Tectonothermal analysis of a major unit of the Cantabrian Zone: the Ponga unit (Variscan belt, NW Spain)

The paleothermometric evolution of the Ponga unit at the core of the Cantabrian Zone, the arcuate foreland fold and thrust belt of the Variscan orogen in NW Spain, is analyzed using the conodont Color Alteration Index and the Kübler Index of illite. The results indicate that the distribution of the...

Full description

Saved in:
Bibliographic Details
Published in:International journal of earth sciences : Geologische Rundschau 2018-11, Vol.107 (8), p.2727-2740
Main Authors: García-López, Susana, Voldman, Gustavo G., Bastida, Fernando, Aller, Jesús
Format: Article
Language:English
Subjects:
Basins
Carboniferous
Colour
Diagenesis
Earth and Environmental Science
Earth Sciences
Evolution
Fluids
Geochemistry
Geology
Geophysics/Geodesy
Heat flow
Heat transmission
Illite
Illites
Metamorphic rocks
Metamorphism
Metamorphism (geology)
Mineral Resources
Original Paper
Permian
Sedimentology
Stratigraphy
Structural Geology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The paleothermometric evolution of the Ponga unit at the core of the Cantabrian Zone, the arcuate foreland fold and thrust belt of the Variscan orogen in NW Spain, is analyzed using the conodont Color Alteration Index and the Kübler Index of illite. The results indicate that the distribution of the thermal maturity patterns is independent of the stratigraphy and the structure of the unit. These include the occurrence of dominant diagenetic values and very low-to-low-grade metamorphism in the southern area. The main thermal event is interpreted to be related to hydrothermal fluids ascending through late-Variscan extensional faults. The anomalous high heat flow in the southern sector of the Ponga unit is part of a previously identified large band in the Cantabrian Zone, where the common occurrence of low-grade metamorphic rocks, hydrothermal dolostones, and ore mineralizations is related to an extensional orogenic episode that started near the Carboniferous–Permian boundary, soon after the closure of the Asturian arc.
ISSN:1437-3254
1437-3262
DOI:10.1007/s00531-018-1623-9