Major and trace éléments have been determined in monzonoritic rocks (hypersthenemonzodiorite or jotunite) frqm two intrusions belonging to the South R ogaland anorthositic complex (Norway). The rarcearth abundance pattern reveals no Eu anomaly, or only a very small one, This fact together with field observations suggest that thèse rocks represent the parental magma of the anorthositic suite. High Ti and P abundances, low Si content, high l'e/Mg and K20/Si02 ratios are charactcristics of the major élément geochemistry. Absolute amounts of some trace éléments abundances vary distinctly between the two intrusions. K/R b ratios as high as 1700 are observed. Partial fusion of upper mantle kaersutite is proposed as a possible mechanism of magma génération. Partition coefficients between plagioclase phenocrysts and liquid are determined. 335 Printed in The Netherlands * Similar values (Th = 0.48 ppm; U = 0.25 ppm) have been measured [36] in a monzonoritic dyke related to the E-R main body.

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