WorldWide Drilling Resource

Frequently-Used Geological Terms Part 62 Glossary Adapted from the Dictionary of Geological Terms P Paleogeography - The study of the physical geography of all, or a part, of the earth’s surface in the geological past. Palingenesis - The formation of newmagma by the melting of preexisting magmatic rock in situ. Pallasite - A stony iron meteorite. Panning - A technique of prospecting for heavy metals, such as gold, by washing placer or crushed vein material in a pan. The lighter fractions are washed away, leaving the heavy metals behind in the pan. Paper Shale - A shale which splits into thin laminae, suggesting sheets of paper. Paraffin-Base Crude - Crude oil which will yield large quantities of paraffin in the distillation process. Parent Element - The radioactive element from which a daughter element is pro- duced by radioactive decay. For example, radium is the parent element of radon, which is the daughter element. Patina - A colored film or thin layer produced on the surface of a rock by weathering. Also refers to the greenish film formed on copper and bronze after exposure to a moist atmosphere consisting of a basic carbonate. Pedion - A crystal form with only one face. Pegmite - An exceptionally coarse-grained igneous rock with interlocking crystals usually found as irregular dikes, lenses, or veins. The composition of pegmatites is similar to granite; it may be simple or complex, and may include rare minerals rich in elements such as lithium, boron, fluorine, niobium, tantalum, uranium, and rare earths. Pegmatites represent the last and most hydrous portion of magma to crys- tallize and contain high concentrations of minerals present only in trace amounts in granitic rocks. Pelite - A rock composed of fine parti- cles of clay or mud. Pelitomorphic - Pertaining to clay-sized carbonate particles in limestone or dolomite. Also refers to limestone or dolomite con- sisting of an aggregate of pelitomorphic particles or having amatrix of such particles. Look for more terms next month! WWDR photo of panning. Open the Doorway to all the Event Photos during SaMoTer 2017. To see all the photos from this event, go to: www.worldwidedrillingresource.info/gallery/2017/SaMoTer2017, or just click here. Feel free to download at will and print the photo(s) of your choice. Compliments of WorldWide Drilling Resource ® . Photos are copyrighted and released for personal use only - no commercial use permitted. . . . I really enjoy your magazine. Donald Oehring Don Oehring Well Drilling Woodhaven, MI 46 JUNE 2017 WorldWide Drilling Resource ®