Map of Bouguer gravity of the northern Mississippi Embayment. Illumination is from the west. The Contour interval is 5 mGal. Dots indicate positions of maximum horizontal gravity gradient (density boundaries). B, Bloomfield pluton; C, Covington pluton; J, Jonesboro pluton; M, Maiden pluton; P, Paragould pluton. State boundaries are shown as solid lines \cite{langenheim1995}.