RT journal article
T1 Insights in the exhumation history of the NWZagros frombedrock and detrital apatite fission-track analysis: evidence for a long-lived orogeny
A1 Homke, S.
A1 Vergés, J.
A1 van der Beek, P.
A1 Fernández, M.
A1 Saura, E.
A1 Badics, B.
A1 Labrin, E.
A1 Barbero González, Luis Carlos
A2 Ciencias de la Tierra
K1 thermochronology
AB We present the ¢rst ¢ssion-track (FT) thermochronology results for theNWZagrosBelt (SWIran) inorder to identify denudation episodes that occurred during the protracted Zagros orogeny. Sampleswere collected from the two main detrital successions of the NWZagros foreland basin: thePalaeocene^early Eocene Amiran^Kashkan succession and theMiocene Agha Jari and BakhtyariFormations. In situ bedrock samples were furthermore collected in the Sanandaj-Sirjan Zone. Onlyapatite ¢ssion-track (AFT) data have been successfully obtained, including 26 ages and11track-lengthdistributions. Five families of AFTages have been documented from analyses of in situ bedrock anddetrital samples: pre-middle Jurassic at  171 and  225Ma, early^late Cretaceous at  91Ma,Maastrichtian at  66Ma,middle^late Eocene at  38Ma and Oligocene^early Miocene at 22Ma.The most widespread middle^late Eocene cooling phase, around  38Ma, is documentedby a predominant grain-age population in Agha Jari sediments and by cooling ages of a graniticboulder sample. AFTages document at least three cooling/denudation periods linked to majorgeodynamic events related to the Zagros orogeny, during the lateCretaceous oceanic obduction event,during the middle and late Eocene and during the earlyMiocene. Both late Cretaceous and earlyMiocene orogenic processes produced bending of the Arabian plate and concomitant forelanddeposition. Between the two major £exural foreland episodes, the middle^late Eocene phase mostlyproduced a long-lasting slow- or nondepositional episode in the inner part of the foreland basin,whereas deposition and tectonics migrated to theNE along the Sanandaj-Sirjan domain and itsGaveh Rud fore-arc basin. As evidenced in this study, the Zagros orogeny was long-lived and multiepisodic,implying that the timing of accretion of the di¡erent tectonic domains that form the ZagrosMountains requires cautious interpretation.
YR 2009
FD 2009-04-01T00:00:00Z
LK http://hdl.handle.net/10498/7441
UL http://hdl.handle.net/10498/7441
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026