Influence of upwelling on the sedimentation and biota of the segmented margin of the western Neotethys: a case study from the Middle Triassic of the Balaton Highland (Hungary)

Abstract

western Neotethys margin, regional factors such as the establishment of an extensional tectonic regime and related marginal basin formation, monsoon-driven upwelling, and related high surface water productivity seem to be of critical importance in controlling the depositional conditions.

Geochemical characteristics of Triassic and Cretaceous phosphorite horizons from the Transdanubian Mountain Range (western Hungary): genetic implications

“…The models above are supported by the known geological background because the host rock of the phosphorite of Pécsely formed in a pelagic-basin environment, while the bed rock of the phosphorite from Tata represents a deep bathyal-basin facies and the cover rock (the Tata Limestone Formation) formed in a sublitoral external shelf environment (Budai et al , 2017; Fülöp, 1954, 1964, 1975).…”

“…The low oxygen level could result in the release of phosphorous to form synsedimentary phosphorite, which is in good agreement with the age data. The other possible source is the monsoon-derived upwelling model (De Wever et al , 2014), as Budai et al (2017) have used to describe this area. According to that model, the high fertility of the surface water (supported by an extraordinary diverse ammonite fauna) was related to monsoon-derived up-welling, where the coeval volcanic tuff input might have contributed to the fertilization.…”

“…According to that model, the high fertility of the surface water (supported by an extraordinary diverse ammonite fauna) was related to monsoon-derived up-welling, where the coeval volcanic tuff input might have contributed to the fertilization. As the area studied is a small isolated platform and the phosphorite occurs just at the NE part, a local control is suggested, such as the effect of wind-driven currents along the windward margin of the submarine high (Budai et al , 2017). Based on the present study, all these models of phosphorite formation are possible.…”

“…13). The phosphorite layers were formed with microbial mediation from the dissolved phosphate of seawater, induced partly by the nearby volcanic activity and the effects of a monsoon-derived upwelling (Budai et al , 2017). The mostly super-chondritic Y/Ho ratios and positive Y anomalies suggest a predominant seawater source for apatite formation and the lower Y/Ho values may indicate some hydrothermal input (Bau, 1996) that may be connected to the gradual weakening of the hydrothermal activity related to the Triassic volcanism (Pálfy et al , 2003) or to the hydrothermal fluids derived along normal faults (Győri et al , 2014).…”

Smectite appearance in the footwall of the Úrkút manganese ore deposit, Bakony Mts., Hungary

“…We support the second possibility: several details point to a complex flow system (upwelling controlled the ore formation): asymmetric location of the manganese-rich T-OAE-related sediments (Vörös and Galácz 1998); local appearance of the SiO 2 -rich footwall limestone, where the SiO 2 could have come from radiolarians (Polgári et al 2005); locally, high amount of radiolarians could represent an upwelling system (Smith 1968;Hartline 1981;Molina-Cruz 1984) and common details with other upwelling-controlled sedimentation within the TDR: radiolarite (tripoli)-containing carbonate, isolated areas connected to the opening of the Neotethys Ocean, and asymmetric sedimentation (Budai et al 2017).…”