Magnetic Fabric: Methods and Applications (Geological Society Special Publication No. 238)

Contents......Page 6
Magnetic fabric: methods and applications – an introduction......Page 8
Determination of the orientation of magnetic minerals from the anisotropy of magnetic susceptibility......Page 16
Fig. 1. Estimating of orientation tensors from magnetic susceptibility. Parameters I, T .........Page 19
Fig. 2. The influence on orientation tensors estimation caused by deviations from .........Page 22
Fig. 3. For unbalanced distributions of y and z axes (here a .........Page 24
Fig. 4. Simulations versus estimates of the relative errors of I and .........Page 25
Fig. 5. Simulations versus estimates of the relative errors of I and .........Page 26
Table 1. An analysis of the off-diagonal terms of the orientation .........Page 21
A comparison of anisotropy of magnetic remanence methods – a user's guide for application to palaeomagnetism and magnetic fabric studies......Page 28
Fig. 1. Schematic diagram showing the relative orientations of the AF, DF, .........Page 33
Fig. 2. The GRM components (circles) relating to the results for the .........Page 37
Fig. 3. Diagram illustrating a typical single-axis AF application in the .........Page 38
Table 1. A summary comparison of different magnetic anisotropy techniques......Page 30
Table 2. A comparison of anisotropy of magnetic remanence (AMR) methods, and .........Page 36
Table 3. A comparison of anisotropy of magnetic remanence (AMR) methods, and .........Page 39
Distribution anisotropy: the influence of magnetic interactions on the anisotropy of magnetic remanence......Page 44
Fig. 1. Schematic showing the lineation (chain) arrangement in the model. Two .........Page 46
Fig. 2. SIRM versus d/r for chains of ideal SD grains with .........Page 47
Fig. 4. Degree of anisotropy P[sub(J)] for a random assemblage of uniform .........Page 48
Fig. 5. Schematic showing the foliation (grid) arrangement in the model. Two .........Page 49
Fig. 6. SIRM versus d/r for grids (foliation) of ideal SD grains .........Page 50
Fig. 8. Domain states occurring in cubic grains of magnetite-like minerals .........Page 51
Fig. 9. Two middle-segments from the lineation model, showing the contribution .........Page 52
Fig. 10. Shape parameter T versus d/r for the PSD models: (a) .........Page 53
Problems in interpreting AMS parameters in diamagnetic rocks......Page 56
Fig. 1. Anisotropy of magnetic susceptibility in diamagnetic evaporite in a locality .........Page 57
Fig. 3. Possible definitions of the AMS of diamagnetic rocks......Page 58
Fig. 4. Model relationship between the whole-rock degree of AMS (P,P[sub(a)] .........Page 60
Fig. 5. Model relationship between the whole-rock shape parameter and the .........Page 61
Fig. 6. Model relationship between the whole-rock degree of AMS and .........Page 62
Fig. 7. Model relationship between the whole-rock shape parameter and the .........Page 63
Fig. 8. Model relationship between the whole-rock degree of AMS (P) .........Page 64
Fig. 9. Empiric relationship between the whole-rock degree of AMS (P) .........Page 65
Metamorphic control of magnetic susceptibility and magnetic fabrics: a 3-D projection......Page 68
Fig. 1. Traditional 2-D Jelinek plot and P[sub(j-K)] plot of metamorphic rocks .........Page 69
Table 1. Multiple linear regression data and their statistics......Page 71
Fig. 3. Traditional P[sub(j-K)] plot with 95% confidence envelopes (dotted lines) for .........Page 72
Fig. 4. Traditional P[sub(j-k)] plot, with 95% confidence envelopes (dotted lines) for .........Page 73
Anisotropy of magnetic susceptibility of rocks measured in variable weak magnetic fields using the KLY-4S Kappabridge......Page 76
Fig. 1. Field variation of the principal susceptibilities in a specimen of .........Page 78
Fig. 3. Field variation of the susceptibility along the basal plane and .........Page 79
Fig. 5. Standard errors in the determination of the maximum susceptibility direction .........Page 80
Fig. 7. Field variation of the degree of AMS and the shape .........Page 81
Table 1. Field intensity in various AMS and susceptibility meters......Page 77
The anisotropy of magnetic susceptibility (AMS) in low-grade, cleaved pelitic rocks: influence of cleavage/bedding angle and type and relative orientation of magnetic carriers......Page 84
Fig. 1. Geological subcrop map of the Brabant Massif (after De Vos .........Page 86
Fig. 2. Sample positions within, and structural architecture of, the three sampled .........Page 87
Fig. 3. Demagnetization curves of one sample of the Ripain Member (TD001), .........Page 92
Fig. 4. Lower-hemisphere equal-area stereographic projections showing the principal magnetic .........Page 93
Fig. 5. Graph of degree of anisotropy (Pj) versus bulk magnetic susceptibility. ........Page 95
Fig. 6. (a) Graph of cleavage/bedding angle versus shape parameter (T). .........Page 96
Fig. 6. (b) Graph of the cleavage/bedding angle versus the degree .........Page 97
Fig. 7. Graph of the shape parameter (T) versus the degree of .........Page 99
Fig. 8. Lower-hemisphere equal-area stereographic projections showing the principal axes .........Page 100
Fig. 9. Coercivity spectra of the Oisquercq Formation (above: Ripain and Asquempont .........Page 101
Fig. 10. Lower-hemisphere equal-area stereographic projections showing the principal axes .........Page 102
Fig. 11. Graphs of the degree of anisotropy of AMS (Pj) versus .........Page 103
Fig. 12. Graph of the shape parameter of AMS (T) versus the .........Page 104
Fig. 13. Phyllosilicate X-ray pole figures of mica (d001; left) and chlorite .........Page 105
Fig. 14. Graph of the angle between cleavage and bedding versus degree .........Page 106
Fig. 15. Schematic representation of the probable magnetic (s.l.) fabric orientation with .........Page 107
Table 1. Main parameters of the investigated samples, averaged over the measured specimens (cubes, cylinders)......Page 90
Magnetic and mineral fabric development in the Ordovician Martinsburg Formation in the Central Appalachian Fold and Thrust Belt, Pennsylvania......Page 116
Fig. 1. (a) Map showing the sampling localities in the Appalachian fold .........Page 118
Fig. 2. (a) ARM acquisition and (b) IRM acquisition in representative samples .........Page 121
Fig. 3. SEM secondary electron images of the Lehigh Gap samples showing .........Page 122
Fig. 4. X-ray texture goniometry pole figures of mica and chlorite for .........Page 123
Fig. 5. Orientations of the principal axes of the low-field AMS .........Page 124
Fig. 6. Orientation of the principal axes of the chlorite (black symbols) .........Page 125
Fig. 7. Orientations of the principal axes of the AARM ellipsoids for .........Page 126
Fig. 8. SEM secondary electron images of the Appalachian fold and thrust .........Page 127
Fig. 9. X-ray texture goniometry pole figures of the Appalachian fold and .........Page 128
Fig. 10. (a) Orientations of the principal axes of the AMS ellipsoids .........Page 129
Table 1. Site locations and geological information......Page 119
An integrated AMS, structural, palaeo- and rock-magnetic study of the Eocene marine marls from the Jaca-Pamplona basin (Pyrenees, N Spain); new insights into the timing of magnetic fabric acquisition in weakly deformed mudrocks......Page 134
Fig. 1. Geological sketch map of the western sector of the Jaca- .........Page 136
Fig. 2. Equal area, lower hemisphere projections showing a comparison between the .........Page 138
Table 1. Comparison of fold axis direction, mean direction of site-mean .........Page 139
Fig. 4. Comparison of the four different types of magnetic fabrics with .........Page 140
Fig. 5. Comparison of the different types of magnetic fabrics with a .........Page 144
Fig. 6. Incremental fold tests performed for different structural units. The Pamplona .........Page 145
Fig. 7. (a) Schematic representation of a remanence affected by shear at .........Page 146
Fig. 8. (a) Relative chronology between deposition, blocking of the magnetic fabrics, .........Page 148
Table 2. List of palaeomagnetic, AMS and structural data at every site......Page 141
Magnetic properties and magnetic fabrics of Pleistocene loess/palaeosol deposits along west-central Siberian transect and their palaeoclimatic implications......Page 152
Fig. 1. Geographic map showing the location of the sections studied (black .........Page 155
Fig. 2. Lithologies and variations of magnetic susceptibility (K) and frequency-dependent .........Page 158
Fig. 3. Generalized relief profiles and changes in average values of magnetic .........Page 161
Fig. 4. Temperature dependence of magnetic low-field susceptibility (K), thermal demagnetization .........Page 163
Fig. 5. Variations of the S-ratio versus depth of the studied sections.......Page 166
Fig. 6. Variations of AMS degree P', inclinations of minimal and maximal .........Page 169
Fig. 7. Stereoplots of K[sub(max)] (squares) and K[sub(min)] (dots) principal AMS axes .........Page 173
Table 1. AMS characteristics of some loess/palaeosol deposits......Page 153
Table 2. Some present-day climatic characteristics in localities of studied sections......Page 156
Table 3. Mean magnetic susceptibilities and corresponding standard deviations for loess (L1 .........Page 160
Table 4. AMS data for loess (L1 and L2) and palaeosol (PC1 and PC2) units of studied sections......Page 172
The puzzle of axis-normal magnetic lineations in folded low-grade sediments (Bude Formation, SW England)......Page 182
Fig. 1. (a) Simplified geology of the North Cornwall and Devon, showing .........Page 183
Fig. 2. Detailed geological map of the foreshore south of Widemouth Sand .........Page 186
Fig. 3. (a) Detailed N–S cross-section along line A–B (Figure 2) showing .........Page 187
Fig. 4. Summary of structural (stereograms a and b) and AMS data .........Page 188
Fig. 5. Typical rock magnetic data: (a) Variation of low field magnetic .........Page 190
Fig. 7. Anisotropy of IRM data from the sample fold. Symbols as for AMS data in Figure 4.......Page 191
Fig. 9. Variation of AMS shape parameters with distance north of the .........Page 193
Fig. 10. Geological models for superimposing N–S stretch on pre-existing chevron .........Page 194
Table 1. Eigenvectors determined for each of the 3 principal axes of .........Page 192
How deformed are weakly deformed mudrocks? Insights from magnetic anisotropy......Page 198
Fig. 1. Histogram showing the average percentage mineral composition of mudrocks of .........Page 199
Fig. 2. Cleavage types observable in mudrocks and relationship to the magnetic .........Page 200
Fig. 3. Model for anisotropy of magnetic susceptibility ellipsoid distribution as a .........Page 203
Fig. 4. Single-mineral model of rock magnetic anisotropy versus degree of .........Page 204
Fig. 5. (a) Plot of the shape parameter (T) versus degree of .........Page 206
Anisotropy of magnetic susceptibility of lava flows and dykes: a historical account......Page 212
Fig. 1. Diagrams illustrating the three sources of the AMS in igneous .........Page 213
Fig. 2. Diagrams showing three types of igneous rocks that can be .........Page 215
Fig. 3. Examples of the earlier AMS results obtained in dykes and .........Page 217
Fig. 4. Examples of AMS results obtained from columnar basalts, (a) Orientation .........Page 218
Fig. 5. (a) Diagram showing the imbrication angle of both elongated and .........Page 219
Fig. 6. Diagrams showing the various relations among crystal orientation, magma flow .........Page 221
Fig. 7. Three examples of the variability in the orientation of principal .........Page 222
Fig. 8. Equal area projections (lower hemisphere) showing the principal susceptibilities of .........Page 225
Fig. 9. Diagrams showing the predicted particle rotation as the result of .........Page 227
Theoretical aspects of particle movement in flowing magma: implications for the anisotropy of magnetic susceptibility of dykes......Page 234
Fig. 1. Flow diagram of the program used to calculate the AMS .........Page 237
Fig. 2. Schematic relationship between the plane of intrusion, magma flow direction, .........Page 241
Fig. 3. Examples of the five magnetic behaviours obtained by modelling the .........Page 242
Fig. 4. Proportions of magnetic behaviours for systems of either prolate or oblate particles.......Page 243
Fig. 5. (a) Scheme of a vertical dyke showing a typical velocity .........Page 245
Fig. 6. Examples of the AMS obtained by collecting 10 samples along .........Page 248
Fig. 8. Examples of the AMS obtained by collecting 10 samples along .........Page 249
Fig. 9. Examples of the AMS obtained by collecting 10 samples along .........Page 250
Table 1......Page 239
Table 2......Page 240
Magmatic flow paths and palaeomagnetism of the Miocene Stoddard Mountain laccolith, Iron Axis region, Southwestern Utah, USA......Page 258
Fig. 1. (a) Selected igneous features of the Colorado Plateau. Black circles .........Page 259
Fig. 2. (a) Simplified geological map.......Page 261
Fig. 2. (b) cross-section (A–A' and B–B') of the Stoddard Mountain .........Page 262
Fig. 3. Thin section of representative texture from chilled zone rocks (a) .........Page 263
Fig. 4. Outline of the Stoddard Mountain laccolith. Numbered sample locations indicated .........Page 265
Fig. 5. Representative modified demagnetization diagrams (Zijderveld 1967; Roy & Park 1974) .........Page 268
Fig. 6. Equal area projections of in situ site mean directions from .........Page 272
Fig. 7. Palaeomagnetic chilled margin test. Samples (indicated by black triangles in .........Page 273
Fig. 9. Representative normalized IRM acquisition and back-field IRM demagnetization curves.......Page 274
Fig. 10. Modified Lowrie-Fuller test (Johnson et al. 1975) comparing AF .........Page 275
Fig. 11. Continuous susceptibility vs. temperature experiments and bulk susceptibility as a .........Page 276
Fig. 12. Representative thermal demagnetization curves of three-component orthogonal IRM (Lowrie 1990).......Page 278
Fig. 13. Lower hemisphere equal area projections of AMS principal susceptibility axes .........Page 279
Fig. 14. Relationship between the degree of magnetic anisotropy, Pj, and (a) .........Page 280
Fig. 15. Summary of accepted AMS data from the Stoddard Laccolith, (a) .........Page 282
Fig. 16. Lower hemisphere equal area projections of maximum susceptibility axes (K[sub(1)] .........Page 283
Fig. 17. Idealized schematic models for laccolith formation, (a) Magma flow paths .........Page 285
Fig. 18. Interpretative diagram depicting our inferred magma flow model that led .........Page 286
Table 1. Anisotropy of magnetic susceptibility data from the Stoddard Mountain laccolith, .........Page 270
Table 2. Palaeomagnetic data from the Stoddard Mountain laccolith......Page 281
Magma flow inferred from preferred orientations of plagioclase of the Rio Ceará-Mirim dyke swarm (NE Brazil) and its AMS significance......Page 292
Fig. 1. Geological map of the mafic rocks of northeastern Brazil, with .........Page 293
Fig. 2. (a) Magnetic lineation of the 'normal' (type-A) fabric and the .........Page 294
Fig. 3. Oxide microstmctures of dykes. Euhedral to subhedral titanomagnetite showing conspicuous, .........Page 295
Fig. 4. (a) Ratio of saturation remanence (Mrs) to saturation magnetization (Ms) .........Page 296
Fig. 5. (a) Mafic dyke trending E–W (North = left) with fresh, unweathered .........Page 297
Table 1. AMS parameters of the specimens used for determining the plagioclase fabric......Page 298
Table 2. Plagioclase fabric parameters of the Rio Ceará-Mirim dykes......Page 299
Fig. 10. AMS of the sites and corresponding plagioclase shape preferred orientation .........Page 300
Fig. 11. Shape preferred orientation of fine and coarse plagioclase laths and .........Page 301
Fig. 13. Model for emplacement of dykes along an E-trending fracture .........Page 303
Anisotropy of magnetic susceptibility (AMS): magnetic petrofabrics of deformed rocks......Page 306
Fig. 1. For pure minerals, AMS principal axes are controlled by crystal .........Page 311
Fig. 2. (a) K increases with magnetite-concentration and in some igneous .........Page 313
Fig. 3. (a), (b) In weakly susceptible limestone (K < + 100 µSI), .........Page 314
Fig. 4. Susceptibility has a characteristic temperature-dependence for antiferromagnets and for .........Page 316
Fig. 5. Magnetocrystalline anisotropy arises from the nature of the effective interactions .........Page 317
Fig. 6. Self-demagnetization becomes significant for intrinsic susceptibilities greater than about .........Page 319
Fig. 7. Shape anisotropy results from differences in self-demagnetization in different .........Page 321
Fig. 8. The dashed curve M shows the in-field magnetization of .........Page 323
Fig. 9. In two dimensions, the tensorial induced magnetization vector M (square .........Page 325
Fig. 10. (a, b) Anisotropy plots for magnitude-ellipsoids of tensors in structural .........Page 329
Fig. 11. (a) Orientation distributions (ODs) may be described by second-rank .........Page 331
Fig. 12. AMS magnitude ellipsoid shape is dictated primarily by rock composition, .........Page 332
Fig. 13. (a) Flinn's (1965) qualitative L-S fabric scheme describes ODs of .........Page 335
Fig. 14. (a) The peak-density for a certain set of axes, .........Page 337
Fig. 15. (a) AMS of Borrowdale volcanic slate defines a good S .........Page 339
Fig. 16 The AMS of a specimen depends on the proportions of .........Page 341
Fig. 17. (a) Combined AMS subfabrics due to bedding (S[sub(0)] and cleavage .........Page 343
Fig. 18. (a) Simple AMS-magnitude relations may exist for two dominant .........Page 345
Fig. 19. During regional metamorphism and tectonism, subfabrics are normally initiated in .........Page 348
Fig. 20. (a–c) March (1932) envisaged the re-distribution of orientations .........Page 349
Fig. 21. Metamorphic effects, sensu stricto, have largely been neglected and under- .........Page 350
Fig. 22. A deformation mechanism map (rear wall of diagram) represents dominant .........Page 351
Fig. 23. (a) Geographic or specimen coordinate systems are the usual and .........Page 353
Fig. 24. Comparisons of AMS, pAARM and finite strain illustrate differently shaped .........Page 355
Fig. 25. In general, laboratory heating changes AMS orientations and also the .........Page 356
Fig. 26. Calcite petrofabrics are sensitive to weak strains and thus correspond .........Page 358
Table 1. Glossary of magnetic and tectonic fabric terminology......Page 307
Table 2. Selected susceptibilities and anisotropy of dominantly paramagnetic ( + ve) or minerals .........Page 312
Phyllosilicate preferred orientation as a control of magnetic fabric: evidence from neutron texture goniometry and low and high-field magnetic anisotropy (SE Rhenohercynian Zone of Bohemia......Page 368
Fig. 1. Simplified geological map of the SE part of the Rhenohercynian .........Page 370
Fig. 2. Examples of the thermomagnetic heating curves of powder samples. The .........Page 374
Fig. 3. Backscattered images of the selected mudstone samples, (a) DV45, (b) .........Page 375
Fig. 4. (a) The anisotropy degree (P) vs. the mean susceptibility (k) .........Page 376
Fig. 7. Pole figures of the chlorite (001) or biotite (001), denoted .........Page 377
Fig. 8. (a) Correlation between theoretical degree of anisotropy calculated from chlorite .........Page 380
Fig. 8. (c) Correlation between the standard deviatoric susceptibility of HFP (k'[sub(HFP)]) .........Page 381
Fig. 9. (a) Correlation between the theoretical shape parameter (U[sub(Tch)] calculated from .........Page 382
Fig. 10. The degree of model of rock anisotropy (P[sub(T)] composed of .........Page 384
Table 1. Sample names, lithology, measured mineral, AMS and HFP parameters, neutron .........Page 371
Anisotropy of magnetic susceptibility in the Montes de Toledo area (Hercynian Iberian Belt, Spain) and its petrostructural significance......Page 388
Fig. 1. Geological map of the Toledo Complex. The location of AMS .........Page 389
Table 1. Mean anisotropy susceptibility data......Page 392
Fig. 3. (a) K[sub(m)] versus P[(sub(j)] plots for samples from the hanging .........Page 393
Fig. 5. Plots of (a) degree of anisotropy P[(sub(j)] and (b) bulk .........Page 394
Fig. 6. (a) Frequency stereogram of K[sub(1)] axes of Mora granite. The .........Page 395
Fig. 7. Plots of (a) degree of anisotropy P[(sub(j)], (b) bulk susceptibility .........Page 396
Fig. 8. (a) Frequency stereogram of K[sub(1)] axes of Layos granite, (b) .........Page 397
Fig. 9. Idealized scheme of the structural relationship between the epizonal batholith .........Page 398
Statistical significance of magnetic fabric data in studies of paramagnetic granites......Page 402
Fig. 1. (a) Geological sketch map (modified after Barrera Morate et al. .........Page 404
Fig. 1. (b) Histograms of the bulk susceptibility magnitudes of the Trives .........Page 405
Fig. 2. Reliability of the anisotropy values, (a) Jelinek's sample error between .........Page 407
Fig. 3. Reliability of anisotropy (P') and shape (T) at (Veiga) massif .........Page 408
Fig. 4. Reliability of magnetic lineation. (a) At sample scale: individual sample .........Page 409
Fig. 5. Strength and shape of lineation distributions (Woodcock diagram). The whole .........Page 411
Fig. 6. Reliability and quality of lineations at the massif scale, (a) .........Page 412
Fig. 7. Geological sketch map showing the location of magnetic bodies in .........Page 413
Fig. 8. Reliability of magnetic foliations, (a) At sample scale: foliation parameter .........Page 415
Fig. 9. Variation of statistical parameters as a function of the number .........Page 416
Table 1. Percentages of samples and sites in the Veiga and Trives .........Page 410
Magnetic fabric constraints on oroclinal bending of the Texas and Coffs Harbour blocks: New England Orogen, eastern Australia......Page 428
Fig. 1. (a) Outline of the Texas, Coffs Harbour and Manning oroclines .........Page 430
Fig. 2. Geology of the Texas–Coffs Harbour region (after Fergusson 1982a) .........Page 431
Fig. 3. Schematic diagram showing the time of deposition of sediments, D[sub(1)] .........Page 432
Fig. 4. (a) Histogram of mean magnetic susceptibility K[sub(m)] for the Texas .........Page 435
Fig. 5. Examples of three-axes stepwise thermal demagnetization of IRM following .........Page 437
Fig. 6. Comparison of magnetic fabric results for two representative sites using .........Page 439
Fig. 7. Comparison between mesoscopic structural observations (left-hand figures) and magnetic .........Page 442
Fig. 7. (c) Texas block, structural data according to Butler (1974). These .........Page 443
Fig. 8. Overview of (a, d) the mean shape parameter (T*) versus the .........Page 444
Fig. 9. Overview of Terrica beds AMS results CTTA-H, ATTO). Density diagram .........Page 445
Fig. 10. The mean degree of anisotropy (P'*) and its standard deviation .........Page 446
Table 1 Sampling sites and structural data......Page 434
Table 2 Rock magnetic properties......Page 436
Table 3. AMS mean tensorial data......Page 440
Application of magnetic fabrics to the emplacement and tectonic history of Devonian granitoids in central Argentina......Page 454
Fig. 1. Schematic map showing the Palaeozoic metamorphic belts and granitoids units .........Page 456
Fig. 2. Geological map of La Totora granite with field data for foliation.......Page 459
Fig. 3. (a–c) Outcrop scale features of the La Totora batholith: (a) .........Page 460
Fig. 4. Typical demagnetization behaviour of samples from the La Totora batholith .........Page 464
Fig. 5. Distribution of geometric mean site k values on the La .........Page 465
Fig. 6. (a) P' vs. K plot for each site of the .........Page 466
Fig. 7. Distribution of magnetic foliation planes for the La Totora, Renca .........Page 468
Fig. 8. Distribution of magnetic lineations for the La Totora, Renca and .........Page 469
Fig. 9. (a) Comparison of the biotite texture (density plot) based theoretical .........Page 471
Fig. 10. Stereographic projections (equal area, lower hemisphere) for the magnetic lineations .........Page 473
Fig. 11. Satellite image showing the Sierra de San Luis. The major .........Page 475
Fig. 12. Schematic model showing the transtensional stress field during the emplacement .........Page 477
Table 1. Summary of the main geological features and ages for the .........Page 458
Table 2. Mean site AMS data for the La Totora batholith......Page 463
Relationships between magnetic and structural fabrics revealed by Variscan basement rocks subjected to heterogeneous deformation—a case study from the Klodzko Metamorphic Complex, Central Sudets.Poland......Page 482
Fig. 1. (a) Geological setting of the Klodzko Metamorphic Complex (denoted by .........Page 483
Fig. 2. A generalized geological map of the Klodzko Metamorphic Complex showing .........Page 484
Fig. 3. Synoptic stereoplots showing the orientation of different structural fabrics in .........Page 485
Fig. 4. AMS results: directions of K[sub(max)] (full squares) and K[sub(min)] (full circles) .........Page 489
Fig. 5. AMS results: (a) KLM metabreccia, (b) KLM crystalline limestones (only .........Page 491
Fig. 6. AMS results, (a) KSA, (b) KSS, (c) KOG, (d) KK, (e) KOA, (f) KSG.......Page 492
Fig. 7. AMS results, (a) KP3, (b) KP2, (c) KW, (d) annealing .........Page 494
Fig. 8. AMS results, (a) KP1, (b) KLW site 1, (c) KLW site 2, (d) KLW site 3.......Page 495
Table 1. The statistics of collected samples and their susceptibilities......Page 487
Table 2. The mean orientations of directions of mineral and magnetic fabric......Page 488
Oblique magnetic fabric in siderite-bearing pelitic rocks of the Upper Carboniferous Culm Basin, SW England: an indicator for palaeo-fluid migration?......Page 500
Fig. 1. Simplified geological map showing the Upper Carboniferous Culm Basin in .........Page 501
Fig. 2. AMS data obtained from along the Culm section for the .........Page 504
Fig. 3. Thermomagnetic analysis of magnetic susceptibility for a siderite-bearing sample .........Page 505
Fig. 4. (a) Random powder X-ray diffraction pattern of a sample from .........Page 506
Fig. 5. High resolution TEM images (x88 000) of a mudstone sample .........Page 507
Fig. 6. The Crackington Haven fold structure with a flat upper limb .........Page 508
Fig. 7. Orientation of the long axes of AMS ellipsoids (K[sub(max)] magnetic .........Page 509
Fig. 8. (a) Shape of AMS ellispoids for samples from the upper .........Page 510
Fig. 9. Model for the interpretation of magnetic fabric geometry in siderite- .........Page 511
Development of magnetic fabrics during hydrothermal alteration in the Soultz-sous-Forêts granite from the EPS-1 borehole, Upper Rhine Graben......Page 516
Fig. 1. Location map of the central Upper Rhine Graben (dashed line) .........Page 517
Fig. 2. Lithological section (modified after Genter & Traineau 1996) and magnetic .........Page 518
Fig. 4. Micrographs (SEM) from thin sections parallel to the magnetic foliation .........Page 519
Fig. 5. Rock magnetic properties of fresh and hydrothermally altered granite from .........Page 522
Fig. 6. (a) Variation of the shape parameter T with the anisotropy .........Page 525
Fig. 7. Mean magnetic susceptibility versus dip of magnetic foliation for fresh .........Page 526
Fig. 9. Separation of ferrimagnetic and paramagnetic fabric by high-field AMS .........Page 527
Fig. 10. Development of magnetic fabric during progressive hydrothermal alteration with typical .........Page 530
Sub-fabric identification by standardization of AMS: an example of inferred neotectonic structures from Cyprus......Page 534
Fig. 1. Geology of Cyprus, (a) Major lithological units of Cyprus (Geological .........Page 536
Fig. 2. Simplified stratigraphic and tectonic events for the Troodos terrane, and its sedimentary cover rocks.......Page 537
Fig. 3. Frequency distribution of bulk magnetic susceptibility (K) for (a) sub- .........Page 538
Fig. 4. Polar plots (see Borradaile & Jackson, this volume) of four .........Page 539
Fig. 5. Idealized symmetry of confidence cones about the mean orientations of .........Page 541
Fig. 6. Sub-areas of Cyprus (I–VI) and their magnetic fabrics as .........Page 543
Fig. 7. Regional domains of Cyprus (I–V) and their magnetic fabrics, (a) .........Page 544
A......Page 548
C......Page 549
E......Page 550
H......Page 551
M......Page 552
N......Page 554
P......Page 555
S......Page 556
T......Page 557
X......Page 558