Unlike silicilastic sediments, where structures and textures reflect the physical factors in the depositional environment, the structures and textures of carbonate rocks commonly reflect intrabasinal, biological factors. The source for carbonate sediments is almost exclusively biological. Although carbonates form in colder water and more specialized settings such as 'hot' springs and caves, most thick buildups represent high organic accumulation in shallow, warm seas in areas removed from significant siliciclastic input .
Permanent ice is found at both poles, resulting in a strong equator to pole temperature gradient.
In addition to temperature, sea level and sedimentation rate play important roles in carbonate accumulation. Shallow epeiric seas were widespead over large parts of the North American craton throughout much of the Paleozoic and Mesozoic. Consequently, many areas of the North American craton were a broad shallow platform, remote from siliclastic input. This combination of low detrital sedimentation rates, high sea levels and a more southerly geographic position resulted in widespread deposition of carbonate sediments all over the North American craton. For example, the Devonian reefs of Alberta are of broad regional extent and host a large percentage of Canada's petroleum resources.