Publications
Sort:
Open Access Issue
Mesoproterozoic tectonic and paleogeographic evolution of the Yanliao Rift Basin in the northern North China Craton: Constraints from detrital zircon ages of the Xiamaling Formation in the Jixian area
Journal of Northwest University (Natural Science Edition) 2023, 53(2): 296-312
Published: 25 April 2023
Abstract PDF (3.9 MB) Collect
Downloads:3

The Yanliao Rift Basin is located in the northern part of the North China Craton, which recorded the intracontinental extension following the Paleoproterozoic collision of the North China Craton, the breakup of the Nuna supercontinent, along with the Mesoproterozoic oxygenation event. However, studies on the Mesoproterozoic Paleogeography and tectonic evolution of the Yanliao rift basin is less studied. In this paper, we systematically investigated the sedimentary characteristics of the Jixian system in the Jixian area, and obtained detrital zircon U-Pb ages for the clastic rock samples from the standard stratigraphic section of the Xiamaling Formation of the Jixian system. LA-ICP-MS zircon U-Pb dating results show that the 207Pb/206Pb ages of detrital zircons from the Xiamaling Formation quartz sandstone samples range from 3270 to 1806 Ma, with two significant age peaks at 1880 Ma and 2530 Ma. The results show that the sandstone of Xiamaling Formation is mainly composed of detritus from Neoarchean and late Paleoproterozoic, and the two most significant age peaks correspond to the Middle Archean-Paleoproterozoic geological events in the North China Craton respectively. In addition, a few older detrital zircons (~2750 Ma and 3200 Ma) also occur, corresponding to Archean magmatic events in the North China Craton, respectively. The detrital zircon age distribution indicate that the Xiamaling Formation was deposited in an extensional setting. Given the sedimentary assemblages of the Jixian system and the underlying Changcheng System, we here conclude that the tectonic evolution of the Yanliao Rift Basin can be roughly divided into four stages: ① The post-collision extensional transition stage (1.85~1.60 Ga); ② Early intracontinental extension (1.60~1.40 Ga); ③ The rifting basin stage corresponding to the global breakup of the Nuna supercontinent (1.40~1.30 Ga); ④ Overall uplifting stage (1.32~1.0 Ga).

Open Access Issue
From tectonic-environmental factors of Early life diversification during Gondwana assembly to Earth Science System
Journal of Northwest University (Natural Science Edition) 2025, 55(3): 475-488
Published: 25 June 2025
Abstract PDF (2.5 MB) Collect
Downloads:1

The Cambrian animal diversification is a milestone in life evolution history. This also coincides well the Neoproterozoic atmospheric oxygenation (NOE), Gondwana assembly (~680~430 Ma) and Snowball Earth event, as well as magnetic field extreme evolution and formation of Earth inner core. Moreover, modern plate tectonics may have also been established during this period. Thus, solid Earth and surficial system evolution must be closely linked. However, the tectonic factors that drove the evolution of surficial systems during Gondwana assembly are less constrained, as is the driving mechanism. Most earlier studies are limited to conceptual models. Here, a review of data patterns shows that this period initiated with the breakup of the Rodinia supercontinent, whic’h induced the Snowball Earth and oxygenation events. The subsequent Gondwana assembly, within the modern plate tectonic regime, generated super-orogens that lasted for more than 200 million years. The elevations of these over 9000 km long super orogens might have been comparable to those of modern Earth, which should have served as a continuous driving force for the Earth’s surficial environs. The large-scale Himalaya type collision orogenic belt during this period is consistent with the sudden drops of the global thermobaric ratio (T/P) and the large-scale occurrence of high-pressure and ultrahigh-pressure metamorphism. On the other hand, due to secular mantle cooling and thinning of the oceanic crust, the duality of ocean and continental crust became more significant at this time. This indicates that the topographic relief might have reached an unprecedented level during this period, which can provide ecological space for ocean animal system. This, together with low-latitude orogenic belts caused extensive weathering and supplied a huge amount of continental sediments to the ocean, consist with the seawater Sr isotope that reached the highest value in the history. Meanwhile, snowball Earth also contributed to continental weathering. Huge sediments and nutrients supply profoundly changed ocean composition and increased ocean productivity, triggering oxygenation events. In addition, in the late Neoproterozoic to the Cambrian time, the Earth had an extremely weak magnetic field, possibly related to the formation of the Earth’s inner core. Ediacaran true polar wander path and high frequency magnetic field reversing also occurred. This indicates high cosmic radiation that might have contributed to genetic mutation. Therefore, multiple accidental and inevitable factors provided genetic, environmental and ecological conditions for Ediacaran life radiation and Cambrian life explosion. In addition, the increased supply of sediments reduced the friction coefficient within subduction zone and increases the plate subduction rate, which can explain the rapid continental plate drift during Gondwana cycle Overall, the Gondwana cycle is a critical period in the evolution of the Earth system.

Total 2