Langness Unconformity - Langness, Isle of Man
Posted by: 
Mike_bjm
N 54° 03.523 W 004° 37.550
30U E 393581 N 5991277
Langness Unconformity represent a gap of 135 million year in the laying down of sedimentary rock.
Waymark Code: WMV4K4
Location: Isle of Man
Date Posted: 02/22/2017
Views: 6
An unconformity may be defined as follows:
"An unconformity is the contact between sedimentary rocks that are significantly different in age, or between sedimentary rocks and older, eroded igneous or metamorphic rocks."
At Langness Manx Group rocks formed around 480 million years ago are over laid by gravel deposited by flash floods in the Carboniferous period, around 350 million years ago. The uneven surface separating these two rock types is the the 'unconformity' and represents a gap of around 135 million years when no rocks have been preserved.
The whole area was subsequently submerged below the sea leading to the deposition of Castletown Limestones on top of the gravel.
The unconformity can be seen most clear where coastal erosion has exposed the rocks of both layers as at the Langness Acrh.
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