Magnetostratigraphy of the lower Cretaceous strata in Tlayúa Quarry, Tepexi de Rodriguez, State of Puebla, Mexico
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2006
Received: 23 November 2005
Accepted: 11 May 2006
Published: 8 November 2006
A stratigraphic sequence of magnetic polarity reversals consisting of nine magnetozones is recognized in Early Cretaceous sedimentary strata in the Tlayúa Quarry of Tepexi de Rodriguez, state of Puebla. Combined with biostratigraphic age assignments using ammonites that apparently belonging to the Albian, the geomagnetic polarity sequence can be correlated with the middle part of chron C34n (C34n.1n-C34n.2n chrons, with an age of 100–105 Myr), the Cretaceous long normal interval. The magnetic properties and characteristic remanence of magnetization are dominated by soft and hard coercivity magnetic minerals. Rock-magnetic properties and a positive reversal test suggest that remanence is primary. The section displays both reverse and normal polarities with mean directions: D=344.9°, I=32.4°, k=21, a95=4.2° and D=149.4°, I=−36.6°, k=17, a95=8.7°, respectively. Comparison with the North American apparent polar wander path indicates tectonic stability of the region since the Cretaceous.