“drumlin”的概念、定义、翻译、参考文献-科学参考

drumlin

Geology and Earth Sciences

Smooth, streamlined, oval-shaped land-form, one end of which is blunt and the other tapered. Drumlins may occur singly, but more commonly they are found within a large group, called a ‘drumlin field’ or ‘drumlin swarm’. Usually they are composed of boulder clay, but occasionally they are made of solid rock (hence ‘rock drumlin’). They are believed to be formed beneath the outer zone of an expanding ice sheet, during a major advance: they result from the selective deposition of material that is then streamlined by the moving ice. The long axis of a drumlin lies parallel to the direction of the advance.

Geography

A long hummock or hill deposited and shaped under an ice sheet or very broad glacier, while the ice was still moving. The classic view sees the drumlin longitudinal profile as asymmetric, with a steeper stoss (upstream) side and a gentler lee (downstream) side. However, in a study of 29000 British drumlins, Spagnolo et al. (2011) ESPL 36, 6, 790 found that the average profile built from all mapped drumlins appears almost symmetric. Furthermore, they found that drumlin shape is not a good indicator of the palaeo ice flow direction. Drumlins have been formed via a variety of mechanisms; see Murray (in J. Holden, ed. (2012) pp. 496–7), for a very accessible summary of drumlin formation theories. Phillips et al. (2010) Sediment. Geol. 232, 98 highlight the role played by bedrock geology on the distribution of drumlins beneath an ice stream (this entire issue of Sediment. Geol. is devoted to drumlins. A large group of drumlins is a drumlin swarm, or drumlin field. Briner (2007) Boreas 36, 2 argues that the bedforms in the New York drumlin field indicate fast ice flow. Rock drumlins are more commonly known as roches moutonnées.

单词	drumlin
释义	drumlin Geology and Earth Sciences Smooth, streamlined, oval-shaped land-form, one end of which is blunt and the other tapered. Drumlins may occur singly, but more commonly they are found within a large group, called a ‘drumlin field’ or ‘drumlin swarm’. Usually they are composed of boulder clay, but occasionally they are made of solid rock (hence ‘rock drumlin’). They are believed to be formed beneath the outer zone of an expanding ice sheet, during a major advance: they result from the selective deposition of material that is then streamlined by the moving ice. The long axis of a drumlin lies parallel to the direction of the advance. Geography A long hummock or hill deposited and shaped under an ice sheet or very broad glacier, while the ice was still moving. The classic view sees the drumlin longitudinal profile as asymmetric, with a steeper stoss (upstream) side and a gentler lee (downstream) side. However, in a study of 29000 British drumlins, Spagnolo et al. (2011) ESPL 36, 6, 790 found that the average profile built from all mapped drumlins appears almost symmetric. Furthermore, they found that drumlin shape is not a good indicator of the palaeo ice flow direction. Drumlins have been formed via a variety of mechanisms; see Murray (in J. Holden, ed. (2012) pp. 496–7), for a very accessible summary of drumlin formation theories. Phillips et al. (2010) Sediment. Geol. 232, 98 highlight the role played by bedrock geology on the distribution of drumlins beneath an ice stream (this entire issue of Sediment. Geol. is devoted to drumlins. A large group of drumlins is a drumlin swarm, or drumlin field. Briner (2007) Boreas 36, 2 argues that the bedforms in the New York drumlin field indicate fast ice flow. Rock drumlins are more commonly known as roches moutonnées.
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