Recent sediments flooring the Pacific Ocean basin fall into 5 major categories; calcareous, biosiliceous, deep-sea clay, glaciogenic and terrestrial. Smear slide photographs of representative sediments of a central Pacific mid-ocean transect (Fig. 1) are presented below. Click on the photographs to view larger images.
Fig. 1. Distribution of major sediment types in the Pacific basin. Numbers indicate approximate location of the representative samples shown in the photographs below.
(Map after R. G. Rothwell, 1989, Minerals and Mineraloids in Marine Sediments, p.16.)
FLUCTUATING SEDIMENTATION PATTERNS
|Distribution of Recent sediments in the Pacific Basin is shown in Figure 2. A sequence of samples taken from core PROA-131G-2, however, demonstrates that patterns of sedimentation have fluctuated during the geologic past. (Click on photographs below to view larger images).|
|Fig. 2. Recent sediment distribution on the floor of the Pacific Ocean. Down-core samples from site PROA 131G-2 (X) demonstrate changing depositional environments at a single site. (Map after Rothwell, "Minerals and Mineraloids in Marine Sediments," p.16).|