The Cretaceous Tectono-Stratigraphic Complexes of Priamurye (Far East of Russia) ()
1. Introduction
The structure of Priamyrye was described as synclinal and anticlinal structures on previous geological maps, because of lacking the faunal evidence. Since the determination of microfaunas (like radiolarians), the structure of Priamyrye became clear. It consists of a series of small plates, and presents a giant accretionary system at the East Asian continental margin.
2. Study Area
Studied area is shown in Figure 1.
3. Data and Method
The main Method is geological mapping scale 1:50,000 and 1:200,000.
4. Results
East Asian continental margin (EACM) presents a giant accretionary system stretching for 5000 km and gradually increasing to the east for the last 450
![]()
Figure 1. Geologic map of the Amur-Gorin fragment of Late Mesozoicc East Asian margin [1] [2] : Gorin SFZ and Lower Amurian SFZ (Limuri and Chayatyn SFSZ). 1, Quaternary deposits. 2, Boktor unit. 3, Kholvasi unit. 4, Gorin Formation. 5, Pioneer Formation. 6, Limuri unit. 7, Zhormin unit. 8, Kiselevka Formation. 9, Lower Silasinsky subformation. 10, Upper Silasinsky subformation. 11, Utitsky Formation. 12, Uktur Formation. 13 - 15, Upper Cretaceous: 13, Granitoids; 14, Medium volcanites; 15, Acid volcanites. 16, Neogene-Quaternary basalts. 17, Stratone boundary. 18, Faults: a) Major, b) Subordinate. 19. Faunal foundings. 20, Floral foundings.
![]()
Figure 2. Zonal correlation scheme of lithostratigraphic units. 1, Sandstones. 2, Tufaceous sandstones. 3, Conglomerates. 4, Sedimentation breccia. 5, Siltstones. 6, Clayey shales and aleuropelites. 7, Siliceous-clayey shales. 8, Clayey cherts. 9, Jasper and cherts. 10, Tuff and basic hyaloclastites. 11, Basic lavas. 12, Limestones. 13, Bivalves. 14, Radiolarian. 15, Conodonts. 16, Flora.
million years by accretionary complexes. In Mesozoic, within the boundaries of EACM 6 main periods of accretion are established: T2; J1; J2; J3; J3-K1 and #Math_5#, that were previously discussed in general terms. Accretionary complexes are divided into belts or zones (SFZ) as shown in Figure 1.
In Priamurye, three main tectono-stratigraphic systems can be distinguished: a system of oceanic plate, composed of laminar chert, rare volcanites, a system of oceanic plate cover during its approach to the subduction zone (siliceous mudstone), and the overlying terrigenous formations. Fragments of these systems are presented as shown in Figure 2.
Acknowledgements
This work was fulfilled supported by the project of the Russian Foundation for Basic Research (No. 19-05-000 97/19) and in part by the State task for Y.A. Kosygin of the Institute of Tectonics and Geophysics of the Far Eastern Branch, Russian Academy of Sciences. This is a contribution to UNESCO-IUGS IGCP Project 679.