Data Description

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Scasso, RA et al. (2011): Tab. 1: Mineralogical composition and chemical analyses of major and trace elements of Ameghino Formation rocks. doi:10.1594/PANGAEA.763364,
Supplement to: Scasso, RA; Grunenberg, Thomas; Bausch, WM (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, hdl:10013/epic.29640.d001
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 the sequence, some epiclastic supply is revealed by petrographic evidence and illite crystallinity index. The clay mineral association (illite, chlorite and illite-smectite mixed layers) is mainly of diagenetic origin in the stratigraphically lower sections. Low percentages of expandable layers in the illite-smectite mixed layers, as well as the general mineralogical association, suggest a late mesodiagenetic stage, and together with geological evidence, a relatively deep burial (> 1000 m - probably > 2500 m) and temperatures exceeding 100°C.
Latitude: -64.500000 * Longitude: -59.000000
Ameghino * * Latitude: -64.500000 * Longitude: -59.000000 * Location: Ameghino Formation, Antarctic Peninsula * * Device: Geological sample (GEOS) *
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Sample code/label *LabelScasso, RA *
2Sample ID *Sample IDScasso, RA *
3Quartz *QzScasso, RA *
4Plagioclase *PlScasso, RA *
5Feldspar *FspScasso, RA *
6Pyrite *PyScasso, RA *
7Calcite *CalScasso, RA *
8Smectite *SmeScasso, RA *
9Illite *IllScasso, RA *
10Chlorite *ChlScasso, RA *
11Minerals *MineralsScasso, RA *other
12Lithology/composition/facies *LithologyScasso, RA *
13Silicon dioxide *SiO2%Scasso, RA *
14Aluminium oxide *Al2O3%Scasso, RA *
15Iron oxide, Fe2O3 *Fe2O3%Scasso, RA *
16Manganese oxide *MnO%Scasso, RA *
17Magnesium oxide *MgO%Scasso, RA *
18Calcium oxide *CaO%Scasso, RA *
19Sodium oxide *Na2O%Scasso, RA *
20Potassium oxide *K2O%Scasso, RA *
21Titanium oxide *TiO2%Scasso, RA *
22Phosphorus oxide *P2O5%Scasso, RA *
23Sulfur, total *Smg/kgScasso, RA *
24Rubidium *Rbmg/kgScasso, RA *
25Strontium *Srmg/kgScasso, RA *
26Zinc *Znmg/kgScasso, RA *
27Zirconium *Zrmg/kgScasso, RA *
1870 data points

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