Discovering Blackhall’s Permian Reef Evolution: Boulder Conglomerate and Crinkly Beds
At Blackhall Rocks, south of the Gin Cave, we’ll explore two rock structures revealing the Permian reef’s evolution.
In the lower part of the sequence, we find the Boulder conglomerate, showing evidence of high wave energy at the reef rampart where waves collide with the reef. Over time, reef rubble gets reworked, forming a boulder-like deposit.
Above, we see a different structure called the ‘crinkly beds’. These fine, laminated layers are indicative of a quieter, shallow water environment, possibly the intertidal lagoon behind the reef. Here, biofilms or microbial mats trap mineral material, building up carbonate layers over time. The crinkly beds are associated with stromatolites, dome-like structures indicating microbial activity.
These formations provide valuable insights into the changing conditions and environments that shaped Blackhall’s ancient reef during the Permian period.
360 Degree Interactive Panorama
