Kim Long Fm
Type Locality and Naming
Malay Basin. The type section is located within the Hole Kim Long-IX, at a depth of 3140-3534 m (N = 8°32’; E = 112°46’). It was named by
Synonym: Hệ tàng Kim Long: Dỗ Bat 2002.
Lithology and Thickness
Grey, brown-grey claystone containing silt and carbonate interbedded with fine- to medium-grained, sometimes coarse-grained sandstone, and locally with thin coal seams. The thickness of the formation in this borehole is 394 m. However, the borehole did not reach the basement; therefore the true thickness of the formation as well its basal beds are not yet clarified.
In the basin, other sections of the Fm are composed of grey claystone interbedded with siltstone, sandstone and brown coal seams, in some places, white carbonate beds. The members of claystone are rich in organic matter, considered as oil source rocks and, in some places, local petroleum confining beds. The most part of sandstone members of the Fm have been considered as medium to good petroleum reservoir beds.
Relationships and Distribution
Lower contact
As of 2011, no boreholes had penetrated to the bottom of the formation, therefore its thickness, age span and underlying units are not known. Presumed to rest unconformably upon basement.
Upper contact
Unconformably under the Ngoc Hien Fm
Regional extent
The Fm is largely distributed in the Malaya - Tho Chu Basin. The Fm is usually distributed in grabens and slope of structures with the thickness varying from 500 to 1000 m.
GeoJSON
Fossils
Fossils of the formation are relatively poor and consist only of spores and pollen of the Florschuetzia trilobata Zone and some other species, such as Cicatricosisporites dorogensis, Magnatriatites howardii, Mayeripollis nahakoteris etc.
Age
Depositional setting
It is interpreted as delta plain to marshy-lacustrine environments interbedded with marine sediments in the upper part.
Additional Information