BULLETIN OF THE GEOLOGICAL SOG.ETY OF AMERICA 

 Vol. 21, pp. 663-676, PLS. 48-52 DECEMBER 15. 1910 



EOCK STKEAMS OF VBTA PEAK, COLOEADO^ 



BY HORACE B. PATTON 



(Presented before the Society December 29, 1909) 



CONTENTS 



Page 



Definition and previous descriptions 663 



Description of Veta Peak 665 



Description of the nortli rocli stream 666 



General characteristics 666 



Character of the materials 667 



Size and elevation 668 



Surface features 668 



Details of structure 670 



The north branch 670 



The south branch 671 



Rock streams and glacial action 672 



Description of plates 675 



Definition and previous Descriptions 



The name "rock stream" as a geologic term has been in use but a very 

 short time, having been first employed by AYhitman Cross and Ernest 

 Howe in connection with certain very remarkable accumulations of rock 

 debris described by them in the Silverton Folio (Colorado),^ which was 

 published in 1905. These rock-debris masses were found only on the 

 floors of glacial cirques at the head of the valle^^s and presented features 

 strikingly different from ordinary talus slopes. To quote the above 

 named authors : 



"The most striking of these masses, and those to which attention was first 

 directed, closely resemble debris-covered glaciers at the heads of the basins or 

 cirques in which they occur. The surfaces are hummocky and uneven, de- 

 pressions that strangely simulate crevasses frequently occur, and concentric 

 ridges and depressions are often seen at the end of the accumulations, which 

 are abrupt and have steep faces often rising 100 feet or more above the floor 



^ Manuscript received by the Secretary of the Society October 29, 1910. 

 ■U. S. Geological Survey, Geologic Atlas, Silverton Folio (No. 120), p. 25. 



(663) 



