U‐Pb Dating and Lu‐Hf Isotopes of Detrital Zircons From the Southern Sikhote‐Alin Orogenic Belt, Russian Far East: Tectonic Implications for the Early Cretaceous Evolution of the Northwest Pacific Margin

Abstract

The Sikhote‐Alin orogenic belt in Russian Far East is comprised of several N‐S trending belts, including the Late Jurassic to Early Cretaceous accretionary prisms and turbidite basin which are now separated by thrusts and strike‐slip faults. The origin and collage of the belts have been studied for decades. However, the provenance of the belts remains unclear. Six sandstone samples were collected along a 200 km long east‐west traverse across the major belts in the southern Sikhote‐Alin for U‐Pb dating and Lu‐Hf isotope analysis to constrain the provenance and evaluate the evolution of the northwest Pacific margin at this time. The result reveals that the sediments from the main Samarka belt was mainly from the adjacent Bureya‐Jiamusi‐Khanka Block (BJKB); the eastern Samarka belt and the Zhuravlevka turbidite basin were supplied by detritus from both the North China Craton (NCC) and the BJKB; the Taukha belt was mainly fed by sediments from the NCC; whereas the data from the Sergeevka nappes are insufficient to resolve their provenance. In the Late Jurassic to Early Cretaceous, collision and subduction was important in the initial collage of most belts in Sikhote‐Alin. However, merely E‐W trending collage cannot explain the increasing importance of the NCC provenance from west to east. It is proposed that the main Samarka belt was located adjacent to the BJKB when deposited, whereas the other belts were farther south to accept the materials from the NCC. Sinistral strike‐slip faulting transported the eastern belts northward after their initial collage by thrusting.

Roles of Subducted Pelagic and Terrigenous Sediments in Early Jurassic Mafic Magmatism in NE China: Constraints on the Architecture of Paleo‐Pacific Subduction Zone

“…This suggests that at least in the Early Jurassic, these Paleozoic terrains were still located in the southeastern CAOB. The sedimentary records and U‐ Pb ages of detrital zircons from the accretionary complexes in NE China and Far East of Russia also support such a hypothesis (K. Liu, Zhang, Wilde, Liu, et al, ; Z. W. Wang, Pei, et al, ; Zhou & Wilde, ). Thus, we develop a geodynamic model to link the petrogenesis of the Yanbian mafic intrusions with the Early Jurassic Paleo‐Pacific Oceanic subduction.…”

“…In Lu/Hf versus Th/La and Lu/Hf versus Th/Yb plots, the mafic rocks from the northern LHZR clearly have higher Lu/Hf and lower Th/La and Th/Yb ratios than those from southern Yanbian area (Figures a and b), indicating that the mantle source of the Yanbian mafic rocks was predominantly enriched by terrigenous sediments, whereas the mantle source for the LHZR mafic intrusions was likely metasomatized by a component composed mainly of pelagic sediments. On the other hand, in the northern segment of the subduction zone, deep‐sea oceanic radiolarian silicalite, cherts, and oozes of pelagic origin are well developed in the subduction‐accretionary complexes such as the Heilongjiang Complex, Raohe Complex, and the accretionary wedge in the southern Sikhote‐Alin orogenic belt of the Russian Far East (Cheng et al, ; K. Liu, Zhang, Wilde, Liu, et al, ; Zhou et al, , ). The sedimentary records also indicate the important contribution of subducted pelagic sediments to the enrichment process of subarc mantle beneath the northern segment of NE China.…”

“…The Paleo‐Pacific Plate subducted beneath the Mudanjiang Oceanic Plate and formed an oceanic arc (Figure b). The 140–120 Ma (Figure c). With the oceanic ridge spreading and the strong displacement along the transform faults, the Paleo‐Pacific Plate (Izanagi Plate) moved from a NW direction to a northward direction (Koppers et al, ; K. Liu, Zhang, Wilde, Liu, et al, ; Seton et al, ; W. D. Sun et al, ; J. W. Xu et al, ). Oblique subduction toward the East Asian continent occurred, leading to the large‐scale strike‐slipping movement of the Tan‐Lu Fault System (J. W. Xu et al, ).…”

Zircon U–Pb dating and whole‐rock geochemistry of volcanic rocks in eastern Heilongjiang Province, NE China: Implications for the tectonic evolution of the Mudanjiang and Paleo‐Pacific oceans from the Jurassic to Cretaceous

“…It is important to discuss the Heilongjiang Complex and the Sikhote‐Alin accretionary complexes (or “Sikhote‐Alin orogenic belt”; Jahn et al, ; Tang et al, ; K. Liu, Zhang, Wilde, Liu, et al, ) before discussing the tectonic environment of the volcanic rocks in this area.…”

“…However, the tectonic settings of the Zhangguangcai Range and Bureya‐Jiamusi‐Khanka Block during the Mesozoic remain controversial and are one of the key questions to be resolved in geological study of the eastern CAOB. Some researchers consider that the Lesser Xing'an‐Zhangguangcai Range and the Jiamusi Block were active continental margins in the Early Jurassic (K. Liu, Zhang, Wilde, Zhou, et al, ; Wu et al, ; Zhou et al, ), whereas others argue that this area was in extension during the Late Triassic to Early Jurassic (F. Wang, Xu, Xu, Gao, & Ge, ; W. L. Xu et al, ; Yu, Wang, Xu, Gao, & Pei, ). As for the tectonic environment in the Cretaceous, only a few studies (e.g., M. D. Sun et al, ) have been carried out.…”