Tab. 1: Mineralogical composition and chemical analyses of major and trace elements of Ameghino Formation rocks ...

• Main Authors: Scasso, R A, Grunenberg, Thomas, Bausch, W M
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Sample code/label; Sample ID; Quartz; Plagioclase; Feldspar; Pyrite; Calcite; Smectite; Illite; Chlorite; Minerals; Lithology/composition/facies; Silicon dioxide; Aluminium oxide; Iron oxide, Fe2O3; Manganese oxide; Magnesium oxide; Calcium oxide; Sodium oxide; Potassium oxide; Titanium dioxide; Phosphorus pentoxide; Sulfur, total; Rubidium; Strontium; Zinc; Zirconium; Geological sample; Antarc*; Antarctic; Antarctic Peninsula
• Online Access: https://dx.doi.org/10.1594/pangaea.763364; https://doi.pangaea.de/10.1594/PANGAEA.763364

As a result of a petrographical, mineralogical and geochemical characterization of the Ameghino Formation mudstones (Upper Jurassic- Lower Cretaceous, Antarctic Peninsula), "epiclastic" radiolaria-rich and mixed (radiolaria-rich + tuff) mudstone types were recognized. Contents of clastic material in the mudstones generally increase with younger paleontological age, but local exceptions to this trend have been found. The anoxic environment of the lower part of the sequence changes to more oxidizing conditions towards the top, in transition to the Hauterivian - Barrêmian conglomerates. Element to element correlations show good agreement with the normal differentiation trends of volcanic (andesite-rhyolite) rocks, suggesting that the overall sequence is mainly volcanic in origin with various grade of reworking. For example, the radiolaria-rich mudstone matrix could have been originated from very fine touffaceous suspensions deposited very slowly after the main fall of the tuffs. However, in the upper part of ... : Supplement to: Scasso, R A; Grunenberg, Thomas; Bausch, W M (1991): Mineralogical and geochemical characterization of the Ameghino Formation Mudstones (Upper Jurassie, Antarctic Peninsula) and its stratigraphieal, diagenetical and paleoenvironmental Meaning. Polarforschung, 59(3), 179-198 ...