Graphic Representations 



857 



and visual clarity of the lithologies. Plastic templates are frequently era- 

 ployed during plotting. Graphic symbols are favored in the event multiple 

 copies of the log are required. 



It is now possible to duplicate colored logs directly from the original 

 by photographic methods. This procedure eliminates checking for errors 

 and permits wide distribution of log strips and the establishment of com- 

 plete log files. The photographic method of reproducing log strips will 

 be gratefully received by sample-log services and companies. 



A unique method of combining lithologic and electric data is shown 

 in figure 433, wherein the electric-log-profile characteristics serve as 

 boundaries for the lithologic plot. 



Abbreviations commonly used in log description work are the follow- 



ing: 



abundant — A or abd. 



agglomerate — aggl. 



angular — ang. 



arenaceous — aren. 



argillaceous — argill. 



arkosic — ark. 



anhydrite — anhyd. or anhy. 



bentonite- — bent. 



biotite — bio. 



bituminous — bit. or bitum. 



black— blk. 



blue— bl. 



bottom — bot. or bott. 



brown — brn. 



calcareous — calc. 



carbonaceous — carb. 



cement — cmt. 



chert — cht. or ch. 



clay — cl. 



coarse — cse. 



common — C 



compact — cpt. 



composition — comp. 



concretion — cone. 



crystalline — xlh. 



dark — dk. 



dense — ds. or d/ 



distributed — dist. or distrib. 



dolomite — dol. or dolo. 



ferruginous — ferr. 



fibrous — fib. 



fine — fn. 



fissile — fss. 



flint— fl. 



formation — fm. 



frosted — fstd. 



Foraminifera — Forams. or F. 



fossil (iferous) — foss. 



fracture — fract. 



glauconite — glauc. or g/ 



grain — grn. 



granite — grt. 



granular — grnl. 



gray— gy. 



green — gn. 



gypsum— gyp. 



hard — hd. 



igneous — ign. 



indurated — indur. 



laminated — lam. 



limestone — Is. 



loose — 1/ 



massive — mass. 



marl — ml. 



material — matl. 



medium — med. 



Correlation Charts 



micaceous — mic. 

 mollusc — moll. (M.F.) 

 mottled — mot. 

 oolith — ool. 

 pyrite — pyr. 

 rare — R. 

 regular — reg. 

 residue — res. 

 rock— rk. 

 rounded — rdd. 

 sand — sd. 

 sandstone— ss. 

 sandy — sdy. 

 scarce — S - 



shale — sh. 

 siderite — sid. 

 . slightly — si/ 

 siliceous — sil. or silic. 

 some — s/ 



streak — stk. or strk. 

 the— t/ 



thin-bedded — t.b. 

 tuflaceous — tu£F. 

 variable — var. 

 very — yl 

 with — ^w/ 

 yellow — yl. 



Correlation charts are variously arranged and drafted. Scales used 

 are governed by the problem. Stratigraphic sections may be shown by 

 single lines or by graphic or colored columns. SufiEcient data should be 

 included in order to clarify fundamental lithologic and paleontologic 

 characteristics of each formation. If correlations are well established, 

 lines connecting correlative units should be solid; if inferred or ques- 

 tionable correlations are involved, the lines should be dashed or dotted. 

 If a series of well colimins are involved, it is required that the sea-level 

 datum and correlative depth and formation names and ages be shown. 

 A scaled index map showing the location of sections and a graphic vertical 



