Apatite trace elements

Belousova, E.A., Griffin, W.L., O Reilly, S.Y., Fisher, N.I. 2002. Apatite as an indicator mineral for mineral exploration trace-element compositions and their relationship to host rock type. Journal of Geochemical Exploration, 76, 45-69. 

Contents of REE in massive sulfides from the BMC are strongly controlled by the abundance of and REE concentrations in phosphate minerals, specifically apatite, xenotime and monazite. Strong positive Eu anomalies in apatite, account for the anomalous Eu signatures of exhalative sulfides whereas REE in monazite masses are largely reflective of detrital sources and may mask hydrothermal signatures. Limited release of mobile trace elements (LREE and Eu) during green-schist facies metamorphism has partly modified REE profiles for VMS deposits of the BMC. 

As the human body is able to store many minerals, deviations from the daily ration are balanced out over a given period of time. Minerals stored in the body include water, which is distributed throughout the whole body calcium, stored in the form of apatite in the bones (see p. 340) iodine, stored as thyroglobulin in the thyroid and iron, stored in the form of ferritin and hemosiderin in the bone marrow, spleen, and liver (see p. 286). The storage site for many trace elements is the liver. In many cases, the metabolism of minerals is regulated by hormones—for example, the uptake and excretion of H2O, Na, ... 

Carbonate-fluor-apatite accommodates large quantities of trace elements, mainly uranium, which are potential luminescence centers. It has been proposed that uranium may occur in phosphorites in the following forms as a separate uraninite phase as an adsorbed or structurally incorporated uranyl ion as a dominantly replacement for Ca +, to be structurally incorporated... 

Trueman CN, Tuross N (2002) Trace elements in recent and fossil bone apatite. Rev Mineral Geochem 48 489-521... 

Suspended solid surfaces (particles or colloids) in waters play a prominent role in controlling the concentration of dissolved trace elements. Most of these elements are eliminated by sedimentation after incorporation on to or into particles, generally by complexation with the surface sites. The most common inorganic particles and colloids are non-clay silicates (quartz, potash feldspar, plagioclase, opaline silica (diatoms)) clays (illite, smectite) carbonates (calcite, dolomite) Fe-Mn oxides (goethite, magnetite) phosphates (apatite) sulfides (mackinawite). Particles and colloids in a water body may be classified as a function of their origin ... 

Figure 16 Trace-element mass-balance for deformed and granular lherzolites and harzburgites from E. Africa illustrating the contribution of a pervasive grain boundary component (PGBC), apatite and spinel reaction rims in wt.% of the total elemental whole-rock budget (after Bedini and Bodinier, 1999).

A full theoretical prediction for a specific bulk composition (Figure 20 Pyle and Spear, 2003) has intriguing implications for the control exerted by major minerals on accessory mineral stability (e.g.. Ferry, 2000), and for the repartitioning of trace elements among major and accessory minerals at different P and T. For example, the increase in monazite abundance at the expense of apatite with decreasing P accords with... 

Figure 24 X-ray maps of trace elements and Ca from garnet-bearing quartzite, showing spatially coincident, pronounced spikes. The location of these spikes is systematically different in different-sized garnets, relative to Fe-Mg-Mn systematics (Chernoff and Carlson, 1997,1999). Diffusionally produced haloes around growing crystals can cause sudden stabilization or destabilization of minerals (Johnson and Carlson, 1990). The coincidence of spikes in many trace elements as well as Ca is interpreted to reflect modal changes in a mineral like apatite or allanite. A common, diffusional mechanism for intergranular diffusion of trace elements and Ca may also be required, possibly by complexing with a common, slow-diffusing carrier element (Chernoff and Carlson, 1999) (reproduced by permission of GSA from Geology, 1999, 27, 555-558).

Accessory minerals commonly contain high concentrations of radioactive elements, and are a common target of radiogenic isotope measurements. Specific elements include uranium (zircon, apatite, titanite, monazite, xenotime, allanite) and thorium (monazite and allanite). Each accessory mineral is stabilized in a rock via a single element or suite of related elements, specifically phosphorous (apatite), REE (allanite, monazite, xenotime), zirconium (zircon), and titanium (titanite). Trace elements also occur in the major minerals (particularly phosphorous, zirconium, and titanium), so accessory minerals participate directly in major mineral reactions (Pyle and Spear, 1999, 2000, 2003 Ferry, 2000 Pyle et al, 2001 ... 

---