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Geomagnetic polarity epochs: Nunivak Island, Alaska

January 1, 1967

New paleomagnetic and potassium-argon dating measurements have been made of basalt flows from Nunivak Island, Alaska, with the following results. (1) The best estimate of the age of the Brunhes/Matuyama polarity epoch boundary is found to be 0.694 m.y. (2) The best estimate of the age of the Gauss/Gilbert boundary is 3.32 m.y. (3) Three normally magnetized flows with ages from 0.93 to 0.88 m.y. are in accord with previous estimates of the age and duration of the Jaramillo normal event. (4) One normally magnetized flow with an age of 1.65 ± 0.09 m.y. supplies additional evidence for the Gilsá normal event. (5) Two new normal events are identified within the Gilbert reversed epoch, the “Cochiti normal event” with an age of 3.7 m.y. and the “Nunivak normal event” with an age of 4.1 m.y.

Publication Year 1967
Title Geomagnetic polarity epochs: Nunivak Island, Alaska
DOI 10.1016/0012-821X(67)90031-3
Authors A. Cox, G. B. Dalrymple
Publication Type Article
Publication Subtype Journal Article
Series Title Earth and Planetary Science Letters
Index ID 70011610
Record Source USGS Publications Warehouse