地质科技通报 (Sep 2021)

Structural characteristics of Jan Mayen microcontinent and tectonic evolution model of volcanic passive margin in distal domain

  • Ye Jiang,
  • Qiong Liu,
  • Yingde Zhang

DOI
https://doi.org/10.19509/j.cnki.dzkq.2021.0031
Journal volume & issue
Vol. 40, no. 5
pp. 112 – 122

Abstract

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With the deepening of global oil and gas exploration research, the North Atlantic polar region has gradually become the frontier of oil and gas exploration, but the exploration degree of Jan Mayan micro-continent is very low.The study on stratigraphy, structures and tectonic evolution modelling of the Jan Mayan microcontinent (JMMC)is presented in the paper based on seismic, gravity and magnetic data newly acquired by CNOOC in its contract area and other new published papers which show the most update progress of the JMMC. Located in the central part of the Norwegian-Greenland Sea of the North Atlantic, the JMMC is conjugate with the Jameson Land Basin on the Greenland continent margin and the Vøring Basin on the Norwegian shelf margin of the Beltic Continent in accordance with similar Paleozoic-Mesozoic stratigraphy. The JMMC extends southwards from the Jan Mayan fracture zone towards northern Iceland and its architecture shows the characteristics of detachment faults which is similar to the Mesozoic fault system of the Vøring Basin. The distribution of SDR, volcanic intrusion and explosion can be interpreted on the seismic data which indicates the JMMC is the distal domain of the volcanic passive margin in the North Atlantic mostly during the Cenozoic age. The tectonic evolution model is setup by analogic basin analysis and is supposed to start from the Paleozoic-Mesozoic orogeny to rifting, and then be influenced by the twice seafloor spreading of the age 55 Ma and 25 Ma. The first seafloor spreading of 55 Ma age caused the continental crust break-up and formed the volcanic passive margin between the Greenland and Beltic, especially the JMMC's separating from the conjugate Norwegian shelf margin. The second seafloor spreading of 25 Ma age caused the oceanic ridge jump due to the Iceland mantle plume drifting off the Greenland and also caused the JMMC's separation from the Greenland Continent as an 'abandoned orphan' floating on the oceanic crust. The meaning of this study is to discuss kinematic evolution of residual continental crust detached from the distal domain of the plate and to indicate lithospheric extension and break while the embryonic oceanic crust generating through the detachment movements and mantle upwelling.

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