新GRE阅读机经：冰川沉积物.

　　下面是小编为大家整理的新GRE机经的阅读部分，这篇是关于“冰川沉积物”的新GRE阅读机经，希望可以帮助各位考生打开阅读思路，提高新GRE阅读能力。

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　　冰川沉积物

　　Tills are commonly classified according to the perceived process of deposition. However, it is increasingly recognised that this classification, which is mainly based on macroscopic field data, has severe limitations. At the same time the concept of the dorming glacier bed has become more realistic as a framework for discussing tills and their properties, and this (tectonic) concept is irreconcilable with the existing (depositional) till classification scheme. Over the last 20 years large thin sections have been used to study tills, which has provided new insights into the textural and structural properties of tills. These results have revolutionised till sedimentology as they show that, in the main, subglacial tills possess dormational characteristics. Depositional properties are rare. 21

　　Based on this new insight the process of subglacial till formation is discussed in terms of glacier/ice sheet basal velocity, clay, water and carbonate content and the variability of these properties in space and time. The end result of this discussion is: till, the dorming glacier bed. To distinguish subglacial till from depositional sediments the term ‘tectomict’ is proposed. Within the single framework of subglacial till as the dorming glacier bed, many textural,structural and geomorphological features of till beds can be more clearly and coherentlyexplained and understood.

　　以上就是关于冰川沉积物的新GRE阅读机经，希望能够帮助各位考生更好地备考新GRE。机经的作用是非常重要的，有很多机经会反复考到，大家可以进行认真阅读，从中推断出出题人的出题思路，总结出新GRE阅读的解题，做到杀G成功!