Evidence for geomagnetic excursions recorded in Brunhes and Matuyama Chron lavas from the trans‐Mexican volcanic belt

Abstract

[1] This study presents paleomagnetic data from 59 independent lava flows from the trans-Mexican volcanic belt (TMVB) with ages from 6.4 Ma to recent, 52 being younger than 1 Ma, and 11 new 40 Ar/ 39 Ar age determinations. Most remanence carriers are Ti-poor titanomagnetite of pseudosingle-domain magnetic structure, nine lavas contain small amounts of titanomaghemite, and four lavas additional (titano-) hematite. Paleosecular variation of lava flows younger than 1.7 Ma is consistent with latitude-dependent Model G and also in agreement with other Pleistocene paleomagnetic data from the TMVB. The directional record of Brunhes and Matuyama Chrons lavas was correlated to the geomagnetic polarity timescale and there is evidence for at least four geomagnetic excursions. One lava flow dated at 592 AE 20 ka has a fully reversed paleodirection and most likely erupted during the Big Lost excursion. Another fully reversed flow, dated at 671 AE 12 ka, gives new volcanic evidence for the Delta/Stage 17 excursion. This excursion is supported by a reversed intermediate direction of another flow from a different volcanic field but of very close age of 673 AE 10 ka. From the Matuyama age lavas, one flow with normal polarity magnetization, dated at 949 AE 37 ka, could either be related to the Kamikatsura or the Santa Rosa excursion and a normal polarity flow, dated at 1628 AE 56 ka, could have been emplaced during the Gilsa excursion. The results presented here confirm in one case but disagree in four cases with results presented in two previous studies of the same lava flows and interpreted as geomagnetic excursions.

Paleomagnetic record determined in cores from deep research wells in the Quaternary Santa Clara basin, California

“…Evidence for three excursions in the age range of our interest (Fig. 3) was reported by Michalk et al (2013) from the trans-Mexican volcanic belt. These may correspond to the Big Lost, the Kula-Santa Rosa, and a previously unreported excursion from western North America ca.…”

New chronology of the best developed loess/paleosol sequence of Hungary capturing the past 1.1 ma: Implications for correlation and proposed pan-Eurasian stratigraphic schemes

“…The formerly unidentified polarity zones were determined. These new and previously interpreted paleomagnetic excursions were recorrelated with the global geomagnetic polarity timescale (GITS) presented in Michalk et al (2013) and Singer et al (2014) compiled from their and other authors' datasets (Langereis et al, 1997.;Nowaczyk and Frederichs, 1999;Nowaczyk and Knies, 2000;Lund et al, 2001Lund et al, , 2006Singer, 2007Singer, , 2014Singer et al, 2002Singer et al, , 2008aSinger et al, , 2008bSinger et al, , 2014. In addition, the paleomagnetic record of the latest INQUA 2016 Global chronostratigraphical correlation table for the past 2.7 ma was used as well (Cohen and Gibbard, 2016).…”

“…It is the cornerstone of future correlation with other regional and extraregional records, as well as the assessment of temporal variation of mass accumulation rates and paleoclimatic cycles. Availability of new marine (Lisiecki and Raymo, 2005) and terrestrial proxy reference records (Liu et al, 1987(Liu et al, , 1988Lu et al, 2004;Guo et al, 2009a;b;Sun et al, 2009;Wu and Wu, 2011;Zhou et al, 2014) as well as geomagnetic intensity timescales (Michalk et al, 2013;Singer et al, 2014) called for a revision as well.…”

La Sucesión Volcánica Carmichael del Bloque Jalisco, México: Magnetoestratigrafía e implicaciones tectónicas

“…En México, la mayoría de los estudios paleomagnéticos se concentran en la Faja Volcánica Transmexicana (FVTM), teniendo algunos resultados contradictorios desde el punto de vista paleomagnético y sus implicaciones tectónicas, p.e. Goguitchaichvili et al (2004), Michalk et al (2013) y Cervantes-Solano et al (2017.…”