The wide range of features produced by glacial erosion, over scales from millimeters to kilometers, results from both the complexity of the processes and their glaciological controls, and interactions with heterogeneous substrates. Small-scale features include striations or striae and chattermarks that are produced by clasts in basal ice being forced against underlying bedrock, as well as smoothed and sculpted rock surfaces (s-forms). Intermediate scale such as whalebacks and rock drumlins are smoothed, subglacially formed, elongate bedrock landforms produced by glacial abrasion, and somewhat similar are roche moutonnées which have a smoothed up-glacier surface and a plucked, quarried surface in the down-flow direction. Other classic landforms that result from a combination of erosion and deposition include crag and tails, drumlins and flutings. Larger scale characteristic features of glaciated landscapes reflect patterns of erosion controlled by ice dynamics and glacial history, and include glacial troughs and fjords, over-deepened rock basins, cirques, and large areas of extensively scoured bedrock.