ISSN: 1130-4995 This is the scientific journal of the Geology Museum. It was established in 1990 as part of the publications produced by Barcelona's City Hall. This journal fills a need for a source of geological information that has not been available in the natural science museums of Barcelonasince 1947. The aim of the journal is to promote and disseminate research from the various branches of the earth sciences, to expand understanding of Catalonia's geology, and to promote the study of the Museum's holdings. Papers are accepted in Catalan, Spanish, English, and French. Topics may include the earth sciences -especially the geology of Catalonia- as well as mineralogy, paleontology, petrology, studies of the Museum's collections, and the history of science.