The term "ophiolite" originated from publications of Alexandre Brongniart in 1813 and 1821. In the first, he used "ophiolite" for serpentinite rocks found in large-scale breccias called mélanges. In the second publication, he expanded the definition to encompass a variety of igneous rocks as well such as gabbro, diabase, ultramafic and volcanic rocks. Ophiolites thus became a name for a well-known association of rocks occurring in the Alps and Apennines of Italy. Following work in these two mountains systems, Gustav Steinmann defined what later became known as the "Steinmann Trinity": the mixture of serpentine, diabase-spilite and chert. The recognition of the Steinmann Trinity served years later to build up the theory around seafloor spreading and plate tectonics. A key observation by Steinmann was that ophiolites were associated to sedimentary rocks reflecting former deep sea environments. Steinmann himself interpreted ophiolites (the Trinity) using the geosyncline concept. He held that Alpine ophiolites were "submarine effusions issuing along thrust faults into the active flank of an asymmetrically shortening geosyncline". The apparent lack of ophiolites in the Peruvian Andes, Steinmann theorized, was either due to the Andes being preceded by a shallow geosyncline or representing just the margin of a geosyncline. Thus, Cordilleran-type and Alpine-type mountains were to be different in this regard. In Hans Stille's models a type of geosyncline called eugeosynclines were characterized by producing an "initial magmatism" that in some cases corresponded to ophiolitic magmatism.