Contrasting Lu–Hf isotopes in zircon from Precambrian metamorphic rocks in the Jiaodong Peninsula: Constraints on the tectonic suture between North China and South China

2014 ◽  
Vol 245 ◽  
pp. 29-50 ◽  
Author(s):  
Shao-Bing Zhang ◽  
Jun Tang ◽  
Yong-Fei Zheng
2020 ◽  
Vol 222 (2) ◽  
pp. 956-964
Author(s):  
Chenglong Wu ◽  
Tao Xu ◽  
Yinshuang Ai ◽  
Weiyu Dong ◽  
Long Li

SUMMARY The Jiaodong Peninsula consists of the Jiaobei massif and the Northern Sulu UHP massif. These are separated by the Wulian suture zone (WSZ), a key region for understanding the collision between the North China Craton (NCC) and South China Block (SCB). To interpret this collisional zone, a broad-band seismic profile of 20 stations was installed across the WSZ. Shear wave splitting analysis of teleseismic data revealed a contrast in the splitting patterns beneath different structural zones of the Jiaodong Peninsula. The anisotropic structures of the Jiaobei massif and Northern Sulu UHP massif can be explained by a single anisotropic layer model with WNW-ESE or E-W oriented fast directions. In the WSZ, splitting parameters exhibit pronounced variation in backazimuths indicating a two-layer anisotropy pattern. The lower layer exhibits a WNW-ESE fast direction consistent with that observed in the other two regions. Because the fast direction is generally parallel to the present-day direction of Pacific plate subduction, the anisotropy most likely represents asthenospheric return flow in the big mantle wedge caused by Pacific plate subduction. The upper layer exhibits an NE fast direction, that is, parallel to faulting associated with the WSZ. The lithosphere may preserve fossilized anisotropy induced by the Late Triassic collision of the NCC and SCB even after subsequent destruction and thinning from the Late Mesozoic to Cenozoic. We infer that the WSZ represents a lithospheric-scale structural boundary between the NCC and SCB.


2011 ◽  
Vol 85 (2) ◽  
pp. 279-297 ◽  
Author(s):  
Seung-Bae Lee ◽  
Duck K. Choi

TheEosaukiafauna is proposed for the upper Furongian trilobite assemblage from the interval spanning from the upper part of the Hwajeol Formation to the lowermost part of the Dongjeom Formation in the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by the dominance of dikelocephalid trilobites comprisingEosaukia micropora, E. bella, E. acuta, Mictosaukiacf.M. globosa, andTaebaeksaukia spinatan. gen. n. sp. Taxonomic reappraisal of the genusMictosaukiathat has been employed as an upper Cambrian index taxon in eastern Gondwana reveals that more than half of the species ofMictosaukiabelong inEosaukia.This study clarifies the generic concept ofEosaukia, which provides a more reliable biostratigraphic correlation for the upper Furongian strata in eastern Gondwanan regions. TheEosaukiafauna is correlated with the“Mictosaukia”faunas from the upper Fengshanian of North China, upper Taoyuanian of South China, and upper Payntonian of Australia.


2005 ◽  
Vol 361 (1469) ◽  
pp. 835-842 ◽  
Author(s):  
Jing Ma ◽  
Arjen Y Hoekstra ◽  
Hao Wang ◽  
Ashok K Chapagain ◽  
Dangxian Wang

North China faces severe water scarcity—more than 40% of the annual renewable water resources are abstracted for human use. Nevertheless, nearly 10% of the water used in agriculture is employed in producing food exported to south China. To compensate for this ‘virtual water flow’ and to reduce water scarcity in the north, the huge south–north Water Transfer Project is currently being implemented. This paradox—the transfer of huge volumes of water from the water-rich south to the water-poor north versus transfer of substantial volumes of food from the food-sufficient north to the food-deficit south—is receiving increased attention, but the research in this field has not yet reached further than rough estimation and qualitative description. The aim of this paper is to review and quantify the volumes of virtual water flows between the regions in China and to put them in the context of water availability per region. The analysis shows that north China annually exports about 52 billion m 3 of water in virtual form to south China, which is more than the maximum proposed water transfer volume along the three routes of the Water Transfer Project from south to north.


2021 ◽  
Author(s):  
Naihui Zang ◽  
Junhu Zhao ◽  
Pengcheng Yan ◽  
Han Zhang ◽  
Shankai Tang ◽  
...  

Abstract Persistent extreme heat events (PEHEs) exert a more negative impact on society, including agriculture, plant phenology, power production and human health, compared to general EHEs. The temporal and spatial characteristics of summer PEHEs in eastern China were analysed based on a daily maximum temperature dataset from 759 stations over the period of 1961–2018. The results show the following: Persistent distributions of PEHEs show that they are characterized by an exponential decay with a drop in the decay rate. In terms of spatial distribution, there is an apparent regional difference in the duration of PEHEs. North China is dominated by multi-frequency and short-duration EHEs, while South China is the opposite. PEHEs in North China and the Huanghuai region mainly occur in June-July but mostly in July and August in South China. Strongly responding to global warming, the frequency and duration of PEHEs in North China have increased since the 1990s. However, the frequency of PEHEs in North China and the Huanghuai region has shown opposite trends in June-July since the beginning of the 21st century. Affected by the atmospheric circulations, the regional differences in PEHE frequency are also apparent. Since the beginning of the 21st century, the PEHEs in North China and the Huanghuai area have shown an increasing trend in August. The short-term PEHEs in the middle and lower reaches of the Yangtze River and South China increased rapidly in the 2000s, while long-term PEHEs increased in the 2010s. This study implies that attention should be paid to not only the frequency of EH days but also to the persistence of EHE which is a key characteristic of damaging EH.


Author(s):  
A.M. Celal Şengör ◽  
Nalan Lom ◽  
Ali Polat

To the memory of Nicholas John (Nick) Archibald (1951−2014), master of cratonic geology. Cratons, defined by their resistance to deformation, are guardians of crustal and lithospheric material over billion-year time scales. Archean and Proterozoic rocks can be found in many places on earth, but not all of them represent cratonic areas. Some of these old terrains, inappropriately termed “cratons” by some, have been parts of mobile belts and have experienced widespread deformations in response to mantle-plume-generated thermal weakening, uplift and consequent extension and/or various plate boundary deformations well into the Phanerozoic. It is a common misconception that cratons consist only of metamorphosed crystalline rocks at their surface, as shown by the indiscriminate designation of them by many as “shields.” Our compilation shows that this conviction is not completely true. Some recent models argue that craton formation results from crustal thickening caused by shortening and subsequent removal of the upper crust by erosion. This process would expose a high-grade metamorphic crust at the surface, but greenschist-grade metamorphic rocks and even unmetamorphosed supracrustal sedimentary rocks are widespread on some cratonic surfaces today, showing that craton formation does not require total removal of the upper crust. Instead, the granulitization of the roots of arcs may have been responsible for weighing down the collided and thickened pieces and keeping their top surfaces usually near sea level. In this study, we review the nature and origin of cratons on four well-studied examples. The Superior Province (the Canadian Shield), the Barberton Mountain (Kaapvaal province, South Africa), and the Yilgarn province (Western Australia) show the diversity of rocks with different origin and metamorphic degree at their surface. These fairly extensive examples are chosen because they are typical. It would have been impractical to review the entire extant cratonic surfaces on earth today. We chose the inappropriately named North China “Craton” to discuss the requirements to be classified as a craton.


Sign in / Sign up

Export Citation Format

Share Document