A high-quality mid-Neoproterozoic paleomagnetic pole from South China, with implications for ice ages and the breakup configuration of Rodinia

The historical evolution of an ancient forest that developed at Gaoyao, south China, can be divided into 4 stages of radiocarbon intervals (1.1–1.5, 2.0–3.5, 3.6–4.0, and 4.3–4.9 ka) in which the last 3 stages all developed in a wetland and formed humic layers of 2.0, 0.5, and 0.7 m depth, respectively. The humic layers were interrupted by 2 white-gray silty clay layers that most likely formed during climate fluctuations. Four drought events were identified during the evolution of the ancient forest, occurring around 4.3, 3.6, 2.0, and 1.1 ka, respectively, with durations of ∼1000 14C yr. These events are consistent with other records both in low- and high-latitude areas, in particular with the little ice ages occurring since the mid-Holocene. Precipitation likely increased from 5.0 to 3.6 ka in south China, then decreased, which is probably the main cause for the development as well as the demise of the ancient forest.

Download Full-text

On Campus Communication - Take South China University of Technology for Example

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.250-253.3893 ◽

2011 ◽

Vol 250-253 ◽

pp. 3893-3897

Author(s):

Ju Xue

Keyword(s):

South China ◽

Open Space ◽

Design Method ◽

High Quality ◽

Campus Environment ◽

Space Design ◽

Public Open Space ◽

University Of Technology ◽

Communication Space ◽

Development Of Students

Nowadays high-quality and versatile-quality talents are in demand and study place is no longer confined to classroom, which makes people realize the importance of campus communication space for cultivating people. How to create a special and connotative campus environment with culture foundation by combining the space design is the focus of this paper, and take South China University of Technology for example, I will discuss how the campus public open space help the development of students in order to find a design method suitable for campus public open space.

Download Full-text

Formalin-Fixed Fish Larvae Could Be Effectively Identified by DNA Barcodes: A Case Study on Thousands of Specimens in South China Sea

Frontiers in Marine Science ◽

10.3389/fmars.2021.634575 ◽

2021 ◽

Vol 8 ◽

Author(s):

Gang Hou ◽

Yanying Chen ◽

Sijin Wang ◽

Jinrun Wang ◽

Weitao Chen ◽

...

Keyword(s):

South China Sea ◽

South China ◽

Large Scale ◽

Fish Larvae ◽

Morphological Characters ◽

Dna Barcodes ◽

High Quality ◽

China Sea ◽

Early Stages ◽

Formalin Fixed

Delimiting ichthyoplankton is fundamental work for monitoring the recruitment process and identifying the spawning and nursing grounds of fishes. Nevertheless, it is extremely difficult to identify the fish during the early stages at the species level based on morphological characters because of the paucity of diagnostic features. In this study, we investigated the fish larval community through large-scale ecosystemic sampling in South China Sea (SCS) during 2013 and 2017 using DNA barcodes. To maintain the morphologies of fish larvae, we preserved the larvae in formalin and developed a technique to recover their DNA. Among the 3,500 chosen larvae, we successfully extracted DNA from 2,787 larval samples and obtained 1,006 high-quality sequences. Blast searches showed that 408 larvae (i.e., 40.5%) could be unambiguously identified to species, 413 larvae (i.e., 41.1%) were ambiguously species delimitation, and 185 larvae (i.e., 18.4%) showed a low match similarity with target sequences. A total of 101 species were identified, among which 38 and 33 species corresponded to demersal and reef-associated species, whereas the remaining 30 species corresponded to benthopelagic, pelagic-oceanic, bathypelagic, and pelagic-neritic species. High-quality larval photographs of the 101 diagnosed species showed intact morphological characters and thus provided a reference for identifying fish species during the early stages based on morphological characters. Our study highlighted the possibility of recovering and amplifying DNA from formalin-fixed samples and provided new insight into the fish larval community in the SCS.

Download Full-text

Depositional Palaeoenvironment and Models of the Eocene Lacustrine Source Rocks in the Northern South China Sea

10.5194/egusphere-egu21-298 ◽

2021 ◽

Author(s):

Niubin Zhao

Keyword(s):

Organic Matter ◽

South China Sea ◽

South China ◽

Deep Water ◽

Northern South China Sea ◽

Volcanic Rocks ◽

Source Rocks ◽

High Quality ◽

Reducing Conditions ◽

Parent Rocks

&#160; &#160; &#160; Element geochemical analysis of 94 ditch cutting samples of the shale source rock from the Wenchang Formation in the Zhuyi sub-basin and the Liushagang Formation in the Weixinan sub-basin was conducted to determine their palaeoenvironment and main controlling factors and to further establish development models. The results indicate that freshwater and a warm and humid climate were characteristics of the depositional palaeoenvironment between Wenchang and Liushagang formations. During the deposition of Wenchang Formation, the parent rocks mainly consisted of felsic volcanic rocks, the water was characterized by a high palaeoproductivity, shallow-deep water depths, and weakly reducing conditions, whereas during the deposition of Liushagang Formation, the parent rocks mainly consisted of mafic volcanic rocks, and the palaeoproductivity, palaeowater depth, and reducing conditions of the water were better than during the deposition of Wenchang Formation. The formation of high-quality source rocks in the Liushagang Formation were mainly controlled by two factors: (1) the mafic igneous rock provenance and strong weathering provided macronutrients (e.g. P, Fe) for water; (2) high palaeoproductivity provided the source of organic matter, which played a much important role than preservation condition of organic matter. For Wenchang Formation, the good preservation of organic matter which was created by the reducing environment in deep water was also necessary. Accordingly, two models were briefly summarized: a productivity and preservation model for the Wenchang Formation source rocks and a productivity model for the Liushagang Formation source rocks, both of them can develop high-quality source rocks, but the source rock quality of the former were lower than of the latter, this was mainly attributed to the difference in the nutrients and palaeoproductivity. This study provides valuable guidance for oil and gas exploration in the northern South China Sea and the study of lacustrine source rocks in other areas.

Download Full-text