Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera

Abstract. Oxygen minimum zones (OMZs) are oceanic areas largely depleted in dissolved oxygen, nowadays considered expansion the face of global warming. To investigate relationship between OMZ and climate changes during late Quaternary, quantitative oxygen reconstructions needed but still their early development. Here, past bottom water oxygenation (BWO) was quantitatively assessed through a new, fast, semi-automated, taxon-independent morphometric analysis benthic foraminiferal tests, developed calibrated using WNP (western North Pacific, including its marginal seas), ENP (eastern Pacific), ESP South Pacific) samples. This new approach is based on an average size shape index for each sample. method, as well two already published micropalaeontological techniques assemblages' variability porosity investigation single species, here availability data from 45 core tops recovered along gradient (from 0.03 to 2.88 mL L?1) WNP, ENP, EEP Equatorial ESP, SWACM (southwest African continental margin), AS (Arabian Sea) OMZs. Global transfer functions herein proposed these methods. These reconstruction approaches were then applied palaeorecord examine consistency limits methods, relative influence pore waters tools. Both assemblage (which also ultimately ecological response complete faunal succession according BWO) gave similar consistent BWO reconstructions, while (based species unique mixed signal waters) showed ambiguous estimations.