We report new paleomagnetic and structural data from late Cretaceous to Mio-Pliocene continental sandy/silty sedimentary rocks from the Eastern Cordillera (central Andes). Here, N–S to NNE– SSW ridges hosting Paleozoic basement and upper Cretaceous continental red beds overthrust thick adjacent Cenozoic basins. Pretilting (and likely primary) reliable directions gathered at 15 sites document 45.9 ± 9.4, 30.1 ± 23.9, and 15.4 ± 19.3 clockwise (CW) rotations with respect to South America occurring after the late Cretaceous (80 Ma), Oligo-Miocene (20–30 Ma), and late Miocene- Pliocene (5–10 Ma), respectively. Conversely, four upper Cretaceous sites from the walls of a N–S leftlateral strike-slip fault (Yavi–Abra Pampa fault) yield a null rotation. About 20 km to the west, flower structures and subvertical syntectonic strata dated at 14.26 ± 0.19 Ma are exposed along the subparallel Abra Moreta left-lateral strike-slip fault. Relying on data from the literature on the period when deformation began, we suggest that since Eo-
Maffione, M., F., S., Faccenna, C., A., C., G., V., AND L., S. (2008). A synchronous Alpine and Corsica-Sardinia rotation. JOURNAL OF GEOPHYSICAL RESEARCH, 113 [10.1029/2007JB005214].
A synchronous Alpine and Corsica-Sardinia rotation
FACCENNA, CLAUDIO;
2008-01-01
Abstract
We report new paleomagnetic and structural data from late Cretaceous to Mio-Pliocene continental sandy/silty sedimentary rocks from the Eastern Cordillera (central Andes). Here, N–S to NNE– SSW ridges hosting Paleozoic basement and upper Cretaceous continental red beds overthrust thick adjacent Cenozoic basins. Pretilting (and likely primary) reliable directions gathered at 15 sites document 45.9 ± 9.4, 30.1 ± 23.9, and 15.4 ± 19.3 clockwise (CW) rotations with respect to South America occurring after the late Cretaceous (80 Ma), Oligo-Miocene (20–30 Ma), and late Miocene- Pliocene (5–10 Ma), respectively. Conversely, four upper Cretaceous sites from the walls of a N–S leftlateral strike-slip fault (Yavi–Abra Pampa fault) yield a null rotation. About 20 km to the west, flower structures and subvertical syntectonic strata dated at 14.26 ± 0.19 Ma are exposed along the subparallel Abra Moreta left-lateral strike-slip fault. Relying on data from the literature on the period when deformation began, we suggest that since Eo-I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
