Interesting Fact: Thrust fault at Bolton Hill Quarry

Bolton Hill Quarry hosts an outstanding exposure of the Johnston Thrust – a locally and regionally significant tectonic feature caused by continental collision, which led to the formation of the super-continent, Pangaea.

A thrust fault is a low-angle reverse fault which forms during compressional tectonic settings, resulting in older rocks being pushed above younger rocks. At Bolton Hill, we quarry the 650-million-year-old igneous rock which has been displaced from a depth of 4km and forced on top of the younger Carboniferous Coal Measures, which are only 300 million years old.