Recognizing the Kačák Event in the Devonian terrestrial environment and its implications for understanding land–sea interactions

Abstract

The Kačák Event is a late Eifelian (Mid-Devonian) episode of marine dysoxia/anoxia with associated extinctions. It has been widely recognized in the shelf seas that surrounded the Old Red Sandstone continent. It was contemporary with the lacustrine Orcadian Basin in Scotland. This basin contains the distinctive Achanarras lake horizon that contains a rich and diverse fish fauna. The Achanarras lake was wide and deep and would have been filled by rainfall from a monsoon system at an insolation maximum. Faunal elements within the lake are in common with the Kernavė Member in Estonia and this level can be conodont dated as late Eifelian eiflius or ensensis Zone. Therefore the group of lacustrine flooding climatic events that occur at and above the Achanarras level can be correlated with the marine Kačák Event (sensu lato) and both can be regarded as having a common climatic cause and driven by an insolation maximum. A reconstruction of the Orcadian Basin drainage system and a water balance model based on the calcium flux within the lake shows that a very significant volume of water would have been seasonally discharged to the Rheic Ocean and would have caused an additional environmental effect.

Detrital zircon ages of Cambrian and Devonian sandstones from Estonia, central Baltica: a possible link to Avalonia during the Late Neoproterozoic

“…The shallow-marine deposition of carbonate facies continued in Estonia during most of the Ordovician to Silurian (Nestor & Einasto 1997), whereas terrigenous clastics dominated the Devonian (e.g. Kleesment 1997;Marshall et al 2007;MarkKurik & Põldvere 2012), analogous with the classic "Old Red Sandstone" in the UK.…”

“…Sample DV, consisting of reddish-and yellowish-brown, weakly cemented, very-fine to fine quartz sandstone with micarich levels and abundant fossil fish remains, corresponds to the lowermost part of the Givetian Stage (Aruküla Regional Stage; Mark-Kurik & Põldvere 2012; 387.7 -382.7 Ma, according to Becker et al 2012). Paleocurrent data are not available from the outcrop but regional basin study (Marshall et al 2007) suggests major clastic supply from the northeastern interior of Baltica.…”

Devonian stratigraphy in Estonia: current state and problems

“…?Desmochitina minor and Angochitina devonica (both by Plicher 1971) were identified in a sample of this core (Marshall et al 2007).…”

“…Conodonts are more common in the Kostyukovitchi RS, which is coeval with the Kernavė Fm Valiukevičius 1998;Kruchek et al 2001;Marshall et al 2007). These are Polygnathus linguiformis linguiformis, P. parawebbi, Icriodus nodosus (Huddle), I. symmetricus Branson & Mehl, etc.…”

Mid-Late Devonian assemblages of herbaceous lycophytes from northern Argentina and Bolivia: Age assessment with palynomorphs and invertebrates and paleobiogeographic importance

“…The basal mudstones of the Los Monos Formation appear to be related to a regional Ka c ak flooding event occurring during the late Eifelian (Marshall et al, 2007;Troth et al, 2011;Bosetti et al, 2011;Horodyski et al, 2013). The Givetian was characterized by shallow siliciclastic marine environments frequently influenced by storms and the Frasnian represented a transgressive interval; this is supported by an increase in the marine palynomorphs as part of the palynoassemblages documented in northern Argentina and southern Bolivia (Ottone, 1996;di Pasquo, 2007;Noetinger, 2010Noetinger, , 2014Noetinger and di Pasquo, 2011, and references therein).…”