Documenting Exhumation in the Central and Northern Menderes Massif (Western Turkey): New Insights from Garnet-Based P-T Estimates and K-Feldspar Ar-40/Ar-39 Geochronology

Etzel T. M., Catlos E. J., Cemen I., Ozerdem C., OYMAN T., Miggins D.

LITHOSPHERE, cilt.2020, sa.1, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 2020 Sayı: 1
  • Basım Tarihi: 2020
  • Doi Numarası: 10.2113/2020/8818289
  • Dergi Adı: LITHOSPHERE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aquatic Science & Fisheries Abstracts (ASFA), Compendex, Geobase, Directory of Open Access Journals
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The Menderes Massif (Turkey) is a metamorphic core complex that records Alpine crustal shortening and extension. Here, nine garnet-bearing schist samples in the Central Menderes Massif (CMM) from below the Alasehir detachment (AD) were studied to reconstruct their growth history. P-T estimates made using a chemical zoning approach, and petrological observations, indicate garnet grew between similar to 6 kbar and 550 degrees C and 7.5-9 kbar and 625-650 degrees C. Two P-T path shapes from two samples emerged (isobaric and burial), suggesting that either separate garnet-growth events occurred, or different garnet generations from the same metamorphic event were sampled. Despite observable diffusional modification in most garnets, thermobarometric estimates for crystal-rim growth yield P-T estimates similar to those reported elsewhere in the region. Ion microprobe monazite ages, paired with textural observations, from three of the samples time early retrograde metamorphism (similar to 36-28 Ma). To better understand Neogene extension/exhumation, K-feldspar Ar-40/Ar-39 ages were obtained from two synextensional granites (Salihli and Turgutlu) exposed along the AD and two from the northern Simav detachment (Koyunoba and Egrigoz). This data suggests the Simav detachment footwall rapidly exhumed at similar to 20 Ma, whereas the AD experienced two periods of exhumation/cooling (similar to 14Ma and similar to 5 Ma). AD ages support a pulsed exhumation model for the massif.