| 释义 |
Helderberg Geol.|ˈhɛldəbɜːg|
The name of a range of hills in New York State, used attrib. to designate a group of strata found there and later also the lower division of the Lower Devonian in North America and the fossils, etc., typical of it. Hence Helderˈbergian |-bɜːg-, -bɜːdʒ-|, a.
1840W. W. Mather in Geol. Surv. State N.Y. (Assembly No. 50) 212 The subjoined nomenclature of these rock groups is presented as local, and one of convenience merely... (3) The next in order is the Helderberg group, which is composed of various strata of common and hydraulic limestones..interstratified with grits and shales. 1880J. Dana Man. Geol. (ed. 3) iii. ii. 236 The Lower Helderberg period..is so named because its beds are well displayed in the Helderberg Mountains, south of Albany, beneath Devonian beds called the ‘Upper Helderberg’. Ibid., The Helderberg rocks outcrop also over a large area in western Ohio. 1906Chamberlin & Salisbury Geol. II. 454 From this intermediate or transitional assemblage the Helderberg fauna seems to have taken its origin. Ibid. 455 The capulid shells which abound at some localities in the Helderbergian..faunas. 1949C. O. Dunbar Hist. Geol. x. 207 Two stages [of the American Devonian] are recognized, the Helderbergian and the Deerparkian, each with several formations. The Helderberg stage includes only limestone and calcareous shales. |