WorldWide Drilling Resource

Northern Plains Chapter of the ISEE President: Ron Eastman Tel: 307-680-8805 www.npcisee.org 29 WorldWide Drilling Resource ® MARCH 2014 Frequently-Used Geological Terms Part 28 Glossary Adapted from the Dictionary of Geological Terms I - Continued Ice Wedge - Wedge-shaped, foliated ground ice produced in permafrost, occur- ring as a vertical or inclined sheet, dike, or vein tapering downward. Iddings’ Classification - A classification of igneous rocks by J.P. Iddings where the mineralogical classifications of Harry Rosenbusch and Ferdinand Zirkel are correlated with the norm classification system. Identified Resources - Specific bodies of mineral-bearing rocks whose existence and location are known. Identified re- sources also include reserves and iden- tified subeconomic resources. Idioblast - A mineral element of a meta- morphic rock formed by recrystalliza- tion and bound by its own crystal faces. Igneous - A rock or mineral solidified from molten, or partially molten, material. The term also appl ies to processes related to the formation of such rocks. Igneous rocks are one of the three main classifications of rocks. Igneous Breccia - A breccia com- posed of fragments of igneous rock. Any breccia produced by the igneous process. Igneous Complex - A group of intimately associated igneous rocks differing in form or type. Igneous Facies - A part of a body of igneous rock different in structure, tex- ture, or composition from the typical rock of the body such as granite. Ilmenite - An iron-black rhombohedral mineral. It is the main ore of titanium. It is a common mineral in basic igneous rocks. Imbibition - The tendency of granular rock or any porous medium to absorb a fluid, usually water, under the force of capillary attraction and in the absence of any pressure. Impermeable - Used to define rock, sed- iment, or soil which is incapable of trans- mitting fluids under pressure. Impulse - A short period force or action. In seismograph prospecting, the effect of an explosive or mechanical source of seismic waves. Inclination - A deviation from the verti- cal or horizontal; also the rate of slope or the slope itself. Can also refer to the angle of a well bore measured from the vertical at a stated depth. Granite is classified as an igneous rock. WWDR photo. " ; # 511-,(2 0) 20'5&43 %9 4+(3( ,/( $/5)$&452(23 ; 08 029'0/ # ! : : $8 $,- 3$-(3 *,6(/3,/4(2/$4,0/$- &0. "(% ,4( 777 *,6(/3,/4(2/$4,0/$- &0. More terms next month!