Helderbergn.

/ˈhɛldəbəːɡ/

Etymology: < Helderberg, the name of a range of hills in New York State.

Geology.

Used attributively to designate a group of strata found in the Helderberg region and later also the lower division of the Lower Devonian in North America and the fossils, etc., typical of it.

ΘΚΠ

the world > the earth > structure of the earth > age or period > stratigraphic units > [adjective] > primary or Palaeozoic > Devonian > specific

Helderberg1840

Coblenzian1853

Rhenan1853

Vergent1858

hercynian1880

Famennian1882

Frasnian1882

Givetian1882

Helderbergian1906

Siegenian1922

1840 W. W. Mather in Communication transmitting Rep. Geol. Surv. State (N.Y. State 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.

1880 J. D. 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’.

1880 J. D. Dana Man. Geol. (ed. 3) iii. ii. 236 The Helderberg rocks outcrop also over a large area in western Ohio.

1906 T. C. Chamberlin & R. D. Salisbury Geol. II. 454 From this intermediate or transitional assemblage the Helderberg fauna seems to have taken its origin.

Derivatives

Helderˈbergian adj.

/hɛldəˈbɜːɡɪən/

/hɛldəˈbɜːdʒɪən/

ΘΚΠ