Detrital zircon (U‐Th)/(He‐Pb) double‐dating constraints on provenance and foreland basin evolution of the Ainsa Basin, south‐central Pyrenees, Spain

South central Pyrenean foreland basin fill preserves the eroded remnants of the early stages of fold‐thrust belt evolution and topographic growth. Specifically, the Eocene Hecho Group in the Ainsa Basin contains a succession of turbiditic channels and levees deposited in the transition zone between...

Full description

Saved in:
Bibliographic Details
Published in:Tectonics (Washington, D.C.) D.C.), 2017-07, Vol.36 (7), p.1352-1375
Main Authors: Thomson, Kelly D., Stockli, Daniel F., Clark, Julian D., Puigdefàbregas, Cai, Fildani, Andrea
Format: Article
Language:English
Subjects:
Basins
Cooling
Cretaceous
Ecological succession
Eocene
Evolution
foreland basin
Geological time
Growth
Levees
Mesozoic
Metamorphic rocks
Provenance
Pyrenees
Rifting
Rock
Sediment
Sediment sources
Sediments
Spectra
thermochronology detrital zircon double dating
Transition zone
Turbidites
Uplift
Zircon
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:South central Pyrenean foreland basin fill preserves the eroded remnants of the early stages of fold‐thrust belt evolution and topographic growth. Specifically, the Eocene Hecho Group in the Ainsa Basin contains a succession of turbiditic channels and levees deposited in the transition zone between the fluvial‐deltaic and deep marine depozones. Detailed isotopic provenance analyses allow for the reconstruction of sediment sources of the ancient sediment routing systems. This study presents 2332 new detrital zircon (DZ) U‐Pb ages and 246 new DZ double‐dated (U‐Th)/(He‐Pb) ages from 19 turbiditic and fluvio‐deltatic sandstones in the Ainsa Basin. These data indicate a progressive provenance shift from Cadomian/Caledonian plutonic and metamorphic rocks of the eastern Pyrenees to Variscan plutonic rocks in the central Pyrenees. Minor sediment contributions from sources located to the S and SE of the basin are seen throughout the section. New DZ (U‐Th)/He results identify four main cooling events: Pyrenean orogenesis (~56 Ma), initial basin inversion (~80 Ma), Cretaceous rifting (~100 Ma), and pre‐Mesozoic cooling ages related to earlier tectonic phases. This study imposes new constraints on the paleogeographic evolution of the Pyrenees and illustrates that high‐frequency fluctuations in sediment delivery processes and sediment routing introduce superimposed noise upon the basin‐scale long‐term provenance evolution during orogenesis. Key Points Pyrenean foreland basin sediment sources progressively evolved from east to west in response to diachronous uplift across the Pyrenees Sediment from nonorogenic sources are present throughout the Eocene deposits, from either first cycle or recycled from early foreland deposits Fluctuation of U‐Pb and (U‐Th)/He spectra indicates high‐frequency provenance changes superimposed over primary trends
ISSN:0278-7407
1944-9194
DOI:10.1002/2017TC004504