Long‐Term Landscape Evolution of the Northparkes Region of the Lachlan Fold Belt, Australia: Constraints from Fission Track and Paleomagnetic Data: A Reply

The Tethyside orogen, a direct consequence of the separation of the Gondwanaland and the accretion of Eurasia, is a huge composite orogenic system that was generated during Paleozoic–Mesozoic Tethyan accretionary and Cenozoic continent–continent collisional orogenesis within the Tethyan domain. The Tethyside orogenic system consists of a group of diverse Tethyan blocks, including the Istanbul, Sakarya, Anatolide–Taurides, Central Iran, Afghanistan, Songpan–Ganzi, Eastern Qiangtang, Western Qiangtang, Lhasa, Indochina, Sibumasu, and Western Burma blocks, which were separated from Gondwana, drifted northwards, and accreted to the Eurasian continent by opening and closing of two successive Tethyan oceanic basins (Paleo-Tethyan and Neo-Tethyan), and subsequent continental collision. The Tethyan domain represents a metallogenic amalgamation across diverse geodynamic settings, and is the best endowed of all large orogenic systems, such as those associated with the Cordilleran and Variscan orogenies. The ore deposits within the Tethyan domain include porphyry Cu–Mo–Au, granite-related Sn–W, podiform chromite, sediment-hosted Pb–Zn deposits, volcanogenic massive sulfide (VMS) Cu–Pb–Zn deposits, epithermal and orogenic Au polymetallic deposits, as well as skarn Fe polymetallic deposits. At least two metallogenic supergroups have been identified within the eastern Tethyan metallogenic domain (ETMD): (1) metallogenesis related to the accretionary orogen, including the Zhongdian, Bangonghu, and Pontides porphyry Cu belts, the Pontides, Sanandaj–Sirjan, and Sanjiang VMS belts, the Lasbela–Khuzdar sedimentary exhalative-type (SEDEX) Pb–Zn deposits, and podiform chromite deposits along the Tethyan ophiolite zone; and (2) metallogenesis related to continental collision, including the Gangdese, Yulong, Arasbaran–Kerman and Chagai porphyry Cu belts, the Taurus, Sanandaj–Sirjan, and Sanjiang Mississippi Valley-type (MVT) Pb–Zn belts, the Southeast Asia and Tengchong–Lianghe Sn–W belts or districts, the Himalayan epithermal Sb–Au–Pb–Zn belt, the Piranshahr–Saqez–Sardasht and Ailaoshan orogenic Au belts, and the northwest Iran and northeastern Gangdese skarn Fe polymetallic belts. Mineral deposits that are generated with tectonic evolution of the Tethys form in specific settings, such as accretionary wedges, magmatic arcs, backarcs, and passive continental margins within accretionary orogens, and the foreland basins, foreland thrust zones, collisional sutures, collisional magmatic zones, and collisional deformation zones within collisional orogens. Synthesizing the architecture and tectonic evolution of collisional orogens within the ETMD and comparisons with other collisional orogenic systems have led to the identification of four basic types of collision: orthogonal and asymmetric (e.g., the Tibetan collision), orthogonal and symmetric (Pyrenees), oblique and symmetric (Alpine), and oblique and asymmetric (Zagros). The tectonic evolution of collisional orogens typically includes three major processes: (1) syn-collisional continental convergence, (2) late-collisional tectonic transform, and (3) post-collisional crustal extension, each forming distinct types of ore deposits in specific settings. The resulting synthesis leads us to propose a new conceptual framework for the collision-related metallogenic systems, which may aid in deciphering relationships among ore types in other comparable collisional orogens. Three significant processes, such as breaking-off of subducted Tethyan slab, large-scale strike-slip faulting, shearing and thrusting, and delamination (or broken-off) of lithosphere, developed in syn-, late- and post-collisional periods, repsectively, were proposed to act as major driving forces, resulting in the formation of the collision-related metallogenic systems. Widespread appearance of juvenile crust and intense inteaction between mantle and crust within the Himalayan–Zagros orogens indicate that collisional orogens have great potential for the discovery of large or giant mineral deposits.

Metallogeny

Orogeny

geodynamics

Supercontinent

continental collision

10.1016/j.oregeorev.2014.10.026

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Citations (170)

Cretaceous two stage extensional tectonic in eastern Eurasia continent and its geodynamics

Acta Petrologica Sinica (2021)

Lin Wei LI JinYan

以变质核杂岩或伸展穹隆为代表的晚中生代伸展构造在欧亚大陆东部广泛发育。与北美西部的科迪勒拉型变质核杂岩既相似,又存在很大的不同。区域上可以进一步划分为次一级的伸展构造带,由北向南依次为泛贝加尔-蒙古-鄂霍茨克带、华北西部带、华北东部带、华北南缘及秦岭-大别带及华南中部带。与北美地区显著不同的是它们并非平行于俯冲带展布,而是呈面状分布于太平洋西部广大的地区,不仅发育在岩石圈薄弱带或造山带相关的构造单元之上,而且还发育在稳定的克拉通之上。这些穹隆构造记录了NW-SE向的区域伸展方向,构成了全球最大的伸展构造发育区。通过对各带伸展穹隆的结构样式、时空分布和发育过程的系统分析、归纳和总结,我们将这些伸展穹隆分为早晚两期。两期伸展构造所具有的不同特点决定了他们的动力学机制的不同。早期伸展构造发生在早白垩世早期,其具有对称性、等时性和等深性的特点,决定了其动力学机制以沉坠作用(foundering)为主导,是对华北克拉通破坏的峰期响应。晚期伸展构造形成时间为早白垩世晚期-晚白垩世早期,时空分布上具有向S或SW迁移的规律,或指示了古太平洋板块的俯冲回撤(roll-back)过程对欧亚大陆板块的渐次影响。;The Cretaceous tectonics of the North China Craton (NCC) and its adjacent regions were characterized by a general lithospheric extension and remarked by extensional dome structures. This makes the largest crustal scale extensional tectonic realm in the world. Based on our field and laboratory work, five extensional domains have been delineated, namely Transbaikalia-Mongol-Okhotsk, western part of NCC, eastern part of NCC and Korea, Qinling-Dabie and its neighbouring, and the interior of South China Block (SCB), respectively. These domains are featured by a NW-SE extensional direction with intensive extensional exhumation of middle to lower crust rocks to the surface along detachment faults. Two stage extension tectonics have been suggested, which took place at ca. 130~120Ma and ca. 118~85Ma. The early stage constrains a narrow activity period, and the foundering of the lower part of the lithosphere could be a possible mechanism for this continent-scale extensional tectonics. This geodynamic model could help us to enhance the knowledge of the time, scale, and mechanism of the NCC destruction from the view of structural analysis. The timing of late-stage extensional tectonics is suggested by a younging trend from the northeast (Liaodong Peninsula) to the southwest (Yuechengling massif in SW Hunan Province). The slab roll-back of westward subducted 'Palaeo-Pacific' or Izanagi plate may lead to this regional extension event.

Extensional tectonics

geodynamics

Massif

Lineament

Extensional fault

10.18654/1000-0569/2021.08.04

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Citations (8)

Devonian-Carboniferous paleopoles for Africa: Consequences for Hercynian geodynamics

Tectonophysics (1990)

Tahar Aı̈fa Hugues Feinberg Jean‐Pierre Pozzi

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