| 释义 |
rudaceous, a. Geol.|ruːˈdeɪʃəs|
[f. L. rūd-us rubble + -aceous.]
Of a rock: composed of larger grains than is an arenaceous rock.
1904A. W. Grabau in Amer. Geologist XXXIII. 242 In the further subdivision of the clastic rocks, texture or size of grain takes precedence over chemical composition... We commonly recognize these sizes of grain, 1st that larger than what is commonly considered the normal sandgrain, 2d, the sand-grain, and 3d, the rock flour or impalpable powder. The first texture is most appropriately called rudaceous. 1920― Gen. Geol. xviii. 570 Rocks of all textures may be argillaceous, those of rubbly (rudaceous) texture and those of arenaceous texture generally carrying the clay as an admixture or as part of the cement. 1949F. J. Pettijohn Sedimentary Rocks vii. 196 The rudaceous subtypes..are marked by characteristic compositional and textural features. 1977A. Hallam Planet Earth 168 Most sedimentary rocks, classified as either detrital or chemical-organic, are also classified according to their grain-size as rudaceous rocks, arenaceous rocks or argillaceous rocks. |