Amazing - Things seem to have returned to the original topic area.
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I'm by no means a limestone expert, but as I understand it, most limestone is of direct or indirect biogenic origin. More life yields more limestone.
Now, limestone and carbonate is not unheard of in the preCambrian. But my understanding is that the abundant production of limestone started after the preCambrian.
The geology cliche is "Limestone means that nothing was happening". This "nothing" refers to area tectonic activity, and the detrital sediments that result from the tectonic activity. In other words, you get limestones because your are in an area that was not receiving any sand, silt, or clay input. Limestone by default.
Moose