ABSTRACT

This work is based on the study of three rocks dredged from the mouth of the Gulf of California. Chemical and petrographic analyses of these samples show their association as tholeiitic basalts. The three samples contain finely dispersed olivine and are composed mainly of basic glass and plagioclase microliths. They show chlorite too as evidence of alteration. Tectonic implications of their chemical and petrographic characteristics are briefly discussed.