The Taralgon Formation contains by far the largest brown coal resources in the Gippsland Basin, and is probably unequalled in the World for any single basin deposit of its type. Out of an indicated resource of 345 billion tonnes (Gt), approximately 10 Gt are currently listed as economically recoverable reserves. Low ash content (ave. 2.9% db) but higher organic sulphur contents (ave. 1.72% db) largely reflect the near-coastal depositional environments under which much of the original extensive peat swamps accumulated. The contained plant matter and coal types indicate a high-latitude rainforest environment where rainfall and temperatures were higher than present, and where lithotype cycling occurs. The coals appear to have accumulated at specific high stand periods of coastal onlap towards the end of the Middle and Late Eocene, and eustatic sea-level changes play an important role in development of the coal seams. The timing for maximum coal accumulation takes place at the apogee of a greenhouse world shortly before the cooling trends into the early Oligocene. During this time over 100 Gt of carbon was sequestered into these coal deposits. (C) 2000 Elsevier Science B.V. All rights reserved.