A preferred orientation of intrusion of Precambrian dykes

AN analysis of the original orientation of Precambrian dykes has produced a nonrandom pattern that implies the existence of a Precambrian stress field of global extent. In general, dyke intrusion tends to occur in a north–south orientation, and is concentrated in low latitudes. This distribution has many similarities to the present distribution of sheeted diabase complexes of present day oceanic ridge crests, and may reflect the persistence of …