Celadonite and smectite formation in the Úrkút Mn-carbonate ore deposit (Hungary)

Abstract

13Synsedimentary and early diagenetic oxygen levels are estimated by evaluating celadonite-14 smectite formation in marine Jurassic black shale-hosted manganese-carbonates. Celadonite 15 formed under suboxic-dysaerobic conditions, Al-rich Fe-smectite formed at suboxic-anaerobic 16 conditions, and nontronite formed at anoxic-anaerobic conditions during sedimentary burial. A 17 genetic pathway by direct precipitation from solution is proposed for the enormous mass of 18 celadonite, based on mineral and textural evidence. Lamination of the manganese ore is 19 independent of clay-mineral composition and was given by a series of mineralized microbial Fe-20 rich biomats. 21

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

“…In particular, the injection of sulfate aerosols into the stratosphere is the most studied method, as it mimics the episodic action of natural volcanoes (Ming et al, 2014;Pope et al, 2012). Injected particles into the stratosphere reduce the radiative balance of Earth by scattering solar radiation back to space, so several types of particles are envisioned with a wide range of side effects (Jones et al, 2015).…”

“…After the arrival of the pore water originating from the anoxic deeper sediment or from the bedrock at the suboxic surface-near sediment layers, the oxidized HA releases Si(OH) 4 and NO − 3 produced by microbial NH + 4 nitrification (Daims et al, 2015;van Kessel et al, 2015). Depending on the Si(OH) 4 concentration produced, this can trigger the precipitation of layered silicates such as smectites, glauconite and celadonite as well as silica (Bjorlykke, 2010;Charpentier et al, 2011;Gaudin et al, 2005;Polgári et al, 2013;Pufahl and Hiatt, 2012;Zijlstra, 1995). Similar to HA, the clay mineral formation within the sediment and the use of the redox potential of these authigenic minerals are, at least in part, the result of microbial action (Konhauser and Urrutia, 1999;Kostka et al, 1996).…”

“…The ISA method appears to be the climate cooling method of choice because it accelerates the conversion of atmospheric carbons into solid and even liquid carbons with the means of nature. Compared to the artificial aerosol systems based on TiO 2 or H 2 SO 4 (Pope et al, 2012), sea-salt aerosol has advantages, such as better controllability and economy.…”

Correlated chemostratigraphy of Mn-carbonate microbialites (Úrkút, Hungary)

“…The most part of the Úrkút Mn carbonate deposit is pyrite free, as in the ore zones the organic 230 matter alteration took place via microbially mediated Mn(IV,III) reduction and the system did 231 not reach the sulfate reduction zone; it remained suboxic (Polgári et al, 2012a(Polgári et al, , 2013. The 232 principal pyrite-bearing zones are within the black shales towards the top of the sequence.…”

“…%; Hahn, 2009), but 312 the organic material content was enough to lead to barite mineralization. The formation and 313 diagenetic conditions based on clay mineralogy reflect suboxic conditions (Polgári et al, 2013). 314…”