216 Geological Society. 



therefore, are a part of the lower, all the upper green-sand, and 

 probably a portion of the chalk. 



9. Lower Nummulitic Limestone and Shale, fyc. (Sonthofen Iron 

 Ores). The strata containing the iron ores at Sonthofen surmount 

 the preceding series in the gorge of the Starzlach. The author 

 considers them, from the character of their fossils, particularly Spa- 

 tangi, certain species of Nummulites, Belemnites, Terebratulae, 

 and Trigoniae, to be more connected with the cretaceous than with 

 the superior formations. To show the essential difference be- 

 tween the age of these iron ores of Sonthofen and those of the 

 Kressenberg, a detailed section is described from south to north on 

 the banks of the Traun, where a vast thickness of lower, nummu- 

 litic, calcareous grit, with shales, marls, and cretaceous beds, as ex- 

 hibited in vertical strata opposite the town of Arzt, are shown to 

 be of the same age as those of Sonthofen, and are clearly proved 

 to be overlaid by the nummulitic iron ores of the Kressenberg. 



10. Upper Nummulitic Iron Ores. It is to the shelly iron ores at 

 Kressenberg, and not to those of Sonthofen, that Professor Sedg- 

 wick and the author assigned the place of transition -tertiary beds, 

 a place, the correctness of which, it is contended, is now established 

 as clearly by the evidences of superposition, given in this memoir, 

 as it formerly was by Count Minister, from the vast predominance 

 of tertiary fossils. 



The natural section on the Traun is then completed, by showing 

 that the iransition-tej-tiarybeds are conformably overlaid by inclined 

 strata of pebbly sandstone and marls, in the higher part of which, 

 near Traunstein, there are a number of shells unquestionably of 

 tertiary age. All these inclined strata are capped by a thick range 

 of horizontal coarse conglomerate. Sections made on the flanks of 

 the Untersberg confirm the observations of the previous year, and 

 show the Hippurite limestone dipping under the green sand and 

 shale, the green sand and cretaceous beds surmounted by a vast 

 thickness of nummulitic, green grit; and this again overlaid by blue 

 marls with shells of the age of Gosau and Kressenberg *. 



Other localities are noticed, where detached remnants of both 

 the lower and upper nummulitic groups were visited by the author, 

 (St. Pancratz, Mattsee, &c.), and the Gryphite abounding in these 

 beds is stated to be not the Gryphcea columba, but a new spe- 

 cies. Through the labours of Mr. Lonsdale, eight species at least of 

 Nummulites have been distinguished, some of which characterize the 

 lower or secondary strata at Sonthofen, Arzt, and Mattsee, others 

 together with a coral (Nummulina complanata) prevail in the transi- 

 tion-tertiary groups of Kressenberg, Schweiger Mill, &c. Having 

 thus, both by superposition and by fossils, shown the existence on 

 the' flanks of the chain of a deposit with a predominance of tertiary 

 and very few secondary shells, as distinguished from a lower group 



* This section as given last year was necessarily terminated by the river 

 Saal, because the Hogl on its northern bank consists of an unconformable 

 mass of secondary grit and shale (green sand), which is thrown off from 

 the Stauffen, a promontory of Alpine limestone. 



in 



