Geology of Fossil Fuels --- Coal

Proceedings of the 30th International Geological Congress, Volume 18 Part B

Yang Qi

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9781000083040
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

This volume contains papers presented at the 30th International Geological Congress on coal. It includes information on the applications of high-resolution sequence stratigraphy to paralicand terrestrial coal-bearing strata and petrology and depositional environment of Early Jurassic coal.

Variations in Coal Rank Parameters with Depth Correlated with Variscan Compressional Deformation in the South Wales Coalfield.

ROD GAYER and RICHARD FOWLER

Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, PO Box 914, Cardiff, CF1 3YE, UK.

Abstract

Coal maturity data in the form of volatile matter (%Vm_daf and %Vm_dmmf) and random vitrinite reflectance (%Ro) have been analysed for the South Wales coalfield. They show that in general coals increase in rank with depth, obeying Hilt’s law, and increase in rank laterally from high volatile bituminous coals in the south and east of the coalfield to anthracite in the north-west of the coalfield. Coal rank was acquired both before and during Variscan deformation of the coal-bearing foreland basin. The rank pattern with depth in the eastern half of the coalfield suggests a palaeogeothermal gradient of approximately 218 °C km⁻¹. Detailed analysis of both %Vm_daf and %Ro data from individual collieries reveals the presence of excursions from Hilt’s law which affect one or more coal seams within the Westphalian A - lower Westphalian C sequence. It is shown that the excursions commonly correlate with thrust detachments within the coal seams. Detailed petrological and structural analysis of a sequence of coal seams from Llanilid West Opencast coal site show a complex pattern of variation in %Vm_daf and %Ro, similar to the maturity variations recorded in boreholes through the Westphalian Coal Measures in the Netherlands. However, in South Wales no correlation with coal composition is apparent, but a strong correlation with a newly defined Numerical Deformation Index (NDI) suggests a relationship between coal maturity parameters and deformation. The high pelaeo-geothermal gradients present in the coal-bearing sequence have been modelled using BasinMod^® software. Initial results suggest that a...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• The applications of high-resolution sequence stratigraphy to paralic and terrestrial coal-bearing strata: Two case studies from the Western North China Paleozoic Basin and the Tulufan-Hami Jurassic Basin
• Petrology and depositional environment of Early Jurassic coal, Western Australia
• Depositional evolution and coal accumulation of Ordos Basin
• Geologic factors affecting the abundance, distribution, and speciation of sulfur in coals
• Multistage metamorphic evolution and superimposed metamorphism through multithermo-sources in Chinese coal
• Variations in coal rank parameters with depth correlated with Variscan compressional deformation in the South Wales coalfield
• Coalification jumps, stages and mechanism of high-rank coals in China
• Advances of the exploration and research of oil from coal in China
• Study on Jurassic coal and carbonaceous mudstone as oil source rocks in Tuha Basin, North-Western China
• Reaction kinetics of coalification in the Ordos Basin, China