10.6084/m9.figshare.3453446.v1
A. Licht
A.
Licht
C. France-Lanord
C.
France-Lanord
L. Reisberg
L.
Reisberg
C. Fontaine
C.
Fontaine
Aung Naing Soe
Aung
Naing Soe
J.-J. Jaeger
J.-J.
Jaeger
A palaeo Tibet–Myanmar connection? Reconstructing the Late Eocene drainage system of central Myanmar using a multi-proxy approach
Geological Society of London
2016
petrographic data
source area
palaeo Tsangpo drainage
Tibetan provinces share
magmatic arc source
Irrawaddy River
basement material
Burmese margin
hypothesis
Palaeogene
Yaw Formations
Isotopic analysis
Asian drainage patterns
Central Myanmar
Asian margin
Eocene drainage system
bulk sediments
Indian Ocean
lithological features
Geology
2016-06-21 11:25:21
Journal contribution
https://geolsoc.figshare.com/articles/journal_contribution/A_palaeo_Tibet_Myanmar_connection_Reconstructing_the_Late_Eocene_drainage_system_of_central_Myanmar_using_a_multi-proxy_approach/3453446
<p>Strain resulting from the collision of India with Asia has caused fundamental changes to Asian drainage patterns, but the
timing and nature of these changes are poorly understood. One frequently proposed hypothesis involves the connection of the
palaeo Tsangpo drainage to a precursor to the Irrawaddy River of central Myanmar in the Palaeogene. To test this hypothesis,
we studied the provenance of Palaeogene fluvio-clastic sedimentary rocks that crop out in central Myanmar, namely the Late
Middle Eocene–Early Oligocene Pondaung and Yaw Formations. Isotopic analysis on bulk-rock and petrographic data indicate a
primary magmatic arc source, and a secondary source composed of recycled, metamorphosed basement material. Although the exact
location of both sources is hardly distinguishable because Burmese and Tibetan provinces share common lithological features,
the presence of low-grade metamorphic fragments, the heterogeneity in Sr–Nd isotopic values of bulk sediments and westward-directed
palaeoflow orientations indicate a proximal source area located on the eastern Asian margin. Central Myanmar was the locus
of westward-prograding deltas opening into the Indian Ocean, supplied by the unroofing of an Andean-type cordillera that extended
along the Burmese margin. We found no evidence to support a palaeo Tsangpo–Irrawaddy River, at least during the Late Eocene.
</p>