TY - JOUR
T1 - Microbially induced sedimentary structures from the Mesoproterozoic Huangqikou Formation, Helan Mountain region, northern China
AU - Lan, Zhong Wu
AU - Chen, Zhong Qiang
AU - Li, Xian Hua
AU - Kaiho, Kuino
N1 - Funding Information:
Constructive comments from Nora Noffke, an anonymous reviewer, and the handling editor Guochun Zhao have greatly improved the quality of this paper. We thank Saihong Yang and Xin Yan for assistance during SEM imaging. Junfang Zhao is appreciated for assisting in acquiring the Raman spectrum. We are also indebted to Jianhua Wang for making thin sections, and Hongwei Li for analyzing carbon isotopes. This work was supported by NSFC Grants ( 41173010 to XHL, and 41273069 to ZWL), China Postdoctoral Science Foundation Grant ( 2012M510537 to ZWL), and a grant in aid from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Wuhan) (grant number: GPMR200901 to ZQC).
PY - 2013/8
Y1 - 2013/8
N2 - Seven types of microbially induced sedimentary structures (MISS): wrinkle structures, levelled ripple marks, organic carbonaceous laminae, microsequences, polygonal sand cracks, polygonal sand crack fills, and gas domes are documented from the Mesoproterozoic Huangqikou Formation of the Helan Mountain region, western part of North China. Facies analysis suggests that the MISS-hosting rocks were deposited in a supertidal to intertidal setting. Both wrinkle structures and gas domes are morphologically different from those previously documented from other ancient siliciclastic rocks, but probably formed by the same microbially mediated process as those published elsewhere. Other MISS resemble their ancient and modern counterparts in both morphology and size. The presence of carbonaceous laminae, coupled with laser Raman and carbon isotopic data (-25. ±. 0.5‰), indicates a biogenic origin of the wrinkle structures. The absence of intercalating mudstone layers as well as different lithologic composition between polygonal sand cracks/crack fills and host rock indicate that both the polygonal sand cracks and polygonal sand crack fills likely resulted from dehydration and desiccation of organic rich microbial mats. The biogenicity of gas domes is supported by the different lithologic composition between infillings and wall.
AB - Seven types of microbially induced sedimentary structures (MISS): wrinkle structures, levelled ripple marks, organic carbonaceous laminae, microsequences, polygonal sand cracks, polygonal sand crack fills, and gas domes are documented from the Mesoproterozoic Huangqikou Formation of the Helan Mountain region, western part of North China. Facies analysis suggests that the MISS-hosting rocks were deposited in a supertidal to intertidal setting. Both wrinkle structures and gas domes are morphologically different from those previously documented from other ancient siliciclastic rocks, but probably formed by the same microbially mediated process as those published elsewhere. Other MISS resemble their ancient and modern counterparts in both morphology and size. The presence of carbonaceous laminae, coupled with laser Raman and carbon isotopic data (-25. ±. 0.5‰), indicates a biogenic origin of the wrinkle structures. The absence of intercalating mudstone layers as well as different lithologic composition between polygonal sand cracks/crack fills and host rock indicate that both the polygonal sand cracks and polygonal sand crack fills likely resulted from dehydration and desiccation of organic rich microbial mats. The biogenicity of gas domes is supported by the different lithologic composition between infillings and wall.
KW - Biogenicity
KW - Huangqikou Formation
KW - Mesoproterozoic
KW - Microbially induced sedimentary structures
KW - North China
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U2 - 10.1016/j.precamres.2013.04.006
DO - 10.1016/j.precamres.2013.04.006
M3 - Article
AN - SCOPUS:84878197285
VL - 233
SP - 73
EP - 92
JO - Precambrian Research
JF - Precambrian Research
SN - 0301-9268
ER -