328 University of California Publications in Geology [Vol. 11 



grains of iron oxide. Pantelli states that it is possible, in many cases, 

 to dissolve the iron from this matrix, by the use of acid, leaving it 

 nearly colorless. The radiolaria are better preserved in the red 

 cherts than in the lighter colored varieties. According to Pantelli, 

 the fossils appear to the best advantage in sections cut parallel or 

 perpendicular to the planes of stratification. He states that he has 

 looked for diatoms but never discovered them in these rocks. 



The earlier Italian geologists regarded the jaspers as argillaceous 

 rocks, silicified as a result of contact metamorphism around intrusive 

 masses of serpentine and diabase. Savi, however, had noted the fact 

 that jaspers often occurred at considerable distances from bodies of 

 igneous rocks. 



In 1879, De Stefani stated that the jaspers and siliceous argillites 

 and also the manganese deposits associated with them were laid down 

 as sediments in the deep sea. In 1879, Bonney, 81 in describing the 

 serpentines of Tuscany and Liguria, referred to a banded, red, flinty 

 rock, which he found on the border of a serpentine mass. In thin 

 section this rock was found to be crowded with the remains of organ- 

 isms. Bonney believed some of these to be minute gasteropods ; some 

 were believed to be sponge spicules ; others were regarded as minute 

 siliceous organisms. While he first recognized the presence of these 

 organisms in the cherts, he does not seem to have been at all certain 

 of their nature nor to have realized their importance. In the year 

 1880 there appeared the paper by Pantelli which gave an excellent 

 description of the radiolarian jaspers and showed that they contained 

 great numbers of radiolaria. 



Pantelli regards the radiolarian jaspers as marine sediments be- 

 cause of the great number of radiolaria which they contain, and the 

 association with manganese. He states that the jaspers, the siliceous 

 argillites, and the associated red calcareous rocks were laid down 

 far from land and in water over 1000 meters deep. He believes it 

 impossible to regard the jaspers as clue to contact metamorphism 

 because of the great thickness and extent of some of the masses. He 

 points out that certain areas of jasper are separated from the serpen- 

 tines by a considerable distance, and that in some instances unaltered 

 limestone occurs between. 



Pantelli notes the common association of jaspers with basic igneous 

 rocks and accounts for it on his hypothesis that the igneous rocks 

 were submarine lavas. He believes that during the extrusion of these 



si Bonney, op. cit. 



