12 GEOLOGICAL MEMOIRS. 



On the Geology of Caeinthia and Isteia. By Dr. Stache. 



, [Proc. Imp. Geol. Instit. Vienna, Jan. 11, 1859.] 



The portion of these provinces surveyed by Dr. Stache during the 

 summer of 1858 comprises the territories of Cosina, Concedo, Pin- 

 guente, Castua, and San Stefano, Inner Carniola between the Yalley 

 of Wippach, the River Poik, the Lake of Zirknitz, and the bogs 

 around Laibach. Observations made in excursions between Gorice 

 and Trieste, along the Laibach-Trieste Railroad, and into the Karst, 

 are also added. The geological formations constituting this region 

 are : — 



I. Alluvia and present deposits in the extensive peat-bogs near 

 Laibach, along the Isonzo and its affluents, in the large plain S.W. 

 of Gradisca, and on the western shores of the Gulf of Monfalcone 

 and Trieste. In the valleys on the western banks of the Recca, 

 the small rivulets, when transitorily swollen by continuous rain or 

 melted snow, accumulate cones of materials torn from the sand- 

 stones and marls through which they take their course. 



II. Biluvia. — These acquire some importance in the gravels ex- 

 tensively deposited along the Isonzo, between Gorice, Cormony, and 

 Gradisca, and in the loams of Copriva, Massan, and Biglia. They 

 are represented in the rest of the territory by — 1, sporadic deposits 

 of red ferruginous loams, originating in the destruction of Werf en- 

 strata, and filling the clefts and caves in more ancient limestones ; 

 2, by pisiform iron-ores, derived from the detritus of pyritiferous 

 Eocene marls ; and 3, by secondary deposits of alum-ores in the 

 cavities of Upper cretaceous limestones. 



III. Eocene Deposits. — A. Superior or Tassello Group. This consists 

 of alternations of thick-bedded solid sandstones associated with thin 

 layers of marl, and thick beds of marl or marl-slates, including 

 seams of sandstone. The strata are frequently folded and rolled up, 

 and so appear thicker than they really were in their normal hori- 

 zontal position. Except Fucoids, indistinct remains of carbonized 

 plants, and local accumulations of carbonized stems and branches, 

 this group shows no traces of former organic life. It is well deve- 

 loped on the banks of the Rivers Recca, Poik, and Quieto in the 

 Wippach valley, and along the shore between Trieste and Pirano. 



B. Middle or INTummulitic Group. — This occurs rather constantly 

 between the upper group A and the Lower Nummulitie group, in 

 the shape of a conglomerate of solid Nummulitic limestones, of large 

 fragments of older Nummuhtic deposits, or of Nummulitiferous 

 nodules, imbedded in a soft marly cement. Where they overlie the 

 Tassello group it is only in consequence of local disturbances, the 

 effects of which are visible in the frequent and various foldings of 

 the whole group. Nummulites and other Foraminifera, and casts of 

 Bivalves, "Univalves, and EcMnidce are of frequent occurrence. The 

 lowermost persistent stratum is a narrow zone of bluish or yellowish, 

 somewhat slaty limestone, with Fucoids (Trieste-Optschina) and 

 Crustacea (Sterna). This group is most conspicuous on the margins 

 of the Recca Yalley, around Pinguente, and near San Stefano. 



