1|Hg Chemostratigraphy and Hg isotopes from sections straddling the KTB in Europe, India and South America

SIAL, ALCIDES N.; JIUBIN CHEN; L. D. LACERDA; V.C. TEWARI; M.K. PANDIT; C. GAUCHER6; R. FREI; S. CIRILLI; V. P. FERREIRA1; S. PERALTA; J. A. BARBOSA; N. S. PEREIRA

Prague

Conferencia; Goldschmidt 2015 Conference Prague - August 2015; 2015

International Association Isope Geology

We review and further investigate the use of Hg as a proxy for volcanism, using six distal and two proximal sections in relation to the Deccan volcanic center, straddling the KTB: (a) Europe (Stevns Klint, Gubbio, Padriciano), (b) India (Meghalaya, Jhilmili) and (c) South America (Bajada del Jagüel, Cabra Corral, Poty Quarry). Complete sections display strong negative δ13C excursions at the KTB, while in near-complete sections, gradual fall of δ13C values predates the KTB. Volcanogenic CO2 enrichment of the atmosphere during the KTB transition led to large negative δ13C excursions. O-isotope signals recorded a warming event predating the KTB, likely related to Deccan phase 2, followed by strong cooling at the KTB, probably related to high amounts of SO2 released to atmosphere by the Deccan phase 2 and accumulated in the KTB transition. Warming events in the early Danian are, perhaps, related to early eruptions of Deccan phase 3. Almost all sections exhibit three Hg spikes. The one which predates the KTB and the spike that coincides with the KTB layer are likely related to Deccan phase 2. A third spike, probably related to the Deccan phase 3, is present in the early Danian in almost all sections. δ202Hg values for the KTB layer at Stevns Klint, Gubbio and Jagüel Formation (˗1 to ˗2 ?) lie within the range for volcanogenic Hg. Most of the analyzed samples show small (but significantly higher than analytical precision of 0.04?) positive Δ201Hg, in favor of long-term atmospheric transport prior to deposition.