Yom Fm
Period:
Neogene
Age Interval:
Late Miocene-Pliocene (6)
Province:
Sibumasu: Central Plain
Type Locality and Naming
Phitsanulok Basin (northern Central Plain). 7th (upward) of 8 formations in the Phitsanulok Gr.
Synonym: หมวดหินยม
[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, page 224).]
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Lithology and Thickness
Fluviatile medium-to coarse-grained sand, gravel and varicolored clay. 1000 m.
Lithology Pattern:
Coarse-grained sandstone
Relationships and Distribution
Lower contact
Overlies the Pratu Tao Fm
Upper contact
Overlain by the Ping Fm
Regional extent
Phitsanulok Basin (northern Central Plain) is the largest individual rift basin complex in Thailand. Sukhothai and Kamphaeng Phet provinces.
GeoJSON
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Fossils
Age
Late Miocene-Pliocene
Age Span:
Beginning stage:
Tortonian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
11.63
Ending stage:
Gelasian
Fraction up in the ending stage:
0.0
Ending date (Ma):
2.58
Depositional setting
Fluvial
Depositional pattern:
Additional Information
Compiler:
Wen Du - modified from Christopher K. Morley & Andrew Racey, 2011, Chapter 10 Tertiary stratigraphy in: Ridd, M.F., Barber, A.J., and Grow, M.J., editors, The Geology of Thailand, Geol. Soc. of London.; and Lexicon of Stratigraphic Names of Thailand of 2013.