Rogen moraine: an example of glacial reshaping of pre-existing landforms
Rogen moraine: an example of glacial reshaping of pre-existing landforms
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罗根冰碛：冰川重塑原有地貌的一个例子
DOI：
10.1016/j.quascirev.2005.01.011
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发表时间：
2006
影响因子：
4
通讯作者：
P. Möller
中科院分区：
文献类型：
--
作者：
P. Möller
罗根冰碛广泛分布于前斯堪的纳维亚和劳伦泰德冰盖的核心区域。人们普遍认为，这些温和的拱形，冰流横脊可以用于重建古冰流模式，它们表明一个融床或多热基冰制度。然而，海脊的形成过程一直存在争议。本研究提出了一个两阶段的形成罗根冰碛，详细的沉积学和结构调查的基础上挖掘的沟槽在罗根冰碛景观在达拉纳省，瑞典中部。野外资料表明，罗根冰碛脊是先前存在的横向冰碛脊的重塑遗迹，最初是由冰边缘区的冰芯冰碛沉积而成。由于冰芯的背面和向下消耗，脊间槽充满了泥石流和河流沉积物，景观反转后转化为横向和丘状冰碛区。据建议，这主要的景观形成发生在早期Weichselian冰川消退。这一残留景观后来被保存在冷基的中晚期韦克塞尔冰盖下，在前北方冰消阶段变成湿基，并将前体地貌重塑为罗根冰碛。
Rogen moraine is widely distributed in the core areas of the former Scandinavian and Laurentide ice sheets. It is generally agreed upon that these gently arched, ice-flow transverse ridges can be used in reconstructions of paleo-ice-flow patterns and that they indicate a melted-bed or poly-thermal basal ice regime. However, the processes of ridge generation have been contentious. This study proposes a two-stage formation of Rogen moraine, based on detailed sedimentological and structural investigations in excavated trenches in a Rogen moraine landscape in the province of Dalarna, central Sweden. Field data suggest that Rogen moraine ridges are the reshaped remains of pre-existing transverse moraine ridges, originally deposited from ice-cored moraines in an ice-marginal zone. Due to back- and down-wasting of ice-cores, inter-ridge troughs were filled with debris flow and fluvial deposits, which after landscape inversion were transformed to areas of transverse and hummocky moraines. It is proposed that this primary landscape formation occurred during an Early Weichselian deglaciation. This relict landscape was later preserved beneath cold-based Mid- to Late-Weichselian ice sheet(s), which turned wet-based during the Preboreal deglaciation phase and re-moulded the precursor landforms into Rogen moraine.