Glacial furrows, striae and elongated troughs are met with everywhere, running mostly from north-west to south-east, as well as asar or eskers, which have the same direction.
Noteworthy local features in the landscape of the central lowlands are the eskers or gravel-ridges ((tsar), traversing the land in a direction from N.N.W.
Boulder-clays and sands, and gravels rearranged by water, occur throughout the lowlands; while the eskers or " green hills," characteristic grasscovered ridges of gravel, rise from the great plain, or run athwart valleys and over hill-sides, marking the courses of sub-glacial streams. When the superficial deposits are removed, the underlying rocks are found to be scored and smoothed by ice-action, and whole mountain-sides in the south and west have been similarly moulded during the Glacial epoch.
In places where the low ground is marshy, roads and railways often follow the ridge-lines of hills, or, as in Finland, the old glacial eskers, which run parallel to the shore.
All along Cape Cod; eskers, kames and river terraces afford the plainest evidences of the extent of the glacial sheet.