QUICK-SET ROCK

No time to even finish your lunch!

Apparently there are 200 million fossils stored in museums worldwide and these are predominantly marine fossils recovered from the sedimentary rock which covers ¾ of Earth’s continental area ( plus most of the ocean floor). Scientists seem agreed that catastrophic flooding by sea water has occurred on all continents and that animals must have been rapidly buried in sediment to be preserved as fossils before disintegration occurred.
(Even children know this!)

So, do sedimentary rocks take millions of years to form? 

Actually, no. Cementing agents such as calcite (lime or Calcium Oxide) and/or silica (Silicon Dioxide) must be present with water; pressure facilitates the process by forcing out the water. 
These same agents are the major ingredients of Portland cement which has to have gypsum (Calcium Sulphate) added to.....SLOW the process.

How quickly can cement start to set?...after 15 minutes!

How quickly did Mt. St.Helens sediment turn rock hard?
In less than 5 years.

It's not rocket science...it's rock science!....that children easily understand.