In geology, a terrace is a level plain, usually with a steep front, bordering a river, a lake, or sometimes the sea. Many rivers are bordered by a series of terraces at different levels, indicating the flood plains at successive periods in their history. Research Terrace
In geology, a till is a stiff unstratified deposit of clay mixed with sand, gravel and boulders without lamination, formed in a glaciervalley by means of the waters derived from the melting glaciers. The term is sometimes applied to alluvium of an upper river terrace, when not laminated, and appearing as if formed in the same manner. Research Till
Glenroy is a deep valley in the Highlands of Scotland, parallel to Glenmore (the Great Glen), in Lochaber, Invernessshire. It is nearly 14 miles in length, and little more than 0.5 miles in breadth, and is celebrated for its so-called Parallel Roads, which are three parallel terraces running along either side of the glen. Not only do the lines on the same side run parallel to each other, but on both sides they respectively occupy the same horizontal level. These terraces project, at some parts only a few feet from the hill-side, and at others widen out so as to be a number of yards in breadth. The lowest terrace is 850 to 862 feet above the sea-level; the middle, 1062 to 1077 feet;
and the highest 1144 to 1155 feet. Their origin has been much disputed, but according to Macculloch, Agassiz, Buckland, and Geikie, the roads are shore-lines of freshwaterlakes. As, however, no land-barrier is discoverable in the vicinity, they refer the lake or lakes to the glacial period, holding that glaciers must have descended from Ben Nevis and dammed up the water in Glenroy. As these glaciers did not disappear simultaneously, the surface of the lake had different elevations successively, and thus distinct shore-lines or beaches were formed at different times. Research Glenroy
Abbreviations
Research Terrace
