1. Grd. Ground; the bottom of the ocean; the sea floor. 



2. S. Sand; loose detrital material consisting of small but 



easily distinguishable separate grains ranging between 

 0,0025 and 0.0787 inch (0.0625 and 2.0000 millimeters) 

 in diameter. 



3. M. Mud; pelagic or terrigenous detrital material consisting 



of particles smaller than sand; that is, an undifferen- 

 tiated sediment made up of particles mostly within the 

 silt-clay range smaller than 0.0025 inch (0.0625 milli- 

 meter). 



4. Oz. Ooze; an unconsolidated deep sea deposit composed of 



30 percent or more of the shells (tests) of foraminifera, 

 diatoms, and other marine orgeinisms, for example, 

 diatom ooze and globigerina ooze. 



5. Ml. Marl; a calcareous clay which may include silts and 



sand. This sediment is classed as mud- sand. 



6. CI. Clay; fine-grained sediments with particle size smaller 



than approximately 0.00008 inch (0.004 millimeter). 

 When not separately designated on a bottonm sediment 

 chart, clay is classed as mud. 



7. G. Gravel; loose detrital material which consists of frag- 



ments ranging in size from approximately 0.08 to 10.08 

 inches (2 to 256 millimeters). 



8. Sn. Shingle; roixnded, often flat waterworn rock fragments 



(very coarse gravel). Shingle is classed as gravel on 

 bottom sediment charts. 



9. P. Pebbles; small, usually rounded rock fragments ranging 



in size from 0.16 to 2.59 (4 to 64 millimeters) in 

 diameter. Pebbles are classed as gravel on bottom 

 sediment charts. 



10. St. Stones; detached particles of rock usually smaller than 



10 inches (256 millimeters) in diameter. Stones are 

 classed as gravel on bottom sediment charts. 



