The initiation of plate tectonics on Earth is significant for early tectonic evolution, crustal growth, and paleo-environment. The North China Craton is one of the ideal places for studying this topic. However, because of Mesozoic craton destruction, the Archean rocks within the North China Craton were split into many small pieces by later strike-slip faults and extensional fault systems. Therefore, structural restoration of the original position of the Archean rocks in this Eo-Neoarchean (3.8–2.5 Ga) terrane is the first step to our Precambrian research work. After detailed structural deciphering and restoration, Tian et al. (2022) discovered that the tectonic units and BIF in Archean supracrustal rocks cropping out in the Eastern Block of the North China Craton are arranged in line with the NNW-SSE strike, which is consistent with their oriented gneissic foliations. Combined with its Archean deformational age, the regional stress field in the Eastern Block was inferred as ~E-W direction. The Jiao-Liao-Ji back-arc basin was presented as a depositional central for the Paleoproterozoic sediments in the Eastern Block. The Liaohe Group is typical sediments in this basin, from the bottom to top, the Langzishan Formation was deposited in a passive margin, the volcanic sediments in the Li’eryu Formation were related to an active tectonic setting, the Gaojiayu Formaiton was presented as a Paleoprotezrozoic turbidite that deposited in a deep-sea setting (Tian et al., 2021), and the Dashiqiao carbonate rocks associated with mafic rock including pillow lava was presented depositing in a seamount nearby the extensional ridge. Early Paleoproterozoic orogenesis deeply affected these sediments and an N-S direction orogenic contraction was presented by Tian et al. (2020) according to detailed geological mapping and structural deciphering. Therefore, from the late Archean to the early Paleoproterozoic, the regional stress field in the Eastern Blocks of the North China Craton was transferred from the ~E-W direction to the N-S direction. Modern subduction belt migration and evolution often result in regional stress field transformation, therefore, we presented that regional stress field transfer in late Archean to early Plaeoproterozoic is a significant indicator for the initiation of plate tectonics.

Reference(s)

Tian Z.H., Nutman AP. Structural restoration of an Eo-Mesoarchean (3.8–2.9 Ga) terrane, Eastern China, dissected by the Tanlu fault zone. Journal of Structural Geology. 2022;161:104629.

Tian, Z.H., Liu, F., Yan, Z., Liu, P., Xu, W., Liu, L., Wen, F., and Xiao, W., 2021, Paleoproterozoic turbidite deposition in the Liaodong Peninsula, northeastern North China Craton: Constraints from the Gaojiayu formation of the Liaohe Group: Precambrian Research, 352:106008.

Tian, Z.H., Liu, F., Liu, P., Wen, F., and Xiao, W., 2020, A Paleoproterozoic nappe on Meso-Archean gneisses exhumed by a Cretaceous metamorphic core complex in northeastern North China Craton: International Journal of Earth Sciences, 109 (4): 1403-1420.