A Timescale and Summary of Geological History
Geological time is divided into the Eras and Periods shown, with the ages before the present day given in millions of years. The colour bands in the chart indicate those periods of geological time represented in the district’s rocks. Also included are events that occurred during the long periods of time for which no record remains; their presence has been inferred from evidence in adjoining areas.
The enormity of geological time may be appreciated by representing the whole of Earth history by a single day. On this scale, the oldest rocks in the National Park formed around 9.45 pm, the Carboniferous limestone and sandstone that make up most of the central and southern parts were laid down between 10.10 and 10.30 pm, and the Quaternary ice ages began less than one minute to midnight. Man first walked across the Northumberland moors at less than one second to midnight.
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Geological Timescale © BGS