Total intensity [[magnetics]] responds to rock types over broad areas as well as those deep within the crust. We can see by a careful examination of map B, however, that many of the features shown by the residual map are vaguely apparent in the total intensity data. Fortunately, we no longer have to interpret such total intensity maps in petroleum basins because many enhancement techniques employing residuals, derivatives, polynomials, or downward continuation exist to reveal the subtle magnetic anomalies that result from the changes in rock type across basement block boundaries. | Total intensity [[magnetics]] responds to rock types over broad areas as well as those deep within the crust. We can see by a careful examination of map B, however, that many of the features shown by the residual map are vaguely apparent in the total intensity data. Fortunately, we no longer have to interpret such total intensity maps in petroleum basins because many enhancement techniques employing residuals, derivatives, polynomials, or downward continuation exist to reveal the subtle magnetic anomalies that result from the changes in rock type across basement block boundaries. |