Geochemical studies of feldspathic fragmental breccias and the nature of North Ray Crater ejecta

Major and trace element analyses of clasts and matrix from feldspathic fragmental breccias show that these breccias are not all alike but vary widely in their bulk compositions and clast assemblages. These studies, together with analyses of other North Ray Crater large rocks, reveal the major components to be anorthosites, ferroan anorthositic norites, magnesian granulites, feldspathic melt rocks, and VHA impact melts. The ferroan anorthositic norites are important lunar crustal rocks identified here for the first time. The KREEPy VHA melts are found to be much more important in North Ray Crater ejecta than was previously assumed. Sodic ferrogabbro is an important minor component. The compositional characteristics of bulk breccias and feldspathic melt rocks are modeled quantitatively as mixtures of two to five components: anorthosites, ferroan anorthositic norites, magnesian granulites, sodic ferrogabbros, and VHA melt rocks. Breccia 67455 is unique in consisting wholly of ferroan, KREEP‐free components.