A period within the Paleozoic era, 440 to 400 million years ago
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Tag: <span>S</span>
Settled concentrations of sediment usually under an aqueous body
An orthorhombic, trimorphous mineral, Al2SiO5
A mass of igneous rock intruding between older rock strata
A chemical agent used to liquefy gold and silver for the purpose of refinement or possible transportation
A mass of igneous rock intruding between older rock strata
A soft, light alkaline element. Symbol, Na
A light non-metallic element. Symbol, Si
Sodium carbonate, Na2CO3
A rock whose major constituent is quartz