- Tytuł:
- Successive dispersion, amalgamation and accretion of terranes of Myanmar from the Gondwana
- Autorzy:
- Aung, Hla Hla
- Powiązania:
- https://bibliotekanauki.pl/articles/24202107.pdf
- Data publikacji:
- 2023
- Wydawca:
- Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
- Tematy:
-
Myanmar
Indochina plate
dispersion - Opis:
- Myanmar represents an evolving continent of two crustal formation histories consisting of the Burma plate and the Indochina plate. The Burma plate (western part of Myanmar) consists of three distinct lithotectonic entities: 1) a continental fragment, 2) a subduction-related accreted complex (NeoTethys suture zone) in the westernmost part of Myanmar and 3) a coastal area. Eastern Myanmar that is western continuation of Indochina plate is composed of three tectonostratigraphic terranes: 1) Shan boundary belt (Meso-Tethys suture zone) in the western edge of Indochina plate, 2) Sibumasu terrane, 3) the Than Lwin Belt (Paleo-Tethys suture zone) in the easternmost part of Myanmar. The Than Lwin Belt is a tectonic linkage between Inthanon Zone of West Thailand in the south and Changning-Menglian belt of West Yunnan in the north (Aung, 2009). Shan Boundary Belt of Meso-Tethys suture in the western edge of Indochina plate extend to the south to Malay Peninsula. The Rakhine Western Ranges of Neo-Tethys suture at the westernmost part of Myanmar is a northern continuation of Andaman-Nicobar belt. Story of the Tethys is the story of extinctions of sea and telling that story was learned from clues in rocks and fossils. Biostratigraphic correlation between the known distribution of dominant Mesozoic representatives of Monotis, Halobia, and Daonella fauna and microfossil assemblages of Triassic age from Myanmar are made with those from neighboring countries of SE Asia for reconstruction of tectonic terranes for Myanmar. The terranes in Myanmar may have originated in Gondwana in Paleozoic (Figs 1, 2). The accretionary episodes which ended in early Tertiary, have been followed by post-accretionary deformation of strike- slip faulting of the Sagaing Fault in Myanmar; West Andaman Fault and Sumatra Fault System in Sumatra; and spreading in Andaman backarc basin. To reconstruct the palaeogeography of Myanmar terranes distribution of Mesozoic representatives of Monotis, Halobia, and Daonella faunas and Tethyan fusulinids are used. Various species of thin-shelled pectinacid bivalves of Triassic faunas are dominant family and occur in open-marine strata of allochthonous accretionary terranes. These strata are related to different parts of single ocean: Tethys, palaeoequatorial ocean populated by these faunas containing Tethyan fusulinids. Their occurrences in mudstones, sandstones, shale and limestone are very important for Triassic sedimentary succession as diagnostic fossils. Distribution of these faunas and biogeographic studies are an importance in reconstructing post-Triassic intraoceanic plate boundaries and motion. Distribution of these faunas in Triassic marine strata of Shan Massif and correlation with those of neighboring terranes of Asia gave the evidences that Shan Massif was a part of Gondwana in Carboniferous-Permian time facing Paleo-Tethys Ocean. Shan Massif probably separated from Gondwana in Early Triassic time and moved northward from equatorial position. Ophiolites thrusted onto Mesozoic sequences of Halobia shales in pre-Middle Eocene (Rangin, 1996–1999). Their position above the metasedimentary rocks is similar to the Halobia shales of Sumatra which also lies on top of metasedimentary rocks of Permo-Carboniferous Sequences (Bender, 1983). All the Tertiary sequences of Central Myanmar Basin are considered to be deposited on the underlying Burma plate as basement. Initial collision between India and Burma plate in middle Eocene (45–35-Ma) and hard collision during Oligocene to Miocene (23 Ma) and Rakhine Western Ranges became uplifted during Middle Miocene to Late Miocene (Curray, 2005) by thrusting the remnants of NeoTethys sea floor and trench deposits to become Rakhine accretionnary wedge and ophiolites belt at the western part of Burma plate.
- Źródło:
-
Geotourism / Geoturystyka; 2023, 1-2 (72-73); 12--13
1731-0830 - Pojawia się w:
- Geotourism / Geoturystyka
- Dostawca treści:
- Biblioteka Nauki
Artykuł