretion of an arc–forearc in the northeast Proto-Tethys Ocean

Geology ◽  
2021 ◽  
Author(s):  
Dong Fu ◽  
Bo Huang ◽  
Tim E. Johnson ◽  
Simon A. Wilde ◽  
Fred Jourdan ◽  
...  
Keyword(s):  
Subduction Zones ◽  
Plate Tectonics ◽  
Oceanic Lithosphere ◽  
Island Arc ◽  
Early Paleozoic ◽  
Subduction Initiation ◽  
North Qilian Orogenic Belt ◽  
Mariana Arc ◽  
Tethys Ocean ◽  
North Qilian

Subduction of oceanic lithosphere is a diagnostic characteristic of plate tectonics. However, the geodynamic processes from initiation to termination of subduction zones remain enigmatic mainly due to the scarcity of appropriate rock records. We report the first discovery of early Paleozoic boninitic blueschists and associated greenschists from the eastern Proto-Tethyan North Qilian orogenic belt, northeastern Tibet, which have geochemical affinities that are typical of forearc boninites and island arc basalts, respectively. The boninitic protoliths of the blueschists record intra-oceanic subduction initiation at ca. 492–488 Ma in the eastern North Qilian arc/forearc–backarc system, whereas peak blueschist facies metamorphism reflects subsequent subduction of the arc/forearc complex to high pressure at ca. 455 Ma. These relations therefore record the life circle of an intra-oceanic subduction zone within the northeastern Proto-Tethys Ocean. The geodynamic evolution provides an early Paleozoic analogue of the early development of the Izu–Bonin–Mariana arc and its later subduction beneath the extant Japanese arc margin. This finding highlights the important role of subduction of former upper plate island arc/forearcs in reducing the likelihood of preservation of initial subduction-related rock records in ancient orogenic belts.

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