A new method of rock disintegration and foraminiferal extraction with the use of liquid nitrogen [LN2]. Do conventional methods lead to biased paleoecological and paleoenviromental interpretations?

Paleoenvironments and Geochemical Signals from the Late Barremian to the Middle Aptian in a Tethyan Marginal Basin, Northeast Spain: Implications for Carbon Sequestration in Restricted Basins

“…Because the samples were well indurated, normal disaggregation method using a detergent was unsuccessful therefore we attempted the liquid nitrogen [LN2] method for foraminifera (Remin et al 2012), which enabled extraction of a few loose specimens of G. blowi (Sanchez-Hernandez and Maurrasse 2014). However, the LN2 method did not yield loose specimens of the co-occurring species such as Globigerinelloides maridalensis and Globigerinelloides paragottisi, or any other planktonic foraminifera.…”

“…4.5, Sanchez-Hernandez and Maurrasse, 2014) from partly indurated marl. The few loose specimens obtained were extracted with liquid nitrogen [LN2] following the treatment proposed by Remin et al (2012). The new LN2 method falls into the category of freeze-thaw method in which a rock sample previously soaked in water is treated alternately with LN2, and then boiling water until the sample is sufficiently disintegrated.…”

“…The effective mechanism of this method resides in the fact that LN2 [-196°C] causes complete and instantaneous formation of ice crystals in the pore system that expands by approximately 10%. The sudden addition of boiling water [100°C] produces a significant temperature shift of 300°C, and the difference in thermal expansion between rock matrix and the various microfossils leads to partial disintegration and the release of the foraminifera from the matrix (Remin et al, 2012). The micropaleontological analysis for planktonic foraminifera was accomplished primarily with thin sections using the help of illustrations in the published literature (e.g.…”

Turonian–Coniacian (Upper Cretaceous) of the Babadag Basin (North Dobrogea, Romania): integrated biostratigraphy and microfacies succession

“…A stan dard pro ce dure us ing so dium sul phate (Glau ber's salt) was em ployed. To ac cel er ate the mac er a tion pro cess, the freez ing was ac cel er ated us ing liq uid ni tro gen (Remin et al, 2012). The mac er ates ob tained were sifted to ob tain ma te rial in the 0.065-0.6 mm size in ter val.…”

Modified cleaning method for biomineralized components

“…Hence, a variety of methods have been developed to satisfy one or the other requirement. These include the use of sodium sulfate, sodium hydroxide, boron, hydrochloric acid, zinc chloride, hydrogen fluoride, hydrogen peroxide, acetone, ethanol, liquid nitrogen, potassium permanganate, hot water, and naphtha (e.g., Franke, 1922;Bourdon, 1962;Nishida, 1969;Hanken, 1979;Faegri et al, 1989;Shiono and Jordan, 1995;Lirer, 2000;Nielsen and Jakobsen, 2004;Abrantes et al, 2005;Remin et al, 2012;Jarochowska et al, 2013;Ikeya and Chinzei, 2007;Oda and Sato, 2013). Some extraction methods may require particular pieces of equipment, e.g., a sand bath, water bath, ultrasonic bath, dry oven, refrigerator, stirrer, settling chamber, or centrifuge.…”