Iron oxyhydroxide and sulphide mineralization in hydrocarbon seep-related carbonate submarine chimneys, Gulf of Cadiz (SW Iberian Peninsula)

A unique Fe-rich carbonate chimney associated with cold seeps in the Northern Okinawa Trough, East China Sea

“…possibility that the preformed pyrite was completely oxidized and disappeared from the chimney wall. However, we could not observe the occurrence of "pyrite pseudomorph", which is a common product of the pyrite transforming to Fe oxide during an oxidizing alteration (Merinero et al, 2008). This may be a further convincing proof hinting at the absence of primary pyrite.…”

“…Among them, chimney becomes the most obvious proof of the cold seep activities due to its distinctive fluid conduit and cylindrical shape. Through the investigations in the past several decades, numerous carbonate chimneys associated to the cold seepage have been discovered at the continental margins (Sakai et al, 1992;Orpin, 1997;Stakes et al, 1999;Peckmann et al, 2001;Michaelis et al, 2002;Gulin et al, 2003;Chen et al, 2005;Takeuchi et al, 2007;Zitter et al, 2008;Merinero et al, 2008;Wirsig et al, 2012;Magalhães et al, 2012;Bayon et al, 2013), most of which has been linked to the underlying natural gas hydrate reservoir. To date, some studies have discussed the source origin, formation process, and geological and environmental information contained in the carbonate chimneys, and proposed several growth models (Orpin, 1997;Reitner et al, 2005;Bayon et al, 2009Bayon et al, , 2013Magalhães et al, 2012;Wirsig et al, 2012).…”

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

“…Compensation by hydrogen carbonate induces authigenic precipitation of microbial dolomite (Roberts et al, 2004), Ca or Fe carbonate (Dewangan et al, 2013;Merinero et al, 2008;Solomon et al, 2014;Sun and Turchyn, 2014;Vorhies and Gaines, 2009;Wallmann et al, 2008), and other minerals (Tribovillard et al, 2013). generation produces a pH increase and additional alkalinity.…”

Mechanisms of trace metal enrichment in submarine, methane-derived carbonate chimneys from the Gulf of Cadiz

“…Since their formation, chimneys have undergone changes in redox conditions: they likely formed under oxygen-depleted conditions and they were in contact with oxygenated waters before sampling Merinero et al, 2008). In order to know how these changes have affected the levels of redox-sensitive elements in the chimneys, we determined the relative enrichment of some trace metals and used their concentrations to calculate several redox indices.…”