160 me. j. b. sceivenor on the [Mayi903, 



15. Notes on the Geology of Patagonia. By John Beooke 

 Sceivenoe, Esq., M.A., F.G.S. (Eead February 4th, 1903.) 



[Plate XIII— Map.] 



Contents. 



Page 



I. Previous Literature 160 



II. The Sedimentary Rocks 160 



III. The Igneous Eocks 163 



IV. The Basalt-Flows 165 



V. The Tehuelcbe Pebble-Bed 167 



VI. The Origin of the Tehuelche Pebble-Bed 169 



VII. The Drainage-System 173 



VIII. The River-Valleys 176 



IX. Summary 178 



I. PEEVIOUS LlTERATUEE. 



Apart from the papers dealing with the extinct vertebrate faunas, 

 the following are important works on the geology of Patagonia. 

 For further literature, see the bibliography appended to Dr. Ort- 

 mann's Beport. 



D'Orbigny, Alcide. ' Voyage dans l'Amerique meridionale ' vol. iii : Geologie & 



Paleontologie. Fo. Paris, 1842. 

 Darwin, Charles. ' Geology of the Falkland Islands.' Quart. Journ. Geol. Soc. 



vol. ii (1846) pp. 267-74. 

 Dabwin, Charles. ' Geological Observations.' 2nd ed. 8vo. London, 1876. 

 Agassiz, Louis. [' South-America Expedition.'] ' Nature ' vol. vi (1872) 



p. 272. 

 Engelhardt, H. ' Ueber Tertiserpflanzen von Chile.' Abhandl. d. Senckenberg 



Naturforsch. Gesellsch. vol. xvi (1891) pp. 629-92 & 14 plates. 

 Mercerat, Alcide. ' Essai de Classification des Terrains sedimentaires du Ver- 



sant oriental de la Patagonie australe.' Anales del Museo de Buenos Aires, 



ser. 2, vol.'ii (1896-97) pp. 105-30. 

 Ameghino, Florentino. 'Notes on the Geology & Palaeontology of Argentina.' 



Geol. Mag. 1897, pp. 4-20. 

 Hatcher, J. B. 'The Cape-Fairweather Beds.' Am. Journ. Sci. ser. 4, vol. iv 



(1897) pp.. 246-48. 

 Hatcher, J. B. ' On the Geoloey of Southern Patagonia.' Am. Journ. Sci. ser. 4, 



vol. iv (1897) pp. 327-54. 

 Nordenskjo3LD, Otto. 'Tertiary & Quaternary Deposits in the Magellan 



Territories.' Am. Geol. vol. xxi (1898) p. 300. 

 Hatcher, J. B. 'Sedimentary Rocks of Southern Patagonia.' Am. Journ. Sci. 



ser. 4, vol. ix (1900) pp. 85-108. 

 Hatcher, J. B. ' The Lake-Systems of Southern Patagonia.' Am. Geol. vol. xxvii 



(1901) pp. 167-73. 

 Moreno, Francisco P. ' Explorations in Patagonia.' Geogr. Journ. vol.xiv (1899) 



pp. 241, 353. 

 Stanton, T. W. ' Reports of the Princeton University Expeditions to Patagonia, 



1896-1899, vol. iv, pt, 1 : The Marine Cretaceous Invertebrates.' 1901. 

 Ortmann, A. E. ' Reports of the Princeton University Expeditions to Patagonia 



vol. iv, pt. 2 : Tertiary Invertebrates.' 1902. 



II. The Sedimentaet. Pocks. 



The latest classification of the Patagonian sediments is that by 

 Mr. J. B. Hatcher, who conducted the Princeton University Expe- 

 ditions. Previous to its appearance, M. Alcide Mercerat, of Buenos 



