a. Geol. [= F. turonien, f. L. Turonēs: see prec. and -IAN.] Denoting a subdivision of the Cretaceous or Chalk period and series of strata, answering to the ‘Lower White Chalk without flints’ of English geologists.
1850. Ansted, Elem. Geol., Min., etc., Index, Turonian formation. [Ibid., § 792. These beds are represented in France by the lower members of the ‘Terrain turonien,’ which exhibit nearly the same peculiarities as in England, though to a somewhat greater extent.]
1885. Geikie, Text Bk. Geol., VI. II. iii. § 2 (ed. 2), 820. The Cretaceous system of Europe has been subdivided as follows:—Upper … Danian, Senonian, Turonian, Cenomanian, Gault. Lower … Neocomian.
