Deccan volcanic eruptions and their impact on flora: Palynological evidence

Palaeoenvironmental changes associated with Deccan volcanism, examples from terrestrial deposits from Central India

“…Several geochemical proxies (CIA-K, Ti/Al, K/Fe+Mg) combined with sedimentology and palynology (Samant and Mohabey, 2014) and magnetic susceptibility (Font et al, this volume) show that the Podgawan intertrappean, which is coeval with the main DVP phase-2, was marked by extreme and detrimental events culminating in the upper part (units 3 and 4) ( Fig. 8 and 5).…”

“…Paleomagnetic data indicate that the DA intertrappean was deposited during the upper Maastrichtian in the geomagnetic polarity chron 29r and therefore corresponds to the onset of the main phase-2 (GSI map 2000; Mohabey et al, 1993;Hansen et al, 2005;Samant and Mohabey, 2014) (Fig. 2).…”

“…The intertrappean sediments of Podgawan (PO) are intercalated between flow F8 of the Ajanta Formation and flow F2 of the Karnja Formation (GSI map 2000). Palynological data (Samant and Mohabey, 2014) indicate an early Paleocene age equivalent or sligthly younger than the Jhilmili intertrappean ( Fig. 2) (Keller et al, 2008) and therefore corresponds to the upper part of phase-2 (C29r).…”

“…1, 3) is 5.4 meters thick (the contact with the Precambrian basement was not visible) and mainly composed of green claystones and siltstones with carbonate nodules and finely laminated marly limestone layers, which contain rare ostracods (Unit 1). The overlying Unit 2 consists of massive basalts of the Sahyadri Group, which erupted at the beginning of C29r (Samant and Mohabey, 2014) and hence at the onset of phase-2 (Chenet et al, 2008).…”

“…For this purpose, we focus on five sections: the Dongargaon section located below the volcanic sequence, and the Government Well, Daiwal, Podgawan and Umaria-Isra sections deposited during periods of volcanic quiescence. The stratigraphic positions of the Lameta and intertrappean sediments within the three Deccan phases are based on palynologic, biostratigraphic and paleomagnetic data (Mohabey et al, 1993;Hansen et al, 2005;Samant and Mohabey, 2014).…”