Sedimentary changes and sealevel

This event is related to pronounced facies shifts in Laurentia, Baltica and peri-Gondwana, independent of basin type: contemporaneous facies anomalies are known from rapidly subsiding rift basins (Kaljo et al. 1995), from deep shale basins (Por^bska et al. 2004) as well as from shallow intercontinental carbonate platforms (Calner and Jeppsson 2003) and off-platform slope and basin settings (Calner et al. 2006a; Lenz et al. 2006). In shaly successions on peri-Gondwana as well as on Baltica, the event is associated formation of phophorites (Pittau et al. 2006; Jaeger 1991). On Gotland, sea-level fall during the earliest part of the event (flemingii-dubius Zone) is manifested by influx of siliciclastic material and formation of epikarst and a rocky shoreline with an erosional relief of at least 16 m (Calner and Sall 1999; Calner 2002). In this area, the maximum sea-level lowstand (the karst surface) is at or very close to Datum 2 of the event. The sea-level lowstand surface is overlain by a thin oolitic unit that can be followed across Gotland and which reappears at the same level in the East Baltic Area more than 200 km away. The oolite formed during the earliest part of a marked transgression that continued through the dubius, parvus-nassa, and dubius-nassa zones. This transgression gave rise to famous stratigraphic units such as the Mulde Formation on Gotland (now termed the Mulde Brick-clay Member) and the Waldron Shale across south and central USA. Equivalents to these shaly units are found also in Arctic Canada (cf. Lenz et al. 2006). The time period of extremely low diversity and carbon isotope excursion correlates with increased deposition of organic carbon in the oceans (Por^bska et al. 2004; Calner et al. 2006a; Lenz et al. 2006). The precise relationship between extinctions, sea-level change and carbon isotope excursion in carbonate platforms has been demonstrated by Calner et al. (2006a).

Fig. 9. The figure shows locations where previous studies have presented firm evidence for anomalies either in stable isotopes, biodiversity, or facies during the Mulde Event. Stars with white dot indicate that the cited study does not include stable isotope data. AC - Arctic Canada (Lenz et al. 2006), CR - Czech Republic (Kaljo et al. 1995; Kozlowska-Dawidziuk et al. 2001), EB - East Baltic Area (Kaljo et al. 1997, 2003), GB - Great Britain (Corfield et al. 1992), GE -Germany (Jaeger 1991), IB - Iberian Peninsula (Gutiérrez-Marco et al. 1996), KA - Kazakhstan (Koren'1991), NE - Nevada (Cramer et al. 2006), NSW - New South Wales (Rickards et al. 1995), PO - Poland (Porçbska et al. 2004), SA -Sardinia (Pittau et al. 2006), SW - Sweden (Calner et al. 2006a), TN - Tennessee (Cramer et al. 2006).

Fig. 9. The figure shows locations where previous studies have presented firm evidence for anomalies either in stable isotopes, biodiversity, or facies during the Mulde Event. Stars with white dot indicate that the cited study does not include stable isotope data. AC - Arctic Canada (Lenz et al. 2006), CR - Czech Republic (Kaljo et al. 1995; Kozlowska-Dawidziuk et al. 2001), EB - East Baltic Area (Kaljo et al. 1997, 2003), GB - Great Britain (Corfield et al. 1992), GE -Germany (Jaeger 1991), IB - Iberian Peninsula (Gutiérrez-Marco et al. 1996), KA - Kazakhstan (Koren'1991), NE - Nevada (Cramer et al. 2006), NSW - New South Wales (Rickards et al. 1995), PO - Poland (Porçbska et al. 2004), SA -Sardinia (Pittau et al. 2006), SW - Sweden (Calner et al. 2006a), TN - Tennessee (Cramer et al. 2006).

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