Abstract
The Jebel Ja’alan and Qalhat inliers of Oman represent the easternmost exposures in the Arabian peninsula of the Neoproterozoic basement associated with the East African Orogen (EAO) and the assembly of East and West Gondwana. These inliers expose tonalitic gneisses and metasediments intruded by granodiorites and granites of the Ja’alan batholith. Zircons from the gneisses yield U–Pb SIMS ages of ca. 900–880 Ma, which are interpreted as crystallization ages. These represent the oldest magmatic events associated with the closure of the Mozambique Ocean reported to date. Zircon of this age is also the dominant component in the metasediments. The Ja’alan batholith yields ages of ca. 840–825 Ma. Nd isotopes indicate that both the gneisses and the batholith range from juvenile to slightly more evolved, with εNd(t) of +6 to +1.5 interpreted to reflect variable contamination by older, evolved continental material; this is also indicated by >900 Ma detrital zircon from the metasediments. The Nd data also contrast with the uniformly juvenile signature of younger, ca. 840 Ma, rocks of the Marbat region of southern Oman that lie structurally to the west. The Ja’alan and Qalhat inliers thus document eastward increasing age and continental influence, consistent with the progressive development of arc rocks onto the western margin of East Gondwana, although the location and nature of the eastern continental block remain elusive.
| Original language | English |
|---|---|
| Pages (from-to) | 2046-2064 |
| Number of pages | 19 |
| Journal | International Geology Review |
| Volume | 58 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - Dec 9 2016 |
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Keywords
- Arabian basement
- crustal growth
- East African Orogen
- geochronology
- Gondwana
- Neoproterozoic
ASJC Scopus subject areas
- Geology
Cite this
Neoproterozoic crustal growth at the margin of the East Gondwana continent – age and isotopic constraints from the easternmost inliers of Oman. / Whitehouse, M. J.; Pease, V.; Al-Khirbash, S.
In: International Geology Review, Vol. 58, No. 16, 09.12.2016, p. 2046-2064.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Neoproterozoic crustal growth at the margin of the East Gondwana continent – age and isotopic constraints from the easternmost inliers of Oman
AU - Whitehouse, M. J.
AU - Pease, V.
AU - Al-Khirbash, S.
PY - 2016/12/9
Y1 - 2016/12/9
N2 - The Jebel Ja’alan and Qalhat inliers of Oman represent the easternmost exposures in the Arabian peninsula of the Neoproterozoic basement associated with the East African Orogen (EAO) and the assembly of East and West Gondwana. These inliers expose tonalitic gneisses and metasediments intruded by granodiorites and granites of the Ja’alan batholith. Zircons from the gneisses yield U–Pb SIMS ages of ca. 900–880 Ma, which are interpreted as crystallization ages. These represent the oldest magmatic events associated with the closure of the Mozambique Ocean reported to date. Zircon of this age is also the dominant component in the metasediments. The Ja’alan batholith yields ages of ca. 840–825 Ma. Nd isotopes indicate that both the gneisses and the batholith range from juvenile to slightly more evolved, with εNd(t) of +6 to +1.5 interpreted to reflect variable contamination by older, evolved continental material; this is also indicated by >900 Ma detrital zircon from the metasediments. The Nd data also contrast with the uniformly juvenile signature of younger, ca. 840 Ma, rocks of the Marbat region of southern Oman that lie structurally to the west. The Ja’alan and Qalhat inliers thus document eastward increasing age and continental influence, consistent with the progressive development of arc rocks onto the western margin of East Gondwana, although the location and nature of the eastern continental block remain elusive.
AB - The Jebel Ja’alan and Qalhat inliers of Oman represent the easternmost exposures in the Arabian peninsula of the Neoproterozoic basement associated with the East African Orogen (EAO) and the assembly of East and West Gondwana. These inliers expose tonalitic gneisses and metasediments intruded by granodiorites and granites of the Ja’alan batholith. Zircons from the gneisses yield U–Pb SIMS ages of ca. 900–880 Ma, which are interpreted as crystallization ages. These represent the oldest magmatic events associated with the closure of the Mozambique Ocean reported to date. Zircon of this age is also the dominant component in the metasediments. The Ja’alan batholith yields ages of ca. 840–825 Ma. Nd isotopes indicate that both the gneisses and the batholith range from juvenile to slightly more evolved, with εNd(t) of +6 to +1.5 interpreted to reflect variable contamination by older, evolved continental material; this is also indicated by >900 Ma detrital zircon from the metasediments. The Nd data also contrast with the uniformly juvenile signature of younger, ca. 840 Ma, rocks of the Marbat region of southern Oman that lie structurally to the west. The Ja’alan and Qalhat inliers thus document eastward increasing age and continental influence, consistent with the progressive development of arc rocks onto the western margin of East Gondwana, although the location and nature of the eastern continental block remain elusive.
KW - Arabian basement
KW - crustal growth
KW - East African Orogen
KW - geochronology
KW - Gondwana
KW - Neoproterozoic
UR - http://www.scopus.com/inward/record.url?scp=84978538760&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84978538760&partnerID=8YFLogxK
U2 - 10.1080/00206814.2016.1207207
DO - 10.1080/00206814.2016.1207207
M3 - Article
VL - 58
SP - 2046
EP - 2064
JO - International Geology Review
JF - International Geology Review
SN - 0020-6814
IS - 16
ER -