Niagara period : A subdivision or the American Upper Silurian system, embracing the Medina, Clinton, and Niagara epoch. The rocks of the Niagara epoch, mostly limestones, are extensively distributed, and at Niagara Falls consist of about eighty feet of shale supporting a greater thickness of limestone, which is gradually undermined by the removal of the shale. See Chart of Geology.

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Niagara, dictionary, encyclopedia, online dictionary, thesaurus browser, Free Online Dictionary, epoch, English dictionary, limestones, shale, free online English dictionary, Medina, Niagara Falls, Niagara Regional Police, Translations, law, explanation, Acronyms.

Defination from the web:
Niagara period in the Online Dictionary. Meaning of Niagara period. Pronunciation of Niagara period. Translations of Niagara period. ... The rocks of the Niagara epoch, mostly limestones, are extensively distributed, and at Niagara Falls consist of about eighty feet of shale ...