I live in Kingston, Ontario (The Limestone City). I have always been fascinated by the different thicknesses of strata in the exposed formations. I am wondering if there is any quick and fast rule of thumb as to how long it takes to form a limestone strata or layer. 1" (2.5cm) over 10 000 years? Over 100 000 years? Longer? I realize that there are many variables involved - depth of water, temperature etc. So if I look at a meter thick layer, can I tell, generally speaking, how long it took to form that layer. Thanks in advance


1 Answer 1


There is no general rule.

Depositon of limestone is the outcome of biologic activity and that depends on climate cycles. There are a few special cases where it is thought that Milankovitch cycles have played a role in the building of alternating limestone layers. Those are climate cycles induced by oscillations in earth's orbital parameters.

An example is the Upper Jurassic in SW Germany, and possibly the French Jura and its continuation in the North American East. Random foto. The cycles there are long term (40ky or 100ky) and the layers are 10 to 80cm thick. https://www.sciencedirect.com/science/article/abs/pii/S0037073802003792.

Other examples for Milankovitch cycles in the sediment record exist, e.g. in the Permian, and surely more.

I don't know about the conditions in your area. A brief search reveals that the limestone is Ordovician, and part of a unit named Black River Group. Maybe you can find specific publications, analyses of trace or other indicative fossils, if it is not too mangled ... idk.


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