Abstract

Two distinct structural trends compose the Atlantic Margin of Central Morocco, the northwesternmost Hercynian of Morocco, and reflect the form and position of a positive Bouguer anomaly underlying this area. Major fold elements of the Northern Sector strike 060; minor fold axes define a girdle striking 060. In the Western Sector major folds trend generally 330; fold axes define 2 girdles striking 040 and 330. Major fold trends in the Northern and Western Sectors converge on the Rabat area where they display a type 2 interference pattern.

Trends of lineaments are not very consistent within either sector. However, a distinctive bimodal set of lineaments shows a similar shift in orientation. In the Southern part of the Western Sector the mean of the double peak trends 019 changing to 054 to the north and in the Rabat area it is 101. Eastward from Rabat the bisector changes to 095 after which the double peak merges into a single mode striking 090.

Geological evidence indicates deformation in the two sectors proceeded almost simultaneously but with the locus of most intense deformation in the northern sector. These data are consistent with two most obvious models: (1) folding and fracturing around a passive ancient dome acting as a buttress,(2) uplift and southeastward movement of a large section of crust.