Geochemistry of upper Permian siliceous rocks from the Lower Yangtze region, southeastern China:implications for the origin of chert and Permian ocean chemistry

The Permian Chert Event is of great significance to understanding the geological evolution of the entire Permian; however,the origin of widespread chert formation is debated. We report new geochemical data from deep-marine siliceous rocks of the upper Permian Da-long Formation, Lower Yangtze region, southeastern China. Their geochemical results show that these thin-bedded siliceous rocks have a clear biologic origin, with rare to no evidence of hydrothermal influence. The values of Al/(Al + Fe + Mn) and Eu/Eu~* are 0.60-0.84(mean = 0.72) and 0.45-1.08(mean = 0.77), respectively, and Mn/Ti ratios are relatively low(mean = 0.72). The correlations of LaN/CeN, LaN/YbN, and Fe203/Ti02 with Al_2 O_3/(Al_2 O_3 + Fe_2 O_3), along with the Ce anomaly, indicate that the Da-long siliceous rocks were deposited at a transitional zone between a continental margin and the open ocean; i.e., relatively close to terrestrial sediment input and far from hydrothermal activity. The accumulation of chert is related to its unique paleogeographic location in an equatorial setting with many submarine paleo-highlands.Intense upwelling and frequent local volcanism are the main factors that promoted the development of siliceous rocks in the studied area. Ocean acidification triggered by large-scale volcanism(Large Igneous Province) during the late Permian led to extensive silica precipitation and preservation.

A New Species of Coniopteris moguqiensis sp. nov. from the Middle Jurassic Wanbao Formation in Eastern Inner Mongolia, China

In recent years, an increasing number of plant fossil leaves and petrified woods have been discovered from the Middle Jurassic Wanbao Formation in Moguqi Town of Inner Mongolia, NE China. Here, we describe a new species of Coniopteris moguqiensis sp. nov. preserved as a fragment with fertile and sterile pinnules. The sterile ultimate pinnules are elongate ovate with sphenopteriod type venation, and fertile pinnules are usually isolated, bipinnate at least with the sorus apical, elliptical, 1 mm in diameter;sporangia are almost globular, 100-150 μm in diameter, and the annulus is vertical. In situ spores are rounded-triangular in polar view, 25-30 μm in diameter with sides straight and slightly convex;trilete, laesurae are thin and slightly straight;the exine surface is usually psilate under the light microscope but finely reticuloid sculptured on the proximal view under a scanning electronic microscope. The fern genus Coniopteris usually suggests a warm and humid environment, which is consistent with the palaeoclimatic conditions of petrified wood and megafossil plants. The new discovery further supplements the floral composition of the Wanbao Formation, providing new material for understanding the evolutionary trend and classification of Coniopteris.

First Discovery of Dicerorhinus sumatrensis from Yanjinggou Provides Insights into the Pleistocene Rhinocerotidae of South China

The Rhinocerotidae is one of the most common and important families in the Pleistocene mammalian fauna of South China.Since the last century,most of the Pleistocene rhinocerotid fossils were prematurely assigned to Rhinoceros sinensis,which has resulted in confusion of taxonomy for decades,especially in South China.The Yanjinggou area in Chongqing Municipality of China,where the neotype of R.sinensis came from,has yielded abundant rhinocerotid fossils and is a key area to solve this problem.A recently discovered juvenile skull from a karstic fissure in this area can be referred to Dicerorhinus sumatrensis(Fischer,1814),which is the first confirmed non-Rhinoceros rhinocerotid from the area.This new finding indicates that non-Rhinoceros fossils might have been mixed in AMNH collection from Yanjinggou and thus the diagnosis of Rhinoceros sinensis needs reformation.On the other hand,Stephanorhinus?kirchbergensis is also detected in Granger’s collection based on our reobservation.The coexistence of Rhinoceros,Dicerorhinus and Stephanorhinus shows the higher diversity of Pleistocene rhinocerotids in South China.

Asplenium sanshuiense sp. nov.:the Lowest Latitude Fossil Record of the Genus

Extant Asplenium is one of the most widespread fern groups and occurs in the temperate and tropical regions. However, the fossil records of this genus are poorly documented, especially in the low latitudes. Here, a new species, Asplenium sanshuiense sp. nov. is described from the early Eocene of Sanshui Basin, Guangdong Province, South China. This is the lowest modern latitude fossil record of Asplenium and the first fossil assignment of A. section Darea （Jussieu） Bak., as well as the first fossil record of Asplenium reported from South China. This new species shows that Asplenium had already spread into South China by the early Eocene and the section Darea （Jussieu） Bak. was identifiable within the genus Asplenium during that time. This new species, combined with previous fossil spore-pollen records indicates a warm and humid climate in the Sanshui Basin of the early Eocene.

New Discovery of Nyssidium from the Yong’ancun Formation in Jiayin,China

Objective Follicular fruits in raceme infructescences with subparallel longitudinal ridges attached to the shoots were assigned to a widely used extinct genus of Nyssidium,which was suggested by Iljinskaja(1974)as the earliest appropriate generic name for this kind of fruits.

Ordovician integrative stratigraphy and timescale of China

In this chapter, starting with a brief review of the research history and current status in the studies of the Ordovician chronostratigraphy in China, the subdivision of the Ordovician System, definition and recognition of its series and stage boundaries, and possible stratigraphic gaps are discussed in details in order to establish a multidisciplinary stratigraphic correlation through an integrated approach including lithostratigraphy, biostratigraphy, radiometric dating, chemostratigraphy and magnetostratigraphy. Being internationally accepted, the Ordovician System is now subdivided into three series and seven stages, in ascending order, Lower(Tremadocian, Floian), Middle(Dapingian, Darriwilian) and Upper series(Sandbian, Katian,Hirnantian). Three of the seven "Golden Spikes" defining the bases of the Ordovician stages, which were established in 1997–2007, are located in China. As a regionally applied chronostratigraphy, the Ordovician System was subdivided in China into Lower(Xinchangian, Yiyangian), Middle(Dapingian, Darriwilian) and Upper series(Neichiashanian, Chientangkiangian,Hirnantian). This scheme agrees largely with the standard international classification, which can actually be directly applied to China, except for some special circumstances where the Neichiashanian and Chientangkiangian stages of the Upper Ordovician are used. Based on the new studies in recent years and distinctions and differences recognized in the development of the Ordovician System in the constituent terranes of China, a new framework for correlation among the major Chinese palaeoplates or terranes, e.g. South China, North China(including Tarim and Qaidam) and Xizang(Tibet)-western Yunnan, has been established. However, it has been recognized herein that uncertainties still remain on defining the base of the Tremadocian,Dapingian and Katian, and on the correlation between different mega-facies. More specifically, for the Tremadocian, the precise correlation of its base will depend on the better-defined conodont taxonomy, while for the Dapingian and Katian, on the correlation between different mega-facies. It is worthwhile to note that the chemostratigraphic studies of the Ordovician System in China produced the carbonate δ13 C curves for the Darriwilian(Middle Ordovician) and Katian(Upper Ordovician), which show significant differences from the composite global curve. Record of the Ordovician isotopic dating is relatively rare in China, with only three reliable ages from zircons that are all from the upper Katian to Hirnantian of the Upper Ordovician.Abundant bentonite beds in the Upper Ordovician of South China will also provide unique opportunities to advance the isotopic dating and related researches. Studies on the Ordovician magnetostratigraphy need to be significantly enhanced in China, as currently all the available results are restricted to the Lower Ordovician of North China, although they can be correlated with those known from other parts of the world. The analysis of the durational unevenness of the seven stages in the Ordovician supports the possibility to further subdivide the long-durational Tremadocian, Darriwilian and Katian stages, each into two substages.

New coryphoid fossil palm leaves (Arecaceae:Coryphoideae) from the Eocene Changchang Basin of Hainan Island,South China

Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.