Haikou Fm
Type Locality and Naming
No type section was given when the formation was named and described by Hsieh C.Y. (=Xie Jiarong) in 1941, but he pointed out two sections for reference. One section was assigned to the Haikou Village, nearby Dianchi Lake of Kunming City (102o 36’ E-24o46’N) and the other is exposed along the Qujing-Zhanyi Railway, where the thickness reaches about 200 m in the Longhuashan and Cuifengshan Hills of eastern Qujing with several beds of limestones. A well-preserved, continuous section outcropped at Lushitang of Wuding is proposed here as lectostratotype, which has been described by Wu et al. and Pan et al. in 1978..
Lithology and Thickness
Sandstone. At the naming section, the Haikou Fm (s.s.), 43 m thick, is dominated by a set of light-gray or grayish-brown sandstone, siltstone and silty mudstone with lenses of fine conglomerate. It gradually transits to yellow mudstone bearing-ostracods in the middle-upper parts, yielding fish fossils. In Xichong of Zhanyi, the total thickness of the Formation (s.l.) reaches about 650 m. Its lithology is dominated by gray, grayish-brown, grayish purple, grayish yellow and grayish-white fine-grained quartz sandstone, clayey siltstone, sandy mudstone and dolostones. It is commonly subdivided into three parts (or members) throughout Yunnan except the Kunming area, where the deposits were complete:
Lower (Chuandong Mbr) with variegated sandy and muddy rocks and sandstones bearing-pebbles in the base. Middle ('Nanpanjaing' Mbr) with several limestone and dolostone bearing ostracods. Upper (Shangshuanghe Mbr) with variegated, unequal thick alternations of quartz sandstones and sandy mudstones.
[Figure Column section of Haikou Fm in the Tanglishu of Wuding.]
Relationships and Distribution
Lower contact
In Haikou, this formation is unconformable contact with the underlying Pre-Cambrian and conformable contact with the underlying Xujiachong Fm in Qujing area. On regional scale, it can be rested disconformably on the Cuifengshan Gr, the Pojiao Fm of Lower Devonian or the Qiongchusi Fm (= Chingchusze Fm) of Lower Cambrian..
Upper contact
It is generally in a conformable contact with the overlying Qujing Fm (=Kutsing Fm).
Regional extent
This formation is widely distributed in northeastern and eastern Yunnan with similar lithology and thickness, in addition to few individual areas. In the Wuding-Luquan area, this formation (s.l.) has been selected as standard reference section and was given a special name of Tanglishu Member of Yuzidian Fm, which also can be subdivided into three parts: a number of black-grayish to black shale with red oolitic hematite in the lower, gray-white thin bedded dolostone or sandy dolomite with ostrocod-bearing limestone and calcareous sandstone in the middle and purple red mudstone, light grayish quartz sandstones and mudstone in the upper, whole thickness up to 240 m and to 270-360 m northward. See Additional Information for discussion.
GeoJSON
Fossils
The formation in type locality contains Plants Protolepidodendron scharyanum, Barrandeina duslinana, Protoleridium minbutun; Fish Bothriolepis sp.; Ostracods Leperditia sp.; charophytes Trochiliscus ingrica; and Bivalves Modiomorpha sp. On the regional scale, it yields abundant Fish including Bothriolepis sinensis, B. yunnanensis, B. tunseni, Wudinolepis weni, Xichonolepis qujingensis, Dianolepis liui, Hunanolepis tieni.
Age
Depositional setting
Wide range of lithology reflects very different depositional environments, including continental (alluvial, lacustrine) restricted marine (lagoon) and shallow marine (tidal, barrier) settings.
Additional Information
GeoJSON:
Fossils:
The formation in type locality contains Plants Protolepidodendron scharyanum, Barrandeina duslinana, Protoleridium minbutun; Fish Bothriolepis sp.; Ostracods Leperditia sp.; charophytes Trochiliscus ingrica; and Bivalves Modiomorpha sp. On the regional scale, it yields abundant Fish including Bothriolepis sinensis, B. yunnanensis, B. tunseni, Wudinolepis weni, Xichonolepis qujingensis, Dianolepis liui, Hunanolepis tieni.
Age:
Early and Middle Givetian (Late Middle Devonian); range varies regionally.
Age Span:
Beginning stage: Givetian
Fraction up in beginning stage: 0.0
Beginning date (Ma):
Ending stage: Givetian
Fraction up in ending stage: 0.3
Ending date (Ma):
Depositional setting:
Wide range of lithology reflects very different depositional environments, including continental (alluvial, lacustrine) restricted marine (lagoon) and shallow marine (tidal, barrier) settings.
Depositional-pattern:
Additional Information
The misunderstanding of most literatures (Hou et al., 2000; Gao et al., 2014; Zhang S.X., 2000) attributes the naming of Haikou Fm to Deprati in 1921. After a detailed review of the Deprati’s monography, we found that only one Hai-kueou Horizon was mentioned on page 118, without any stratigraphic information. Its original text is “Nous oberservous encore ici l’absence des calcaires noirs á Spirifer mosquensis de l’horizon d’Eul-kai et d’Hai-keuou” (see Deprati, 1921 p. 118). The other names of Hai-kueou appeared in the book are all geographic names. Haikou Town, located at northeast of Fuxianhu Lake（Fou Sien Hou of Deprati）, is an outlet, from which the lake water passing through Haikou River enters the Nanpajian River. Therefore, the Deprati’s name Haikueou Horizon is invalid. However, the name of Haikou Fm described by Hsieh is a duplicate name derived from West Hill of Kunming and is also an outlet, Dianchi Lake.
Since Haikou Formation has been erected it is widely applied in the Yunnan (Wang H.C., 1942). It is characterized by the siliciclastic rocks with fish fossil Bothriolepis. In a summary of continental Devonian Pan et al. (1978) proposed two different meaning of Haikou Fm in the narrow and in the broad senses. The former (s.s.) is marked mainly by siliciclastics with relatively small thickness (30-50 m), represented by the type locality at Haikou. The latter (s.l.) is widely distributed in the north, east and south of Yunnan, and is marked by siliciclastics intercalated with limestones and dolostones with relatively large thickness (few hundred meters) and marine benthic fossils. In the book of Yunnan lithostratigraphy (Zhang YZ, 1995), the authors emphasized that the name of Haikou Fm should be restrictively used for its type locality, while the stratigraphic sequences, lithology and contents in other regions have changed greatly, and a new formation name should be erected. Thus, the homologous strata with Haikou Fm (s.l.) were given different names in various map-sheets, such as the Xichong Fm in Qujing, the Yuzidian Fm in Wuding-Songming, the Shuangjing Mbr in Jianshui and Yuanjiang, the Wutian Fm in Mile, and the Hongyapo Fm in Chaotong respectively. However, these formations, including all Bothrioplepis-bearing units of Givetian are equivalent to the Haikou Fm (s.l.). Therefore, the present authors retain the original name used by Xie.
NOTE: The Chuandong Mbr is sometimes given Chuandong Fm status with type section is located at Xiashuanghe Village of Zhanyi County (99o35’E-24 o 52’N), and named by Yunnan Team of Regional Geological Survey in 1977, and formally quoted by Pan Jiang et al. in 1977. The lithology is mainly characterized by a set of variegated sandy and muddy rocks, being alternating grayish, brownish-red feldspathic quartz sandstone and purplish-gray silty mudstone. Mudstones increase in the upper part with dolomite interbeds at top and sandstones and conglomerates in the base. It is 95 m in thickness. The lower contact is conformable with Xujiachong Fm and is conformable in contact with the overlying pisolite-bearing limestone of Haikou Fm. The lower part yields Antiarchi fish: Bothriolepis sp., Wudinolepis sp.; in upper part it yields Bothriolepis sp., Xichonolepis qujingensis and ostracods: Briatina sp., Hermmannina sp. A beach facies is suggested.