Field Trip Guidebook on Chinese Sedimentary Geology

Ephemeral streams are rivers with high values of annual peak discharge variability. Therefore, the ephemeral rivers are often catastrophic, yet represent an important sediment routing system from source to sink that show unique bedding structures and internal architectures. The rivers surrounding the rifted Daihai Lake in a semi-arid area are mostly ephemeral streams with high inter-annual peak discharge variation, which document sedimentary architectures and reveal sedimentary processes of fluvial to deltaic system with strongly peaked discharge. This field trip describes sedimentary structures in alluvial fan to river to delta deposits, and investigates that how the structures and the morphodynamics change from the mountainous rivers to their delta fronts. Clinoforms with different geometries are examined in deltaic deposits, which reflect the controls of relative lake-level changes, paleobathymetry, and sediment supply.

The exploration of the universe, of the earth's interior and of the oceans are three great endeavors of humanity challenging nature in order to improve living conditions for humans. Scientific drilling is a significant exploration tool in current earth science research. We can directly observe the lithosphere which we know little about and obtain the rock record from its deeper parts through scientific drilling programs. Drilling provides important information about natural resources, disaster prediction and a variety of environmental problems currently facing modern human society. The Deep Sea Drilling Project (DSDP) in 1968, followed by the Ocean Drilling Program (ODP) and the Integrated Ocean Drilling Program (IODP), led early to a major scientific breakthrough and geosciences revolution which has changed our views of the Earth.

This field trip is an invitation to observe the Cambrian outcrops at the Xiaweidian Section located in the Miaofengshan Town, western Beijing.

The Luanping Basin is a typical continental rift basin that developed during the Middle Jurassic to Early Cretaceous in the Yanshan fold-thrust belt in Northeast China. The Yanshan fold-thrust belt, which is characterized by terrestrial sedimentation, magmatism and deformation—including multiple phases of folding and contractional, extensional, and strike-slip faulting throughout China during the Jurassic‒Cretaceous Cretaceous—was mentioned in the Chinese literature as a result of deformation episodes named the Yanshan (or Yenshan) movement, Yanshanian movement, or Yanshanian deformation (Cope, 2003; Davis et al. 1998, 2001; Dou et al. 2020; Li et al. 2003, 2007). The Luanping Basin is a small half-graben and elongated in a NE‒SW direction, approximately 40 km long and 20 km wide. Controlled by multiepisodic Yanshanian movements, the basin experienced extensional and transtensional stresses leading to a complex rifting process. Three rifting episodes were divided: the first episode occurred in the early Middle Jurassic, the second episode occurred in the middle to late Middle Jurassic, and the third episode took place during the late Jurassic to early Cretaceous. During these rifting episodes, thick nonmarine terrestrial volcanic and clastic synrift successions (~5000 m) accumulated. The synrift strata are composed of five lithologic stratigraphic units: the Jiulongshan, Tiaojishan, Houcheng, Zhanjiakou and Xiguayuan Formations.

The Songliao Basin (SB), situated on the Mongol-North China Plate, contain China's largest oil field, the Daqing Field, which is one of the very few supergiant oil fields in the world that produces lacustrine oil.

This field trip examines the Carboniferous-Permian strata of the Shuiyuguan section in the vicinity of Taiyuan City, and the Palougou section along the Yellow River as the main investigation subjects, and the trip also includes visits to the Antaibao Open Pit Coal Mine at Pingshuo and the Yungang Buddhist Grottoes at Datong City. The aim of this field trip is to investigate the important geological phenomena preserved in the Late Paleozoic strata of the North China plate, in relation to coal-forming models for cratonic paralic environments, channel sand body types representing different coefficients of discharge variance, coal-bearing cyclothems in response to the Gondwanan glacial periods, and end-Permian boundary events. On the basis of investigating the geological phenomena of the Late Paleozoic strata in the North China Plate, the scientific significance will be discussed: (1) Types of Carboniferous-Permian coal-forming environments; (2) Carboniferous-Permian paleoclimate evolution; (3) Geological events and sedimentary characteristics near the Permian-Triassic boundary; (4) Carboniferous-Permian fluvial deposit characteristics based on interpreted peak discharge variability; (5) Milankovitch cycle signals recorded in Late Paleozoic strata. This route is a pre-congress route, including four days of investigation.

This field trip guide provides an opportunity for participants to study the Cretaceous stratigraphy and sedimentology in the Jiaolai Basin, eastern Shandong province. This sedimentary cover consists of terrestrial clastic sediments and volcaniclastics that belong to the Laiyang Group, the Qingshan Group, and the Wangshi Group. The sediments of these groups contain the Jehol biota, composed of hadrosaur fauna and dinosaur eggs, respectively. Lingshan Island, which is located in the western Yellow Sea, 37 km south of Qingdao, originated in the Early Cretaceous as part of a depositional basin and subsequently as part of a volcanic arc. It became uplifted by later extrusion-related tectonic tilting. The overall dip direction of the rocks is ENE. In spite of this overall simple structure, the tectonic setting is still under debate. Several well-exposed gravity-flow deposits in the Late Cretaceous Lingshandao Formation provide a rare opportunity to study deep-water processes and soft-sediment deformation structures. The Hongtuya Formation of the Wangshi Group in the Laiyang Cretaceous National Geopark contains a set of red clastic rocks which reflect sedimentation in a fluvial delta; a giant hadrosaur was found in these deposits. There are several dinosaur-bearing Late Cretaceous beds in the Shandong Zhucheng National Dinosaur Geopark. It houses the world’s largest dinosaur thanatocoenosis in its Dinosaur Ravine fossil gallery, which is about 500 m long and 30 m deep, exposing 10,000 fossil remnants. This tour also includes a visit to the Jimo Mashan Geopark. The boundary between the Cretaceous Laiyang Group and the Qingshan Group with metamorphic rocks is situated here.

The investigation area is located in the western mountainous area of Henan Province. It is midsummer in late August, with an average temperature of about 21–33 ℃. During this period, it is mostly sunny with thunderstorms. We recommend wearing thinner clothes and long shirts, and to come equipped with sunscreen and rainwear. The routes are generally along simple roads or flat sand roads, but it often requires short-distance walking. Meanwhile, to prevent mosquito bites and spiny plants, it is best to wear scratch-resistant long-sleeved tops and trousers, and hiking shoes or outdoor shoes are recommended.

The Triassic marine strata are well developed and completely preserved in the Xingyi-Guanling area, where sediment differentiations are obvious, and marine reptile fossils are abundant and perfect.

The Yangtze region is one of the regions with the best stratigraphic record and the most abundant fossils of the Permian–Triassic in the East Tethys and even in the world. It records the evolution of the Paleotethys, the Permian–Triassic Boundary (PTB) mass extinction, the Emei tafrogenesis and other important geological events. The proposed investigation route in Upper Yangtze region, i.e., the marginal reef of Jiantianba platform in Lichuan and the marginal reef and shoal of Panlongdong platform in Xuanhan—Puguang gas field, demonstrates the Late Permian platform margin sedimentary system, and development of typical Late Permian reefs—Early Triassic grain shoals in the world. It shows the successful application that the sedimentological study serves oil and gas exploration. The Jiantianba outcrop in Lichuan (hereinafter referred to as the Jiantianba outcrop) reveals a complete sedimentary system which contains basin, slope, carbonate platform margin, and open platform, where the platform margin reef core is observed with very clear assemblages of architecture units and a variety of identifiable microfacies. Calcisponge is the main reef-building organism with abundant species and various form. It is one of the most typical reefs of Late Permian in Yangtze region. The Panlongdong outcrop is located in Xuanhan County (hereinafter referred to as the Panlongdong outcrop), and platform margin reefs and shoals are developed here. The platform margin zone developed across the Permian–Triassic biological mass extinction event, formed the platform margin sedimentary characteristics that the reefs of Changxing stage on the lower part while the shoals of Feixianguan stage on the upper part. Platform margin reef and shoal are superimposed and inherited spatially. The sedimentary evolution sequence of reef base–reef core–reef cap is clear and complete. The platform margin shoal is mainly oolitic, and gravel clasts the second, with tabular and wedged cross-bedding developed. Puguang gas field is represented by the reef and shoal reservoirs with high porosity and high permeability of the Permian Changxing Formation and the Lower Triassic Feixianguan Formation. This discovery benefited from the breakthrough in sedimentological study on sedimentary facies and favorable reservoir. The Science and Technology Exhibition Hall of Puguang gas field exhibits the process and achievements of the discovery, development and construction of Puguagn gas field in various forms, provides a good reference for the exploration and development of ultra-deep marine carbonates in the world.

Participants will examine (1) the main facies and physical stratigraphy of the organic-rich shales of the Upper Ordovician Wufeng Formation and the first member of the Lower Silurian Longmaxi Formation; (2) differences in the lateral distribution of these shales within or around the eastern margin of the Sichuan Basin as a result of the changes in tectonic uplift, volcanism and glacio-eustatic sea level; (3) great karst landscape; and (4) Fuling Shale Gas Field, a great milestone of China’s shale gas industry.

The Ordos Basin is located in the western part of the North China Plateau (Fig. 1).

Guilin is a well-known tourist city in China and abroad, marked by the breathtaking scenery of spectacular karstic landforms. These landforms dominantly comprise the Devonian carbonates with subordinate Lower Carboniferous carbonates deposited principally in the fault-controlled platform-basin system in which mass extinction events of Late Devonian (Frasnian-Famennian and Devonian-Carboniferous transitions), also known as Kellwasser and Hangenberg events, were well recorded as well. Besides, fault-controlled hydrothermal dolostones were also developed in some carbonate successions such as the basal successions of Devonian carbonates (Givetian) and the lower part of Carboniferous (Visean). This excursion will show you the diversified depositional facies (restricted carbonate platform interior, open platform-platform margin, and marginal slope-basinal facies), time- and facies-specific faunal assemblages (i.e., stromatoporoids, tentaculitids), and the stratigraphic-geochemical records of Late Devonian biocrisises, as well as the hydrothermal dolostones in the Givetian and Visean carbonates in Guilin area. As a bonus, this trip will also show you how the primary (intraplatform) facies had largely controlled the development and distribution of the most spectacular karstic landforms including the cave (speleothem) systems in Guilin.

Guizhou Province in South China contains relatively completed Neoproterozoic—Late Paleozoic strata, providing valuable records for some important geological events, such as the “Snowball Earth” Event, the Ediacaran biota, the far-field effect of Late Paleozoic Ice Age (LPIA) and the Emeishan Large Ingenious Province (ELIP). Interestingly, these geological events not only had critical effects in the evolution of surface environment of Earth, but also had oblivious metallogenic effects. A series of sedimentary deposits are found in the contemporaneous strata of these geological events, The “Datangpo-type” manganese deposit within the interglacial strata of Cryogenian, the phosphorite deposit coexists with the Ediacaran biota (Weng’an Biota), the Carboniferous bauxite deposit indicating the regression of the LPIA, the Permian manganese deposit linked with the ELIP. In this fieldtrip, we will travel through the most representative sections of all these sedimentary deposits, including the orebodies and depositional deformations in the basal Datangpo Formation in Songtao, the cap carbonate, phosphorite deposit and the Weng’an Biota in the Doushantuo Formation in Weng’an, and the Carboniferous bauxite deposit and the Permian manganese deposit in Zunyi.