Palaeoecological reconstruction of the late Oligocene Maar Lake of Enspel, Germany using lacustrine organic walled algae

Abstract

The fine laminated black pelites of fossil Lake Enspel (Upper Oligocene, Westerwald, W-Germany) have been analysed using palynological methods. With the help of lacustrine organic walled algae it was possible to reconstruct some aspects of the ecology of the palaeolake. Two organic walled primary producers have been recognized (Botryococcus and the freshwater dinoflagellate Cleistosphaeridium lacustre). During holomictic periods of the lake, freshwater dinoflagellates and Botryococcus coexisted. In more meromictic phases, however, Botryococcus and Cleistosphaeridium lacustre act as competitors. During times of oligotrophic and acidic water conditions with less or nearly no nutrient input into the lake, Botryococcus was prevailing. In times with more eutrophic and alkaline water chemistry caused by increasing nutrient input into the palaeolake, Cleistosphaeridium lacustre was predominant. Subordinate algal cysts of Zygnemataceae together with pollen of shore plants (Typha, Sparganium) indicate areas of shallow water or even a swampy shoreland of unknown size around Lake Enspel during some time periods.

First record of siliceous shell plates of Scutiglypha sp. (Amoebozoa: Thecamoeba: Euglyphidae) from Lake Enspel (upper Oligocene, Westerwald Mountains, Germany)

“…1) is part of the Cenozoic volcanic field of the High Westerwald Mountains (Germany). The crater probably formed as a phreatomagmatic eruption around 24.79±0.05 Ma (Mertz et al 2007), and an extremely deep, enclosed lake developed (original depth 240 m, with a diameter of 1.7×1.3 km ;Pirrung 1998;Pirrung et al 2001) which existed for up to 230,000 years (Mertz et al 2007;Herrmann 2010). Afterwards, it was filled by a basaltic flow.…”

“…2, layer S12, black arrow). Palaeolimnological information of Lake Enspel for that interval can partly be reconstructed from the palynological data of Köhler and Clausing (2000), Clausing (2001), and Herrmann (2010).…”

“…Cysts of Zygnemataceae (green algae) together with pollen of shallow water to shore plants like bulrush (Typha) and bur-reed (Sparganium) indicate areas of shallow water or even a swampy shore (Herrmann 2010). These areas were probably restricted to small fan deltas at the terminus of gullies that incised the crater wall (Gaupp and Wilke 1998;Schindler and Wuttke 2015).…”

Preliminary note on fossil flowers and inflorescences from the late Oligocene of Enspel (Westerwald, W-Germany)

“…Previous studies on the flora from this locality have dealt with algae (Köhler and Clausing 2000;Herrmann 2010), terrestrial palynomorphs (Herrmann et al 2009, and the abundant leaves and carpo-remains (Köhler and Uhl 2014). However, apart from a short notice about the existence of fossil flowers in Enspel (Köhler and Uhl 2014), nothing has so far been published about the abundant remains of fossil flowers excavated at this locality.…”

Fossil-Lagerstätte Enspel–a short review of current knowledge, the fossil association, and a bibliography

“…The lake sediments, consisting essentially of intercalated 'oilshales' and volcaniclastics, were subject to further sedimentological (e.g., Sieber et al 1993; Gaupp and Wilke 1998;Clausing 2001;Felder 2002), geophysical (e.g., Pirrung 1998), and geochemical investigations (e.g., Schwark et al 1995;Schulz et al 1997;Felder and Gaupp 2006), which, along with volcanology (e.g., Jung 1996;Hahn 1999;Hilder 2003) contributed essential new data to the understanding of the genesis and function of this palaeoecosystem.…”