Trace element concentrations in conodonts measured by the Bochum proton microprobe

The Proton Microprobe at Bochum has been used to study trace element contents and elemental distributions in a suite of Devonian and Triassic conodonts, skeletal parts of marine invertebrates composed of the CO3- and F-rich modification of apatite (francolite). The conodonts contain a plethora of substituting elements (Mn, Fe, Sr, Y, light REE) at high concentrations, and linescans and elemental maps reveal preferential enrichments of many of these elements around skeletal rims. This observation tends to support the concept of post-depositional chemical alteration of the conodonts, but within an environment that still reflects the ambient marine conditions. Consequently, despite the high degree of substitution in the apatite structure, the Sr isotope signals of ancient seawater may still be retained by the samples. (C) 1997 Elsevier Science B.V.