Damoguaihe Fm
Type Locality and Naming
Hailar Basin. Liu Guochang, Han Jingui and Zhang Youzheng erected the Damoguaihe series in 1951. The type locality for the designation is in the Xuguit Qi of Inner Mongolia. The reference section is at Damoguaihe of the Xuguit Qi of Inner Mongolia (121°27′; 49°30′).
Liu Guochang, Han Jingui and Zhang Youzheng named the coal-bearing strata in the Jiuwu-Mianduhe area as the Damoguaihe coal series, being of Late Jurassic age. No stratotype section was defined. In 1959 Ning Jisheng and Tang Kedong measured the Damoguaihe section, which has been considered as a typical section and has extensively been used. During the stratigraphic sorting of Inner Mongolia (1994), it was considered that the Jiufengshan Fm and the Huolinhe Fm were actually of contemporaneous sedimentation, which were all assigned to the Damoguaihe Fm according to the regulations of the optimum nomenclature. [However, Kosenko et al., 2021, considered the basalt- and tuff-bearing Jiufengshan Fm and Ganhe Fm (which they placed as the upper part of their Xinganling Gr in Hailar Basin) to be separate formations. But see their Additional Information note in Xinganling Gr about the need for standardization and reassignments.]
Lithology and Thickness
The Damoguaihe Formation is composed of sandy conglomerate, sandstone, mudstone and coal beds. Its Lower part is dominated by conglomerate and sandy conglomerate, with mudstone, thin-bedded siltstone and gray white tuffaceous grit. Middle part is gray white and gray yellow conglomerate, sandstone, mudstone and coal beds. Upper part is yellow gray tuffaceous grit, sandstone interbedded with mudstone with coal streaks. The formation is 501 m thick.
Relationships and Distribution
Lower contact
Its lower limit is marked by conglomerate and contacts unconformably with the underlying unit. Regionally, the next older unit in Hailar Basin is the Nantun Fm.
Upper contact
Overlain unconformably by the Yimin Fm.
Regional extent
The present formation occurs in the Erenhot, Hailar, Huolinhe and Xilin Hot areas. In Dayangshu of the Oroqen Qi, it is represented by a series of normal sedimentary coal-bearing strata with volcanic rocks, measuring 651 m in thickness. In the Jalaidnor basin, it is mainly built up by gray, dark gray and yellow gray sandy mudstone, sandstone, conglomerate and coal beds, with its upper part separating from the overlying Yimin Fm by thick-bedded mudstone. It is 1110 m thick. In the Huolinhe area, the lower part of the formation is built up by sandstone, siltstone and grit with coal beds while the upper part gray and dark gray siltstone and mudstone intercalated with siltstone and coal beds. The formation is 753 m thick. In the Bayanhua area, the lower part of the formation is represented by a set of variegated sandy conglomerate with mudstone; the middle part dark gray mudstone and siltstone with coal beds; the upper part gray green conglomerate and mudstone. This formation is 218 m thick. On the margin of the Xilin Hot basin, it is represented by brown yellow gravel-bearing grit and feldspar fine sandstone, while its lower part is loess-colored and yellow green shale. It is 131 m thick.
GeoJSON
Fossils
The formation yields estherias Ligrapta sp., Howellites sp.; floras Ciniopteris hymenophylloides, Acanthopteris gothani, Sphenobaiera longifolia; in the Mianduhe Coalmine, bivalves Ferganoconcha sibirica; floras Coniopteris nympharum; on the western slope of the Da Hinggan Ling the sporopollen assemblages represented by the Cicatricosisporites- Pilosisporites-Appendicisporites.
Age
Depositional setting
It is of river-bed facies, valley flat facies, swamp facies and locally volcanic facies.
Additional Information
Lithology and Thickness:
The Damoguaihe Formation is composed of sandy conglomerate, sandstone, mudstone and coal beds. Its Lower part is dominated by conglomerate and sandy conglomerate, with mudstone, thin-bedded siltstone and gray white tuffaceous grit. Middle part is gray white and gray yellow conglomerate, sandstone, mudstone and coal beds. Upper part is yellow gray tuffaceous grit, sandstone interbedded with mudstone with coal streaks. The formation is 501 m thick.
Lithology-pattern: Coarse-grained sandstone
Relationships and Distribution:
Lower contact:
Its lower limit is marked by conglomerate and contacts unconformably with the underlying unit. Regionally, the next older unit in Hailar Basin is the Nantun Fm.
Upper contact:
Overlain unconformably by the Yimin Fm.
Regional extent:
The present formation occurs in the Erenhot, Hailar, Huolinhe and Xilin Hot areas. In Dayangshu of the Oroqen Qi, it is represented by a series of normal sedimentary coal-bearing strata with volcanic rocks, measuring 651 m in thickness. In the Jalaidnor basin, it is mainly built up by gray, dark gray and yellow gray sandy mudstone, sandstone, conglomerate and coal beds, with its upper part separating from the overlying Yimin Fm by thick-bedded mudstone. It is 1110 m thick. In the Huolinhe area, the lower part of the formation is built up by sandstone, siltstone and grit with coal beds while the upper part gray and dark gray siltstone and mudstone intercalated with siltstone and coal beds. The formation is 753 m thick. In the Bayanhua area, the lower part of the formation is represented by a set of variegated sandy conglomerate with mudstone; the middle part dark gray mudstone and siltstone with coal beds; the upper part gray green conglomerate and mudstone. This formation is 218 m thick. On the margin of the Xilin Hot basin, it is represented by brown yellow gravel-bearing grit and feldspar fine sandstone, while its lower part is loess-colored and yellow green shale. It is 131 m thick.
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Fossils:
The formation yields estherias Ligrapta sp., Howellites sp.; floras Ciniopteris hymenophylloides, Acanthopteris gothani, Sphenobaiera longifolia; in the Mianduhe Coalmine, bivalves Ferganoconcha sibirica; floras Coniopteris nympharum; on the western slope of the Da Hinggan Ling the sporopollen assemblages represented by the Cicatricosisporites- Pilosisporites-Appendicisporites.
Age:
Zheng Ji et al. (2020, " Chronostratigraphic framework of late Mesozoic terrestrial strata in the Hailar–Tamtsag Basin, Northeast China, and its geodynamic implication", Geol. Jour.) conclude that this formation spans mid-early Albian to mid-Albian; due to a 111 Ma date at the top of Nantun Fm. Kosenko et al. (2021) had indicated a span of Aptian through early Albian.
Age Span:
Beginning stage: Albian
Fraction up in beginning stage: 0.2
Beginning date (Ma):
Ending stage: Albian
Fraction up in ending stage: 0.4
Ending date (Ma):
Depositional setting:
It is of river-bed facies, valley flat facies, swamp facies and locally volcanic facies.
Depositional-pattern:
Additional Information
Enhanced with Igor N. Kosenko, Jingeng Sha and Boris N. Shurygin (2021). Upper Mesozoic stratigraphy of Sikhote-Alin (Russian Far East) and northeastern China: Non-marine and marine correlations. Part 1: Upper Jurassic-Hauterivian AND 2. Barremian-Aptian. Cretaceous Research, 124: articles 104811 (https://doi.org/10.1016/j.cretres.2021.104811) AND 104812 (https://doi.org/10.1016/j.cretres.2021.104812)