Coal-bearing strata sequence stratigraphy of Paleogene Meihe Formation, Meihe Basin, NE China
- PDF / 6,617,530 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 55 Downloads / 181 Views
Coal-bearing strata sequence stratigraphy of Paleogene Meihe Formation, Meihe Basin, NE China Yueyue Bai1 • Qingtian Lu¨1 • Zhaojun Liu2 • Pingchang Sun2 • Rong Liu2 Shuqing Yao2
•
Received: 13 April 2020 / Revised: 29 July 2020 / Accepted: 3 November 2020 Ó The Author(s) 2020
Abstract The Meihe Basin is an important Paleogene coal-bearing basin located in the Dunhua-Mishan Fault Zone, northeastern China. Based on a comprehensive study of well logs, seismic profiles, cores and rock geochemical properties, the coal distribution, paleoenvironment evolution within a sequence stratigraphic framework and the accumulation model to explain how coal seams developed in small fault basin were discussed in detail. Three-third-order sequences were identified in the Paleogene Meihe Formation of Meihe Basin and the two coal-bearing sequences are the Lower Coalbearing Member of Sequence I and the Upper Coal-bearing Member of Sequence III. All three types of system tracts are developed in both sequences, i.e., the lowstand systems tract (LST), the transgressive systems tract (TST), and the highstand systems tract (HST). In LST of Sequence I, fan delta plain marsh is the main coal accumulating environment where coal seams are thin, discontinuous and therefore uneconomic for mining, and it is the same with all coal seams developed in Sequence III. While in TST and HST of Sequence I, lake swamp is the main sedimentary environment where coal seams are thick, continuous, widely distributed, and thus economically attractive for mining. In the study area, the nice thick economical coal seams are usually developed in an ideal stable depositional environment where organic matter accommodation space grows at a balanced rate with peat, in other words, free of sediment input or channel migration. The key findings of this study could provide guidance for the exploration of coal seams in the Meihe Basin and other similar basins. Keywords Coal seam Sequence stratigraphy Fan delta Swamp Meihe Basin
1 Introduction The occurrence and distribution of coals is primarily controlled by base level changes, but also affected by accommodation space, sediment supply, peat-accumulation rate and climate changes (Flint et al. 1995; Diessel et al. 2000; Buillit et al. 2002; Oplusˇtil et al. 2013). Ryer
& Yueyue Bai [email protected] 1
SinoProbe-China Deep Exploration Center, Chinese Academy of Geological Sciences, Beijng 100037, China
2
Key Laboratory for Oil Shale and Coexisting Minerals Mineralization and Exploration and Exploitation, Jilin University, Changchun 130061, China
(1981, 2009) claimed that the thickest and most widely distributed coal seams in delta sand bodies accumulated mainly near the maximum flooding surface. Bohacs and Suter (1997) found that thick and widely-distributed coal seams are usually deposited in the transgression systems tract (TST) typical of, rising accommodation space. Diessel (1992, 2007) investigated different coal seams developed in eight countries and argued that the economically minable coal seams are m
Data Loading...
