Changliu Fm
Type Locality and Naming
Beibu Gulf region. The naming section is located in well Xu4, Liushagang, Haikang County (Leizhou City), Guangdong. The 1914.0–2270.0 m interval of well Xu4 is taken as the stratotype section. Named by the South China Sea Branch, China National Petroleum Corporation in 1978.
Lithology and Thickness
The formation refers to variegated clastic rocks between the Sanyajiang Formation and Liushagang Formation. Lithologies are unequal-thickness alternating beds of brownish red and brown mudstone and grayish green and dark gray mudstone; the lower part is intercalated with calcareous sandstone, pebbly sandstone and sandy conglomerate; and the upper part is interacted with grayish white and brownish red siltstone and sandstone. The total thickness is 356 m in well Xu4. It is ~100 m thick in the Beibu Gulf and 278–574 m thick in the Leizhou Peninsula, and southward the lithology becomes fine and the thickness increases, being mostly ~200 m in Northern Hainan Island.
Relationships and Distribution
Lower contact
It is in unconformable contact with the underlying Sanyajiang Fm [not yet in English Lexicon for Cretaceous] or pre-Tertiary basement.
Upper contact
It is in unconformable contact with the overlying Liushagang Fm.
Regional extent
Distributed in Beibu Gulf and the Leiqiong area.
GeoJSON
Fossils
It contains the ostracods Sinocypris funingensis, Echinocypris elongata and Limnocythere cf. hupeiensis assemblage and the sporopollen Celtispollenites-Pentapollenites assemblage.
Age
Depositional setting
The formation consists of diluvial-alluvial fan deposits.
Additional Information