Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Late Eocene Uplift of the Al Hajar Mountains, Oman, Supported by Stratigraphy and Low-Temperature Thermochronology
Stockholm University, Faculty of Science, Department of Geological Sciences.
Stockholm University, Faculty of Science, Department of Geological Sciences.
Show others and affiliations
Number of Authors: 52017 (English)In: Tectonics, ISSN 0278-7407, E-ISSN 1944-9194, Vol. 36, no 12, p. 3081-3109Article in journal (Refereed) Published
Abstract [en]

Uplift of the Al Hajar Mountains in Oman has been related to either Late Cretaceous ophiolite obduction or the Neogene Zagros collision. To test these hypotheses, the cooling of the central Al Hajar Mountains is constrained by 10 apatite (U-Th)/He (AHe), 15 fission track (AFT), and four zircon (U-Th)/He (ZHe) sample ages. These data show differential cooling between the two major structural culminations of the mountains. In the 3km high Jabal Akhdar culmination AHe single-grain ages range between 392 Ma and 101 Ma (2 sigma errors), AFT ages range from 518 Ma to 324 Ma, and ZHe single-grain ages range from 62 +/- 3Ma to 39 +/- 2 Ma. In the 2 km high Saih Hatat culmination AHe ages range from 26 +/- 4 to 12 +/- 4 Ma, AFT ages from 73 +/- 19Ma to 57 +/- 8 Ma, and ZHe single-grain ages from 81 +/- 4 Ma to 58 +/- 3 Ma. Thermal modeling demonstrates that cooling associated with uplift and erosion initiated at 40 Ma, indicating that uplift occurred 30 Myr after ophiolite obduction and at least 10 Myr before the Zagros collision. Therefore, this uplift cannot be related to either event. We propose that crustal thickening supporting the topography of the Al Hajar Mountains was caused by a slowdown of Makran subduction and that north Oman took up the residual fraction of N-S convergence between Arabia and Eurasia.

Place, publisher, year, edition, pages
2017. Vol. 36, no 12, p. 3081-3109
Keywords [en]
thermochronology, Oman, uplift, mountains, fission-track, (U-Th), He
National Category
Earth and Related Environmental Sciences
Research subject
Geology
Identifiers
URN: urn:nbn:se:su:diva-153675DOI: 10.1002/2017TC004672ISI: 000423417300017OAI: oai:DiVA.org:su-153675DiVA, id: diva2:1188027
Available from: 2018-03-06 Created: 2018-03-06 Last updated: 2018-06-21Bibliographically approved
In thesis
1. Cryptic Orogeny: uplift of the Al Hajar Mountains at an alleged passive margin
Open this publication in new window or tab >>Cryptic Orogeny: uplift of the Al Hajar Mountains at an alleged passive margin
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Mountains evolve and grow because of the large forces that occur from the collision of tectonic plates. Plate boundaries change and move through time, and regions that were once stable, shallow-marine environments can be dragged into subduction zones and get transformed into vast mountain ranges. The Al Hajar Mountains in Oman consist of carbonate rocks which show that during most of the Mesozoic (c. 268 Ma – 95 Ma) they had not yet formed but were flat and below sea level. Following this, in the Late Cretaceous (c. 95 Ma), a major tectonic event caused oceanic crust to be obducted onto this Mesozoic carbonate platform. Then after obduction a shallow marine environment resumed, and Paleogene sedimentary rocks were deposited. Currently, the central mountains are located on the Arabian Plate and are 200 km away from the convergent plate boundary with Eurasia. Here, Arabia is being subducted. Further towards the northwest Arabia and Eurasia are colliding, forming the Zagros Mountains which initiated no earlier than the Oligocene (c. 30 Ma). At this time the mountains were even further away from the plate boundary. The problem with the Al Hajar Mountains is that they record a collision, but are not in a collisional zone. To better understand the formation of the Al Hajar Mountains, a multidiscipline approach was used to investigate the timing at which they developed. This included applying low-temperature thermochronology, U-Pb dating of brittle structures, and balanced cross-sections. Results indicate that the orogeny began in the late Eocene and had concluded by the early Miocene (40 Ma – 15 Ma). Therefore, the uplift of the Al Hajar Mountains is not related to either the older Late Cretaceous ophiolite obduction or the younger Zagros collision, and a new tectonic model is proposed. This research shows that the Cenozoic tectonic history of northern Oman is more cryptic than what has been formerly presented.

Place, publisher, year, edition, pages
Stockholm: Department of Geological Sciences, Stockholm University, 2018. p. 26
Keywords
uplift, mountains, structural, low-temperature, thermochronology, dating, fission-track, (U-Th)/He, U-Pb, calcite, structure-from-motion, photogrammetry, UAV, trishear, fault-propagation, Hafit, Al Hajar Mountains, United Arab Emirates, Oman
National Category
Geology
Research subject
Geology
Identifiers
urn:nbn:se:su:diva-157506 (URN)978-91-7797-338-6 (ISBN)978-91-7797-339-3 (ISBN)
Public defence
2018-09-07, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.

Available from: 2018-08-15 Created: 2018-06-20 Last updated: 2018-08-15Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Hansman, Reuben J.Ring, UweStübner, Konstanze
By organisation
Department of Geological Sciences
In the same journal
Tectonics
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 11 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf