394 Professor Sedgwick and Mr. Murchison on the 



line limestone — and the third, including all the higher deposits which occupy 

 nearly the whole country on the western frontier of Lower Styria. 



2. Section of the Tertiary Groups near Hartherg. 



If a line be drawn (nearly at right angles to the mean direction of the pre- 

 ceding section) from Radkersberg, through the crests of Gleichenberg, to 

 Riegersberg, and be then produced towards the north, it will meet the 

 primary ridges, at the north-eastern boundary of the Styrian basin, in the 

 neighbourhood of Hartberg : and in the whole of this long traverse, it will 

 pass either through strata subordinate to the highest tertiary group (No. 5.) 

 of the general section, or through igneous rocks associated with them. 



The tertiary beds, on the north-eastern confines of the basin, rest imme- 

 diately on the primary system ; and are so nearly horizontal, that they pro- 

 bably retain the same relative position, in respect of the Friedberg and the 

 Hartberg ridges, which they had at the time they were deposited. The lower 

 groups are almost entirely made up of alternating laminae of micaceous sand, 

 and unctuous marl, together forming a good brick-earth. In the ascending 

 order these beds become more indurated, and pass into a group made up of 

 alternating beds of marly limestone and sandstone, containing a few Cerithia. 

 Some of the beds of calcareous sandstone contain fragments of mica schist, 

 small quartz pebbles, &c., mingled with the Cerithia ; but in none of them is 

 there a trace of any secondary rock — a proof, in addition to the one offered 

 by the collocation of the beds in natural sections, that no secondary rocks 

 existed in this region at the time the tertiary deposits were forming. 



The last-mentioned group is surmounted by a very remarkable calcareous 

 formation, to which the name of grauh-kalk or calcaire grossier has been 

 sometimes given. Mineralogically speaking, such a term may be correct; 

 but as a formation, it is of a much newer age than the calcaire grossier of 

 Paris ; being, if we mistake not, on the exact parallel of the limestone of 

 Radkersberg and Poppendorf. It is surmounted in the quarries south of 

 Hartberg, by beds of marl and sandstone, some of which resemble those of 

 the inferior groups. 



The following descending section from the quarry of Schiildbach, south of 

 Hartberg, will show the nature of the deposits we are here describing. 



1. Earthy marls at the surface, of Irregular thickness. Ft. In. 



2. Coarse J micaceous grit, with small quartz pebbles 6 



3. Unctuous marls ; part light green, part of a deep ochrous colour 1 



4. White and grey, micaceous, laminated marl 1 



6. Greenish laminated, arenaceous marl 3 



6. Thin layer of sand, with broken shells and black and white quartzose pebbles 3 



