Wichian Buri Gr
Period:
Paleogene, Neogene
Age Interval:
Late Oligocene to Middle Miocene (13, 14)
Province:
Indochina Block: Loei Fold Belt
Type Locality and Naming
Six wells drilled in the Wichian Buri sub-basin.
[Figure: Map showing the Tertiary basins of Thailand, with Phetchabun basin highlighted. The solid black lines onshore are the principal rivers draining Northern and Central Thailand and the Khorat Plateau (Morley and Racey, 2011).]
Synonym: กลุม่หินวิเชียรบุร
Lithology and Thickness
Claystone with minor interbeds of siltstone and sandstone in the lower part; sandstone proportion increases upward, and change to sandstone, claystone, siltstone and tuff in the upper part. Minor lignite occurred locally. Informally subdivided into Unit 4 upward to Unit 1. Thickness: 1,352 m (Lexicon of Stratigraphic Names of Thailand, 2013); up to 1800m (Geology of Thailand, 2011)
Lithology Pattern:
Clayey sandstone
Relationships and Distribution
Lower contact
‘Basal Tertiary’ beds of Late Oligocene age (conformable)
Upper contact
Chaliang Lab Fm (unconformable). An unconformity dated at 11.6 Ma separates the Wichian Buri Gr from the overlying Chaliang Lab Fm.
Regional extent
The Central Plain: Phetchabun intermontane basin, Phetchabun province.
GeoJSON
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Fossils
Age
Late Oligocene to Middle Miocene. An unconformity dated at 11.6 Ma separates the underlying Wichian Buri Gr from the Chaliang Lab Fm => top is base Tortonian
Age Span:
Beginning stage:
Chattian
Fraction up in beginning stage:
0
Beginning date (Ma):
28.09
Ending stage:
Tortonian
Fraction up in the ending stage:
0
Ending date (Ma):
11.63
Depositional setting
Fluvial- Deltaic- Lacustrine
Depositional pattern:
Additional Information
Compiler:
Wen Du -modified from Remus and others (1993)C. K. Morley & A. Racey, 2011, Chapter 10 Tertiary in Ridd, M.F., Barber, A.J., and Grow, M.J., editors, The Geology of Thailand, Geol. Soc. of London.
Lexicon of Stratigraphic Names of Thailand of 2013