Mélanges and other types of block-in-matrix formations in the Cantabrian Zone (Variscan Orogen, northwest Spain): origin and significance
| Autor: | Angela Suárez, Alberto Marcos, Juan Luis Alonso Alonso, Luis Pedro Fernández, Elisa Villa, Oscar Merino-Tomé |
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| Rok vydání: | 2014 |
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| Zdroj: | International Geology Review. 57:563-580 |
| ISSN: | 1938-2839 0020-6814 |
| DOI: | 10.1080/00206814.2014.950608 |
| Popis: | Block-in-matrix formations in the Variscan foreland of Spain (Cantabrian Zone) occur in two different geological settings. The major block-in-matrix formations are melanges, which appear as carpets beneath or ahead of submarine thrust systems. These melanges may reach up to kilometric thickness and are mostly composed of broken formations (boudinaged sequences) of late Carboniferous age and scattered ‘exotic’ blocks derived from older Palaeozoic formations. Moreover, the melanges in the Cantabrian Zone also include subordinate debris flow deposits with a chaotic block-in-matrix fabric (olistostromes). The source of the melange blocks was the front of advancing nappes, chiefly the upper part of the nappe stacks. Therefore, the Cantabrian melanges are interpreted as originated through submarine sliding and slumping associated with steep slopes at the orogenic front. The different types of rock bodies of these melanges may be related to the degree of lithification of the sediments or rocks during slumping. S... |
| Databáze: | OpenAIRE |
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