About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
Le Devonien de l’Espagne
There are two Devonian areas in Spain 1) Northern: consisting of the Cantabrian, Pyrenees, Iberic and Catalanian basins and 2) Southern: consisting of the Carpetian basins including those of Ciudad Real, Extremadura and Andalucia. From the Llandoverian to the Lower Couvinian the Iberic basin was linked to the Carpetian basin; from the Lower Couvinian on, the northern area was separated from the southern by a positive epeirogenesis which caused the Iberic and Catalanian basins to emerge.
Thus the Devonian deposits range from Lladloverian to Famennian in the Cantabrian, Pyrenees and Carpetian basins, but sedimentation was interrupted by hiatuses and complicated by sedimentary cycles and numerous lateral facies changes. The stratigraphic column has been worked out by the study of abundant brachiopod, trilobite, tetracoral and conodont faunas. The most extensive and characteristic facies are:
1) Ludlovian-Gedinnian: terrigenous facies composed of a twofold rhythm of sandstones and shales which are strongly developed in the western part of the Cantabrian, Iberic, Carpetian and western Pyrenees basins. This facies is absent in the centre and eastern part of the Pyrenees basin, and in Cataluna where the Gedinnian is progressively condensed from west to east until it almost disappears.
2) Siegenian-Emsian-Middle Couvinian: marine shelf facies with brachiopods, reefs and crinoids—the Cantabro-Iberic facies. Rhythmic sequences of lime mudstones with biostromes and bioherms. The reefs are concentrated in the west and are not present in the east or in Cataluna.
3) Upper Couvinian to Givetian: a terrigenous facies at the base correlating with the epeirogenesis which raised the Iberic and Catalanian basins followed by rhythmic sequences of lime mudstones in the Cantabrian basin and pelagic facies in the central Pyrenees. There is an impoverishment in the faunas from west to east in the Pyrenees. In the Carpetian basin detrital terrigenous faunas return.
4) Frasnian-Famennian: in the north there is a development of neritic to pelagic facies with cephalopods called the “griotte limestone.” In the Carpetian area there is a terrigenous facies with brachiopods.
Towards the southern part of the Carpetian region, at Huelva, there was probably an area of pelagic mudstone sedimentation, but this is little known owing to the absence of diagnostic fauna.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
|Watermarked PDF Document: $14|
|Open PDF Document: $24|