During this period, which lasted from 125,000 to 70,000 years ago, the climates in Nova Scotia fluctuated from as warm as Georgia to as cold as northern Quebec. During the last cold phase of the interglacial, mastodons roamed Nova Scotia, and one fell in some muck in a sink hole and died. Later, glaciers passed over the quarry several times depositing several layers of boulder-clay or till. Click for a location map . Since the quarry opened in 1954 many geologists have made observations at the site.
Quaternary sediments rest on and infill a karst gypsum bedrock surface.
The karst is manifest as steep-walled, scoured, linear and ovoid channels varying from a few metres to 10s of metres in depth. Veinlets of gypsum penetrate this unit which, although not directly dated, is Cretaceous in age, based on fossil pollen and lithic similarity to lignite, kaolinitic clay and silica sand deposits at Gays River, Shubenacadie and Musquodoboit in the Hants Lowlands. The lowest till is called the Miller Creek Till, named from a type locality in a gypsum quarry near Windsor, Nova Scotia. Till underlies a thick peat and wood layer that has a soil developed on it suggesting an interglacial interval of some unknown duration. Within the karst sinkholes the apparent stratigraphic relations are unclear because of mixing due to solution collapse or subglacial deformation.