General review of tectonic history and further careful research on deformed coal rocks form the basic way to clarify problems of coalbed gas genesis.
In China, one increasing attention should be the Mesozoic tectonic history of North China and its surrounding areas, and also the related coalbed gas genesis study in this most important coalbed gas product area of China.
Geometry, kinematics, and geochronology data from outcrops of the China Central Orogen and the North China offered excellent clues of extension event for understanding the tectonic conditions of coalbed gas. Q. Hou et al. studied the Mesozoic Tectonic Dynamics and Chronology in the Eastern North China Block.
Central Orogen of China, related to Tethys Closure and mainly formed during the Triassic Period, includes both the Qinling Orogen in the west and the Dabie Mountains in the east. H. Zhang et al. separately concluded the Mesozoic tectonic evolution of the Lincang Batholith, during palaeo-Tethys collision, and reviewed the structural framework of the Erlangping Group in North Qinling. Q. Hou clarified the framework of the Dabie Extensional Tectonic System. Furthermore, Q. Liu made out the different origins of the fractionation of Platinum-Group elements in Raobazhai and Bixiling Mafic-Ultramafic Rocks from the Dabie Orogen.
Several achievements of coal field research in Northern China showed us the characteristics, developments, and genesis of coalbed gas. Y. Ju et al. gave us general properties of tectonically deformed coal rocks. J. Fan et al. studied the characterization of coal reservoirs in two major coal fields of China. Y. Wu et al. showed a case study of vitrinite anisotropy from Huaibei Coalfield from southern North China.
Some kinds of techniques on brittle, brittle-ductile, and ductile deformation zones are very important for future research. M. S. Tairo et al. studied the “Pan-African paleostresses and reactivation of the eburnean basement complex in Southeast Ghana (West Africa)”. X. Li et al. took use of the Fourier transform infrared and Raman Spectral to study the metamorphism and deformation of coal. J. Fan et al. gave us one new coal rank evaluation method by total scanning fluorescence characteristics.
In general, the eleven papers here constitute a significant contribution to our knowledge by reporting the tectonic settings, characteristics, and research methods of coalbed gas genesis. The papers also laid a research system for further work of coal geology.
Quanlin Hou
Yiwen Ju
Jonathan Aitchison
Hongyuan Zhang
Yudong Wu