Paleomagnetic results of Tertiary sediments from Corsica: evidence of post-Eocene rotation

Abstract

Middle Eocene (Lutetian) and Lower to Middle Miocene (Burdigalian-Langhian) sediments from Corsica have been investigated in a paleomagnetic study to constrain the amount and timing of tectonic rotation of the Corsican block with respect to Sardinia and stable Eurasia. The sediments are generally characterized by weak and unstable magnetization, and only five Eocene and five Miocene sites out of 23 sites sampled provided interpretable data. Our best estimate for the Eocene paleomagnetic field for Corsica suggests ∼ 37° of counter-clockwise rotation, and no latitudinal change, with respect to stable Eurasia in post-Eocene time. This is similar to the amount of tectonic rotation documented from Oligo-Miocene volcanics from Sardinia, which is therefore consistent with Corsica and Sardinia being part of the same tectonic block since at least the early to middle Tertiary. Paleomagnetic results from the Miocene sites may represent remagnetizations but the presence of reversed polarity magnetization at three of the five accepted sites indicates acquisition before the late Pleistocene. The final rotation history of Corsica nevertheless is left unresolved