Devonian climate, sea level and evolutionary events: an introduction

Becker, Ralph Thomas; Königshof, Peter; Brett, Carlton E.

doi:10.1144/sp423.15

Cited by 83 publications

(60 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This sequence boundary, which involves a dramatic sea‐level fall, is located exactly at the FF boundary in the studied section. Moreover, the strong environmental anomalies associated with the Kellwasser event in the studied sequence reinforce this chronostratigraphical assignation (Denayer & Mottequin, ; Becker et al ., ).…”

Section: Discussionmentioning

confidence: 88%

The Upper Devonian Kellwasser event recorded in a regressive sequence from inner shelf to lagoonal pond, Catalan Coastal Ranges, Spain

et al. 2018

View full text Add to dashboard Cite

This study, conducted in the Catalan Coastal Ranges, north‐east Spain, describes the Upper Devonian Kellwasser event in a shallowing‐upward sequence of black shales, siltstones and quartz arenites. This sequence was deposited in a progradational and regressive coastal system where the sedimentary environment evolved from the inner shelf to a lagoonal pond located landward of the shoreline. Three anomalous succeeding steps have been identified by geochemical analysis. The first one, detected on the inner shelf, was characterized by oxygen depletion and high organic productivity. The second, detected in the nearshore, was caused by hydrothermal activity occurring under normal oxic conditions. The third and most intense step was identified in the muds of the lagoonal pond and has been linked to strong anoxic conditions, elevated clastic input derived from changes in the weathering regime at the source area and moderate hydrothermal activity. The Kellwasser event is thus defined in the study area as stepwise and multi‐causal. This is the first time that the Kellwasser event has been identified in a sedimentary environment behind the shoreline. It is also the first time that it has been reported in the Catalan Coastal Ranges.

show abstract

Section: Discussionmentioning

confidence: 88%

The Upper Devonian Kellwasser event recorded in a regressive sequence from inner shelf to lagoonal pond, Catalan Coastal Ranges, Spain

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The nature of the Kačák Event is hotly debated with very little consensus in terms of its timing, duration, causes and effects (García‐Alcalde ; Becker et al . ). It is generally considered to have occurred at or near to the Eifelian–Givetian boundary.…”

Section: The Kačák Eventmentioning

confidence: 97%

“…Recently Becker et al . () suggested that the Kačák Event was a third‐order global event with globally elevated extinction rates (at the lower taxonomic level of species and genera) within many taxonomic clades and several ecosystems. They illustrated the event as being more‐or‐less confined to the lower ensensis conodont zone and pulsed with a lower and upper event.…”

Section: The Kačák Eventmentioning

confidence: 99%

“…; Becker et al . ). The aim of this study is to describe the composition and distribution of dispersed spore assemblages from throughout this sequence and use them to test and refine previously erected spore biostratigraphical schemes, identify palaeophytogeographical differentiation on this isolated island group, and shed light on the nature of the Kačák Event.…”

mentioning

confidence: 97%

See 1 more Smart Citation

An endemic flora of dispersed spores from the Middle Devonian of Iberia

Askew

Wellman

2018

Papers in Palaeontology

View full text Add to dashboard Cite

Diverse assemblages of dispersed spores have been recovered from Middle Devonian rocks in northern Spain, revealing a significant endemism in the flora. Middle Devonian Iberia was part of a relatively isolated island complex (Armorican Terrane Assemblage), separated by considerable tracts of ocean from Laurussia to the north‐west and Gondwana to the south‐east. The Middle Devonian deposits of the Cantabrian Zone of northern Spain are entirely marine and comprise a thick clastic unit sandwiched between extensive carbonate units. The clastic unit, the laterally equivalent Naranco, Huergas and Gustalapiedra formations of Asturias, León and Palencia provinces, represents a nearshore‐offshore transect across a marine shelf. This unit is also believed to encompass the Kačák Event, an important global extinction event. The recovered palynomorphs include marine (phytoplankton, chitinozoans, scolecodonts) and terrestrial (spores) assemblages. These are abundant and well preserved, although of variable thermal maturity. Here, we describe the dispersed spores and consider their significance as regards biostratigraphy, palaeophytogeography and Kačák Event interpretation. The dispersed spores represent a single assemblage assignable to the lemurata–langii Assemblage Zone (lemurata Subzone) indicating a probable early (but not earliest) Givetian age. Signs of endemism include various taxa known only from this region, some taxa appearing to have discordant ranges compared with elsewhere, and the absence from Iberia of certain prominent taxa characteristic of coeval assemblages elsewhere, such as those with grapnel‐tipped processes. The abrupt interruption of carbonate deposition, with a change to rapid deposition of thick clastic deposits, provides support for a monsoonal cause of the Kačák Event.

show abstract

“…Becker and Kirchgasser 2007;Königshof 2009;Brett et al 2011;Becker et al 2016;Suttner et al 2016;Mottequin et al 2017, this issue), which greatly increased knowledge in many respects. The primary goal of IGCP 596 was to assess the intensity of mid-Palaeozoic climate change and its impact on biodiversity both in marine and terrestrial successions.…”

Section: Past Activities and Future Challengesmentioning

confidence: 99%