Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/335

 MIDDLE CRETACEOUS.

1st. Gault, with Amm. cristatus, lautus, Raulinianus 22 metres.

2nd. Rhotomagian stage.

Lower beds.

Upper beds.

with Amm. auritus, planulatus, rostratus, Pecten asper, &c. ; (" Etage Uraconien" of M. Renevier; Cambridge Greensand) 35

with Turrilites costatus, tuberculatus, Bergeri, Puzosianus, Scaphites equalis, Ammonites Mantelli, rhotomagensis, varians, sulcatus, Mayorianus, Velledoe, Renauxianus, Belemnites ultimus, Janira quinquecostata, Avellana cassis, and Radiolites Mortoni ... 40

This stage corresponds to the upper greensand and the chalk marl.

3rd. Gardonian stage, chalk-marl beds of fluvio-marine origin, with Cyrena, Potamides, and Ostrea vardonensis, Coq., containing several beds of lignite, which are worked in the Departments of the Gard and Vaucluse 75

4th Carentonian stage

with Sphoerulites foliaceus, Caprina adversa, Ostrea flabella, 0. biauriculata, and Heterodiadema libycum (wanting in England). 40

with Inoc. labiatus, Amm. peramplus, A. Woollgari (Mant.), A. navicularis, A. rusticus, and Hemiaster Verneuili, Desml. 160

5th. Angoumian stage, compact limestones, with Hipp. Requienianus and Radiol, cornu-pastoris (wanting in England) 60

6th. Mornasian stage, alternate clays and sandstones, with Amm. Requienianus (wanting in England) 250

7th. Provencian stage, compact limestone, with layers entirely composed of Hipp. organisans, H. corornu-vaccinum, Sphoerulites Sauvagesii, S. Desmoulinsii, and Caprina Coquandiana, La Cadiere, Martigues ; base of the chalk of Gosau ; wanting in England) 120 802

Notwithstanding some very striking points of resemblance between the middle chalk of the two Charentes and that of the south of Provence, we find that the latter differs from the former in many important particulars. In the first place, it possesses the stages of the gault and upper greensand, which are wanting in the other ; further, the beds with Inoceramus labiatus are more than 500 feet in thickness ; and, lastly, between the Angoumian and Provencian stages there intervenes, especially in the Department of the Bouches- du-Rhone (between La Cadiere and La Ciotat), a stratum of sandstone of which there are no traces in the Departments of the south- west, and which is remarkably rich in fossils in the Communes of Uchaux and Mornas. But the most important modifications must be made in the upper chalk, which is subdivided in the following manner : —

THE UPPER CRETACEOUS.

1st. Coniacian stage : Ferruginous sandstone, with Ostrea auricularis (Brong.) in the neighbourhood of Piolene.