Rock magnetic and paleointensity results from Mesozoic baked contacts of Armenia

V. V. Shcherbakova (1) , Mireille M. Perrin (2) , V. P. Shcherbakov (1) , V. E. Pavlov (3) , A. Ayvaz'Yan (4) , G. V. Zhidkov (1)

1 BGO - Borok Geophysical Observatory
2 Géosciences Montpellier
3 IPE - Schmidt United Institute of Physics of the Earth [Moscow]
4 Yerevan State University

Samples were obtained from three baked contacts and one lava flow along the upper Turonian-lower Coniacian Tovuz section, two baked contacts along the upper Coniacian-lower Santonian Paravakar section in the northern part of Armenia, and three baked contacts along the Titonian-Valanginian Kafan section in southern Armenia. A total of 130 samples were studied. Updated mean paleomagnetic poles were calculated for the Upper Cretaceous Tovuz-Paravakar sections (65.6 degrees N, 162.2 degrees E, A(95) = 4.3, paleolatitude = 27.0 +/- 3.4 degrees) and the Upper Jurassic-Lower Cretaceous Kafan section (61.7 degrees N, 158.9 degrees E, A(95) = 4.8 degrees, paleolatitude = 24.7 +/- 3.8 degrees). Paleointensity determinations could be estimated from two of the upper Cretaceous and three of the Upper Jurassic-Lower Cretaceous baked contacts, corresponding to a 30% success rate. The mean virtual dipole moments obtained were low (1.7-5.5 x 10(22) A m(2)), which is in agreement with data published by Bol'shakov and Solodovnikov (1981a, 1983) for the same sections (3.0-4.4 x 10(22) A m(2)). Our results support the hypothesis of the Mesozoic Dipole Low, even though the overall data arc widely dispersed.

Mots clés: Paleointensity; Armenia; Cretaceous; baked contacts; Thellier method

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

V. V. Shcherbakova, Mireille M. Perrin, V. P. Shcherbakov, V. E. Pavlov, A. Ayvaz'Yan, et al.. Rock magnetic and paleointensity results from Mesozoic baked contacts of Armenia. Earth Planets and Space, 2009, 61 (1), pp.23-39. ⟨10.1186/BF03352882⟩. ⟨hal-00413047⟩