F-19 



recovered in dredges shallower than approximately 800 meters. 

 Unconsolidated sediments are all Quaternary. Much of the 

 dredged material is barren of age diagnostic microfossils. 

 Lydonia Canyon 



Examination of the acoustic profile and the photographic 

 records shows that the walls of most of the mid and lower 

 canyon are comprised of outcropping or subcropping strata 

 (Fig. F-9) . These outcrops are also seen in small side 

 tributaries. The area of exposed outcrop appears to be 

 less toward the head of the canyon. The narrow thalweg 

 floor is sandy and rippled. A broad area of cobbles and boulders 

 was noted on the lower east flank of the canyon. A similar 

 smaller patch was also noted on the west flank. 



Sediment analysis of the cored materials shows that the 

 surface sediment is generally fairly sandy both on the canyon 

 walls and in the thalweg. Figure F-10 shows the size dis- 

 tribution of core top (surface) sediments. Sand percentages 

 as high as 8 7% were noted in the thalweg. By and large, 

 thalweg and shelf sediments in Lydonia Canyon are well sorted 

 sands, while wall sediments are sandy silts (Tables F3 and F5) . 



Rocks dredged in Lydonia Canyon are very similar to those 

 recovered in Oceanographer Canyon. The dark grey micaceous 

 glauconitic siltstone found in Oceanographer Canyon was also 

 found in Lydonia Canyon, as well as the upper Miocene silt- 

 stone. This finding is not surprising considering the pro- 

 ximity of these two canyons. Biostratigraphic analysis 

 supports the correlation of rock units between the two canyons. 

 The dredged material was dated as Turonian and upper Miocene. 



