Vol. 50.] GOSATX BEDS OF THE GOSAE DISTRICT. 147 



Gosau Beds. English Chalk Zones. 



f Upper Series of Marls, ^ 

 Sandstones, etc., with | 



Upper { obscure plant - re- }■ (Absent) ? Danian. 



mains, and worm- | 

 (^ tracks J 



( Fossiliferous Marls and~^| f Zone of Belemni- \ 



2nd zone of Hippm- j tella mucronata j u ppER ■> 

 rz'ft?s,EstuarineSeries, )■ ■{ Zone of Marsupites )■ q halk [ Senonian, 

 Limestones with Ac- j j Zone of Micraster, \ ' J 



Lower ■{ twonella and Nerincea ) y var. sp J 



I Limestones with Hipp, j f Zone of Holaster | jy[ IDDLE -1 



cornti-vaccinum and I \ planus or Chalk ', q halk f Turonian. 

 ^ Conglomerate J \ Eock J 



V. Physical History of the Gosae Beds. 



Probably the whole series of the Gosau Beds was deposited in 

 fairly shallow water. At the base we find conglomerates, marls, 

 and limestones, with Hippurites, Actceonella, Cerithimn, Nerincea, 

 etc., beds which are evidently of marine origin, and the limestones 

 are almost entirely made up of forms which most probably dwelt in 

 shallow water. The Hip-purites lived in colonies, like oysters, and 

 built up great banks or reefs, resembling barrier-reefs, along the 

 rocky coasts of older Triassic and Rhaetic limestones, whose frag- 

 ments constitute the basement-conglomerate. Above the limestones 

 we find a series of beds containing a fauna consisting of a mixture 

 of marine and freshwater forms and land-plants. This probably 

 indicates the neighbourhood of the mouth of a river. Stoliczka, 

 referring to the nature of these beds, remarks : — " One can see 

 from these occurrences that during part of the Cretaceous period the 

 valleys of our Alps stood high enough above the sea-level for fresh 

 water to flow down them. These streams or torrents, with their 

 unusually richly ornamented molluscs and the strange assemblage 

 of plants on their banks whose remains have formed the small layers 

 of coal, give the palaeontologist a characteristic illustration of a 

 mountain-region in the Chalk period." ' But I fail to see how the 

 facts illustrate any such thing. The organic remains in the beds 

 certainly prove that they were deposited near the mouth of a river, 

 and possibly part of them may be entirely of freshwater origin, 

 but it seems highly improbable that they could have been deposited 

 so far above the sea-level as to give us molluscs and land-plants 

 of a mountain facies. The whole assemblage denotes estuarine 

 conditions ; and the floor of this estuary evidently underwent gradual 

 depression, as we find the brackish-water beds gradually passing 

 into the thick series of fossiliferous marls with their rich and 

 entirely marine fauna. Here, again, we find Hippurite-banks and 



1 Sitzungsber. d. kaiserl. Akad. Wissensch. Wien, vol. xxxviii. (1859) p. 482. 



