Mikropaleontologiens teknikk.

Abstract

Technique of micropaleontology: The article describes the treatment of Formanifera samples from Norwegian Late Pleistocene marine clays. The samples is collected with a thin-wall, stationary piston samper with entrance diameter 5.4 cm (Vold 1956). For micropaleontological purposes 3 to 4 cm thick transverse slices are cut out of the core of intervals of 50 cm. adry sample should not weigh less than 100 g. The dried sample is crushed between the jaws of a vice until no fragment is larger than 1 cm3. for the purpose of further disintegration the sample is placed in a 2 to 5 per cent solution of hydrogen peroxide (H2O2) for 10 to 15 min. (Wick 1947). The fossils are separated from the clay fraction of the disintegrated sample by washing it through two sieves, the screen of the upper one having a fresh diameter of 1.0 mm and that of the lower one a mesh diameter of 0.1 mm. The construction of the sieve allows the screen to be detached from the frame (see Bartenstein 1954). In sandy samples the fossils are concentrated by the use of a heavy liquid, carbon tetrachloride (CC14). The washed and dried residue is poured in a single layer into a perforated, rectangular extraction tray, and studied under a binocular microscope at a usual magnification of 50x.