| 释义 |
Pebidian, a. Geol.|pəˈbɪdɪən|
[See quot. 1877 and -an.]
Epithet of a thick sequence of volcanic rocks of Pre-Cambrian age exposed in Preseli, SW Wales. Also absol.
1877H. Hicks in Q. Jrnl. Geol. Soc. XXIII. 230, I propose now to divide the Pre-Cambrian rocks [in the vicinity of St. David's] into two distinct series under the local names of Dimetian..for the lower, and Pebidian (Pebidiauc being the name of the division or hundred in which the rocks are chiefly exposed) for the upper series. 1880Ibid. XXXVI. 538, I have long been disposed to consider the felspathic series in Shropshire, or at least the Lilleshall group, as representing the Pebidian. 1937Pringle & George S. Wales ii. 15 In the neighbourhood of St. David's, the Pebidian tuffs occupy a broad anticlinal area which extends inland for several miles in an east-north⁓east direction. 1969Bennison & Wright Geol. Hist. Brit. Isles iv. 80 The Caerfai Series commences with a reddish basal conglomerate, some of the pebbles being derived from the adjacent Precambrian volcanics, the Pebidian. |