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The Erfurt Formation is a stratigraphic formation of the Keuper group and the Germanic Trias supergroup. It was deposited during the Ladinian. It lies above the Upper Muschelkalk and below the Middle Keuper.〔(【引用サイトリンク】url=http://www.bgr.de/app/litholex/gesamt_ausgabe_neu.php?id=5000001 )〕 ==Definition== The formation was defined in Erfurt-Melchendorf in 1830 by the late Franz Xaver Hofmann and named for the nearby town of Erfurt.〔 The Erfurt Formation is underlain by the Upper Muschelkalk. The lower boundary to the Erfurt Formation is the "Lettenkohlensandstein" in northern Germany and the "Grenz-bone-beds" in southern Germany. The formation is a sequence of dolomite, lacustrine limestones, claystone, evaporites, and fluviatile sandstones. The color is usually grey but can also be brown or reddish brown. The average thickness is 60 to 80 meter, with a maximum thickness of 700 meter in the Glückstadt-Graben.〔 The upper boundary is marked by dolomites, or claystones of the Grabfeld Formation.〔 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「Erfurt Formation」の詳細全文を読む スポンサード リンク
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