THE second volume of Prof. Johannsen's work on petrography is both a descriptive petrography of the quartz-bearing igneous rocks and an illustration of the author's proposed new method of ...

This is a preview. Log in through your library . Abstract Twelve of the more recent proposals for the classification of igneous rocks are discussed with the intention of noting points of agreement and ...

IN this first volume the author provides an introduction to the science of petrography. After dealing with the constituents (minerals), and their relations (textures), he gives in summary some ...