Also 7 talu, talud. [a. F. talus (16th c.), in Dict. Acad. 1696 talut, OF. (12th c. in Hatz.-Darm.) talu slope:—late pop. L. *tālūt-um, deriv. of tālus ankle (taken in sense of F. talon heel): cf. next.]
1. A slope; spec. in Fortification, the sloping side of a wall or earthwork, which gradually increases in thickness from above downwards.
1645. N. Stone, Enchiridion Fortif., 3. On the inward side they gave them [the walls] a Talud or slooping which increased them in thicknesse towards the bottom.
1672. Phil. Trans., VII. 4081. The first Wall … being much broader below by reason of the Talu or slope.
1704. J. Harris, Lex. Techn., I, Talus, or Talut, properly signifies any Thing that goes sloping, as the Talus of a Wall in Masonry…. In Fortification, the Talus of a Bastion or Rampart, is the Slope allowed to such a Work whether it be of Earth or Stone.
1762. Sterne, Tr. Shandy, VI. xxi. To determine the depths … of the ditches,—the talus of the glacis, and the precise height of the … parapets.
1862. Wraxall, trans. Hugo’s Les Misérables, III. vii. The enemy’s guns had opened a break from the parapet to the talus.
† b. The sloping side of a trench or the like.
1727. Bradley’s Fam. Dict., s.v. Garden, There must be one on the Brink of the Trench to spread the Dung upon the Talus.
2. Geol. A sloping mass of detritus lying at the base of a cliff or the like, and consisting of material which has fallen from its face; also, the slope or inclination of the surface of such a mass.
1830. Lyell, Princ. Geol., I. II. xx. 266. It is only at a few points that the grassy covering of the sloping talus marks a temporary relaxation of the erosive action of the sea. Ibid. (1863) Antiq. Man, xvii. 343. Huge taluses of fallen drift.
1865. Livingstone, Zambesi, vii. 171. The talus of each portal, keeping close together northwards, makes a narrow, upright-sided trough from the cataract up to Pajodze.
1876. Page, Adv. Text-bk. Geol., xv. 275. The cemented fragments of a terrestrial talus or scree.
1881. Darwin, Veg. Mould, 279. An old talus of chalk-fragments (thrown out of a quarry) which had become clothed with turf.
attrib. and Comb. 1867. H. Macmillan, in Macm. Mag., No. 99. 256/2. Great talus-heaps or débris.
1904. Daily Chron., 24 March, 3/1. There was no stratification as might be expected if it were a talus-formation. Ibid. (1906), 20 Feb., 4/2. The water getting into the talus rock, a mass of soft stuff without any regular drainage.
b. A descending slope of a mountain, etc., without reference to its mode of formation.
1830. Sir T. D. Lauder, Moray Floods, 230. We found an extensive marl bank reposing on the inclined talus at the foot of the hill.
1853. Kane, Grinnell Exp., xv. (1856), 108. One of these bergs presented a long inclined talus, which was evidently part of an original slope, unaltered by after changes in equilibrium. Ibid. (1856), Arct. Expl., I. xv. 169. A slide down an inclined plane, whose well-graded talus gave me ample time to contemplate the contingencies at its base.
1865. Livingstone, Zambesi, ii. 61. One point of view on the talus of mount Morumbwa.
1868. Lockyer, trans. Guillemin’s Heavens (ed. 3), 100. Beyond the second ridge a talus slopes gradually down northwards to the general level of the lunar surface.
