%0 Journal Article
%A Osete López, María Luisa
%A Ruiz Martínez, Vicente Carlos
%A Caballero Miranda, Cecilia
%A Galindo Francisco, María Del Carmen
%A Urrutia Fucugauchi, Jaime
%A Tarling, Donald H.
%T Southward migration of continental volcanic activityin the Sierra de Las Cruces, Mexico:palaeomagnetic and radiometric evidence
%D 2000
%@ 0040-1951
%U https://hdl.handle.net/20.500.14352/56988
%X New Palaeomagnetic data for 30 sites (271 samples) and K–Ar data from five units in the Sierra de Las Cruces,western Basin of Mexico, provide constraints on the spatial-temporal evolution of arc magmatism in the centralTrans-Mexican Volcanic Belt. The normal and reversed directions show a polarity pattern with a consistent spatialzonation perpendicular to the NNW–SSE trend of the range. The magnetostratigraphy and K–Ar dates indicate thatvolcanic activity in the Sierra de Las Cruces migrated southeastward at a mean rate of 1.6 cm/a, between 3.6 and1.8 Ma, and that the rate of migration may have been higher, up to 4 cm/a, during the Gauss Chron. Normal andreversed directions pass the reversal test at a 95% confidence level. The mean Plio-Quaternary palaeomagneticdirection for Sierra de Las Cruces is D=350.7°, I=30.6° (N=25, k=30.7, α95=5.3°). The declination deviates to thewest of the expected direction, which suggests that small counterclockwise rotations could take place during formationof the Sierra de Las Cruces volcanics.
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