干旱区生态环境知识资源中心(Arid): Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia

Arid

DOI	10.1016/j.palaeo.2019.109266
	Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia
	Retallack, Gregory J.1; Mao, Xuegang 2
通讯作者	Retallack, Gregory J.
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
ISSN	0031-0182
EISSN	1872-616X
出版年	2019
卷号	532
英文摘要	Controversial hairpin-shaped trace fossils (Myxomitodes stirlingensis) and discoid fossils (Cyclomedusa davidi) are here reinterpreted in a reassessment of sedimentology and paleosols of the 1.9 +/- 0.1 Ga Stirling Range Formation of Western Australia. Paleosols in the Stirling Range Formation were recognized from complex cracking patterns (peds and cutans), chemical and mineralogical zonation (soil horizons), and poikiloblastic crystals (desert roses). Redox profiles of the paleosols are evidence of well-drained profiles of a coastal plain under a low oxygen (433 +/- 116 ppmv) and carbon dioxide (564 +/- 64 ppmv) atmosphere. Gypsum pseudo morphs in paleosols that are deeply weathered chemically, represent a persistence of acid sulfate weathering, better known in Archean paleosols before the Great Oxidation event at 2.45 Ga. Chemical composition of the paleosols is evidence of a humid (1478 +/- 182 mm mean annual precipitation) temperate (11.3 +/- 0.5 degrees C mean annual temperature) paleoclimate. Their paleoenvironmental setting was a coastal plain on a passive tectonic margin. Megafossils were found on paleosols of western red sandstones of the Stirling Range Formation, not in gray shales and sandstones of marine facies to the east. Trace fossils (Myxomitodes stirlingensis) and discoid fossils are both found at the surface of well drained paleosols, and so were not metazoan trails, nor sea jellies. Myxomitodes was more likely a grex (slug) trail of soil slime molds, and the Cyclomedusa discoids, were probably microbial colonies. Pervasive microfilamentous structures in the paleosol surface are additional evidence of Paleoproterozoic microbial earth ecosystems.
英文关键词	Stirling Range Formation Paleosol Paleoclimate Mycetozoa Microbial earth
类型	Article
语种	英语
国家	USA ; Peoples R China
收录类别	SCI-E
WOS记录号	WOS:000484871600012
WOS关键词	ALBANY-FRASER OROGEN ; STIRLING RANGE FORMATION ; RARE-EARTH-ELEMENTS ; PRECAMBRIAN PALEOSOLS ; GREENSTONE-BELT ; IRON-FORMATION ; CAMBRIAN PALEOSOLS ; PILBARA CRATON ; MASS-BALANCE ; MOBILE BELT
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS研究方向	Physical Geography ; Geology ; Paleontology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217870
作者单位	1.Univ Oregon, Dept Earth Sci, Eugene, OR 97403 USA; 2.Fujian Normal Univ, Inst Geog, Fuzhou 350007, Fujian, Peoples R China
推荐引用方式 GB/T 7714	Retallack, Gregory J.,Mao, Xuegang. Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia[J],2019,532.
APA	Retallack, Gregory J.,&Mao, Xuegang.(2019).Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,532.
MLA	Retallack, Gregory J.,et al."Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 532(2019).