Laboratory Manual for Introductory Geology 4e

Recommendations

Info

7.2.2 Changes in MineralogyThe original protolith minerals may not be able to survive the new temperature and pressureconditions and may therefore change in the solid state to new metamorphic mineralsthat are more stable under those new conditions. Such changes may occur in two ways:1. Phase changes: A phase change is a change in a mineral from one polymorph toanother that is more stable under the new conditions. Polymorphs are mineralsthat have the same chemical composition but different internal atomic structures,so a phase change causes a change in atomic structure, but not in chemicalcomposition. A common example is the conversion of andalusite (Al 2SiO 5)to sillimanite (Al 2SiO 5) with increasing heat and pressure.2. Chemical reactions between minerals: Ions from two or more minerals may berecombined to form new metamorphic minerals that are more stable thanthe original assemblage. An example is the conversion of muscovite and quartzto sillimanite, potassium feldspar, and water:KAl 2(AlSi 3O 10)(OH) 21 SiO 2 → Al 2SiO 51 KAlSi 3O 81 H 2O(muscovite) (quartz) (sillimanite) (potassic (water)feldspar)7.2.3 Changes in CompositionLess commonly, hot fluids circulating through rocks during metamorphism maychange the chemical composition of the protolith by adding or removing largeamounts of ions. In extreme cases, this composition change is so great that metamorphicminerals crystallize that could not have formed in the protolith. For example,if a large number of calcium ions are added to a shale, calcareous metamorphicminerals can form that could not have formed in the original clay-based protolith.Sometimes a rock changes only slightly during metamorphism, so that most of itsoriginal sedimentary, igneous, or prior metamorphic characteristics are still recognizable.In many cases, however, the changes are so drastic that a metamorphic rock canlook as different from its protolith as a butterfly does from a caterpillar (FIG. 7.1). If arock changes only a little during metamorphism, we say it has undergone low-grade metamorphism;if it has changed drastically, it has experienced high-grade metamorphism. Wewill see how to determine the metamorphic grade of a hand specimen in section 7.5.3.7.3 Agents of MetamorphismGeologists refer to the heat, pressure, stress, and hydrothermal fluids that cause metamorphicchanges as agents of metamorphism. Each of these agents acting alonecan cause metamorphism, but in most geologic settings two or more act simultaneously.In this section, we will examine how individual agents of metamorphism causechange and their effects on protoliths.7.3.1 The Effect of HeatWhen rocks are heated, either by an intrusive magma or during burial by sedimentation,mountain building, or subduction, their ions vibrate more rapidly. The chemicalbonds holding those ions in mineral structures stretch, and some begin to break.The freed ions migrate slowly through the solid rock by a process called diffusion,much as atoms of food coloring spread when dripped into a glass of water. Eventually,the wandering ions bond with other ions to produce metamorphic minerals that arestable under the higher temperatures. Heat is thus the major cause of phase changesand chemical reactions that replace protolith minerals with metamorphic minerals.7.3 AGENTS OF METAMORPHISM175
FIGURE 7.1 Examples of changes from protolith (left) to metamorphic rock (right).(a) Changes in texture.(i) Very fine-grained calcite in micritic limestone recrystallizes to form coarse-grained calcite in marble.(ii) Coarse quartz and feldspar grains in granite are changed in a fault zone to very fine-grained ultramylonite.(iii) Rounded clasts in conglomerate are flattened in metamorphosed conglomerate.(b) Changes in mineralogy.(i) Clay minerals in mudstone react with quartz to form biotite and garnet in gneiss.(continued)176 CHAPTER 7 INTERPRETING METAMORPHIC ROCKS
Page 2 and 3:
LABORATORY MANUALFOR INTRODUCTORY G
Page 4 and 5:
CONTENTSPreface viiCHAPTER 1Setting
Page 6 and 7:
CHAPTER 8Studying the Earth’s Lan
Page 8 and 9:
PREFACEThis laboratory manual is ba
Page 10 and 11:
exercises interspersed throughout t
Page 12 and 13:
Supplements(available for download
Page 14:
ABOUT THE AUTHORSAllan Ludman is Pr
Page 17 and 18:
LEARNINGOBJECTIVES■ Understand ch
Page 19 and 20:
One way to obtain more data would b
Page 21 and 22:
TABLE 1.1 Basic definitions●●
Page 23 and 24:
EXERCISE 1.2Reservoirs in the Earth
Page 25 and 26:
EXERCISE 1.4Sources of Heat for Geo
Page 27 and 28:
1.3 Units for Geologic MeasurementB
Page 29 and 30:
FIGURE 1.5 Measuring the volume of
Page 31 and 32:
FIGURE 1.6 The white cliffs of Dove
Page 33 and 34:
MileFIGURE 1.7 Methods for dealing
Page 35 and 36:
FIGURE 1.8 An example of the princi
Page 37 and 38:
EXERCISE 1.9Name:Course:How Long Do
Page 39 and 40:
APPENDIX 1.1Metric-U.S. Customary C
Page 41 and 42:
LEARNINGOBJECTIVES■■Become fami
Page 43 and 44:
plate between two continents, conti
Page 45 and 46:
FIGURE 2.4 The Earth’s major clim
Page 47 and 48:
More clues soon came from seismolog
Page 49 and 50:
FIGURE 2.8 Magnetic reversals of th
Page 51 and 52:
FIGURE 2.11 Rates of motion of the
Page 53 and 54:
EXERCISE 2.7A Tale of Two RidgesNam
Page 55 and 56:
EXERCISE 2.8Continental Rifting: Sp
Page 57 and 58:
Even without any earthquake informa
Page 59 and 60:
EXERCISE 2.10Estimating the Amount
Page 61 and 62:
2.5.5 Hot Spots and Hot-Spot Tracks
Page 63 and 64:
EXERCISE 2.11Name:Course:Determinin
Page 65 and 66:
EXERCISE 2.12Name:Course:Long-Term
Page 67 and 68:
GEOTOURS EXERCISE 2Analyzing Plate
Page 69 and 70:
LEARNINGOBJECTIVES■ Understand wh
Page 71 and 72:
When a mineral grows without interf
Page 73 and 74:
FIGURE 3.1 Specimens of the mineral
Page 75 and 76:
3.4.5 HardnessThe hardness of a min
Page 77 and 78:
FIGURE 3.4 Crystals of some common
Page 79 and 80:
FIGURE 3.6 Cleavage in common miner
Page 81 and 82:
3.4.9 MagnetismA few minerals are a
Page 83 and 84:
EXERCISE 3.7Identifying MineralsNam
Page 85 and 86:
The minerals and elements we most r
Page 87 and 88:
EXERCISE 3.9Mineral Resources in Yo
Page 89 and 90:
GEOTOURS EXERCISE 3Extracting Miner
Page 91 and 92:
APPENDIX 3.1Mineral Identification
Page 93 and 94:
APPENDIX 3.2Determinative Tables fo
Page 95 and 96:
APPENDIX 3.2Determinative Tables fo
Page 97 and 98:
APPENDIX 3.3Common Minerals and The
Page 99 and 100:
MINERAL PROFILE DATA SHEET NameSamp
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
LEARNINGOBJECTIVES■■Understand
Page 107 and 108:
FIGURE 4.1 The rock cycle.Heating a
Page 109 and 110:
FIGURE 4.3 Typical grain shapes.(a)
Page 111 and 112:
EXERCISE 4.2Describing a Rock’s T
Page 113 and 114:
EXERCISE 4.3Understanding the Origi
Page 115 and 116:
EXERCISE 4.4Interpreting the Textur
Page 117 and 118:
■ Hardness: Use a steel safety pi
Page 119 and 120:
FIGURE 4.6 Flowchart for determinin
Page 121 and 122:
4.8 The Economic Value of RocksMost
Page 123 and 124:
FIGURE 4.7 Examples of igneous, sed
Page 125 and 126:
GEOTOURS EXERCISE 4Deciphering Land
Page 127 and 128:
LEARNINGOBJECTIVES■■Become fami
Page 129 and 130:
crystalline rocks. Those that are s
Page 131 and 132:
EXERCISE 5.3Interpreting Igneous Co
Page 133 and 134:
FIGURE 5.4 Volcanic glasscontains n
Page 135 and 136:
EXERCISE 5.5Interpreting Fragmental
Page 137 and 138:
Felsic igneous rocks (from feldspar
Page 139 and 140: minerals melt, and (3) how plate-te
Page 141 and 142: EXERCISE 5.8Insights from Melting a
Page 143 and 144: EXERCISE 5.9Explaining Features of
Page 145 and 146: extreme crustal stretching has expo
Page 147 and 148: EXERCISE 5.13Interpreting Plate-Tec
Page 149 and 150: FIGURE 5.12 Distribution of volcano
Page 151 and 152: FIGURE 5.14 Comparison of areas in
Page 153 and 154: EXERCISE 5.15Stratovolcano Disaster
Page 155 and 156: GEOTOURS EXERCISE 5Exploring the Na
Page 157 and 158: IGNEOUS ROCKS STUDY SHEET NameSampl
Page 159 and 160: LEARNINGOBJECTIVES■■Understand
Page 161 and 162: FIGURE 6.2 Chemical weathering of f
Page 163 and 164: FIGURE 6.3 The five steps in clasti
Page 165 and 166: 6.3.2 Chemical Sedimentary RocksChe
Page 167 and 168: 6.3.3 Biochemical and Organic Sedim
Page 169 and 170: TABLE 6.2 Classification of common
Page 171 and 172: FIGURE 6.5 Flow chart for identifyi
Page 173 and 174: FIGURE 6.6 Sediment sorting.(a) Poo
Page 175 and 176: EXERCISE 6.7Recognizing Sediment De
Page 177 and 178: FIGURE 6.9 Sedimentary rock beds.(a
Page 179 and 180: FIGURE 6.12 Cross bedding, a type o
Page 181 and 182: FIGURE 6.15 Fossils reveal remarkab
Page 183 and 184: FIGURE 6.16 Examples of depositiona
Page 185 and 186: EXERCISE 6.10Interpreting Sedimenta
Page 187 and 188: SampleTexture(grain size, shape,sor
Page 189: LEARNINGOBJECTIVES■■Understand
Page 193 and 194: FIGURE 7.2 Growth of metamorphic mi
Page 195 and 196: FIGURE 7.3 Types of stress.(a) Comp
Page 197 and 198: FIGURE 7.5 Photomicrographs of rock
Page 199 and 200: FIGURE 7.6 Varieties of gneiss form
Page 201 and 202: EXERCISE 7.2Identifying Metamorphic
Page 203 and 204: FIGURE 7.11 Settings of metamorphis
Page 205 and 206: EXERCISE 7.4Interpreting the Type o
Page 207 and 208: EXERCISE 7.5Name:Course:Index Miner
Page 209 and 210: Sample Minerals presentMETAMORPHIC
Page 211 and 212: Sample Minerals presentMETAMORPHIC
Page 213 and 214: LEARNINGOBJECTIVES■■Become fami
Page 215 and 216: EXERCISE 8.1Which Image Works Best?
Page 217 and 218: More sophisticated grid systems are
Page 219 and 220: EXERCISE 8.2The Latitude/Longitude
Page 221 and 222: EXERCISE 8.3Locating Points with th
Page 223 and 224: EXERCISE 8.4Locating Points with th
Page 225 and 226: But which north is north? No, this
Page 227 and 228: e300FIGURE 8.10 An area in eastern
Page 229 and 230: 8.4 Vertical Exaggeration:A Matter
Page 231 and 232: GEOTOURS EXERCISE 8Locating Places
Page 233 and 234: LEARNINGOBJECTIVES■ Understand ho
Page 235 and 236: this information on the most recent
Page 237 and 238: FIGURE 9.5 Digital elevation model(
Page 239 and 240: 250300300FIGURE 9.7 Hachured contou
Page 241 and 242:
9.3.4 Rules and Applications of Con
Page 243 and 244:
EXERCISE 9.6Name:Course:Survival of
Page 245 and 246:
FIGURE 9.8 Map of the microwave tow
Page 247 and 248:
FIGURE 9.11 The effect of vertical
Page 249 and 250:
GEOTOURS EXERCISE 9Working with Top
Page 251 and 252:
APPENDIX 9.1Topographic Map Symbols
Page 256 and 257:
Interpreting GeologicStructures on
Page 258 and 259:
of structures on the ground (the ma
Page 260 and 261:
EXERCISE 10.2The Basic Types of Con
Page 262 and 263:
EXERCISE 10.3Determining Strike and
Page 264 and 265:
FIGURE 10.4 Block diagrams.Map view
Page 266 and 267:
FIGURE 10.6 Block diagrams showing
Page 268 and 269:
FIGURE 10.7 Hanging wall, footwall,
Page 270 and 271:
is not the same as that of the beds
Page 272 and 273:
EXERCISE 10.9Name:Course:Interpreti
Page 274 and 275:
FIGURE 10.9 Geologic maps (continue
Page 276 and 277:
EXERCISE 10.11Name:Course:Using Sym
Page 278 and 279:
EXERCISE 10.12Name:Course:Construct
Page 280 and 281:
EXERCISE 10.13Interpreting Simple G
Page 282 and 283:
FIGURE 10.13 Structural control of
Page 284 and 285:
10.6 Reading Real Geologic MapsYou
Page 286 and 287:
FIGURE 10.14 (continued).Geologic M
Page 288 and 289:
EXERCISE 10.18Making a Geologic Map
Page 290:
GEOTOURS EXERCISE 10Name:Course:Und
Page 293 and 294:
LEARNINGOBJECTIVES■■Understand
Page 295 and 296:
S-waves (FIG. 11.2b) are seismic wa
Page 297 and 298:
FIGURE 11.4 Worldwide distribution
Page 299 and 300:
FIGURE 11.5 Travel-time curves show
Page 301 and 302:
EXERCISE 11.4Name:Course:Locating a
Page 303 and 304:
EXERCISE 11.4Locating an Earthquake
Page 305 and 306:
EXERCISE 11.4Name:Course:Locating a
Page 307 and 308:
EXERCISE 11.5Name:Course:Determinin
Page 309 and 310:
11.5 Predicting EarthquakeHazards:
Page 311 and 312:
EXERCISE 11.7Locating Liquefaction
Page 313 and 314:
After watching dramatic images of t
Page 315 and 316:
APPENDIX 11.1Seismic Analysis Works
Page 317 and 318:
LEARNINGOBJECTIVES■■Determine t
Page 319 and 320:
EXERCISE 12.2Relative Ages in Cross
Page 321 and 322:
EXERCISE 12.3Applying the Principle
Page 323 and 324:
EXERCISE 12.4Name:Course:Using Sedi
Page 325 and 326:
FIGURE 12.6 How the three kinds of
Page 327 and 328:
EXERCISE 12.5Name:Course:Decipherin
Page 329 and 330:
becoming extinct. When we find an i
Page 331 and 332:
EXERCISE 12.6Name:Course:Dating Roc
Page 333 and 334:
FIGURE 12.9 Changing parent:daughte
Page 335 and 336:
EXERCISE 12.7Putting It All Togethe
Page 337 and 338:
EXERCISE 12.8What Numerical Ages Ca
Page 339 and 340:
EXERCISE 12.9Correlation (continued
Page 341 and 342:
EXERCISE 12.10Cretaceous Paleogeogr
Page 344 and 345:
Landscapes Formed13by StreamsStream
Page 346 and 347:
EXERCISE 13.1Differences between St
Page 348 and 349:
EXERCISE 13.2Why Some Streams Meand
Page 350 and 351:
RFIGURE 13.5 The Genesee River sout
Page 352 and 353:
EXERCISE 13.2Why Some Streams Meand
Page 354 and 355:
FIGURE 13.8 A floodplain and its as
Page 356 and 357:
ST. FRANCIS CO4070797064UNION PACIF
Page 358 and 359:
1000Big900900B I G H I L LARKANSAS9
Page 360 and 361:
FIGURE 13.13 Major drainage basins
Page 362 and 363:
anchWTJ54MurphyNew BloomfieldTown65
Page 364 and 365:
EXERCISE 13.6Recognizing Stages of
Page 366 and 367:
MT T L E62446267DogRock757266170634
Page 368 and 369:
13.7 When Streams Don’t Seemto Fo
Page 370 and 371:
EXERCISE 13.7Deducing the History o
Page 372 and 373:
13.8 When There’s Too Much Water:
Page 374 and 375:
EXERCISE 13.9Estimating Potential F
Page 376 and 377:
13.9 Streams, Society, and the Envi
Page 382 and 383:
Groundwater as aLandscape Formerand
Page 384 and 385:
EXERCISE 14.1Factors Affecting Infi
Page 386 and 387:
EXERCISE 14.1Name:Course:Factors Af
Page 388 and 389:
FIGURE 14.2 Groundwater landscape e
Page 390 and 391:
60075000750600FIGURE 14.4 Karst top
Page 392 and 393:
FIGURE 14.5 The water table separat
Page 394 and 395:
EXERCISE 14.4Effects of a Changing
Page 396 and 397:
100100100FIGURE 14.9 Karst topograp
Page 398 and 399:
4400B a l d r i d g e C a n y o n42
Page 400 and 401:
EXERCISE 14.7Name:Course:Environmen
Page 402 and 403:
EXERCISE 14.8Name:Course:Environmen
Page 404 and 405:
Glacial Landscapes15These jagged mo
Page 406 and 407:
FIGURE 15.2 Mountain and continenta
Page 408 and 409:
EXERCISE 15.1Comparison of Glaciers
Page 410 and 411:
EXERCISE 15.3Erosional Features of
Page 412 and 413:
15.3.2 Depositional LandscapesLands
Page 414 and 415:
EXERCISE 15.4Landforms at the Termi
Page 416 and 417:
900900800BOWEN1000700C R E E K900RO
Page 418 and 419:
450400LEMON400ROADSLAYTON4504503Spo
Page 420 and 421:
15.4 Landscapes Producedby Mountain
Page 422 and 423:
The base level for a tributary stre
Page 424 and 425:
3700380036003900Northwest BasinLake
Page 426 and 427:
FIGURE 15.17 Atmospheric temperatur
Page 428 and 429:
GEOTOURS EXERCISE 15Flowing Ice as
Page 430 and 431:
GRID: 10/inch = 39,4/10cm
Page 432 and 433:
Page 434 and 435:
Processes and Landforms16in Arid En
Page 436 and 437:
FIGURE 16.2 Types of arid regions.(
Page 438 and 439:
16.2 Processes in Arid RegionsNow l
Page 440 and 441:
16.3 Progressive Evolution of Arid
Page 442 and 443:
EXERCISE 16.3Interpreting Arid Land
Page 444 and 445:
EXERCISE 16.3Interpreting Arid Land
Page 446 and 447:
RiverGila85WatermanWashR A I N B O
Page 448 and 449:
85130011001000FIGURE 16.8 Topograph
Page 450 and 451:
FIGURE 16.10 Characteristics and ev
Page 452 and 453:
400040004000L o w e V a l l e y4100
Page 454 and 455:
FIGURE 16.13 Vulnerability to deser
Page 456 and 457:
Page 458 and 459:
Shoreline Landscapes17Coastlines co
Page 460 and 461:
FIGURE 17.1 Types of shorelines.(a)
Page 462 and 463:
EXERCISE 17.1Erodibility and Stabil
Page 464 and 465:
17.2.5 Emergent and Submergent Shor
Page 466 and 467:
1382427FIGURE 17.5 Maine coastline
Page 468 and 469:
EXERCISE 17.5Measuring Sea-Level (a
Page 470 and 471:
FIGURE 17.7 Area just south of Lake
Page 472 and 473:
17.3.2 Coastal Erosion and Depositi
Page 474 and 475:
FIGURE 17.11 Erosional features of
Page 476 and 477:
EXERCISE 17.7Erosional Processes an
Page 478 and 479:
17.3.5 Depositional FeaturesPromine
Page 480 and 481:
EXERCISE 17.9Depositional Processes
Page 482 and 483:
FIGURE 17.18 The shoreline of theno
Page 484 and 485:
FIGURE 17.21 Aerial view showing ho
Page 486 and 487:
EXERCISE 17.10Name:Course:Unintende
Page 488 and 489:
FIGURE 17.24 Counterclockwise wind
Page 490 and 491:
EXERCISE 17.11Name:Course:Effects o
Page 492 and 493:
FIGURE 17.27 Flooding caused by hur
Page 494 and 495:
EXERCISE 17.12Effects of Storm Path
Page 496:
GEOTOURS EXERCISE 17Understanding T
Page 499 and 500:
Page 501 and 502:
LEARNINGOBJECTIVES■ Explain why p
Page 503 and 504:
EXERCISE 18.1Humans and Earth Syste
Page 505 and 506:
EXERCISE 18.2Short-Term Changes in
Page 507 and 508:
Weather describes atmospheric condi
Page 509 and 510:
FIGURE 18.5 The greenhouse effect.G
Page 511 and 512:
EXERCISE 18.3Name:Course:Assessing
Page 513 and 514:
FIGURE 18.8 Movement of water from
Page 515 and 516:
FIGURE 18.10 Projected sea-level sc
Page 517 and 518:
EXERCISE 18.4Effects of Sea-Level R
Page 519 and 520:
FIGURE 18.13 Estimated human popula
Page 521 and 522:
FIGURE 18.14 Two bird species hunte
Page 523 and 524:
EXERCISE 18.6Name:Course:How Quickl
Page 525 and 526:
GEOTOURS EXERCISE 18Inducing Change
Page 527 and 528:
Courtesy of Allan Ludman; p. 162 (t
Page 530 and 531:
270 280260240 250290 300Clay310 320
Page 532:
Align with northern latitude tick m
show all

Laboratory Manual for Introductory Geology 4e

Create successful ePaper yourself

Delete template?

Save as template?