A study of the major-element (Si, Al, Fe, K, Mg, Ca, Ti, Mn and P) composition of suspended matter in the surface waters of the Zaire River and Estuary revealed that this material was enriched in Al, Fe and P and depleted in Si, Ca, K and Mg relative to recent pelagic sediments and to suspended matter carried by the Amazon River. These enrichments and depletions are characteristic of soils in regions of intense chemical weathering as is the situation in western equatorial Africa. Suspended samples from waters near the bottom of the estuary have compositions which indicate that this material has undergone much less chemical weathering. These particles were of greater size and most likely contained a larger proportion of quartz, micas, feldspars and oxides... |