Editing Late Mesozoic and Cenozoic tectonics and magmatism, Northern England

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== Cenozoic uplift and basin inversion ==
 
== Cenozoic uplift and basin inversion ==
Estimates of Cenozoic exhumation from apatite fission-track studies suggest that some 700 m of strata, mainly Late Cretaceous and possibly Permian and Triassic in age, were removed from the Scafell area of the central Lake District, whereas erosion of a more complex sequence of Carboniferous to Cretaceous rocks from the area around the West Newton Borehole, just to the north of the Maryport Fault in north Cumbria, amounted to about 1550 m. The difference in these figures approximates to the current difference in the elevation of the two localities above sea level.
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Estimates of Cenozoic exhumation from apatite fission-track studies suggest that some 700 m of strata, mainly Late Cretaceous and possibly Permian and Triassic in age, were removed from the Scafell area of the central Lake District, whereas erosion of a more complex sequence of Carboniferous to Cretaceous rocks from the area around the West Newton Borehole, just to the north of the Maryport Fault in north Cumbria, amounted to about 1550 m. The difference in these Chapter approximates to the current difference in the elevation of the two localities above sea level.
  
 
Compressive uplift of the Carlisle Basin occurred probably during Miocene times. This process is referred to as inversion: pre-existing extensional faults are reactivated with a reverse sense and strata are folded. Up to about 2500 m of a mainly Jurassic and Cretaceous succession are thought to have been removed during basin inversion, with the Lias Group accounting for as much as 1500 m of this thickness within the depocentres, thinning to about 600 on the intervening saddle areas. Any overlying Middle Jurassic to Lower Cretaceous strata were either an originally thin sequence, or had been removed prior to deposition of 600–800 m of Upper Cretaceous Chalk Group rocks that are thought likely to have capped the succession. The Lower Jurassic strata in the outlier near Carlisle are situated on one of the saddle areas and have been preserved because they lie within an area that was less affected by inversion than the depocentres.
 
Compressive uplift of the Carlisle Basin occurred probably during Miocene times. This process is referred to as inversion: pre-existing extensional faults are reactivated with a reverse sense and strata are folded. Up to about 2500 m of a mainly Jurassic and Cretaceous succession are thought to have been removed during basin inversion, with the Lias Group accounting for as much as 1500 m of this thickness within the depocentres, thinning to about 600 on the intervening saddle areas. Any overlying Middle Jurassic to Lower Cretaceous strata were either an originally thin sequence, or had been removed prior to deposition of 600–800 m of Upper Cretaceous Chalk Group rocks that are thought likely to have capped the succession. The Lower Jurassic strata in the outlier near Carlisle are situated on one of the saddle areas and have been preserved because they lie within an area that was less affected by inversion than the depocentres.

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