Configuration and Dynamics of the Laurentide Ice Sheet During the Late Wisconsin Maximum
Configuration and Dynamics of the Laurentide Ice Sheet During the Late Wisconsin Maximum
复制标题
威斯康星州极大期晚期劳伦太德冰盖的构造和动力学
DOI：
--
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Vincent
中科院分区：
文献类型：
--
作者：
A. Dyke;L. Dredge;J. Vincent
在1943年之前，劳伦泰德冰盖被认为有三个主要的圆顶，分别位于基瓦廷、拉布拉多和帕特里夏（TYRRELL，1898 a，B; 1913）。弗林特（1943年）认为这些中心只是局部和暂时的重要性，并倾向于单圆顶冰盖。尽管缺乏支持性的地质证据，尽管在此期间提出了福克斯圆顶的主张（伊韦斯和ANDREWS，1963），但单圆顶概念直到20世纪70年代末才受到严重挑战，事实上，它仍然受到大力支持（休斯时代/，1977年;丹顿和HUGHES，1981年）。本文扩展和修改了最近的结论，劳伦泰德冰盖有一个以上的圆顶在晚威斯康星州最大。我们提出了一个模型，包括五个圆顶（麦克林托克，福克斯，拉布拉多，哈德逊，和（？）驯鹿）的基础上的位置，冰分，冰流模式，漂流组成，晚冰期的特点，冰后期均衡恢复和自由空气重力异常。我们的拉布拉多和哈德逊冰穹与泰瑞尔的拉布拉多冰盖和帕特里西亚冰盖密切对应;我们的驯鹿和麦克林托克冰穹以及劳伦泰德冰盖以北伊丽莎白女王群岛上方的富兰克林冰复合体与泰瑞尔的原始基瓦廷冰盖相对应。泰瑞尔对福克斯盆地地区的冰川作用方式并不了解，但我们对福克斯圆顶的重建与伊韦斯和安德鲁斯最初的提议非常一致。像泰瑞尔一样，我们的重建是基于通过广泛的测绘获得的现场证据;单圆顶模型仍然没有地质数据的支持。
Prior to 1943 the Laurentide Ice Sheet was considered to have three major domes centered in Keewatin, Labrador, and Patricia (TYRRELL, 1898 a, b; 1913). FLINT (1943) argued that these centres were of only local and temporary importance and favoured a single-domed ice sheet. Despite the lack of supporting geological evidence, and despite the proposition of a Foxe Dome in the interim (IVES and ANDREWS, 1963), the single-dome concept was not seriously challenged until the late 1970's and, in fact, is still strenuously supported (HUGHES era/., 1977 ; DENTON and HUGHES, 1981). This paper extends and modifies recent conclusions that the Laurentide Ice Sheet had more than one dome at the Late Wisconsin maximum. We propose a model incorporating five domes (M'Clintock, Foxe, Labrador, Hudson, and (?) Caribou) based on the position of ice divides, ice flow patterns, drift composition, late-glacial features, postglacial isostatic recovery and free-air gravity anomalies. Our Labrador and Hudson domes closely correspond to Tyrrell's Labradorean and Patrician ice sheets; our Caribou and M'Clintock domes together with the Franklin Ice Complex over the Queen Elizabeth Islands north of the Laurentide Ice Sheet, correspond to Tyrrell's original Keewatin Ice Sheet. The style of glaciation of the Foxe Basin region was not known to Tyrrell, but our reconstruction of the Foxe Dome is in close agreement with the original proposal of Ives and Andrews. Like Tyrrell, our reconstruction is based on field evidence obtained through extensive mapping; the single dome model continues to be unsupported by geological data.