obvious, but may well represent an underlying tectonic effect due per- 

 haps' to the compressional nature of the area overprinting a long wave- 

 length relief on the smooth sediment. 



This general correspondence of b < -1 in tectonic provinces, and -1 

 < b < for sedimentary provinces is found in many areas outside this 

 study area. The reason for this general relationship can only be specu- 

 lated upon. Recall from the previous section that b < -1 requires that 

 the ratio of height to width of component features, increase at longer 

 wavelengths. If one envisions tectonic relief forming processes, the 

 entire morphology is constructed and then erosional and sedimentary 

 processes begin smoothing small features first, progressing to con- 

 stantly larger scales. In sedimentary processes, one can envision a 

 smooth layer of sediment being affected by bottom current interaction 

 for example. This constructive process begins at the highest spatial 

 frequencies and progresses to larger scales. This is in agreement with 

 the relationship of -1 < b < 0, in which the ratid of height to width of 

 component features increases at shorter wavelengths. 



The study area illustrated in Figure 5-7 was selected because of 

 its rich geological diversity. As such, the distribution of roughness 

 provinces is correspondingly complex. To allow a comparison with a more 

 tectonically stable area of the world ocean floor, a large number of 

 traclclines off the United States east coast were analyzed to compare a 

 passive continental margin. Although the trackline density was not ade- 

 quate for a complete chart to be drawn, one interesting relationship was 

 discovered. An extremely large area of the continental margin, compris- 

 ing most of the continental rise, was found to have in common a very 

 distinct amplitude spectrum. Figure 5-12 illustrates a typical ampli- 



75 



