WATER DEPOSITS 675 



inution of the percentages in the distant coarse admixtures in two of the 

 other samples. None are well sorted. 



List of Samples in Table 19 



176. Brown mud with black specks, containing many magnetic grains, some 



pumice, and mostly quartz, from the middle of the Gulf of California ; 

 volcanoes to the west. Steamer Trenton; Station No. 3436 ; latitude 

 27° 3' 40" north, longitude 110° 53' 40" west; depth, 905 fathoms. 

 April 22, 1891. 



177. All inorganic; not far from volcanoes, 5 to 10 miles away. The largest 



fragments are vesicular pumice, and much of the fine is strongly 

 magnetic. Steamer Albatross; Station No. 2841; latitude 54° 18' 0" 

 north, longitude 165° 55' 0" west; depth, 56 fathoms. 



178. Fine gray sand, gravel; all mechanically sorted and contains some mag- 



netic materials ; 150 miles from the shore north of the Alaska Penin- 

 sula. Steamer Trenton; Station No. 3498; latitude 56° 13' 0" north, 

 longitude 169° 36' 0" west; depth, 142 fathoms. July 17, 1893. 



179. Coarse black sand, gravel, rocks ; some scoriae and magnetite ; from 3 tc 



50 miles from the north end of Unimak Island. Steamer Trenton; 

 Station No. 3324; latitude 53° 33' 50" north, longitude 167° 46' 50" 

 west; depth, 109 fathoms. August 20, 1890. 



180. Green mud, all inorganic. Sample contains some volcanic dust and 



scoriae. Volcanoes 50 miles off. Steamer Albatross; Station No. 3324; 

 latitude 53° 37' 10" north, longitude 167° 50' 10" west; depth, 284 

 fathoms. 



181. Dark gray Sand containing quartz with some mica ; the coarsest part 



organic; from 300 miles west of the Azores. Steamer Albatross; Sta- 

 tion No. 2585; latitude 39° 8' 30" north, longitude 39° 2' 40" west; 

 depth, 328. fathoms. September 19, 1885. 



Deposits near the margins of ocean basins. — Nine samples represent 

 deposits in more open and deeper parts of the sea than those previously 

 described. None of these come from any great or abyssal depths nor 

 from very far out from the land. Even in some of these locations there 

 must be currents of considerable strength sufficiently powerful to stir 

 and sort coarse gravel. Sample 182 contains all grades from coarse 

 sand to coarse gravel, but the main ingredients are very fine sand and 

 coarse silt in most samples. The finest has for its chief ingredient fine 

 silt. For the group the sorting is about the same as we find in lake silts 

 or in harbor silts. 



List of Samples in Table 20 



182. Coral sand containing about one-third scoriae, two-thirds shell fragments 



and foraminifera, and only a small part sand, taken a short distance 

 east of the Galapagos Islands. Steamer Albatross; Station No. 2808; 

 latitude 0° 36' 30" north, longitude 89° 19' 10" west ; depth, 634 fath- 

 oms. April 4, 1888. 



