This chapter presents the results of the authors’ separate and conjoint studies of the palaeobotany, stratigraphy and palaeoecology of the Latrobe Valley Coal Measures, a thick sequence of coal seams and interseam elastics in the Gippsland region of southeastern Australia (Figure 14.1).
The Latrobe Valley Coal Measures are of Middle Eocene-Middle Miocene age and were deposited after the separation of Australia from Antarctica, a time of significant climatic change for the Australian continent and a period during which major global changes in sea levels and climates occurred. The Eocene-Miocene was an important time for the development of the modern Australian flora and the Latrobe Valley Coal Measures provide a window into this critical period. The study of the fossil assemblages of the coals has led to a detailed understanding of the vegetation that formed the coal measures and contributes significantly to our knowledge of the development of the modern Australian flora.
Previous workers have directed their efforts to particular aspects of the nature and relationships of the coal swamp vegetation. Early workers (Chapman, I925a,b; Deane, 1925; Cookson, 1946, 1947, 1950, 1953, 1957, 1959; Cookson & Duigan, 1950, 1951; Cookson & Pike, 1953a,b; 1954a,b; Pike, 1953; Patton, 1958) concentrated upon the taxonomic affinities of macroscopic and microscopic plant remains. Duigan (1966) studied selected micro- and macrofossil plant taxa from a palaeogeographical, ecological and evolutionary viewpoint. Baragwanath & Kiss (1964), Partridge (1971) and Stover & Partridge (1973) were more concerned with establishing stratigraphic relationships with the microfossils. The last of these studies, of pollen and marine microfossils, developed a long-accepted biostratigraphy for the basin.
Recently the biostratigraphy has been revised using more extensive sampling and better correlation with the geology of the basin (Haq et al., 1987; Holdgate, 1985, 1992; Holdgate & Sluiter, 1991). These studies also demonstrated the significance of eustatic sea level changes in influencing sedimentation within the basin and also that significant marine transgressions can be traced in both the lithofacies and the microfossil record.