个人觉得应该是法语,
因为很多石油地质期刊可以用法语,且SCI收录。
比如:Petrology+;Canadian journal of earth sciences;
International journal of earth sciences;Geografiska Annaler: Series A, Physical Geography;
European journal of mineralogy;Geologica Acta;
Hydrogeology journal;Canadian journal of earth sciences;Engineering geology等!