Bottom sediment samples were ob- 

 tained during the nine cruises on as 

 many of the stations as depths and 

 currents permitted the sampler to 

 function. These were taken by means 

 of an orange peel dredge - -modified in 

 weight by addition of lead to the arms, 

 and by welding covers over the blades 

 to prevent the sample being washed out 

 (fig. 2). At sea the samples were placed 

 in double polyethylene bags (without 

 preservative), tightly closed with 

 rubber bands, and stored in this manner 

 until analyzed. Half of each sample was 

 furnished to the Navy Hydrographic 

 Office. 



This report (a joint undertaking 

 between the Bureau of Commercial 

 Fisheries and the Oceanographic Insti- 

 tute, Florida State University, Talla- 

 hassee, Florida) is to explain the 

 bottom sediment program, give methods 

 and procedures, present the assembled 

 chemical and physical data by station 

 (table 1, p. 28), and to outline the gen- 

 eral character of the bottom mate- 

 rials in the work area. 



In the sections to follow, the "Chem- 

 ical Methods and Procedures" were 

 contributed by Moore and the "Geo- 

 logical Methods and Procedures" by 

 Gorsline. 



CHEMICAL METHODS 

 AND PROCEDURES 



GENERAL 



Each half sample retained at the 

 Brunswick laboratory was air dried, 

 thoroughly mixed, and a representa- 

 tive portion ground in a ball mill and 

 stored in a glass bottle. A 3- to 4-gm. 

 portion of each ground sample was 

 dried at 110° C. for 3 hours and then 

 placed in a desiccator with dry calcium 

 sulfate until the portions to be analyzed 

 were weighed. All chemicals used in 

 the various analyses were analytical 

 reagent grade. All sample portions 

 were weighed to the fourth decimal 

 place. 



METHODS 

 Loss on ignition 



Procedure : Weigh 0.5 to 1.0 gm. of 

 sample into a dried and weighed No. 1 

 porcelain crucible and ignite for 45 

 minutes at 850° C. t 25° C. in an elec- 

 tric furnace. Transfer crucible and 

 contents to a desiccator to cool. When 

 cool, reweigh and determine loss in 

 weight. Results are reported as per- 

 cent loss on ignition on dry weight 

 basis. 



Insoluble residue 

 Reagents: 



1. 6N hydrochloric acid (HC 1) - equal 

 volumes of concentrated hydro- 

 chloric acid and distilled water. 



Procedure : Weigh 1.0 gm. of sample 

 into a 150-ml. beaker and add 10 ml. 

 of 6N hydrochloric acid. Evaporate 

 mixture to dryness on a hot plate at 

 medium setting and allow residue to 

 bake 10 minutes. After cooling, add 

 10 ml. of 6N hydrochloric acid, stir 

 thoroughly and filter mixture through a 

 dried, weighed, No. 3 Gooch crucible. 

 Dry crucible and contents in an oven 

 at 110° C. until constant weight is 

 reached, cooling in desiccator between 

 weighings. Results are reported as 

 percent insoluble residue on dry weight 

 basis. 



Aluminum oxide 

 Reagents : 



1. Concentrated ammonium hydrox- 

 ide (NH4OH), 



2. Concentrated nitric acid (HNO3). 



3. Concentrated hydrochloric acid 

 (HCl). 



4. 3N hydrochloric acid (HCl) - 1 

 volume of concentrated hydro- 

 chloric acid and 3 volumes of dis- 

 tilled water. 



