SOME GLACIAL ACTION IN INDIANA.
SOME GLACIAL ACTION IN INDIANA.
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印第安纳州的一些冰川活动。
DOI：
10.1126/science.ns-2.22.6
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发表时间：
1883
期刊：
影响因子：
56.9
通讯作者：
J. Coulter
中科院分区：
文献类型：
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作者：
J. Coulter
我和地质学班上的同学一直在研究这附近（蒙哥马利县）的冰川沉积物。我们的主要水道是所谓的糖溪，是沃巴什河的一条支流，它占据了一个西南方向的山谷，实际上与沃巴什河在向南急转弯之前横穿该州的趋势相同。沿着沃巴什河和糖溪的山谷，有大量的证据表明冰川沿着山谷的方向移动，被称为伊利湖冰川，因为它沿着湖泊的轴线前进，沿着莫米河，穿过韦恩堡的低分水岭，进入沃巴什河。由于这个古老的冰川的沉积，糖溪本身被迫向南急剧弯曲，在我们以西几英里处，并在软的含碳下层砂岩中开辟了新的河道。在这个国家的一个地方，在冰河时代以前的山谷里，有一条小溪，它穿过我们以前认为的一个很大的终末冰碛，这冰碛正好横亘在山谷里。最近的洪水冲走了一些冰碛，露出了乡村的岩石。这块岩石被发现是平整的，完全覆盖着冰川的划痕，所有方向都是北20？W.，或者几乎与溪谷和前冰川的路线成直角。现在，在全国许多地方都可以找到第二冰川的这些划痕；我们古老的终末冰碛被证明是中间冰碛，它的背后有一排巨大的冰碛，同样向西北移动。把这些事实记录在这里，是希望它们对考虑一个非常棘手的问题有所帮助。约翰·m·库尔特。
WITH members of my class in geology, I have been examining the glacial deposits in this vicinity (Montgomery county). Our chief water-course is what is called Sugar Creek, a tributary of the Wabash River, which occupies a valley with a general south-westerly bearing, virtually the same trend which the Wabash has across the state before it makes its sharp bend to the south. Along the valleys of the Wabash and Sugar Creek, there are abundant evidences of a glacier which moved in the direction of the valleys, and is known as the Lake Erie glacier, as it advanced in the direction of the axis of that lake, and so up the Maumee, and across the low divide at Fort Wayne, into the Wabash. Sugar Creek itself has been compelled to bend sharply to the south a few miles to the west of us by the deposits of this old glacier, and has cut its new channel through the soft subcar-boniferous sandstone. At one place in this county, where the creek still occupies its pre-glacial valley, it cuts through what we for-rmerly considered a large terminal moraine, which lies squarely across the valley. Recent floods have swept away some of this moraine, and laid bare the country rock. This rock is found to be smoothly planed, and absolutely covered with glacial scratches all trending N. 20? W., or almost at right angles to the valley of the creek and the course of the former glacier. These scratches of the second glacier are now found in many places throughout the county; and our old terminal moraine proves to be a medial moraine, and bears upon its back a line of huge bowlders with the same north-westerly trend. These facts are recorded here in the hope that they may-be of some use in the consideration of a much-vexed question. JOHN M. COULTER.