804:
103:
492:
29:
556:
378:
311:
441:
The mineralogical composition of a rock is one of the major ways in which it is classified. Igneous rocks are classified by their mineral content whenever practical, using the QAPF classification or special ultramafic or carbonatite classifications. Likewise metamorphic facies, which show the degree
333:
is a measure of the sizes of the crystals in the rock. In igneous rock, this is used to determine the rate at which the material cooled: large crystals typically indicate intrusive igneous rock, while small crystals indicate that the rock was extrusive. Metamorphism of rock composed of mostly a
290:. These textures, from slate to gneiss, define a continually-increasing extent of metamorphism. Metamorphic facies are defined by the pressure-temperature fields in which particular minerals form. Additional metamorphic rock names exist, such as
220:. Where possible, extrusive igneous rocks are also classified by mineral content using the extrusive QAPF classification, but when determining the mineral composition is impractical, they may be classified chemically using the
450:
The colour of a rock or its component parts is a distinctive characteristic of some rocks and is always recorded, sometimes against standard colour charts, such as that produced by the Rock-Color Chart
Committee of the
614:
Unconsolidated surficial materials may also be given a lithology. This is defined by grain size and composition and is often attached to an interpretation of how the unit formed. Surficial lithologies can be given to
243:. Siliciclastic sedimentary rocks are then subcategorized based on their grain size distribution and the relative proportions of quartz, feldspar, and lithic (rock) fragments. Carbonate rocks are classified with the
59:, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include
479:), are characterised by well-developed planar and linear fabrics. Igneous rocks may also have fabrics as a result of flow or the settling out of particular mineral phases during crystallisation, forming
442:
to which a rock has been exposed to heat and pressure and are therefore important in classifying metamorphic rocks, are determined by observing the mineral phases that are present in a sample.
523:, shape and roundness of the clasts. Metamorphic textures include those referring to the timing of growth of large metamorphic minerals relative to a phase of deformationβbefore deformation
141:, which is a mixture of molten rock, dissolved gases, and solid crystals. Sedimentary rock is formed from mineral or organic particles that collect at the Earth's surface and become
349:
In clastic sedimentary rocks, grain size is the diameter of the grains and/or clasts that constitute the rock. These are used to determine which rock naming system to use (e.g., a
1359:
361:). In the case of sandstones and conglomerates, which cover a wide range of grain sizes, a word describing the grain size range is added to the rock name. Examples are "
805:"Descriptive nomenclature and classification of pyroclastic deposits and fragments: recommendations of the IUGS Subcommission on the Systematics of Igneous Rocks"
471:
of a rock describes the spatial and geometric configuration of all the elements that make it up. In sedimentary rocks the main visible fabric is normally
475:, and the scale and degree of development of the bedding is normally recorded as part of the description. Metamorphic rocks (apart from those created by
515:
of a rock describes the relationship between the individual grains or clasts that make up the rock. Sedimentary textures include the degree of
566:
Rocks often contain small-scale structures (smaller than the scale of an individual outcrop). In sedimentary rocks this may include
1366:
1181:. Vol. 1. US Bureau of Reclamation, Technical Service Center Engineering Geology Group. 1998. pp. 57β90. Archived from
1173:
598:
are used to determine the sense of displacement across the zone. In igneous rocks, small-scale structures are mostly observed in
148:
Igneous rocks are further broken into three broad categories. Igneous rock composed of broken rock fragments created directly by
1446:
1266:
762:
248:
1360:"McCarthy, T. & Rubidge, B. 2008. The story of earth and life, Chapter 3, The first continent. 60-91, Struik Publishers"
1328:
A handbook of rocks for use without the microscope : with a glossary of the names of rocks and other lithological terms
752:
1390:
Walker, George P L. (1992-08-01). "Walker, G.P.L. 1992. Morphometric study of pillow-size spectrum among pillow lavas".
995:
883:
787:
735:
702:
586:
and may provide information on paleocurrent directions. In metamorphic rocks associated with the deeper levels of
632:
145:. Metamorphic rock forms by recrystallization of existing solid rock under conditions of great heat or pressure.
91:
426:
rocks or those with possible calcite veins, it is normal to test for the presence of calcite (or other forms of
1070:
1045:
1020:
858:
1438:
694:
452:
631:, and recent volcanic deposits, among others. Examples of surficial lithology classifications used by the
343:
229:
1463:
87:
595:
924:
90:, lithology is described using a standard terminology such as in the European geotechnical standard
583:
410:
In rocks in which mineral grains are large enough to be identified using a hand lens, the visible
919:
539:) to irregular crystals (anhedral), whether the rock shows highly nonuniform crystal sizes (is
350:
1347:
1335:
1331:
1256:
727:
720:
535:
include such properties as grain shape, which varies from crystals with ideal crystal shapes (
660:
536:
423:
319:
244:
1283:
1399:
1295:
911:
668:
476:
456:
173:
55:, or with low magnification microscopy. Physical characteristics include colour, texture,
8:
1403:
1299:
915:
1491:
1415:
1182:
937:
824:
516:
496:
259:
221:
122:
958:
1442:
1419:
1262:
1066:
1041:
1016:
991:
879:
854:
828:
783:
758:
731:
698:
624:
620:
512:
431:
427:
79:
941:
414:
is included as part of the description. In the case of sequences possibly including
1407:
1303:
1040:(4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall. pp. 169β173.
929:
902:
Le Bas, M. J.; Streckeisen, A. L. (1991). "The IUGS systematics of igneous rocks".
816:
532:
468:
382:
157:
134:
130:
212:. Special classifications exist for igneous rock of unusual compositions, such as
587:
225:
213:
201:
520:
240:
189:
181:
169:
44:
1307:
1150:
1065:. Harlow, Essex, England: Longman Scientific & Technical. pp. 21β27.
1485:
990:(2nd ed.). Cambridge, UK: Cambridge University Press. pp. 139β143.
933:
579:
567:
528:
524:
480:
472:
435:
236:
142:
1172:"4 Classification of rocks and description of physical properties of rock".
251:
classification schemes according to the constituents of the carbonate rock.
571:
342:), while metamorphism of sheared rock may decrease grain size (syntectonic
339:
209:
193:
161:
126:
83:
32:
582:. These are recorded as they are generally characteristic of a particular
1461:
603:
540:
291:
217:
205:
111:
52:
1411:
820:
639:", "Saline Lake Sediment", and "Eolian Sediment, Coarse-Textured (Sand
411:
397:
330:
176:, may also be applied. Igneous rocks that have visible mineral grains (
56:
591:
415:
354:
315:
299:
255:
177:
149:
78:
Lithology is the basis of subdividing rock sequences into individual
72:
60:
22:
102:
1015:(2nd ed.). New York: W.H. Freeman. pp. 217β220, 257β258.
575:
560:
544:
393:
385:
358:
279:
185:
500:
491:
419:
389:
366:
323:
271:
165:
48:
47:
unit is a description of its physical characteristics visible at
160:. Pyroclastic rocks are further classified by average fragment (
86:
and correlation between areas. In certain applications, such as
504:
404:
401:
362:
335:
295:
287:
283:
263:
197:
164:) size and whether the fragments are mostly individual mineral
153:
107:
68:
981:
979:
28:
1130:
555:
377:
275:
267:
235:
Sedimentary rocks are further classified by whether they are
138:
115:
64:
750:
717:
1281:
1224:
1084:
1082:
976:
640:
636:
628:
616:
599:
192:. Intrusive igneous rocks are usually classified using the
1212:
1151:"The Acid Test for Carbonate Minerals and Carbonate Rocks"
1118:
842:
688:
16:
Description of the physical characteristics of a rock unit
1094:
310:
172:, or rock fragments. Further classifications, such as by
1344:
Bulletin of the
Geological Society of America, Volume 25
1079:
606:
showing eruption within a body of water or beneath ice.
543:), or whether grains are aligned (which is described as
1236:
1106:
1013:
Petrology : igneous, sedimentary, and metamorphic
966:
British
Geological Survey: Rock Classification Scheme
782:(9th ed.). Hoboken, N.J.: J. Wiley. p. 57.
114:' lava shape characteristic of underwater eruptions,
1200:
711:
318:, the finest-grained sedimentary rock, deposited in
184:, while those that are glassy or very fine-grained (
1004:
1054:
1029:
719:
1330:. 5. Aufl., New York: D. Van Nostrand, 1918, pp.
901:
867:
682:
602:such as pahoehoe versus Κ»AΚ»Δ basaltic flows, and
1483:
21:For the study of rocks and their formation, see
1462:USGS Rocky Mountain Geographic Science Center.
988:Principles of igneous and metamorphic petrology
848:
726:(2 ed.). Oxford University Press. p.
1455:
959:"Rock Classification Scheme - Vol 1 - Igneous"
1433:Harmon, Russel S.; Rapela, Carlos W. (1991).
1142:
985:
849:Fisher, Richard V.; Schmincke, H.-U. (1984).
1464:"Surficial Lithology: Attribute information"
1432:
1282:Carreras, J.; Druguet E.; Griera A. (2005).
1038:Principles of sedimentology and stratigraphy
986:Philpotts, Anthony R.; Ague, Jay J. (2009).
771:
590:, small scale structures such as asymmetric
196:, which is based on the relative content of
1261:. Cambridge University Press. p. 272.
897:
895:
853:. Berlin: Springer-Verlag. pp. 98β99.
796:
689:Bates, R. J.; Jackson, J. A., eds. (1984).
1346:/ Geological Society of America. 1914, p.
1230:
1136:
1010:
757:. Houghton Mifflin Harcourt. p. 364.
751:American Heritage Dictionary, ed. (2005).
121:The naming of a lithology is based on the
1435:Andean Magmatism and Its Tectonic Setting
923:
873:
550:
137:. Igneous rocks are formed directly from
1340:4th Annual Report U.S. Geological Survey
1063:An introduction to metamorphic petrology
1011:Blatt, Harvey; Tracy, Robert J. (1996).
892:
754:The American heritage science dictionary
554:
490:
376:
309:
254:Metamorphic rock naming can be based on
224:. This is based on the total content of
101:
27:
1218:
1148:
1124:
1100:
1088:
1060:
802:
744:
718:Allaby, Ailsa; Allaby, Michael (1999).
1484:
1389:
1254:
1248:
953:
951:
609:
1275:
1242:
1206:
1112:
1035:
777:
334:single mineral, such as quartzite or
298:and other extrusive igneous rock) or
1320:
948:
722:Oxford Dictionary of Earth Sciences
305:
258:, mineral composition, texture, or
13:
329:In igneous and metamorphic rocks,
274:) protolith can be used to define
14:
1503:
904:Journal of the Geological Society
878:. Berlin: Springer. p. 138.
125:. The three major rock types are
1365:. Web.wits.ac.za. Archived from
1175:Engineering Geology Field Manual
262:. Naming based on texture and a
1426:
1383:
1352:
1165:
874:Schmincke, Hans-Ulrich (2003).
365:conglomerate" and "fine quartz
691:Dictionary of Geological Terms
653:
1:
1439:Geological Society of America
1288:Journal of Structural Geology
695:American Geological Institute
646:
453:Geological Society of America
372:
302:(metamorphosed quartz sand).
232:and other chemical criteria.
97:
35:as seen in southeastern Utah
7:
499:basalt is characterized by
338:, may increase grain size (
10:
1508:
1284:"Shear zone-related folds"
1061:Yardley, B. W. D. (1989).
486:
282:. Texture-based names are
82:units for the purposes of
20:
1308:10.1016/j.jsg.2004.08.004
778:Levin, Harold L. (2010).
462:
445:
180:rocks) are classified as
934:10.1144/gsjgs.148.5.0825
584:depositional environment
1392:Bulletin of Volcanology
400:) in a matrix of mafic
1466:. US Geological Survey
1231:Blatt & Tracy 1996
1137:Blatt & Tracy 1996
780:The earth through time
633:U.S. Geological Survey
563:
551:Small-scale structures
508:
495:The lithology of this
407:
326:
118:
36:
558:
494:
380:
320:Glacial Lake Missoula
313:
105:
31:
803:Schmidt, R. (1981).
669:US Geological Survey
635:are, "Glacial Till,
477:contact metamorphism
457:Munsell color system
188:) are classified as
174:chemical composition
156:) are classified as
1404:1992BVol...54..459W
1326:James Furman Kemp:
1300:2005JSG....27.1229C
1255:Fossen, H. (2010).
1221:, pp. 154β170.
1127:, pp. 154β155.
1036:Boggs, Sam (2006).
916:1991JGSoc.148..825L
665:Earthquake Glossary
610:Surficial lithology
527:βafter deformation
396:(altering brown to
230:alkali metal oxides
194:QAPF classification
88:site investigations
1412:10.1007/BF00301392
1258:Structural Geology
1245:, pp. 74β118.
1139:, p. 241-242.
1103:, pp. 21, 26.
821:10.1007/BF01822152
564:
559:Ripple marks from
509:
408:
327:
260:metamorphic facies
222:TAS classification
119:
80:lithostratigraphic
37:
1448:978-0-8137-2265-8
1268:978-0-521-51664-8
1233:, pp. 39β44.
1115:, pp. 58β59.
1091:, pp. 49β51.
851:Pyroclastic rocks
764:978-0-618-45504-1
432:hydrochloric acid
428:calcium carbonate
344:recrystallization
1499:
1476:
1475:
1473:
1471:
1459:
1453:
1452:
1430:
1424:
1423:
1387:
1381:
1380:
1378:
1377:
1371:
1364:
1356:
1350:
1338:: C. E. Dutton,
1324:
1318:
1317:
1315:
1314:
1294:(7): 1229β1251.
1279:
1273:
1272:
1252:
1246:
1240:
1234:
1228:
1222:
1216:
1210:
1204:
1198:
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1195:
1193:
1187:
1180:
1169:
1163:
1162:
1160:
1158:
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1140:
1134:
1128:
1122:
1116:
1110:
1104:
1098:
1092:
1086:
1077:
1076:
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1052:
1051:
1033:
1027:
1026:
1008:
1002:
1001:
983:
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963:
955:
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927:
899:
890:
889:
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865:
864:
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840:
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793:
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748:
742:
741:
725:
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709:
708:
686:
680:
679:
677:
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533:Igneous textures
434:and looking for
306:Grain/clast size
158:pyroclastic rock
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1500:
1498:
1497:
1496:
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1479:
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1431:
1427:
1388:
1384:
1375:
1373:
1369:
1362:
1358:
1357:
1353:
1342:, 1883, S. 95;
1325:
1321:
1312:
1310:
1280:
1276:
1269:
1253:
1249:
1241:
1237:
1229:
1225:
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1189:
1188:on 17 June 2015
1185:
1178:
1171:
1170:
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1156:
1154:
1147:
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1131:
1123:
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1080:
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925:10.1.1.692.4446
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801:
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776:
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749:
745:
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716:
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705:
697:. p. 299.
687:
683:
673:
671:
659:
658:
654:
649:
612:
553:
489:
465:
448:
430:) using dilute
375:
308:
294:(metamorphosed
214:ultramafic rock
202:alkali feldspar
168:, particles of
110:, showing the '
100:
26:
17:
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1495:
1494:
1478:
1477:
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1447:
1441:. p. 24.
1425:
1398:(6): 459β474.
1382:
1351:
1319:
1274:
1267:
1247:
1235:
1223:
1211:
1209:, p. 130.
1199:
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1129:
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1105:
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1078:
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488:
485:
464:
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381:An ultramafic
374:
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190:extrusive rock
170:volcanic glass
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1393:
1386:
1372:on 2009-04-07
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1153:. Geology.com
1152:
1149:Geology.com.
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580:cross-bedding
577:
573:
569:
568:sole markings
562:
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534:
530:
529:porphyroblast
526:
525:porphyroclast
522:
518:
514:
506:
502:
498:
493:
484:
482:
478:
474:
470:
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458:
455:based on the
454:
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436:effervescence
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237:siliciclastic
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1468:. Retrieved
1457:
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1385:
1374:. Retrieved
1367:the original
1354:
1343:
1339:
1327:
1322:
1311:. Retrieved
1291:
1287:
1277:
1257:
1250:
1238:
1226:
1219:Yardley 1989
1214:
1202:
1190:. Retrieved
1183:the original
1174:
1167:
1155:. Retrieved
1144:
1132:
1125:Yardley 1989
1120:
1108:
1101:Yardley 1989
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1089:Yardley 1989
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664:
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565:
510:
507:phenocrysts.
466:
449:
440:
409:
351:conglomerate
348:
340:grain growth
328:
253:
234:
218:carbonatites
210:feldspathoid
147:
120:
77:
53:core samples
40:
38:
33:Stratigraphy
18:
1157:28 November
661:"Lithology"
619:, coastal,
588:fault zones
541:porphyritic
497:porphyritic
292:greenschist
206:plagioclase
152:processes (
135:metamorphic
131:sedimentary
1376:2014-03-10
1313:2009-10-31
1243:Boggs 2006
1207:Boggs 2006
1113:Levin 2010
1072:0582300967
1047:0131547283
1022:0716724383
860:3540127569
674:29 October
647:References
617:lacustrine
596:microfolds
547:texture).
416:carbonates
412:mineralogy
398:iddingsite
373:Mineralogy
331:grain size
178:phaneritic
92:Eurocode 7
57:grain size
1492:Petrology
1420:129797887
920:CiteSeerX
876:Volcanism
829:128375559
815:: 41β43.
576:mudcracks
545:trachytic
481:cumulates
355:sandstone
316:claystone
300:quartzite
256:protolith
241:carbonate
186:aphanitic
182:intrusive
143:lithified
123:rock type
98:Rock type
73:limestone
61:sandstone
41:lithology
23:Petrology
1486:Category
942:28548230
561:Mongolia
537:euhedral
424:cemented
394:pyroxene
386:xenolith
359:mudstone
280:phyllite
166:crystals
150:volcanic
1400:Bibcode
1296:Bibcode
912:Bibcode
809:Geology
629:glacial
625:aeolian
621:fluvial
604:pillows
592:boudins
521:grading
517:sorting
513:texture
501:olivine
487:Texture
473:bedding
420:calcite
390:olivine
367:arenite
324:Montana
272:mudrock
266:(e.g.,
127:igneous
84:mapping
49:outcrop
1445:
1418:
1265:
1192:7 June
1069:
1044:
1019:
994:
940:
922:
882:
857:
827:
786:
761:
734:
701:
505:augite
469:fabric
463:Fabric
446:Colour
405:scoria
402:basalt
383:mantle
363:pebble
336:marble
296:basalt
288:gneiss
284:schist
264:pelite
245:Dunham
226:silica
208:, and
198:quartz
154:tephra
133:, and
112:pillow
108:basalt
69:basalt
1416:S2CID
1370:(PDF)
1363:(PDF)
1186:(PDF)
1179:(PDF)
962:(PDF)
938:S2CID
825:S2CID
641:Dunes
637:Loamy
600:lavas
388:with
357:, or
276:slate
268:shale
162:clast
139:magma
116:Italy
71:, or
65:slate
43:of a
1472:2011
1443:ISBN
1263:ISBN
1194:2010
1159:2016
1067:ISBN
1042:ISBN
1017:ISBN
992:ISBN
880:ISBN
855:ISBN
836:2020
784:ISBN
759:ISBN
732:ISBN
699:ISBN
676:2010
643:)".
594:and
578:and
511:The
503:and
467:The
392:and
286:and
278:and
249:Folk
228:and
45:rock
39:The
1408:doi
1348:639
1336:240
1332:180
1304:doi
930:doi
908:148
817:doi
728:320
369:".
346:).
247:or
239:or
216:or
75:.
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1396:54
1394:.
1334:,
1302:.
1292:27
1290:.
1286:.
1081:^
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968:.
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950:^
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894:^
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627:,
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574:,
570:,
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438:.
418:,
353:,
322:,
314:A
270:,
204:,
200:,
129:,
106:A
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