RT Journal Article
T1 Evaporitic constraints on the southward drifting of the western Gondwana margin during Early Cambrian times
A1 Álvaro, J.J.
A1 Rouchy, J.M.
A1 Bechstädt, T.
A1 Boucot, A.
A1 Boyer, F.
A1 Debrenne, F.
A1 Moreno González De Eiris, Elena
A1 Perejón, A.
A1 Vennin, E.
AB Lower Cambrian evaporites and carbonates are reported from nearly all the platforms of the western Gondwana margin, which comprises the Souss, Ossa–Morena, Cantabro-Iberian, Armorican and Montagne Noire–Sardinian Basins. Both lithologies were deposited in climatically restricted belts and their changing palaeogeographic distributions, according to recent biostratigraphic correlations, are used to infer the latitudinal motion of this margin. As a result, the time span involved in the Cordubian–Ovetian–Marianian interval (8–10 m.y.) requires a relative high rate of drifting, which supports the high apparent polar wander path rates (defined by palaeomagnetic data) proposed for Early Palaeozoic times. The varied and abundant relics of primary to early diagenetic evaporites (gypsum, anhydrite and halite) demonstrate that extensive evaporitic conditions were associated with carbonate and mixed platform systems in an Early Cambrian arid subtropical belt. Evaporites were originally more abundant than suggested by the reported remains because the deposits have undergone a multistep diagenesis that erased most of the former morphologies. Some petrographic criteria are proposed for recognizing silica pseudomorphs after evaporites, such as the development of ‘chicken-wire’ and enterolithic structures, and the presence of lenticular to lozenge-shaped crystals of gypsum and anhydrite relics.
PB Elsevier
SN 0031-0182
YR 2000
FD 2000
LK https://hdl.handle.net/20.500.14352/103671
UL https://hdl.handle.net/20.500.14352/103671
LA eng
NO Álvaro, J.J., Rouchy, J.M., Bechstädt, T., Boucot, A., Boyer, F., Debrenne, F., Moreno-Eiris, E., Perejón A. y Vennin, E (2000): "Evaporitic constraints on the southward drifting of the western Gondwana margin during Early Cambrian times", Palaeogeography, Palaeoclimatology, Palaeoecology, 160 (1-2), pp. 105-122. Disponible en: https://doi.org/10.1016/S0031-0182(00)00061-4
DS Docta Complutense
RD 8 abr 2025