Dissolution of deep-sea carbonate: preliminary calibration of preservational and morphologic aspects

Experimental diatom dissolution and the quantification of microfossil preservation in sediments

“…Barker, 1992), which may reflect losses of both numerically important, but weakly silicified, taxa and partly dissolved valves. Dissolution indices show little change in initially well-preserved assemblages until between 20 and 50% of valves are lost, in agreement with other experimental observations (Johnson 1974;Adelseck 1978). After this initial period, a threshold appears to be crossed, with indices showing a steady increase in dissolution as population declines.…”

“…The range of relative susceptibility reported here (~20 ; Table 1) is similar to that observed from dissolution experiments on foraminifera (Adelseck, 1978), radiolarians, and marine diatoms (Johnson, 1974). Attempts to establish rank orderings of taxa assume distinct, stable differences between species that are greater than those within species.…”

“…Johnson 1974;Malmgrem 1983;Barker et al 1994), intra-specific differences have been observed (e.g. with foraminifera ;Berger 1968;Adelseck 1978). Such differences can be expected for diatoms, if factors that affect resistance to dissolution in the frustule (such as specific surface area and metal ion content within the silica lattice) are highly variable.…”

“…Peterson and Prell 1985;Shemesh et al 1989;McMinn 1995). Absolute ranking systems have also been developed by standardizing relative abundance changes to one taxon (Johnson, 1974) or by comparing the loss rates of different taxa during dissolution experiments (Adelseck, 1978). Rank orderings are not always comparable, because they are sensitive to differences in initial condition of valves.…”

Refinement and application of a new paleotemperature estimation technique

“…In addition to these uncertainties, both planktonic foraminiferal assemblages (Adelseck, 1977;Berger and Killingley, 1977) and a 1 s0 of individual species (Bonneau et al, 1980) are subject to altera:tion by dissolution during sinking and after deposition. Studies have shown that dissolution shifts the foram assemblage towards a colder aspect by dissolving "warm" forams which have more fragile tests, an effect whose magnitude depends on the initial assemblage (Adelseck, 1977).…”