Petrology Petrology Petrology (from the Greek πέτρος, "pétros", "rock" and λόγος, "lógos", "subject matter", see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale
The Gothenburg Study of Children with DAMP conclusion which does not need strengthening by what could have been found in the destroyed research material". (Another problem is the boy:girl ratios in the study; the ratio in the control group is 1:1, whereas the ratio in the index groups is 4:1.) The major Swedish newspapers have had tens of stories on the controversy: Dagens Nyheter, Svenska Dagbladet, Göteborgs-Posten, etc. There was also a one-hour program about DAMP on Swedish TV that discussed the controversy over Gillberg's Gothenburg study at length. In Norway, the newspaper Dagsavisen ran a series of critical stories. The Gothenburg Study of Children with DAMP