A multistratigraphic approach to pinpoint the Permian-Triassic boundary in continental deposits: The Zechstein–Lower Buntsandstein transition in Germany

Abstract

The Central European Basin is very suitable for high-resolution multistratigraphy of Late Permian to Early Triassic continental deposits. Here, the well exposed transition of the lithostratigraphic Zechstein and Buntsandstein Groups of central Germany was studied for isotope-chemostratigraphy (δ 13 Corg, δ 13 Ccarb, δ 18 Ocarb), major-and trace-element geochemistry, magnetostratigraphy, palynology, and conchostracan biostratigraphy. The analyzed material was obtained from both classical key sections (abandoned Nelben clay pit, Caaschwitz quarries, Thale railway cut, abandoned Heinebach clay pit) and a recent drill core section (Caaschwitz 6/2012) spanning the Permian-Triassic boundary. The Zechstein-Buntsandstein transition consists of a complex sedimentary facies comprising sabkha, playalake, aeolian, and fluvial deposits of predominantly red-colored siliciclastics and intercalations of lacustrine oolitic limestones. The new data on δ 13 Corg range from-28.73 ‰ to-21.67 ‰ showing multiple excursions. Strongest negative shifts correlate to single intercalations of oolites and gray-colored clayey siltstones, while isotopically more heavy shifts correspond to an onset of palaeosoil overprint. The δ 13 Ccarb range from-9.69 ‰ to-1.34 ‰ with strongest variations recorded in dolomitic nodules from the Zechstein Group. A correlation of δ 18 Ocarb-values with the carbonate content is interpreted to reflect diagenesis. In contrast to sedimentary facies shifts across the Zechstein-Buntsandstein boundary, majorelement values used as proxy (CIA, CIA*, CIA-K) for palaeoclimate conditions indicate climatic stability. Trace-element data used for a geochemical characterization of the Late Permian to Early Triassic transition in central Germany indicate a decrease in the Rb at the Zechstein-Buntsandstein boundary.New palynological data obtained from the Caaschwitz quarry section reveal occurrences of Late Permian palynomorphs in the Lower Fulda Formation, while Early Triassic elements were recorded in the upper part of the Upper Fulda Formation. The present study confirms an onset of a normal-polarized magnetozone in the Upper Fulda Formation of the Caaschwitz quarry section supporting an interregional correlation of this crucial stratigraphic interval with the normal magnetic polarity of the basal Early Triassic known from marine sections in other regions. Based on a synthesis of the multistratigraphic data, the Permian-Triassic boundary is proposed to be placed in the lower part of the Upper Fulda Formation, which is biostratigraphically confirmed by the first occurrence date of the Early Triassic Euestheria gutta-Palaeolimnadiopsis vilujensis conchostracan fauna. Rare records of conchostracans reported from the siliciclastic deposits of the lower to middle Zechstein Group may point to its potential for further biostratigraphic subdivision of the Late Permian continental deposits.

Integrated multi-stratigraphic study of the Coll de Terrers late Permian–Early Triassic continental succession from the Catalan Pyrenees (NE Iberian Peninsula): A geologic reference record for equatorial Pangaea

“…Particularly, the hematite depletion and the increase of Cu and Sr (and also the minor increase that seems to occur in the case of Ni) possibly denote anoxic conditions. Grey intervals with Cu enrichments, related to anoxia, are recorded in the lowermost Buntsandstein of the Central European Basin, Central Germany (Hiete et al, 2006;Scholze et al, 2017). Noteworthy, the end-Permian extinction is correlated with oceanic anoxia and acidification (Grice et al, 2005;Meyer and Kump, 2008) that influenced atmosphere (Kump et al, 2005).…”

“…Copper is generally related to environments with low oxygen levels (Hofmann et al, 2000;Hiete et al, 2006;Scholze et al, 2017), which could be linked to the decrease of hematite observed by XRD. This mineral is formed in oxic conditions, and therefore the observed hematite reduction may be a consequence of lower atmospheric oxygen levels (Hiete et al, 2006;Benton and Newell, 2014).…”

“…Benton and Newell (2014) have recently considered several key zones to study both the Permian-Triassic continental record and the Permian-Triassic boundary (PTB), including Western and Central Europe, Russia and Siberia, central India, South China, central-eastern South America, South Africa, Australia and Antarctica. In addition, recent works provided new data to characterise the Permian-Triassic transition in terrestrial successions from Central Germany (Scholze et al, 2017) and South China (Chu et al, 2016;Zhang et al, 2016;Xu et al, 2017). In general, Western Europe successions (Western periTethyan domain) are characterised by an important erosive contact around the PTB (Bourquin et al, 2007(Bourquin et al, , 2011.…”

Quartz and zircon decoupling in sandstone: Petrography and quartz cathodoluminescence of the Early Triassic continental Buntsandstein Group in Germany

“…Buntsandstein‐Group deposition lasted from Induan to Anisian time (earliest to early Middle Triassic; 252 to 247 Ma; Szulc, ; Scholze et al ., ). Stratigraphic subdivision is based on basin‐wide large‐scale fining‐upward cycles (Fig.…”

Marine vs. terrestrial environments during Early Triassic deposition on the northeastern margin of the Central European Basin – a multidisciplinary study on the Middle Buntsandstein of the Bartoszyce IG 1 borehole, NE Poland

“…14), ex clud ing the val ues of short-term pos i tive ex cur sions of this iso to pic ra tio (Horacek et al, 2007a). Al most all re ported val ues of d 13 C from Buntsandstein oo lites from the Cen tral Euro pean Ba sin show very nar row ranges be tween +1 and -4‰ (Korte and Kozur, 2005;Becker, 2007;Weidlich, 2007;Scholze et al, 2017;Fig. 14).…”