A PIXE STUDY OF CLOUDED PLAGIOCLASE FROM SOUTHERN SWEDEN

Clouded plagioclase is found in mafic dykes occurring along the Protog ine Zone in southern Sweden. The clouding intensity varies from slight to more pronounced brown/dark or opaque. In order to understand the t race-element partition/contribution in the clouding process, a PIXE (P article Induced X-ray Emission) analysis has been conducted on clouded plagioclase samples (Bjara, Bjarnum, Taberg). The experiments were un dertaken al the Lund Nuclear Microprobe. For each locality, PIXE spect ra and elemental distribution line-profiles (rim to core) are displaye d. This study has shown undulated (inhomogeneous), stepwise (semi-homo geneous), and homogeneous clouding at the elemental level. The result suggests that the trace elements partially contribute to the observed plagioclase clouding.