Compositional variation and palaeoenvironment of the volcanolithic Fort Cooper Coal Measures, Bowen Basin, Australia

Abstract

Megascopic lithotype and microscopic maceral and mineral composition were supplemented by sedimentary logging of the interburden and stable carbon isotope data from a single well to interpret the response of the Late Permian Fort Cooper Coal Measures (FCCM) to regional and global environmental influences. The FCCM are differentiated from underlying, relatively high vitrinite Moranbah Coal Measures, and overlying higher inertinite Rangal Coal Measures in the Bowen Basin by their intercalation with abundant tuff and siliciclastic partings and interbeds. Besides this, there is little described about the variation in the organic composition of the FCCM and its causes. The FCCM can be subdivided into a lower aggradational Fair Hill Formation, transgressed by the shallow marine-derived Black Alley Shale that interfinger with/is overlain by the progradational Middle Main Seams and Burngrove Formation. The coals are dominantly dull with minor bright bands that are more abundant in the Burngrove Formation representing a change in plant composition. The maceral analysis shows that the coals in the Fair Hill Formation and Middle Main Seams are vitrinite-rich (80-90%mmf) albeit with high mineral matter suggesting the formation of precursory peat under rising water levels and with high sediment (tuff) influx and

Carbon isotopic evidence for rapid methane clathrate release recorded in coals at the terminus of the Late Palaeozoic Ice Age

“…Cyclic variation of δ 13 C org in coal at similar scales has been previously observed in high-resolution isotopic studies from Eastern Australia 18–20 . In these works, the primary control on the distribution of δ 13 C cycles within coal is attributed to palaeoenvironmental factors controlling peat accumulation, including water availability, salinity, pH and atmospheric temperature 21 .…”

“…These short-term changes observed in low-latitude sediments, attributed to pluvials, result in changes in base level. These base-level changes, coincident with δ 13 C org cycling, are also observed in coals from Eastern Australia 18–20 , and the 10 3 –10 5 year time-frame is coincident with Milankovitch-scale orbital frequencies 28 , also observed in Mesozoic and Cenozoic coals 29,30 .…”

Characteristics of the physical parameters and the evolution law of anthracite around the coalification jump: A case of the Jincheng and Guxu mining area, China

“…Anthracite is a highly metamorphic coal. During the metamorphic process, exinite first vaporizes to form vitrinite, followed by inertinite, which causes the exinite to disappear and the vitrinite to be enriched (Ayaz et al., 2016; Ward et al., 2005). The volatile content ( V daf ) was between 5.18 and 18.98% and gradually decreased with increasing R o,max (Figure 4(a)), and the change rate of the Jincheng coal was notably greater than that of the Guxu coal.…”

History, Geology, In Situ Stress Pattern, Gas Content and Permeability of Coal Seam Gas Basins in Australia: A Review

“…The thick and laterally continuous nature of the coal seams have contributed to the viability of CSG plays in the Bowen Basin. These coals have a wide range of ranks, vitrinite content and gas content but vitrinite reflectance is generally >0.9% and vitrinite content averages ~70% [12,[66][67][68]. Variations in rank are attributed to the basin's complex tectonic and burial history, with gas sweet spots associated with large anticlinal structures, including the Burunga Anticline, where there is an increase in the permeability of coals (up to 100 mD) [40].…”