| 释义 |
Tremadocian, a. Geol.|trɛməˈdɒkɪən|
[f. prec. + -ian.]
Of, pertaining to, or designating a stratigraphic series typified by the Tremadoc beds, orig. placed in the Upper Cambrian but now sometimes regarded as Lower Ordovician. Also absol.
1910W. G. Fearnsides in Monckton & Herries Geol. in Field xxxii. 795 Across the denuded edges of Tremadocian and Olenidian rocks rest the basal members of the great Arenig series. 1927Q. Jrnl. Geol. Soc. LXXXVIII. 145 The order of that succession is applicable in all its detail to the type-area of the Tremadocian in the western parts of Wales. 1950David & Brown Geol. Commonw. Austral. I. iii. 135 By Tremadocian time graptolites had begun to make their appearance in Victoria. 1974Nature 18 Oct. 575/1 None of the formal papers included any discussion of the boundaries of the Ordovician, most speakers making it clear whether they regarded the Tremadocian as Cambrian (as in English usage) or Ordovician. |