Phra That Fm
Period:
Triassic
Age Interval:
Early Triassic (Upper Griesbachian to Lower Anisian) (11)
Province:
Sukhothai Fold Belt
Type Locality and Naming
Phra That Muang Kham, 11 km southeast of Lampang province. Parent unit: lowermost formation in Lampang Gr.
Synonym: หมวดหินพระธาต
Lithology and Thickness
Red beds in the lower part, often upward to grey beds of mudstone, siltstone, sandstone with occasional intercalated limestone. Thickness:100-840 m, 90 m at the type section.
Lithology Pattern:
Sandy claystone
Relationships and Distribution
Lower contact
Ngao Gr (Unconformable?)
Upper contact
Pha Kan Fm (conformable)
Regional extent
Lampang-Phrae basin, west part of the Northern Region of Sukhothai Fold Belt.: Lampang and Sukhothai provinces
GeoJSON
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Fossils
The formation contains bivalves which indicate an age range from Late Griesbachian (Earliest Triassic) to Early Anisian. (Geology of Thailand, 2011)
Age
Early Triassic in Fig. 6.2 of Chonglakmani, C.P., 2011.
Age Span:
Beginning stage:
Induan
Fraction up in beginning stage:
0.25
Beginning date (Ma):
251.38
Ending stage:
Anisian
Fraction up in the ending stage:
0
Ending date (Ma):
246.80
Depositional setting
Near shore to continental deposits
Depositional pattern:
Additional Information
Compiler:
Wen Du - modified from- Chonglakmani, C.P., 2011, Chapter 6 Triassic 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.