Geology - Pembrokeshire
Rock - Greywacke / Natural Arch
A Natural Arch at the northern end of Newgale Beach, formed of Cambrian
Greywacke Sandstone.
Greywacke is a variety of Sandstone , a mixture of sand sized grains of rock framents
and minerals .
Submarine avalanches or strong turbidity currents can churn sediments and cause
mixed-sediment slurries, which form this unsorted type of Sandstone.
Turbidite Rocks are a mixture of layers of Greywacke , graded Greywacke ,
siltstone, mudstone.
Ref: 11027
Date: 27/10/2012
Location: SM 843.226
