The Eocene-Oligocene transition (EOT), ~34Ma, marks a tipping point in the long-term Cenozoic greenhouse to icehouse climate transition. Paleorecords reveal stepwise rapid cooling and ice growth across the EOT tightly coupled to a transient benthic δC excursion and a major and permanent deepening of the carbonate compensation depth (CCD). Based on biogeochemical box modeling, Merico et al. (200...

Human-induced ocean acidification and warming alter seawater carbonate chemistry reducing the calcification of reef-building crustose coralline algae (CCA), which has implications for reef stability. However, due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. Here ...

In 1976 a National Research Council Panel estimated that Western World lithium reserves and resources totaled 10.6 million tonnes as elemental lithium. Subsequent discoveries, particularly in brines in the southern Andes and the plateaus of western China and Tibet have increased the tonnages significantly. Geothermal brines and lithium bearing clays add to the total. This current estimate total...

We study liquid diphenyl carbonate (DPC) with molecular dynamics simulations in the temperature range from 350 to 600 K. The diiusion behavior as well as structural and relaxation properties of this complex liquid are analyzed in detail. To this end, an all-atom force eld is developed for DPC. We studied two sets of partial charges and the innuence of the torsion barrier at the carbonate group....

The enigma of the Bahamas is that this highly productive carbonate system has existed for at least 100 m.y., building a vast edifice of carbonates, thousands of meters thick, in an essentially nutrientpoor environment. Based on measurements of the insoluble material, the Fe and Mn in the carbonate fraction, and the d15N of the sedimentary organic matter, we suggest a paradigm shift in order to ...

Coordinated taphonomic, geochronologic, and geochemical studies of bivalve death assemblages and their sedimentary environments of San Blas, Caribbean Panama, permit us to identify the major factors controlling skeletal degradation in mixed carbonate-siliciclastic tropical shelf sediments. Ten sites were studied along environmental gradients including water nutrients, grain size, and sediment c...

Inorganic carbonate in soil occurs predominantly as the sparingly soluble alkaline-earth carbonates, calcite (CaCOs) and dolomite (CaMg(CO,),). Calcite is usually the dominant form in active pedogenic environments (Doner & Lynn, 1977; Nelson, 1982). There are only a few reported occurrences of aragonite (CaCOs) and vaterite (CaCOs) in soils. Sodium carbonate and magnesium carbonate and hydroxyc...

The contribution of the fortification of flour with calcium carbonate to the Ca intake of 375, 11-14-year-old Northumbrian children has been calculated. Mean Ca intakes were above those currently recommended for children of this age. The fortification of flour supplied 16% of the total Ca intakes. Without the fortification, the percentage of these children with intakes below the recommended int...

Density functional theory (DFT) calculations have been used to investigate the oxidative carbonylation of methanol on Pd(II)/β zeolite. Activation energies for all the elementary steps involved in the commonly accepted mechanism, including the formation of dimethyl carbonate, methyl formate and dimethoxymethane, are presented. Upon conducting the calculations, we identify that the Pd(2+) cation...

The processing of seawater by the marine teleost fi sh intestine includes high rates of base (bicarbonate) secretion into the intestinal fl uids. The resulting high bicarbonate concentrations in the intestinal fl uids combine with the calcium in the ingested seawater to form calcium carbonate crystals. This process is important for the salt and water balance of the marine teleost fi sh and lead...