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Sixteen Miocene, Pleistocene, and historic lava flows have been sampled in Lanzarote (Canary Islands) for paleointensity analysis with both the Coe and multispecimen methods. Besides obtaining new data, the main goal of the study was the comparison of paleointensity results determined with two different techniques. Characteristic Remanent Magnetization (ChRM) directions were obtained in 15 flows, and 12 were chosen for paleointensity determination. In Thellier-type experiments, a selection of reliable paleointensity determinations (43 of 78 studied samples) was performed using sets of criteria of different stringency, trying to relate the quality of results to the strictness of the chosen criteria. Uncorrected and fraction and domain-state corrected multispecimen paleointensity results were obtained in all flows. Results with the Coe method on historical flows either agree with the expected values or show moderately lower ones, but multispecimen determinations display a large deviation from the expected result in one case. No relation can be detected between correct or anomalous results and paleointensity determination quality or rock-magnetic properties. However, results on historical flows suggest that agreement between both methods could be a good indicator of correct determinations. Comparison of results obtained with both methods on seven Pleistocene flows yields an excellent agreement in four and disagreements in three cases. Pleistocene determinations were only accepted if either results from both methods agreed or a result was based on a sufficiently large number (n > 4) of individual Thellier-type determinations. In most Pleistocene flows, a VADM around 5 3 10

This paper presents new paleomagnetic results from 24 independent cooling units in Tequila area (western Trans-Mexican Volcanic Belt). These units were recently dated by means of state-of-the-art 40 Ar-39 Ar method (Lewis-Kenedy et al., 2005) and span from 1130 to 150 ka. The characteristic paleodirections are successfully isolated for 20 cooling units. The mean paleodirection, discarding intermediate polarity sites, is I = 29.6• ,• , n = 17, which corresponds to the mean paleomagnetic pole position P lat = 85.8• , P long = 84.3• , K = 27.5, A 95 = 6.9• . These directions are practically undistinguishable from the expected Plestocene paleodirections, as derived from reference poles for the North American polar wander curve and in agreement with previously reported directions from western Trans-Mexican Volcanic Belt. This suggests that no major tectonic deformation occurred in studied area since early-middle Plestocene to present. The paleosecular variation is estimated trough the study of the scatter of virtual geomagnetic poles giving S F = 15.4 with S U = 19.9 and S L = 12.5 (upper and lower limits respectively). These values are consistent with those predicted by the latitude-dependent variation model of McFadden et al. (1991) for the last 5 Myr. The interesting feature of the paleomagnetic record obtained here is the occurrence of an intermediate polarity at 671 ± 13 ka which may correspond the worldwide observed Delta excursion at about 680-690 ka. This gives the volcanic evidence of this event. Two independent lava flows dated as 362 ± 13 and 354 ± 5 ka respectively, yield transitional paleodirections as well, probably corresponding to the Levantine excursion.

We report an archeomagnetic study from the Early Iron Age archeological site of Cerro de San Vicente (Salamanca, Spain). The studied materials were sampled from one roundhouse and its central fireplace, a surrounding burnt floor, and slags with a twofold objective. First, to archeomagnetically determine the last use of the central fireplace, because dating with other methods was imprecise. Second, to retrieve information about the Earth's magnetic field in Western Europe from a period when the Levantine Iron Age Anomaly (LIAA) has been occasionally reported. This study includes mineralogical, archeomagnetic directional analyses, and multimethod archeointensity determinations. Paleomagnetic analyses of the central fireplace yield a mean direction: declination D = 15.1°, inclination I = 52.5°; k = 477.1, and α95 = 5.6°. Archeointensity determinations yield a mean anisotropy‐corrected archeointensity of 72.4 ± 2.0 μT (74.7 ± 4.3 μT if a pTRM‐check correction is applied) on the central fireplace and 48.2 ± 2.0 μT on slags. A full‐vector archeomagnetic dating was performed with the SHA.DIF.4k geomagnetic field model which yielded an age interval of last use of the central fireplace between 644 and 575 BCE (654–575 BCE with the pTRM‐check corrected data) at 95% confidence level. This date agrees with the archeological context. Results allows to place the high paleointensity obtained near the maximum observed in Iberia at this age, confirming the existence of this peak related to the LIAA in Western Europe where records of this feature are still scarce.

We report paleomagnetic, rock magnetic, and paleointensity studies for 24 volcanic lava flows from the Michoacan-Guanajuato volcanic field (MGVF), erupted between 2.27 Ma to present according to available radiometric ages and historic records. The MGVF located in the central-western sector of the Plio-Quaternary TransMexican volcanic belt is mainly composed by cinder cones and shield volcanoes. Rock magnetic experiments show remanence is carried in most cases by Ti-poor titanomagnetites, resulting from oxy-exsolution of original titanomagnetites during flow cooling. Unblocking temperature spectra and high coercivities point to "small" pseudo-single domain grains for the titanomagnetites. Single component, linear vector plots are obtained after alternating field and thermal demagnetization. Seven flows yield reverse polarity magnetization while sixteen flows are normally magnetized. The overall mean paleodirection obtained (with 14 flows normal and 6 flows reverse) is I=28.4• , D=357.9• , k=21, α 95 =7.3 • , with a paleomagnetic pole position of P lat =85.7• , P long =104.5• , K=27, A 95 =6.4• . The paleodirection is undistinguishable from expected Plio-Quaternary paleodirections derived from reference poles for the North American polar wander curve, and previously reported paleodirections for central Mexico. Paleointensity experiments give high quality results for only twelve samples from two flows with mean values of 7.3 and 8.1×1022 Am 2 , which are close to present geomagnetic field intensity. The combination of new MGVF directional results with currently available paleomagnetic data from central Mexico yield angular dispersion estimates of S F =15.4 with S U =19.6 and S L =12.7, which are in agreement with the latitude-dependent PSV model of McFadden et al. (1988McFadden et al. ( , 1991 for the last 5 Ma, and show no significant inclination anomaly.