and southern limits of the area where disposed material was 

 detected. All dredged material detected is confined within the 

 FADS designated boundary. 



The distribution of modal grain-size over the area 

 surveyed at FADS is relatively uniform. Most stations consist of 

 silt-clay (> 4 phi) or very fine-sand (4-3 phi) . The coarsest 

 sediment (2-1 phi; medium sand) is found at Station 100E. Many 

 stations located on dredged material have subordinate modes 

 within the sand fraction. All 34 replicate images taken at the 

 FADS Reference station have a major mode of silt-clay (> 4 phi) . 



Based on sediment grain-size, sediment mass properties 

 (as inferred from profile images) , and other REMOTS® parameters 

 that will be discussed below, new or freshly deposited materials 

 were recognized at Stations 200N, Center, 100E, 200S, and 300S. 

 Disposed material occurs in a layer that is thicker than the 

 camera prism penetration depth at these 5 stations (> 2 cm) . It 

 appears that most of the deposited material is dispersed along 

 the north-south transect; this is also illustrated when the 

 measured depositional layers from the 1986 and 1987 REMOTS® 

 survey are compared (Figure 3-3) . The North-South transect shows 

 an increase in the spatial extent of dredged material in this 

 19 87 survey. 



The guality of disposed material can also help to 

 identify sediment derived from specific projects, especially if 

 they have a unigue lithology. The Blue Circle Atlantic dredged 

 materials may have consisted, in part, of highly-cohesive clays; 

 cohesive, high-reflectance mud clasts were found at Station 100 N 

 (Figure 3-4A and 4B) . These clasts are devoid of macrofauna and 

 are apparently overconsolidated; numerous fractures can be seen 

 in these clast cross-sections. This material appears to have the 

 properties of modelling clay. 



Station Center (Figure 3-5) shows evidence of the 

 deposition of fine-grained and reduced sediment at the sediment 

 surface. The inference that this is fresh material is based on 

 the fact that the oxidization of surface sediments by colonizing 

 organisms has not yet occurred to a notable depth. Sand mixed 

 with cohesive mud was seen in images taken at Station 100E 

 (Figure 3-6) . The presence of reduced fine-grained sediment was 

 detected at stations 200S and 300S (Figures 3-7 and 3-8, 

 respectively) . These stations are either not colonized or are in 

 an early stage of colonization. This ecological information 

 further indicates that these stations are located on "new" 

 dredged materials. 



The surface boundary roughness values measured in this 

 survey (Figure 3-9) are not significantly different from those 

 measured in January 1986. The relative "smoothness" of the 

 disposal area surveyed most likely is related to the depth of 



