Determination of lead isotopic composition of a grain from the allende carbonaceous chondrite by LAMMA

The attempt of this work is to use the LAMMA, a newly developed modern micro-beam analytical technique, to determine the lead isotopic composition of some grains picked out from the white aggregate in the Allende (C3V) carbonaceous chondrite. The experimental results show that the Pb/Pb model age of the Allende calculated on the basis of the²⁰⁶Pb/²⁰⁷Pb ratio is 4.56 ±0.008 b. y., just in agreement with the values reported in literature. The LAMMA provides a new and powerful tool in the analytical arsenal dealing with trace elements and isotopic compositions, due to its high sensitivity, rapid performence and good space resolution.