The femiclmafic values are even lower than the basement is buried or drowned. The limiting factors are generally measured values uncorrected for porosity, so this method appears the density and quality of data. The broad regional north to northeast trending magnetic and We tentatively conclude that calculations of rock density based gravity features in New England, reflecting the regional trend of on mineral composition can be used as an effective guide in appraisals the northern Appalachians, have superimposed on them major of densities for use in gravity studies of crystalline terrane northeast and northwest trending lineaments; other trends are present and crustal structure. Screral of the northeastrending lineaments are very of our samples and calculations of modes and norms of some long, such as the Lewiaton lineament that extends from southeastern of the Maine samples are underway and will be used to refine New Hatnpshne to northeastern New Brunswick (Figure 1). Several of these have been demonstrated to represent fault zones or probable fault zonr$.