The petrology of these may be divided into four type classes:—1.
petrology entered upon a new and wider field of investigation.
I got the title of professor from a college back East where I lecture occasionally on mineralogy and petrology.
The investigation of the crust belongs to geology and of rocks in particular to petrology.
He was distinguished for his researches on mineralogy, crystallography and petrology.
Many of the more specialised branches of geology, such as petrology, were as yet in a very rudimentary state.
The more technical portions of the subject, such as petrology and palontology, he considers in much less detail.