Geophysical Resea ch Abs ac s
Vol. 15, EGU2013-7105, 2013
EGU Gene al Assembly 2013
© Au ho (s) 2013. CC A ibu ion 3.0 License.
Combined K-A and 40A /39A da ing o he uppe Ja amillo e e sal
He e Guillou (1), Juan Ca los Ca acedo (2), Ca he ine Kissel (1), Ca lo Laj (1), Sebas ien Nomade (1),
F ancisco Jose Pe ez To ado (2), Alejand o Rod iguez Gonzalez (2), and Camille Wand es (1)
(1) LSCE-CEA-CNRS-UVSQ-IPSL, F ance, (2) Uni e sidad de Las Palmas de G an Cana ia - Espana
The Ja amillo subch on was i s e idenced in 1966 (Doell and Dal ymple) h ough he Rhyolo ic domes o he
Valles Calde a, New Mexico (USA). 40A /39A s udies achie ed by Spell e McDougall (1992), Spell e Ha ison
(1993), Ize and Ob ado ich (1994) and Singe e al. (1994) de ined he base o his subch on a 1053±6 ka,
and he ceiling a 986±5 ka. Channell e al. (2009) delimi ed he age o he Ja amillo subch on by as onomic
calib a ion (base 1071 ka, op 990 ka).
To p o ide addi ional absolu e ages on his geomagne ic pe iod, which is c i ical o imp o e ou knowledge o
he ea h magne ic ield beha iou , we ha e ca ied ou a s udy combining paleomagne ism and iso opic da ing
o a la a sequence om Tene i e island. This sequence o basal ic la a lows is some 500 m hick. The i s 400
m p esen , based on ield magne ome e measu emen s, no mal pola i y la as, wi h dykes o no mal and e e se
pola i y, passing a he op o e e se pola i y la as. P elimina y K-A ages b acke ed his sequence be ween 1018
±18 ka and 978 ±17 ka. The e o e, he uppe Ja amillo e e sal a leas appea ed o be po en ially eco ded in
his sequence. A mo e de ailed paleomagne ic s udy was hen ca ied ou o mo e p ecisely delimi he e e sal
i sel (see Laj e al., session EMRP3.4). We ha e unde aken 40A /39A inc emen al hea ing and unspiked K-A
expe imen s on g oundmass om ou ansi ionally magne ized lows. The i s ansi ional low is K-A da ed
a 993 ±18 ka and 40A /39A da ed a 991 ±13 ka, he second a 981 ±17 ka (K-A ) and 1000 ±13 ka
(40A /39A ), he hi d a 950 ±17 ka (K-A ) and 1000 ±8 ka (40A /39A ) and he ou h a 984 ±17 ka (K-A )
and 977 ±12 (40A /39A ). 40A /39A ages and K-A ages ( ela i e o FCT 28.02 Ma) a e indis inguishable a
2σ. The age o he uppe bounda y o he Ja amillo e en calcula ed combining 40A /39A ages and K-A ages is
992 ±6 ka, in ag eemen wi h p e ious es ima es.