Paleomagnetic study of the Cretaceous Morelos Formation, Guerrero State, southern Mexico
Por:
Urrutia-fucugauchi J.
Publicada:
1 ene 1988
Resumen:
Paleomagnetic results are reported for a ~ 30 m thick limestone section of the Albian-Cenomanian Morelos Formation, Guerrero State, in southern Mexico (-17.75 °N, 99.50° W). Seventy-two specimens from 35 samples were subjected to detailed alternating field (AF) or thermal demagnetizations. Most specimens were stable and presented a single magnetization component remaining after removal of low-coercivity, low-blocking temperature components. End-point and vector analyses give a mean direction and pole position after structural correction (dip ~ 14°) of D = 332.7°, I = 46.8°, k = 215, ?95 = 4° and 63° N, 198° E (dp = 3, dm = 5), respectively. The pole position agrees with mid-Cretaceous poles reported for cratonic North America, suggesting that the area was already keeping a similar latitudinal position relative to the North American craton by mid-Cretaceous time. Most samples present normal polarity, as expected within the Cretaceous normal interval, but four samples from a single bed present intermediate and reverse polarity, suggesting the occurrence of a reverse event during the late Albian-earliest Cenomanian. © 1988.
Filiaciones:
Urrutia-fucugauchi J.:
Laboratorio de Paleomagnetismo y Geofisica Nuclear, Instituto de Geofisica, Universidad Nacional Autónoma de México, D. Coyoacan, 04510 D.F, Mexico
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