Publication | Closed Access
Radiometric age of the Monograptus cyphus graptolite zone in Southeastern Alaska — an estimate of the age of the Ordovician—Silurian boundary
21
Citations
14
References
1977
Year
Southeastern Alaska —Paleoenvironmental ReconstructionEngineeringBiogeographyOrdovician—silurian BoundaryGeographyBiochronologySoutheastern Alaska YieldMinimum AgeRadiometric AgeQuaternary ResearchGeochronologyPaleoecologyMonograptus CyphusEarth ScienceSocial SciencesQuaternary Period
Summary K—Ar age measurements on Esquibel Island, southeastern Alaska yield a minimum age of about 433±3 Ma for the Zone of Monograptus cyphus of the Lower Silurian. An age of approximately 435—437 Ma is estimated for the Ordovician—Silurian boundary.
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