40 Windhausen — The Cretaceous-Tertiary 



from this hike" demonstrate the complete lack of the 

 Salamanca Beds, not their partial denudation. These 

 facts prove that in all probability the shore of the San 

 Jorge-Sea stretched from the Gulf of St. Mathias south- 

 southwesterly to Lake Musters. The masses of quartz 

 porphyry on the Rio Chico and around the Bay of 

 Camerones were probably islands. 



Towards the south, the shore-line is more hypothetical. 

 Fossils, indicating a normal San Jorge-facies, were 

 reported from the upper course of the Rio Sehuen. 

 Ostrea Ameghinoi Ih. occurs on Lake Pueyrredon, as 

 claimed by v. Ihering on the basis of Hatcher's collec- 

 tions. Accordingly, a slight western embayment towards 

 this lake is indicated with a subsequent more or less 

 north-south course along the Cordillera as far as the 

 Rio Sehuen. In the far south, at the Cerro Cazador, 

 brown oyster-banks above the strata with Lahillia luisa 

 indicate a neighboring San Jorge shore. Evidently too, 

 as elsewhere, the large masses of quartz porphyry to the 

 south of the Gulf of St. George, in the lower valley of 

 the Rio Deseado and more southward as far as the Bajo 

 de San Julian, were San Jorge-islands. According to 

 Delhaes, 96 the Patagonian Formation of this region rests 

 directly on Rhaetic sediments with Estheria mangalien- 

 sis Jones. This fact may be regarded as evidence that 

 the Patagonian overlapped a relief, essentially different 

 from the base of the underlying San Jorge. 



As to the southern extension of the American Conti- 

 nent, in the southern part of Santa Cruz, the Magellan- 

 Territory and Fireland, there is no indication of a sea 

 corresponding to the close of the Cretaceous or beginning 

 of the Tertiary. 97 The most noteworthy event following 

 the first and chief phase of Andine folding was the intru- 

 sion and cooling down of the great batholith of the Coast- 

 Cordillera. 98 For the Antarctic regions, Nordenskjold" 



95 Les formations sedimentaires, p. 86, fig. 19. 



96 Ein Khatvorkommen an der patagonischen Kiiste, Centralblatt f . Min. 

 etc., pp. 776 etc., 1912. 



07 Among the many publications issued about the geology of Fireland, 

 may be mentioned the report of Felsch, where special attention was given 

 to, the hiatus between the Cretaceous and Tertiary. See Felsch, Informe 

 sobre el reconocimiento jeolojico de los alrededores de Punta Arenas, 

 Santiago de Chile, 1913. 



98 See Quensel, Geologisch-Petrographische Studien in der Patagonischen 

 Cordillera, pp. 14 etc., Upsala, 1914. — Besides Hauthal and Wilckens (Ob. 

 Kreide Siidpatagoniens etc., p. 17) reported that in the region of Lago 



