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The Xiong'er Volcanic Belt () is a 1770 to 1800 million year-old group of volcanic rocks located on the southern edge of the North China craton (Figure 1).〔〔〔 It covers an area of approximately 60,000 km2 and varies from 3000 m to 7000 m thick. The perimeter of the volcanic belt is composed of three faults: the Jianxian-Lintong fault to the northwest, the Luoyang-Baofeng fault to the northeast, and the Luonan-Luanchan fault to the south (Figure 2).〔〔 The volcanic belt formed at a time in Earth's history when all of the continents were joined together forming the Supercontinent Columbia, the earliest known supercontinent. The Xiong'er Volcanic Belt is very important because it can provide valuable information to help piece together the formation and breakup of the Supercontinent Columbia and the North China craton by identifying what type of boundary was located on the southern edge of the North China craton.〔〔 ==Geologic formations== The Xiong'er Volcanic Belt is made up of four geologic formations which include one sedimentary and three volcanic units.〔〔 Starting at the bottom is the sedimentary Daguish formation and above it are the three volcanic formations, which consist of the Xushan, Jidanping, and Majiahe.〔〔〔 They unconformibly overlie the Archean to Paleoproterozoic formations which make up the basement rock in the area, and they lie unconformibly below the meso-Neoproterozoic sedimentary rocks, which include sandstones and limestones.〔〔 *Daguish Formation :The Daguish formation is the bottommost formation, with a maximum thickness of 212 m.〔 It is composed of sedimentary rocks such as breccia, conglomerate, and mudstone.〔〔〔 *Xushan Formation :The Xushan formation is the second formation from the bottom and is dominantly composed of the volcanic rocks basalt andesite and andesite.〔〔〔 *Jidanping Formation :The Jidanping formation is the third formation from the bottom and is a mixture of volcanic rocks which include dacite, rhyolite, basalt andesite, and andesite.〔〔〔 *Majiahe Formation :The Majiahe formation is the top formation and is dominantly composed of basalt andesite and andesite but also contains pyroclastic and sedimentary rocks as well.〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Xiong'er Volcanic Belt」の詳細全文を読む スポンサード リンク
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