| 释义 |
greywacke Geol.|ˈgreɪwækə|
Also graywacke, greywack.
[Anglicised form of grauwacke.]
A conglomerate or grit rock consisting of rounded pebbles and sand firmly united together; originally applied to various strata of the Silurian series. Also attrib.
1811Pinkerton Petral. I. 293 Almost the whole of the mines in the Hartz are situated in greywack. 1813Bakewell Introd. Geol. (1815) 106 Gray-wacke is nearly allied to clay-slate, and the finer kinds of gray-wacke-slate pass into clay-slate, and are not to be distinguished. 1833Lyell Princ. Geol. III. 194 The fundamental rock of the Eifel is an ancient secondary sandstone and shale, to which the obscure and vague appellation of ‘graywacke’ has been given. 1834H. S. Boase Prim. Geol. 215 The greywacké..and cretaceous groups. 1849Murchison Siluria viii. 172 From its southern margin..greywackès..rise from under the coal-fields. 1853G. Johnston Nat. Hist. E. Bord. I. 5 The greywacke and syenitic hills. 1895A. Harker Petrol. xvi. 193 The old term greywacke (Ger. Grauwacke) has been revived for a complex rock with grains of quartz, felspar, and other minerals and rocks united by a cement usually siliceous. 1939Amer. Jrnl. Sci. CCXXXVII. 29 This is the direction of a marked change in the angle of slope of the hillside..which is inferred to mark the vertical or highly inclined outer margin of the granite at its contact with Silurian shales and greywackes. 1950N.Z. Jrnl. Agric. Jan. 16/3 Sandy silts, silts, clays, and greywacke shingle have been deposited by the Waipawa and Tukituki Rivers. 1963Krumbein & Sloss Stratigr. & Sedimentation (ed. 2) v. 171 Many Precambrian and early Paleozoic graywackes are partially metamorphosed. 1970Nature 3 Jan. 57/2 They resemble ‘gouge-channels’ occurring in graded greywacke beds. |