A comparison is conducted between the remotely sensed abundances of thorium (through gamma-ray spectroscopy) and major chemical elements (through fast neutron spectroscopy) on the lunar surface. These are key elements in the investigation of lunar evolution. Correlations of variations of thorium abundance and fast neutron flux are analyzed on a spatial scale of 180 km through the construction of a covariance map. This technique is an unbiased mathematical method for developing the borders of major formations such as the Procellarum KREEP Terrane. Although thorium variations are positively correlated with those of the fast neutron flux over most of the lunar nearside, several locations within the Procellarum KREEP Terrane have negative correlations. This anticorrelation may denote an emplacement for these materials by transport of impact ejecta. Furthermore, analysis of these data reveals the presence of a distinctive structure in the northwest corner of Oceanus Procellarum marked by a ring of enhanced thorium. This structure may be related to an ancient impact basin. The confirmation of such a ring of thorium around the major basins inside Procellarum KREEP Terrane would reinforce the hypothesis of the redistribution of thorium during impact from shallow depth.