Aggregate – sand and gravel, is an important geological resource for highways, buildings, bridges and water filtration systems. Early European settlers removed beach gravel for their fill and support needs but is no longer used because of environmental concerns. Today, crushed stone is the major aggregate used because of its high quality and low granular qualities.
Chedabucto Aggregates Limited crushes a sedimentary stone called metagraywache, pronounced meta-gray-wacky. This rock, a form of sandstone, has been hardened by metamorphism and makes excellent aggregate. Chedabucto’s stone is the northern tongue of a formation of sedimentary rock that begins at the southern coastline of Nova Scotia from the Atlantic Ocean near Goldboro to Chedabucto Bay.
This formation was a part of the Meguma Terrane that likely broke apart from South Eastern Europe or Africa during the period of continental drift about 390 million years ago. The Meguma Terrane slid into place against the Avalon Terrane from east to west and caused the sedimentary-layered stone to move from a horizontal to a vertical alignment.
In its history, the sedimentary formation has undergone several glacial periods that scoured and exposed the upper layers. The last glacial period around Chedabucto Bay ended approximately 12,500 year ago.