Sepiolite occurrence

Hay R. L. and Stoessell R. K. (1984) Sepiolite in the Amboseli Basin of Kenya a new interpretation. In Palygorskite-Sepiolite, Occurrences, Genesis, and Uses. Developments in Sedimentology 37 (eds. A. Singer and E. Galan). Elsevier, Amsterdam, pp. 125-136. 

Experiments at pressures of one kilobar and above indicate that talc is produced between 100-300°C (Hohling, 1958). However, its occurrence in salt deposits (Braitsch, 1971 Fuchtbauer and Goldschmidt, 1959) and carbonates (Millot, 1964) indicate that it continues to be stable at lower temperatures. The experimental work of Siffert (1962) indicates that talc could be precipitated from concentrated basic solutions (pH > 9) where other magnesian silicates such as sepiolite and trioctahedral montmoril-lonite are not stable. 

Figure 41. Phase diagram for the extensive variables R -R -Si combining the data for synthetic magnesian chlorites and the compositional series of natural sepiolites and palygorskites. Numbers represent the major three-phase assemblages related to sepiolite-palygorskite occurrence in sediments. Chi = chlorite M03 = trioctahedral montmorillonites M02 = dioctahedral montmorillonite Sep = sepiolite Pa = palygorskite Kaol = kaolinite T = talc.

VANDEN HEUVEL (R.C.), 1966. The occurrence of sepiolite and attapulgite in the calcareous zone of a soil near Las Cruces, N. MEX. Clays and Clay Min. JJ, 193-207. 

The present-day sediments of the Atlantic do not contain a substantial amount of zeolite (Elderfield, 1976). Clinoptilolite has been found, however, in association with sepiolite, quartz, and mont-morillonite (Hathaway and Sachs, 1965 Bonatti and Joensuu, 1968). The clay minerals palygorskite and sepiolite are usually minor constituents of marine sediments (Hathaway, 1979), and may be detrital (Weaver and Beck, 1977) or authigenic. Their hydrogenous occurrences are usually in basal sediment sections exposed to fluids of elevated temperarnres (Bonatti and Joensuu, 1968 Church and Velde, 1979 see below). 

Rogers, L. E. R., J. P. Quirk, and K. Norrish, 1956. Occurrence of sepiolite aluminum in a soil having unusual water relationship. Soil Sci. 7 177-183. 

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