Jialingjiang Formation

Geologic feature in China From Wikipedia, the free encyclopedia

The Jialingjiang Formation (嘉陵江组) is a geologic feature associated with the Sichuan Basin of China, generally underlying the area of the basin, with its origins dating to the Early Triassic period of geologic time, around a quarter of a billion years ago, and before. The Jialingjiang Formation is a geologic group feature upon the Yangtze Plate, which is a tectonic feature of the Earth's crust.

TypeGeological formation

UnderliesFeixianguan Formation

OverliesLeikoupo Formation
Guanling Formation

PrimaryLimestone

Quick facts Type, Underlies ...

Jialingjiang Formation
Stratigraphic range: Olenekian ~249.9–246.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Underlies	Feixianguan Formation
Overlies	Leikoupo Formation Guanling Formation
Lithology
Primary	Limestone
Other	Mudstone
Location
Coordinates	31.1°N 111.6°E / 31.1; 111.6
Region	Sichuan, Jiangxi, Chongqing, Hubei
Country	China
Extent	Sichuan Basin
Jialingjiang Formation (China)

The Jialingjiang Formation is important to paleontologists or other people interested in ancient life forms due to the fossil evidence incorporated therein (such as for Eretmorhipis and other Ichthyosaur relatives). Also, scientific study of this formation group provides insight into Late Triassic tectonic inversion based on analysis of detrital zircon U–Pb chronology (involving the element uranium converting to lead over time due to radioactive decay). The Jialingjiang Formation is also of interest in history as it has been a source for humans to extract valuable economic goods such as salt and natural gas for many centuries.^[1]^[2]^[3]

Hydrocarbon resources

The history of the Jialingjiang Formation explains the origins of the hydrocarbon resources which have historically or in the future may be extracted. The primary hydrocarbon resource of the Sichuan Basin is natural gas.^[4]

Fossil contents

Color key

Taxon	Reclassified taxon	Taxon falsely reported as present	Dubious taxon or junior synonym	Ichnotaxon	Ootaxon	Morphotaxon

Notes
Uncertain or tentative taxa are in small text; ~~crossed out~~ taxa are discredited.

Invertebrates

More information Invertebrates of the Jialingjiang Formation, Genus ...

Invertebrates of the Jialingjiang Formation
Genus	Species	Locality	Material	Notes	Images
Claraia	C. sp.	Longmendong, Sichuan	A specimen	A bivalve scallop
Entolium	E. discites microtis
Promysidiella	P. eduliformis praecursor
Liuzhinia^[5]	L. parva	Longmendong, Sichuan	Several specimen	A bairdiidae ostracod
	L. subovata
	L. reniformis
Myophoria	M. ovata			A bivalve mollusk
Pteria ^[6]	P. cf. murchisoni	Longmendong, Sichuan		A bivalve mollusk

Vertebrates

Color key

Taxon	Reclassified taxon	Taxon falsely reported as present	Dubious taxon or junior synonym	Ichnotaxon	Ootaxon	Morphotaxon

Notes
Uncertain or tentative taxa are in small text; ~~crossed out~~ taxa are discredited.

Reptiles

More information Reptiles of the Jialingjiang Formation, Genus ...

Reptiles of the Jialingjiang Formation
Genus	Species	Locality	Material	Notes	Images
Chaohusaurus^[7]	C. zhangjiawanensis	Yuanan, Hubei	A relatively complete skeleton with skull and another skeleton lacking the skull.	An Ichthyosauriform	Hupehsuchus
Chusaurus^[8]	C. xiangensis	Songshugou Village, Hubei	A nearly complete skeleton lacking some cranial and cervical vertebral elements	A pachypleurosaurian nothosaur
Eohupehsuchus^[9]	E. brevicollis	Yangping, Hubei	A skeleton	An aquatic short-necked hupehsuchia reptile
Eretmorhipis^[10]	E. carrolldongi	Yuan'an County, Hubei	Multiple holotype specimens consist of partially preserved skeletons.	A marine hupehsuchian reptile
Hanosaurus	H. hupehensis	Sonshugo locality and Yingzishan locality, Hubei	A partial skeleton	A marine reptile
Hupehsuchus^[11]	H. nanchangensis	Quarry near Minfeng, Hubei	A preserved skeleton	A hupehsuchian marine reptile that resembles a baleen whale.
Keichousaurus^[12]	K. yuananensis	Yingzishan Hill Quarry, Yichang	A partial skeleton	A pachypleurosaurian nothosaur
Lariosaurus	L. sanxiaensis	Yingzishan Hill Quarry, Yichang	A holotype specimen consists of a skeleton	A nothosaur
Lentamanusuchus^[13]	L. hubeiensis	Yingzishan Quarry, Yuan'an, Hubei	A partial articulated skeleton	A hupehsuchian ichthyosauromorph
Nanchangosaurus^[14]	N. suni	Yangping, Yuan'an County, Hubei	A preserved skeleton	A hupehsuchian marine reptile
Parahupehsuchus^[15]	P. longus	Yuan'an County, Hubei	A holotype specimen consists of a mostly complete left half of a skeleton, which lacks the skull and most of the tail.	A hupehsuchian marine reptile
Prosaurosphargis^[16]	P. yingzishanensis	Yingzishan quarry, Hubei	A partial skeleton	A marine saurosphargid reptile

Fish

More information Fish of the Jialingjiang Formation, Genus ...

Fish of the Jialingjiang Formation
Genus	Species	Locality	Material	Notes	Images
Saurichthys^[17]	S. sp.	Yuan'an County, Hubei		A saurichthyid saurichthyiform

References

[1]
[Late Triassic tectonic inversion in the upper Yangtze Block: insights from1 detrital zircon U–Pb geochronology https://discovery.ucl.ac.uk/id/eprint/10037981/1/br_manuscript.pdf]
[2]
Sun, Chunyan; Hu, Mingyi; Hu, Zhonggui; Ngia, Ngong Roger (June 1, 2019). "Sedimentary facies and sequence stratigraphy in the Lower Triassic Jialingjiang Formation, Sichuan Basin, China". Journal of Petroleum Exploration and Production Technology. 9 (2): 837–847. doi:10.1007/s13202-018-0551-3.
[3]
Kuhn, Oliver (2004-06-30). "Ancient Chinese Drilling". Canadian Society of Exploration Geophysicists. 29 (6).
[4]
Zhijun, Jin; Quanyou, Liu; Nansheng, Qiu; Feng, Ding; Guoping, Bai (2012). "Phase states of hydrocarbons in Chinese marine carbonate strata and controlling factors for their formation". Energy Exploration & Exploitation. 30 (5): 753–773. ISSN 0144-5987.
[5]
M. Wei. 1981. Early and Middle Triassic ostracods from Sichuan. Acta Palaeontologica Sinica 20(6):501-507 [M. Clapham/M. Clapham]
[6]
C. Xu. 1978. Lamellibranchiata. Palaeontological Atlas of Southwest China - Sichuan Volume 2:315-364
[7]
CHEN Xiaohong, P. Martin SANDER, CHENG Long, WANG Xiaofeng.2013. A New Triassic Primitive Ichthyosaur from Yuanan, South China[J]. Acta Geologica Sinica(),87(3):672-677
[8]
Liu, Q. L., Cheng, L., Stubbs, T. L., Moon, B. C., Benton, M. J., Yan, C. B., & Tian, L. (2023). Rapid neck elongation in Sauropterygia (Reptilia: Diapsida) revealed by a new basal pachypleurosaur from the Lower Triassic of China. BMC ecology and evolution, 23(1), 44. https://doi.org/10.1186/s12862-023-02150-w
[9]
CHEN Xiaohong, P. Martin SANDER, CHENG Long, WANG Xiaofeng.2013. A New Triassic Primitive Ichthyosaur from Yuanan, South China[J]. Acta Geologica Sinica(),87(3):672-677
[10]
Cheng, Long; Motani, Ryosuke; Jiang, Da-Yong; Yan, Chun-bo; Tintori, Andrea; Rieppel, Olivier (2019). "Early Triassic marine reptile representing the oldest record of unusually small eyes in reptiles, indicating non-visual prey detection". Scientific Reports. 9 (1): 152. Bibcode:2019NatSR...9..152C. doi:10.1038/s41598-018-37754-6. PMC 6345829. PMID 30679783.
[11]
X.-C. Wu, L.-J. Zhao, and T. Sato, S.-X. Gu, X.-S. Jin. 2016. A new specimen of Hupehsuchus nanchangensis Young, 1972 (Diapsida, Hupehsuchia) from the Triassic of Hubei, China. Historical Biology 28(1-2):43-52
[12]
C.-C. Young. 1965. On the new nothosaurs from Hupeh and Kweichou, China. Vertebrata PalAsiatica 9(4):337-356
[13]
Qiao, Y.; Iijima, M.; Liu, J. (2025). "A new hupehsuchian (Reptilia: Ichthyosauromorpha) with widely spaced autopodium from the marine Lower Triassic of South China". Journal of Systematic Palaeontology. 23 2560884. doi:10.1080/14772019.2025.2560884.
[14]
Chen, X. H., Motani, R., Cheng, L., Jiang, D. Y., & Rieppel, O. (2014). A small short-necked hupehsuchian from the lower Triassic of Hubei Province, China. PloS one, 9(12), e115244. https://doi.org/10.1371/journal.pone.0115244
[15]
Chen, X. H., Motani, R., Cheng, L., Jiang, D. Y., & Rieppel, O. (2014). A carapace-like bony 'body tube' in an early triassic marine reptile and the onset of marine tetrapod predation. PloS one, 9(4), e94396. https://doi.org/10.1371/journal.pone.0094396
[16]
A. S. Wolniewicz, Y. Shen, Q. Li, Y. Sun, Y. Qiao, Y. Chen, Y.-W. Hu and J. Liu. 2023. An armoured marine reptile from the Early Triassic of South China and its phylogenetic and evolutionary implications. eLife 12(e83163)
[17]
Zhang, Y.-T.; Wu, F.-X.; Li, Q.; Qiao, Y.; Hu, Y.-W.; Shen, X.-Y.; Liu, J. (2026). "First record of predatory fish Saurichthys from the late Early Triassic Nanzhang-Yuan'an fauna, South China". Historical Biology: An International Journal of Paleobiology: 1–10. doi:10.1080/08912963.2025.2588256.