Geochemistry of tholeiites from North-East American margin; correlation with Morocco

The chemical variations of the early mesozoic tholeiites from North-East American margin pointed out by the american authors are specified by means of multivariate statistical methods (Principal Component Analysis, Stepwise Discriminant Analysis, Multiple Regression). The highly significant correlation between chemical composition and latitude (R = 0.87) can be explained by an evolution of the initial magma from South to North. As in America, Moroccan High Atlas tholeiites are connected with the early opening of the North-Atlantic. By using these statistical methods, it appears that moroccan tholeiites are chemically related to New-Jersey — Connecticut tholeiites. This chemical positioning is compared to predrift reconstruction patterns.