Received: 16 November Accepted: 1 September Two redox-sensitive metalloids, arsenic As and antimony Sb , are examined here to determine what can be their help in the deciphering of past depositional conditions.
The enrichment factors of the two elements are compared for a set of geological formations and marine deposits covering a relatively wide range of paleoenvironmental settings, from oxic to euxinic conditions. This work confirms that As and Sb are not robust paleoredox proxies but examining their relative enrichment may be useful. These preliminary results indicate that a co-enrichment of both elements with Sb being more enriched than As could be the mark of the so-called particulate shuttle effect.
(mh=rlH3QTH9d_RgeBTw)9.jpg "Sluts Châtillon")
Notably, Sb would be more sensitive to Mn-shuttling than As. If confirmed, this trend could be used to further identify the cause of As-enrichment in marine sediments impacted by cold seepage fluids. Arsenic As and antimony Sb are two metalloids often mentioned together due to their belonging to group V of the periodic table, which gives them common characteristics Tab.
They are most often mentioned for problems of toxicity and pollution of soils, lakes and drinking water supply; a large literature is available on this subject. On the other hand, relatively little work has been devoted to the conditions of accumulation of these two elements in marine sediments, when they are considered as paleo-environmental markers.
(mh=LRrBf81LgN7z00_8)14.jpg "Call girl in Châtillon")
Arsenic is much more studied than antimony in this regard. A recent study synthesized the complex geochemistry of sedimentary As Tribovillard, and the behavior of this element in marine environments can be briefly summarized as follows. Arsenic is mainly brought to the sediments with oxyhydr- oxides of iron and manganese. If reducing conditions develop at or below the water-sediment interface, As can react with sulfide ions to form soluble species that can leave the sediment.
