Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Early Paleozoic

Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple

Huai Som Formation

Huai Som Fm

Period:

Carboniferous

Age Interval:

probably mostly Pennsylvanian (14, no strat column)

Province:
Indochina Block: Loei Fold Belt

Type Locality and Naming

Pha Nok Khao Platform (Khon San region; south of Loei region): The type section is at Huai Som, north of Phu Kradung in southern Loei Pro- vince (DMR 1992).

Synonym:

[Figure: Late Paleozoic major facies subdivisions on the western margin of the Indochina Block by Ueno and Charoentitirat (2011). (Slightly modiﬁed from Wielchowsky & Young 1985).]

Lithology and Thickness

The formation consists of shale, sandstone and conglomerate with intercalations of lenticular or banded limestone, frequently with chert.

Lithology Pattern:

Sandy claystone

Relationships and Distribution

Lower contact

The Huai Som Fm is younger than the Dok Du Fm, but details of the stratigraphic relations have not been documented.

Upper contact

Unconformity indicated on age-facies figure of Ueno and Charoentitirat 2011, then overlain by Pha Nok Khao Fm.

Regional extent

It extends northwards along the Loei – Nong Bua Lam Phu provincial boundary to near Na Wang in Nong Bua Lamphu Province.

[Figure: Distribution of Carboniferous and Permian in NE Thailand. Data mainly based on 1:1 million scale geological map of Thailand (DMR 1999) with minor modiﬁcations (Ueno and Charoentitirat 2011).]

[Geo-JSON omitted – would overlap other set.]

GeoJSON

null

Fossils

Reported late Bashkirian to early Kasimovian corals and fusulines (Profusulinella, Fusulinella, Beedeina, Protriticites and Obsoletes).

Age

Probably mostly Pennsylvanian. "The lithology and fossils strengthen the case for correlating the Huai Som Fm to the Wang Saphung Fm. The two formations are therefore likely to have had the same depositional conditions." [Ueno and Charoentitirat, 2011]

Age Span:

Beginning stage:

Kasimovian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

306.65

Ending stage:

Asselian

Fraction up in the ending stage:

0.0

Ending date (Ma):

298.88

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Wen Du -modified from Ueno K. & Charoentitirat T., 2011, Chapter 5 Carboniferous and Permian, and Grow, M.J., editors, The Geology of Thailand, Geol. Soc. of London.;.