278 



Sediments 



many new chemical techniques and instru- 

 ments have been developed that permit the 

 detection and measurement of specific chem- 

 ical materials which had to be grouped 30 

 years ago. Among the materials from the 

 basins and other areas of sea floor off 

 southern California that have been studied 

 are amino acids, pigments, hydrocarbons, 

 and gases. 



Amino Acids 



Living organic matter contains a large 

 number of proteins that range from simple 

 to complex in structure. Many are unstable 

 and difficult to separate; however, hydrolysis 

 leads to the formation of amino acids that 

 are common to many proteins (Doty, 1957). 

 The 21 types of amino acids that occur in 

 living tissue exhibit varying degrees of re- 

 sistance toward oxidation. Eight that in- 

 clude the most resistant ones (alanine, 

 aspartic acid, glutamic acid, glycine, isoleu- 

 cine, leucine, proline, and valine) were de- 

 tected by Abelson (1956, 1957) in bones of 

 Cretaceous dinosaurs and Devonian fish 

 and in shells of Miocene mollusks and an 

 Ordovician brachiopod. Ten (alanine, 

 arginine, aspartic acid, glutamic acid, gluta- 

 mine, glycine, leucine, phenylalanine, pro- 

 line, and serine) were found by Dr. Paul 

 Saltman (personal communication) in a pre- 

 liminary examination of a sample of sur- 

 face sediments from Santa Cruz Basin. 

 Others may also be present. Among those 

 found are several relatively unstable amino 

 acids, arginine, aspartic acid, phenylalanine, 

 and serine. These relationships suggest 

 that a spectrum of amino acids occurs in 

 cores with many at the surface and only the 

 more resistant ones at depth. More detailed 

 studies should reveal depth variations of the 

 number and quantity of amino acids that 

 should relate to the known increase of C/N 

 ratio at depth in the sediments. 



Pigments 



Many diff'erent kinds of pigments are 

 present in sediments, but the ones that have 

 been investigated most thoroughly are the 



green porphyrin pigments — derivatives of 

 chlorophyll (Treibs, 1934) — in a study made 

 possible by a grant from Shell Development 

 Company, Houston. Pigments obtained in 

 acetone extractions (Orr and Grady, 1957) 

 include pheophytin a and pheophorbide a 

 identified through paper chromatography, 

 absorption spectra, and acid numbers. 

 Pheophytin b, pheophorbide b, and higher 

 intermediates appear to be absent. For 

 convenience the mixture will be referred to 

 as simply pheophytin. Pheophytin a is de- 

 rived from chlorophyll by replacement of 

 the magnesium nucleus with two hydrogens; 

 a further replacement of a phytol group by 

 a propionic acid side chain converts pheo- 

 phytin a into pheophorbide a (Fig. 223). 

 Such changes are known to be caused by 

 the acid fluids of animal digestive tracts. 

 Further changes are required before the 

 porphyrin becomes similar to porphyrins 

 found in petroleum, none of which seems to 

 be present in the sediments. Vanadium and 

 nickel, which cormnonly form the porphyrin 

 nucleus in petroleums, have not been de- 

 tected in the extracts from sediments, even 

 though the sediments contain more than ten 

 times enough vanadium and nickel to satisfy 

 the porphyrin requirement (Table 17). 



Pheophytin was found in each of more 

 than 200 sediment samples that were ana- 

 lyzed, ranging from beach sand to deep-sea 

 red clay (Orr, Emery, and Grady, 1958). In 

 beach sands it amounts to 0.02-0.09 ppm 

 dry weight of sediment, in mainland and 

 island shelf and bank top sediment 1-13 

 ppm, in basin sediments 4-103 ppm, and in 

 red clay 0.02-1.6 ppm. The basins with 

 their great range of values (Table 14) are 

 most interesting. Pheophytin has its highest 

 concentration (40 to 103 ppm) in Santa 

 Barbara, Santa Monica, and San Pedro Ba- 

 sins, all of which are close to shore and have 

 the highest rates of deposition of detrital 

 sediment (Table 20). It is also abundant, 39 

 ppm, in Tanner Basin which has a low rate 

 of deposition but is in a favorable position 

 for receiving organic debris from the area of 

 high productivity near the Santa Rosa- 

 Cortes Ridge (Fig. 86). Cores from southern 

 San Clemente, No Name, and Long Basins 



