WorldWide Drilling Resource

12 SEPTEMBER 2014 WorldWide Drilling Resource ® Frequently-Used Geological Terms Part 33 Glossary Adapted from the Dictionary of Geological Terms I - Continued Isopach - A line on a map connecting points of equal thickness in geological layers. Isopach Map - A map showing the thickness of a bed, formation, or other body throughout a geographic area by means of isopachs at regular intervals. Isoseismal Line - A line connecting points on the earth’s surface where earthquake intensity is the same. It is usually a closed curve around the epi- center. Isotherm - A line connecting points of equal temperature. Isotope - one of t wo or more forms of a chemical element, having the same number of protons in the nucleus, but having different numbers of neutrons in the nucleus. J Jacob’s Staff - A straight rod, pointed and shod with iron at its lower end for insertion into the ground, and fitted with a ball-and-socket joint at its upper end for adjustment to a level position, used for mounting and supporting a surveyer’s compass or other instrument. Jasper - A variety of chert associated with iron ores and containing iron-oxide impurities giving it various colors, espe- cially red. Jig - Device for concentrating miner- als. Crushed ore is fed into a box con- taining water. The water level is rapidly raised and lowered by a piston, caus- ing heavier minerals to sink to the bot- tom where they are drawn off. Juvenile - Refers to water, gas, or ore- forming fluid derived from magma. K Kaolin - A soft white nonplastic clay, composed mainly of kaolinite; widely used in making ceramics, refractories, and paper. Karat - The proportion of pure gold in an alloy. Pure or fine gold is 24-karat. Karst - A type of topography formed over limestone, dolomite, or gypsum by dissolution; characterized by sinkholes, caves, and underground drainage. Kelly - A steel pipe of square or hexag- onal cross section forming the top sec- tion of a rotary drill string. It is fitted into and passes through the rotary table, which turns it during drilling, thereby A kelly spins in a turntable on the floor of a rig. Photo courtesy of planooilandgas.com Focus on bC India bC India, International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines, and Construction Vehicles, has become an important event in the Middle East and India. It is presented jointly by Messe München International (orga- nizer of bauma) and the Association of Equipment Manufacturers (CoNExPo- CoN/AGG organizer). The next bC India is being held December 15-18, 2014, at the India Expo Centre in Greater Noida/ Delhi, India. Previously located in Mumbai in February of odd-numbered years, the move to Delhi also changed the expo to December of even-numbered years to accommodate many companies want- ing wider spacing in the trade show cal- endar. A full range of products will be displayed, such as all types of construc- tion machinery; min- ing, extraction, and raw materials pro- cessing equipment; instruments used in the production of building materials, along with compo- nent and service suppliers. You can even get a copy of WWDR while you’re there. For more information, visit www.bcindia.com transmitting the rotary motion of the table to the drill pipe. Kettle - A depression left in a mass of glacial drift, formed by the melting of an isolated block of glacial ice. More terms next month! 4< /*2'3* "& > > > > ,'< ? /2+ '6* /3+6 /3+6 ')1/3- " " !8=2+ /7843 4* 4* ')1/3- !+8 5)7 !8'3*'6* $'2:+ 9((+6 6':+2 $'2:+ 9((+6 !+'87 9((+6 $'2:+ 37+687 #6+8.'3+ $'2:+ 37+687 $'2:+ !56/3- ! ! $'2:+ 4:+6 '71+8 ? !;/:+2 ')1/3- ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 ? !+6/+7 < /3+6 < /3+6 < /3+6 < /3+6 < /3+6 6/)+7 !9(0+)8 "4 .'3-+ %/8.498 48/)+ !@ @ < < < < <