6 FOSSIL FISHES OF LOMPOC 



The probable conditions of the deposits at Lompoc are thus indicated 

 by Dr. Albert Mann of the Carnegie Institution at Washington, to whom 

 we have sent specimens of material from various parts of the beds. 



"The samples of diatom material received seem to indicate the follow- 

 ing facts, unfortunately of small value for your fish-deposit problem: 



"1. Marine, with no infiltration of fresh or brackish water forms. 



"2. Not plankton material. Diatoms all large and massive. Heavy 

 sponge-spicules abundant; heavy Radiolaria present, though few. 



"3. Not transported a great distance nor by swift or violent currents 

 to their present position, as the diatoms, though somewhat broken by 

 pressure, show no wear ; also as there is an absence of any appreciable 

 quantity of sand, shells, clay, etc. 



"4. Not a complex of materials from different localities, as the dia- 

 toms, though abundant, are remarkably few in species, being chiefly 

 two species of COSCINODISCUS. 



"5. Slowly and evenly deposited in their present position, with regular 

 fluctuations in quantity (seasonal ?), resulting in the mass being formed 

 of thin laminated plates, easily separable, but uniform in composition. 



"It looks to me as if my samples were laid down in situ, in some 

 quiet, shallow marine bay, into which no considerable quantity of fresh 

 water drained. . . . 



"As to the oil relationship, I do not know a thing. As you know, 

 all sorts of theories, have been advanced regarding the contribution of 

 diatoms to the so-called mineral oils. But I had the good luck last summer 

 at Woods Hole to secure a perfectly pure gathering of plankton diatoms 

 of a single species, unmixed with a single Copepod, Nematode, or any 

 other organism. I secured a solid liter of it, and it is now in the hands of 

 a chemist for the ether extraction of the oil, which will be sufficient in 

 quantity for the first accurate analysis of diatom oil. . . 



"The large amount of oil laid up as a reserve food material by dia- 

 toms is certainly significant. I have found it making fully 50 per cent of 

 the bulk, and I have never found it to be less than 5 per cent." 



The economic use of these deposits, made up of the silicious shells 

 of microscopic plants, known as diatoms, is at present two-fold. The 

 material is cut into bricks, which, being non-conductors of heat, are used 

 as packing about steam-pipes and the like, and sold as Sil-O-Cel. The 

 second use is for filtering liquids. The silicious shells are insoluble, and 

 poured into any fluid, they carry at once to the bottom all solids in suspen r 

 sion. The whole can then be filtered and the liquid is left perfectly clear. 

 This is "Filter-eel," made of the crushed rock. "Celite" is a meaningless 

 trade name, adopted for the output of this particular deposit. 



