New results of stable isotope and petrographic studies of Jurassic glendonites from Siberia

Database of global glendonite and ikaite records throughout the Phanerozoic

“…δ 13 C values of ikaite-derived calcite range from −27.7 ‰ to −14.3 ‰ PDB, while δ 18 O values range from −5.1 ‰ to +1.3 ‰ PDB (Frank et al, 2008). Lastly, δ 13 C values of secondary carbonate cements range from −20.2 ‰ to −3.9 ‰ PDB, while δ 18 O values range from −23.1 ‰ to −6.2 ‰ PDB (Frank et al, 2008;Vasileva et al, 2019; see Fig. 3).…”

“…The stable isotopic compositions of bulk glendonites and individual carbonate generations differ significantly. δ 13 C values of bulk glendonite samples range from −52.4 ‰ to +0.6 ‰ PDB, while δ 18 O values range from −16.6 ‰ to +4.8 ‰ PDB (Derkachev et al, 2007;Geptner et al, 1994Geptner et al, , 2014Qu et al, 2017;Willscroft et al, 2017;Vickers et al, 2018;Morales et al, 2017;Teichert and Luppold, 2013, among others). δ 13 C values of ikaite-derived calcite range from −27.7 ‰ to −14.3 ‰ PDB, while δ 18 O values range from −5.1 ‰ to +1.3 ‰ PDB (Frank et al, 2008).…”

“…Ikaite-derived calcite does not form the frame of the glendonite and is always supported by cements of different morphology. The first ikaite-derived calcite generation can be overgrown by needle-like or spherulitic calcite cement (e.g., Boggs, 1972;Kaplan, 1979;Huggett et al, 2005;Vickers et al, 2018). Crystals are a yellowish or amber color under the optical microscope with a bright cathodoluminescence (Frank et al, 2008;Teichert and Luppold, 2013, among others).…”

“…These carbonates can contain inclusions of pyrite (either as idiomorphic crystals or with framboidal habits; Greinert and Derkachev, 2004). Blocky, sparry, or radiaxial fibrous calcite can occupy the residual pore space (Teichert and Luppold, 2013) or replace carbonate rims and ikaite-derived calcite (Vasileva et al, 2019), typically displaying an orange to dark red cathodoluminescence. The last calcite generation is typically richest in Mg, Fe, Sr, and P (e.g., Vickers et al, 2020) Besides multiple carbonate generations, some detrital material is also typically found in glendonites.…”

“…The paucity of Barremian glendonites may be related to the HALIP-induced regression in the Arctic and scarcity of marine deposits of this age in the high northern latitudes. Glendonites are particularly abundant within the Valanginian, Aptian, and Albian sediments of Svalbard (Kemper, Schmitz, 1981;Vickers et al, 2018) and Arctic Canada (Herrle et al, 2015), along with the Aptian of Australia (de Lurio, Frakes, 1999). Berriasian glendonites, which mark the initiation of the Early Cretaceous cold interval, are rare and mainly described from Siberia (Rogov et al, 2017).…”