A new 1.32 Ga Tianshui mafic sill in the Liaodong area and its relations to the Yanliao large igneous province in the northern North China Craton

2022 ◽  
Vol 369 ◽  
pp. 106535
Author(s):  
Xin Ping Wang ◽  
Peng Peng ◽  
Chong Wang
Lithos ◽  
2008 ◽  
Vol 101 (3-4) ◽  
pp. 260-280 ◽  
Author(s):  
Peng Peng ◽  
Mingguo Zhai ◽  
Richard E. Ernst ◽  
Jinghui Guo ◽  
Fu Liu ◽  
...  

2020 ◽  
Author(s):  
Huiru Xu ◽  
Tao Yang ◽  
Mark Dekkers ◽  
Peng Peng ◽  
Kunpeng Ge ◽  
...  

<p>The paleo-position of the North China Craton (NCC) within the Supercontinent Nuna/Columbia is controversial. Hindered by ubiquitous alteration of the very ancient rocks, paleomagnetic studies have not been able yet to conclusively solve this puzzle. Comprehensive analysis on the relatively limited Precambrian records is essential to understand the geological history of these cratons. Within the NCC, the tectonic setting of a ~1.78 Ga large igneous province (LIP) is long debated. It is considered to be related to a paleoplume, post-collision extension, or an Andean continental margin. Knowing its mode of formation constrains the geological evolution of the NCC and its paleo-position within the Supercontinent Nuna/Columbia. Here we conduct a study into the anisotropy of magnetic susceptibility (AMS) in the dykes and lavas of the ~1.78 Ga LIP, together with systematic rock magnetic experiments, to constrain the geological background of the igneous event(s), to understand the tectonic evolution of the NCC, as well as its paleo-position within the assembly of the Nuna/Columbia supercontinent.</p><p>Thirty-three dykes in the northern and middle parts and thirty lavas in the southern part of the NCC were collected. Detailed rock magnetic analyses indicate PSD magnetite to be the dominant magnetic mineral in the samples, occasionally with pyrrhotite in the dykes and hematite in the lavas. The often observed relatively weak anisotropy degree suggests that the AMS ellipsoids probably portray magma flow-related fabrics. The inferred directions from the AMS fabrics of the lavas reveal a radial flow pattern with an eruption center located on the south margin of the NCC. The studied dykes show a predominance of horizontally to subhorizontally northward magma flow, with only few vertical intrusions. These observations imply that the ~1.78 Ga LIP may have formed by magma source(s) at the south margin of the NCC. Some localized magma sub-chambers may have formed during the propagation of the magma and could have been responsible for the less common vertically intruded dykes and the EW-trending dykes. Therefore, we favor a plume-related tectonic setting for the ~1.78 Ga LIP with the eruption center along the margin of the NCC. It can serve as an essential criterion to search for possible neighbour(s) of the NCC within Nuna/Columbia, which should preserve the relics of the ~1.78 Ga LIP. Our study, in combination with extant geological and paleomagnetic results suggests a close linkage of the NCC with the São Francisco-Congo, Rio de la Plata and Siberia cratons in the Nuna/Columbia supercontinent.</p>


Geology ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 462-467 ◽  
Author(s):  
Ying Zhou ◽  
Philip A.E. Pogge von Strandmann ◽  
Maoyan Zhu ◽  
Hongfei Ling ◽  
Christina Manning ◽  
...  

Abstract The Tonian Period followed a long interval of relative stasis and led into the climatic extremes and biological radiations of multicellular life during the Cryogenian and Ediacaran Periods, respectively. However, despite its pivotal situation, it remains relatively understudied, in large part due to the lack of robust age constraints. A combination of fossil evidence, radiometric ages, and isotopic constraints reveal that carbonate strata on the North China craton were deposited between ca. 980 and ca. 920 Ma, thereby filling a gap in marine archives. Here we present 87Sr/86Sr data from selected calcite microspar cements, which filled early diagenetic “molar tooth” cracks, along with data from demonstrably well-preserved bulk carbonate samples. These new data show that seawater 87Sr/87Sr rose in stages from ∼0.7052 at ca. 980 Ma to ∼0.7063 by ca. 920 Ma, after which a return to low values coincided with the eruption of the Dashigou large igneous province across the North China craton. We also present a new Neoproterozoic seawater 87Sr/86Sr curve, which reveals that the general trend toward higher 87Sr/87Sr during the Tonian Period was checked repeatedly by the input of less-radiogenic strontium from a series of eruptive events, both coincident with and prior to the main breakup of Rodinia. The weathering of Tonian volcanic provinces has been linked to higher carbon burial, glaciation, and oxygenation due to the high phosphorus content of flood basalts. Here we show that the weathering of major volcanic provinces affected material fluxes and ocean chemistry much earlier than previously envisaged.


2021 ◽  
Vol 118 (40) ◽  
pp. e2109895118 ◽  
Author(s):  
Jing Lu ◽  
Peixin Zhang ◽  
Jacopo Dal Corso ◽  
Minfang Yang ◽  
Paul B. Wignall ◽  
...  

The Late Triassic Carnian Pluvial Episode (CPE) saw a dramatic increase in global humidity and temperature that has been linked to the large-scale volcanism of the Wrangellia large igneous province. The climatic changes coincide with a major biological turnover on land that included the ascent of the dinosaurs and the origin of modern conifers. However, linking the disparate cause and effects of the CPE has yet to be achieved because of the lack of a detailed terrestrial record of these events. Here, we present a multidisciplinary record of volcanism and environmental change from an expanded Carnian lake succession of the Jiyuan Basin, North China. New U–Pb zircon dating, high-resolution chemostratigraphy, and palynological and sedimentological data reveal that terrestrial conditions in the region were in remarkable lockstep with the large-scale volcanism. Using the sedimentary mercury record as a proxy for eruptions reveals four discrete episodes during the CPE interval (ca. 234.0 to 232.4 Ma). Each eruptive phase correlated with large, negative C isotope excursions and major climatic changes to more humid conditions (marked by increased importance of hygrophytic plants), lake expansion, and eutrophication. Our results show that large igneous province eruptions can occur in multiple, discrete pulses, rather than showing a simple acme-and-decline history, and demonstrate their powerful ability to alter the global C cycle, cause climate change, and drive macroevolution, at least in the Triassic.


2019 ◽  
Vol 333 ◽  
pp. 105428 ◽  
Author(s):  
Chuan-Lin Zhang ◽  
Huai-Kun Li ◽  
R.E. Ernst ◽  
Guang-You Zhu ◽  
Xiao-Qiang Liu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document