The detailed study of 455 basement samples from DSDP Leg 37 reveals magnetic properties, particularly inclinations and intensities, different from those commonly considered representative of Layer 2. Non-dipole inclinations are the most common. The deepest hole (582 m) has a vector average intensity of 24.3 × 10−4 emu cm−3 (24.3 × 10−1 A/m) and an inclination of only −14.5°. Induced magnetization never dominates and is usually much less than remanent magnetization, with Q ratio averaging 35 for basalts and 2.6 for plutonic rocks. Viscous magnetization acquisition constant, S, ranges widely from 0.001 to 1 × 10−4 emu cm−3 (0.001 to 1 × 10−1A/m), but is very rarely sufficient to cause VRM to dominate NRM.The major carrier of NRM is cation-deficient titanomagnetite produced by low-temperature oxidation of stoichiometric titantomagnetite. There is no trend of alteration with depth. All the magnetic properties are controlled by conditions within the individual basalt pillows or more massive units. A high degree of cation deficiency is associated with reduced NRM intensity, initial susceptibility, saturation magnetization, and VRM acquisition and increased MDF, Q ratio, and Curie point. Zones of low cation deficiency are presently found only in parts of massive units. With the exception of rare individual samples pillow sequences are highly oxidized throughout.A discussion is given of the kinds of ocean crust drilling and laboratory experiments required to solve the problems of the magnetic structure of Layer 2 as seen at the Leg 37 sites.