Magnetostratigraphy and detrital apatite fission track thermochronology in syntectonic conglomerates: Constraints on the exhumation of the South-Central Pyrenees

Elisabet Beamud, Josep Anton Muñoz, Paul G Fitzgerald, Suzanne L Baldwin, Miguel Garcés, Lluis Cabrera, James R. Metcalf

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

The syntectonic continental conglomerates of the South-Central Pyrenees record the late stages of thin-skinned transport of the South-Pyrenean Central Units and the onset of exhumation of the Pyrenean Axial Zone (AZ) in the core of the orogen. New magnetostratigraphic data of these syntectonic continental conglomerates have established their age as Late Lutetian to Late Oligocene. The data reveal that these materials were deposited during intense periods of tectonic activity of the Pyrenean chain and not during the cessation of the deformation as considered previously. The magnetostratigraphic ages have been combined with new detrital apatite fission track (AFT) thermochronology from AZ-derived granite cobbles within the syntectonic conglomerates. Distribution of the granitic cobbles with different AFT ages and track lengths combined with their depositional ages reveal information on the timing and rate of episodes of exhumation in the orogen. Some AFT ages are considerably older than the AFT ages of the outcropping AZ granitic massifs, indicating erosion from higher crustal levels within the massifs than presently exposed or from completely eroded plutons. Inverse thermal modelling reveals two well-defined periods of rapid cooling in the hinterland at ca. 50-40 and ca. 30-25Ma, with another poorly defined cooling episode at ca. 70-60Ma. The lowest stratigraphic samples experienced postburial annealing caused by the deposition of younger syntectonic sediments during progressive burial of the south Pyrenean thrust and fold belt. Moreover, samples from the deeper stratigraphic levels also reveal postorogenic cooling during the Late Miocene as a response to the excavation of the Ebro River towards the Mediterranean Sea. Our data strongly support previous ideas about the burial of the South Pyrenean fold and thrust belt by Late Palaeogene syntectonic conglomerates and their subsequent re-excavation and are consistent with other thermochronological data and thermal modelling from the interior part of the orogen.

Original languageEnglish (US)
Pages (from-to)309-331
Number of pages23
JournalBasin Research
Volume23
Issue number3
DOIs
StatePublished - Jun 2011

Fingerprint

thermochronology
magnetostratigraphy
exhumation
conglomerate
apatite
fold and thrust belt
cooling
syntectonic sediment
excavation
Lutetian
annealing
Paleogene
modeling
pluton
Oligocene
granite
Miocene
erosion
tectonics
river

ASJC Scopus subject areas

  • Geology

Cite this

Magnetostratigraphy and detrital apatite fission track thermochronology in syntectonic conglomerates : Constraints on the exhumation of the South-Central Pyrenees. / Beamud, Elisabet; Muñoz, Josep Anton; Fitzgerald, Paul G; Baldwin, Suzanne L; Garcés, Miguel; Cabrera, Lluis; Metcalf, James R.

In: Basin Research, Vol. 23, No. 3, 06.2011, p. 309-331.

Research output: Contribution to journalArticle

@article{5ddcc11682cd4501b4a9fe5ea7b8b6be,
title = "Magnetostratigraphy and detrital apatite fission track thermochronology in syntectonic conglomerates: Constraints on the exhumation of the South-Central Pyrenees",
abstract = "The syntectonic continental conglomerates of the South-Central Pyrenees record the late stages of thin-skinned transport of the South-Pyrenean Central Units and the onset of exhumation of the Pyrenean Axial Zone (AZ) in the core of the orogen. New magnetostratigraphic data of these syntectonic continental conglomerates have established their age as Late Lutetian to Late Oligocene. The data reveal that these materials were deposited during intense periods of tectonic activity of the Pyrenean chain and not during the cessation of the deformation as considered previously. The magnetostratigraphic ages have been combined with new detrital apatite fission track (AFT) thermochronology from AZ-derived granite cobbles within the syntectonic conglomerates. Distribution of the granitic cobbles with different AFT ages and track lengths combined with their depositional ages reveal information on the timing and rate of episodes of exhumation in the orogen. Some AFT ages are considerably older than the AFT ages of the outcropping AZ granitic massifs, indicating erosion from higher crustal levels within the massifs than presently exposed or from completely eroded plutons. Inverse thermal modelling reveals two well-defined periods of rapid cooling in the hinterland at ca. 50-40 and ca. 30-25Ma, with another poorly defined cooling episode at ca. 70-60Ma. The lowest stratigraphic samples experienced postburial annealing caused by the deposition of younger syntectonic sediments during progressive burial of the south Pyrenean thrust and fold belt. Moreover, samples from the deeper stratigraphic levels also reveal postorogenic cooling during the Late Miocene as a response to the excavation of the Ebro River towards the Mediterranean Sea. Our data strongly support previous ideas about the burial of the South Pyrenean fold and thrust belt by Late Palaeogene syntectonic conglomerates and their subsequent re-excavation and are consistent with other thermochronological data and thermal modelling from the interior part of the orogen.",
author = "Elisabet Beamud and Mu{\~n}oz, {Josep Anton} and Fitzgerald, {Paul G} and Baldwin, {Suzanne L} and Miguel Garc{\'e}s and Lluis Cabrera and Metcalf, {James R.}",
year = "2011",
month = "6",
doi = "10.1111/j.1365-2117.2010.00492.x",
language = "English (US)",
volume = "23",
pages = "309--331",
journal = "Basin Research",
issn = "0950-091X",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Magnetostratigraphy and detrital apatite fission track thermochronology in syntectonic conglomerates

T2 - Constraints on the exhumation of the South-Central Pyrenees

AU - Beamud, Elisabet

AU - Muñoz, Josep Anton

AU - Fitzgerald, Paul G

AU - Baldwin, Suzanne L

AU - Garcés, Miguel

AU - Cabrera, Lluis

AU - Metcalf, James R.

PY - 2011/6

Y1 - 2011/6

N2 - The syntectonic continental conglomerates of the South-Central Pyrenees record the late stages of thin-skinned transport of the South-Pyrenean Central Units and the onset of exhumation of the Pyrenean Axial Zone (AZ) in the core of the orogen. New magnetostratigraphic data of these syntectonic continental conglomerates have established their age as Late Lutetian to Late Oligocene. The data reveal that these materials were deposited during intense periods of tectonic activity of the Pyrenean chain and not during the cessation of the deformation as considered previously. The magnetostratigraphic ages have been combined with new detrital apatite fission track (AFT) thermochronology from AZ-derived granite cobbles within the syntectonic conglomerates. Distribution of the granitic cobbles with different AFT ages and track lengths combined with their depositional ages reveal information on the timing and rate of episodes of exhumation in the orogen. Some AFT ages are considerably older than the AFT ages of the outcropping AZ granitic massifs, indicating erosion from higher crustal levels within the massifs than presently exposed or from completely eroded plutons. Inverse thermal modelling reveals two well-defined periods of rapid cooling in the hinterland at ca. 50-40 and ca. 30-25Ma, with another poorly defined cooling episode at ca. 70-60Ma. The lowest stratigraphic samples experienced postburial annealing caused by the deposition of younger syntectonic sediments during progressive burial of the south Pyrenean thrust and fold belt. Moreover, samples from the deeper stratigraphic levels also reveal postorogenic cooling during the Late Miocene as a response to the excavation of the Ebro River towards the Mediterranean Sea. Our data strongly support previous ideas about the burial of the South Pyrenean fold and thrust belt by Late Palaeogene syntectonic conglomerates and their subsequent re-excavation and are consistent with other thermochronological data and thermal modelling from the interior part of the orogen.

AB - The syntectonic continental conglomerates of the South-Central Pyrenees record the late stages of thin-skinned transport of the South-Pyrenean Central Units and the onset of exhumation of the Pyrenean Axial Zone (AZ) in the core of the orogen. New magnetostratigraphic data of these syntectonic continental conglomerates have established their age as Late Lutetian to Late Oligocene. The data reveal that these materials were deposited during intense periods of tectonic activity of the Pyrenean chain and not during the cessation of the deformation as considered previously. The magnetostratigraphic ages have been combined with new detrital apatite fission track (AFT) thermochronology from AZ-derived granite cobbles within the syntectonic conglomerates. Distribution of the granitic cobbles with different AFT ages and track lengths combined with their depositional ages reveal information on the timing and rate of episodes of exhumation in the orogen. Some AFT ages are considerably older than the AFT ages of the outcropping AZ granitic massifs, indicating erosion from higher crustal levels within the massifs than presently exposed or from completely eroded plutons. Inverse thermal modelling reveals two well-defined periods of rapid cooling in the hinterland at ca. 50-40 and ca. 30-25Ma, with another poorly defined cooling episode at ca. 70-60Ma. The lowest stratigraphic samples experienced postburial annealing caused by the deposition of younger syntectonic sediments during progressive burial of the south Pyrenean thrust and fold belt. Moreover, samples from the deeper stratigraphic levels also reveal postorogenic cooling during the Late Miocene as a response to the excavation of the Ebro River towards the Mediterranean Sea. Our data strongly support previous ideas about the burial of the South Pyrenean fold and thrust belt by Late Palaeogene syntectonic conglomerates and their subsequent re-excavation and are consistent with other thermochronological data and thermal modelling from the interior part of the orogen.

UR - http://www.scopus.com/inward/record.url?scp=79955013104&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79955013104&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2117.2010.00492.x

DO - 10.1111/j.1365-2117.2010.00492.x

M3 - Article

AN - SCOPUS:79955013104

VL - 23

SP - 309

EP - 331

JO - Basin Research

JF - Basin Research

SN - 0950-091X

IS - 3

ER -