302 



REX AlTD GOLDBERG 



[chap. 5 



Recently, an extensive ash deposit, extending from at least 11°N to 12°S 

 within a few hundred miles off the coast of Central and South America has 

 been described by Worzel (1959) and Ewing, Heezen and Erickson (1959). The 

 ash layer, 5 to 30 cm thick over this area, is attributed to one of the possible 

 volcanic sources, the Galapagos Islands, eastern Ecuador and Central America. 

 Ewing et al. {op. cit.) point out that the prevailing surface winds through the 

 area are easterly and could have transported the ash. Also, currents in the 

 equatorial system may have been responsible for the dispersal. They suggest 

 that, although both atmospheric and marine transport are possible, no combina- 

 tion of such paths could have provided the uniform ash layer over the areas 



CAPRICORN BP 50 WSS N 124°12 W 

 "I — I — I — I — I — I — I — I r~ 



17A PEAK AREA / 10 A PEAK AREA X 4 



Fig. 4. The quartz and montmorillonite/illite ratios of Capricorn 50BP as a function of 

 depth in the core. Station at 14° 55'N, 124° 12'W. Depth 4270 meters. 



investigated without providing substantial amounts over an even far larger 

 area. Certainly further work is needed to understand better this extensive ash 

 layer. 



It appears evident that paleometeorology has only begun to be developed 

 and that in the oceanic accumulations of volcanic, continental and extra- 

 terrestrial sediments we have a means of studying long-period processes in the 

 earth's atmosphere. 



References 



Barbour, G. B., 1927. Loess in China. Ann. Rep. Smithsonian Inst. (1926), 279-296. 



Bramlette, M. N. and W. H. Bradley, 1940. Geology and biology of North Atlantic Deep- 

 Sea cores between Newfoundland and Ireland. Part 1. Lithology and geologic inter- 

 pretations. U.S. Oeol. Surv. Prof. Paper, 196A, 34 pp. 



Brown, W. F., 1952. Volcanic ash over the Carribbean, June 1951. Monthly Weather Rev., 

 80, 59-62. 



