282 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1947 



been supplemented by soundings obtained from the files of the Hy- 

 drographic Office, United States Navy. The origin and age of the 

 flat upper surfaces of guyots represent the main problem of this paper. 

 Secondarily the relation of guyots to atolls of the northern Marshall 

 Islands will be discussed. 



AREAL DISTRIBXTTION OF GXTTOTS 



The distribution of known and suspected guyots is shown in figure 1. 

 Eoughly they are known to occur north of the Carolines and east of 



FiGUBE 1. — ^Areal distribution of guyots in the western and central Pacific. The 

 numerals next to some of the guyots indicate tlie depth in fathoms to the flat 

 upper surface. 



the Marianas and Volcano Islands between latitudes 8°30' and 27° N. 

 and longitudes 165° W. to 146° E. None has been found west and 

 south of the above boundaries though this area has been at least as well 

 explored as the former. North and east of the region outlined above 

 it appears from scattered soundings that the area containing guyots 



