On Silica and the Siliceous Remains of Organisms in Modern Seas

Abstract

In a former jjaper to this Society, we pointed out the important role played by carbonic acid in modern seas, with special reference to the vast deposits of carbonate of lime now taking place in coral reefs and those other calcareous deposits known as Globigerina and Pteropod Oozes. It was pointed out that carbonic acid was the chief agent in the disintegration of felspars and other silicates of the earth's surface, that it was concerned in all the changes that result in the secretion of carbonate of lime by marine organisms from any of the lime salts in sea-water, that a vast amount of Carbonic acid was being locked up in the calcareous deposits now in process of formation on the sea-bed, and that there was an accumulation of these calcareous deposits chiefly towards the equatorial regions of the ocean basins. In the present paper we propose to deal with the great antagonistic power to carbonic acid, viz., silica, and with the siliceous organic remains in the ocean.

Deep-Sea Sedimentation

“…Their arguments concerning differential mobilization and precipitation of trace metals are greatly extended and widely applied by Price and Calvert (1970). They especially stress the influence of postdepositional migrations of manganese and associated elements [Murray and Irvine, 1894;Gripenberg, 1934;Ljunggren, 1953;Fomina, 1962;Hartmann, 1964;Lynn and Bonatti, 1965;Manheim, 1965;Skornyakova, 1965;Presley et al, 1967; as a controlling factor of compositions. The ratio Mn/ Fe, for example, is explained by the varying opportunity for fractionation within the sediment, with Mn being significantly more mobile, since Fe precipitates as oxide or a sulfide over a large range of conditions (Fig.…”

“…Silica release by clays entering seawater and associated silica uptake by diatoms had been proposed by Murray and Irvine (1891). who were impressed by the dearth of this element in the photic zone.…”

Suspended Matter in Surface Waters of the Atlantic Continental Margin from Cape Cod to the Florida Keys

“…Total suspended sedliment concenitriations in open Atlanitic wx aters. SoLIucCs citCd in (3). Nearshore studies, studies involving pa;rticle coLints (22), or optical stuLdies only (23) ai-e not includedl heic.…”

Nondetrital siliceous sediments

“…In addition to extracting soluble silica from water, some diatoms are capable of obtaining silica directly from aluminosilicate minerals (Murray and Irvine, 1889;Hutchinson, 1957, p. 790). Gawel (1950) has noted that cherts (mostly radiolarian) in the Flysch of the Carpathians occur in argillaceous parts of the sequence but are uncommon in the more calcareous parts; he concludes that the siliceous organisms derived their silica from clays and that their growth was favored by periods of argillaceous deposition.…”