How did the coal form during the Carboniferous period?

Diagram: Coal formation

A cyclothem is a series of repeating sediments representing the transgression and regression of wateror the submergence and emergence of land. In coal-bearing strata, changes in depositional environment produced a cyclic repetition of beds. The cyclothem is defined as a series of beds deposited during a single sedimentary cycle. The  consist of shale, limestone, shale, […]

Changing sea-level and coal

Diagram: Changing Sea Level and coal

Diagram showing the formation of a typical cyclothemsequence (from bottom to top). © Elizabeth Pickett, 2022 Sea-levels in the Carboniferous were constantly changing. When sea-level was low, the deltas built out into the sea and swampy conditions prevailed, covered with vegetation. When sea level rose, the deltas and associated forests were drowned, and sea life […]

Carboniferous Coal Measures beneath the Durham coast

Diagram: Carboniferous Coal Measures

An idealised  geological cross section showing the Carboniferous Coal Measures dipping eastwards beneath the Durham coast To the east the coal seams lay several hundreds of metres below surface. To the west the coal seams come the surface Source: