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Twohypothescsonoredepositshavcbeendevelopedinalmostthesamietimesince1970’s,inthetideoftheearthseiencerevolutionontheleadshipofcontinentdrift,occansprcadingandplatetceton-ics.Oneisstrataformandstrataboundorcdeposits,theanotherispolygcncticcompoundorcdcposi