Tectono-metamorphic evolution of the Eastern Fold Belt, Mount Isa, NW Queensland, Australia
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(2) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). LIST OF FIGURES AND TABLES (SECTION D). The tectono-metamorphic evolution of the Snake Creek anticline, Mount Isa Inlier, Australia. Table 1. ----------------------------------------------------------------------------------. 75. Table 2. ----------------------------------------------------------------------------------. 76. Table 3. ----------------------------------------------------------------------------------. 77. Table 4. ----------------------------------------------------------------------------------. 79. Table 5. ----------------------------------------------------------------------------------. 81. Figure 1. ----------------------------------------------------------------------------------. 72. Figure 2. ----------------------------------------------------------------------------------. 73. Figure 3. ----------------------------------------------------------------------------------. 74. Figure 4. ----------------------------------------------------------------------------------. 78. Figure 5. ----------------------------------------------------------------------------------. 80. Figure 6. ----------------------------------------------------------------------------------. 82. Figure 7. ----------------------------------------------------------------------------------. 83. Figure 8. ----------------------------------------------------------------------------------. 84. Figure 9. ----------------------------------------------------------------------------------. 85. Figure 10. ----------------------------------------------------------------------------------. 86. Figure 11. ----------------------------------------------------------------------------------. 87. Figure 12. ----------------------------------------------------------------------------------. 88. Figure 13. ----------------------------------------------------------------------------------. 89. Figure 14. ----------------------------------------------------------------------------------. 90. Figure 15. ----------------------------------------------------------------------------------. 91. Figure 16. ----------------------------------------------------------------------------------. 92. Figure 17. ----------------------------------------------------------------------------------. 93. 71.
(3) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 1. (a) Geologic map of the Mount Isa Inlier showing three N–S-striking tectonostratigraphic belts; Western Fold Belt (WFB), Kalkadoon-Leichhardt Belt, Eastern Fold Belt (EFB). (b) Geologic-structural map of the Snake Creek anticline area. The small black rectangle in (a), showing four groups of folds trending N–S, W–E, NW–SE and NE– SW.. 72.
(4) 140 45. 140 39 N. La n. ds bo ro ug. Hi gh w. ay. 73. 66. 139. 19 00. 80. 141 00. 50 Km. Study area. FB KFB K. 62. 00. WFB. h. GRM. 52. 85. Cre. Mt Isa. 74. 21 00. ek. Sync. line. 68. (a). 70. 58. EFB. To ole. e Anticline tain Hom. Moun. 55. 20 51. line. Sync. vis Da. 65. y urr nc Clo r ea Sh Zo. 82. ne. 65 48 32. 82. 65. 50. 55 45. LEGEND. 70. Mount Norna Quartzite. k. ee. 80. t. Saxby Granite. 43. Cr. Doherty Formation. 112. ke. ul Frray cu on Cl. Tool Creek Volcanics. 62 76. (CS 2). Llewellyn Creek Formation Amphibolite, Metabasalt, Metadolerite. Sna. CS 3 Soldiers Cap Group. STRATIGRAPHY. STRUCTURES. 80. An. 33. tic. Strike and dip. lin. ONW-SEFolds. e. O W-E Folds. Overturned bedding. O N-S Folds. Fault. OSW-NE Folds. Gilded Rose Mine. 54. GRM. 2 Km. (b). Figure 1. 20 57.
(5) 150 Sc7 And. And Grt And. Grt And 1 mm. a. 90 L354. And relics. Ms. 1 mm. b Figure 2.
(6) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 2. (a) Part of a large skeletal andalusite porphyroblast enclosing inclusions of garnet and biotite and overgrowing the matrix foliation. (b) Coarse-grained prograde muscovite replacing andalusite. Vertical thin section with single barbed arrow showing strike and way up. Plane polarized light.. 73.
(7) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 3. (a) Schematic diagram shows the development of a FIA through the intersection between a sub-vertical crenulated cleavage (S1) and a horizontal differentiated crenulation cleavage (S2). (b-d) Diagram shows the technique used for preparing thin sections for FIA measurements; collecting oriented samples from the field (b), cutting horizontal slabs (c), and cutting initially six vertical thin sections every 30o around the compass (d).. 74.
(8) FIA axis. S2. (a) S1. 000. N. 03. 0 090. 150 12. 060. 0. (c). (d) FIA trend. 0. 33 0. (b). 30. 300 60. 270. 90. 240 120. 0. 0. 18. FIA trend. 15. 0 21. Figure 3.
(9) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Table 1. Bulk composition of the samples used to model pseudosections with Thermocalc.. 75.
(10) CC6 SiO2 TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O P2O5 LOI Total. Wt % 66.5 0.59 14.9 7.88 0.22 1.73 0.39 0.47 4.03 0.21 1.52 99.3. mol % 75.1 0.50 9.9 7.44 0.21 2.91 0.47 0.51 2.90 0.10. SAMPLES N17 Wt % mol % 58.5 66.25 0.63 0.54 15.9 10.60 11.81 11.19 0.11 0.11 3.51 5.93 0.62 0.75 4.01 4.40 0.22 0.16 0.14 0.07 2.3 99.1 Table 1.. L5 Wt % 53.6 0.79 22.9 9.23 0.23 2.37 0.32 1.19 3.61 0.18 3.59 99.1. mol % 64.53 0.72 16.29 9.30 0.23 4.26 0.41 1.39 2.77 0.09.
(11) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Table 2. Representative analyses of garnet cores and rims.. 76.
(12) Sample no.. N17. CC6. Comment SiO2 Al2O3 FeO MnO MgO CaO Total. g1core 36.79 20.84 36.98 2.72 2.11 0.43 99.89. g1g2rim core 36.81 36.90 20.81 20.93 38.69 37.70 0.40 2.03 2.26 2.16 0.57 0.44 99.57 100.18. g2rim 36.89 20.87 38.66 0.38 2.20 0.67 99.70. g1core g1-rim 36.87 36.93 20.94 20.90 35.27 37.58 3.97 1.99 2.05 2.21 0.56 0.51 99.68 100.13. g2core g2-rim 36.85 37.09 20.96 21.03 35.20 37.71 4.55 1.64 1.94 2.22 0.46 0.60 99.99 100.33. Oxygens Si Al Fe Mn Mg Ca Total. 12 3.00 2.00 2.52 0.19 0.26 0.04 8.00. 12 3.00 2.00 2.64 0.03 0.27 0.05 8.00. 12 3.00 2.00 2.56 0.14 0.26 0.04 8.00. 12 3.00 2.00 2.63 0.03 0.27 0.06 7.99. 12 3.00 2.01 2.40 0.27 0.25 0.05 7.99. 12 3.00 2.00 2.55 0.14 0.27 0.04 8.00. 12 3.00 2.01 2.39 0.31 0.24 0.04 8.00. 12 3.00 2.01 2.55 0.11 0.27 0.05 7.99. XFe XMn XMg XCa. 0.84 0.06 0.09 0.01. 0.88 0.01 0.09 0.02. 0.85 0.05 0.09 0.01. 0.88 0.01 0.09 0.02. 0.81 0.09 0.08 0.02. 0.85 0.05 0.09 0.01. 0.80 0.11 0.08 0.01. 0.86 0.04 0.09 0.02. Table 2..
(13) FIA Sets Trends Sample No.. Northing. C131 C174 D131 D433 D434 E179 E191 E200 F345 F512 G3 G4 G5 G6 G58 G90 G292 G390 G391 G464 G482 L5 L5` L38 L40 L104 L178 L210 L259 L354 L486 M81 N11 N14 N17 N24 N37 O91. 7685000 7685500 7686800 7687100 7687000 7677800 7678500 7679300 7685500 7686000 7702500 7702500 7702500 7702057 7702800 7701800 7702200 7702500 7701800 7700400 7702500 7682000 7682000 7681500 7681500 7681100 7679800 7679700 7679900 7681000 7686483 76821500 7686250 7686200 7686000 7688993 7687902 7678000. Easting 467000 467500 466600 465800 466000 469700 471000 470400 465700 465700 460300 460300 460300 460484 460100 461300 466300 460300 460800 465800 460300 469000 469000 466600 466300 469100 496400 467700 468400 464200 461373 464800 462000 462450 462250 461237 460751 470600. Gnt Core 135 105. Rim 135. 105. St pFIA. Rim. And pFIA. 105 165. 105 165. 90 90 90. 90 90. Crd. FIA 15. pFIA. 30 100 105 170. 165 100 105. FIA. Cld pFIA. FIA. 105. 90 90. 100 149 110 95 95 95 130 90 90 80 100 45 80. Core. 90 145. 170. 95 95 95 130 165 110 80. 165. 165. 105 15. 15. 90 40 165. 90. 0 60 45. 90 165. 105 0 170. 170 165. 90. 90. 90 15. 165. 90. 90 15. 165. 165 75.
(14) O92 P12 Q130 743 813 814 519.7 Sc 4 Sc 5 Sc 6 Sc 11 Sc 13 Sc 14 Sc 17 Sc 19 Sc 20 Sc 21 Sc 22 Sc 23 Sc 24 Sc25 Sc 855 Sc 865. 7678000 7689663 7695502 7686038 7684343 7681732 7681750 7702743 7684521 7681894 7684929 7685092 7684458 768420 768109 7702216 7682002 7682438 7685126 7680962 7681488 7682465 7684850. 471200 464407 460553 462054 463913 466605 466300 460501 464011 466715 467575 465353 464375 463435 469065 460690 467869 462906 463410 466798 468373 466860 465500. 60 135 100. 90. 165. 135 90. 80. 90 0. 60 50 170 90 15. 165 0 90. 15. 140. 75 165. 105 110 165. 110 30. 165 80 110 105 30 90 90. Table 3.. 121 110.
(15) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Table 3. FIA measurements of garnet, staurolite, andalusite, chloritoid and cordierite porphyroblasts.. 77.
(16) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 4. Rose diagram shows 4 peaks representing 4 FIA trends.. 78.
(17) FIA 2 (n = 6). FIA 0 (n = 35). FIA 1 (n = 59). FIA 3 (n = 13). N = 113 Class interval = 10. Figure 4..
(18) (a) Textural setting: FIA 00 No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24. Analysed spots. Age (Ma). Error (2σ). No. 1664 1619 1651 1672 1655 1616 1614 1644 1647 1670 1666 1667 1717 1603 1627 1691 1652 1670 1622 1650 1618. 75 86 87 81 76 68 76 94 64 72 85 52 85 71 75 60 43 69 76 47 83. 1623 1719 1656. 75 94 85. 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49. 1651 1670 1608 1610 1673 1599 1665 1654 1638 1691 1638 1676 1665 1666 1608 1646 1692 1678 1616 1697 1716 1688 1711 1630 1746 1725. 39 65 72 73 73 105 64 56 57 101 94 110 89 52 66 79 93 80 96 94 69 51 64 90 104 135. AV5 Cd mz1-1 mz1-2 mz1-3 mz 1-4 mz 1-5 mz 1-6 Cd mz 2-1 mz 2-2 mz 2-3 mz 2-4 mz 2-5 mz 2-6 mz 2-7 mz 2-8 mz 2-9 mz 2-10 Cd mz 4-1 mz 4-2 mz 4-3 mz 4-4 mz 4-5 AV3 Cd mz 1-1 mz 1-2 mz 1-3. Analysed spots AV3 mz 1-4 mz 1-5 mz 1-6 mz 1-7 Cd mz 2-1 mz 2-2 mz 2-3 mz 2-4 mz 2-5 mz 2-6 Cd mz 3-1 mz 3-2 mz 3-3 mz 3-4 mz 3-5 mz 3-6 mz 3-7 mz 3-8 Cd mz 5-1 mz 5-2 mz 5-3 mz 5-4 mz 5-5 mz 5-6 mz 5-7. Age (Ma). Error (2σ). 1616 1646 1649 1625 1634 1626 1657 1600 1589 1628 1630 1616 1663 1623 1661 1649 1655 1686 1694 1599 1604 1687 1651 1659 1611. 98 104 66 79 55 62 68 73 70 72 79 60 92 82 88 58 68 84 80 74 80 117 69 77 75. 1671 1655 1676 1664 1659 1650 1649 1671 1652 1693 1735 1706 1695 1613 1620 1604 1614 1610 1585. 68 64 85 86 86 65 79 71 92 91 95 102 96 58 72 56 78 58 120. 1636 1634 1653 1647 1668 1615. 48 49 56 51 47 46. (b) Textural setting: FIA 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26. O92 St1 mz1-1 mz1-2 mz2-1 mz2-2 St2 mz3-1 mz3-2 mz3-3 mz3-4 mz3-5 mz3-6 mz3-7 mz3-8 mz4-1 mz4-2 mz4-3 mz4-4 mz4-5 mz4-6 St4 mz7-2 Gnt1 mz8-1 Gnt1 mz8-2 Gnt2 mz9-1 mz9-2 mz9-3 mz10-1 mz10-2. 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51. mz4-7 mz4-8 mz4-9 St2 mz4-10 mz4-11 mz5-1 mz5-2 mz5-3 mz5-4 mz5-5 mz5-6 mz5-7 mz5-8 mz5-9 St3 mz6-1 mz6-2 mz6-3 St4 mz7-1 Gnt8 mz18-1 L40 And1 mz1-1 mz1-2 mz1-3 And2 mz2-1 mz2-2 mz2-3.
(19) No 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74. Analysed spots. Age (Ma). Error (2σ). No. 1763 1639 1627 1635 1661 1614 1596 1681 1638 1573 1595 1619 1664 1657 1623 1644 1635 1655 1636 1618 1624 1642 1665. 127 87 86 83 93 96 71 58 50 94 84 82 93 75 59 53 49 67 65 75 90 67 74. 75 76 77 78. 81 82 83 84 85 86 87 88 89 90 91 92 93. Gnt7 mz2-4 mz3-1 mz3-2 mz3-3 N14 St1 mz1-1 St2 mz2-1 L5 Gnt1 mz1-1 mz1-2 Gnt2 mz2-1 St1 mz3-1 mz3-2 mz3-3 mz4-1 St2 mz5-1 mz5-2 mz5-3 mz5-4 mz6-1 mz6-2. D131 St1 mz1-1 mz2-1. And2 mz10-3 mz10-4 mz10-5 mz11-1 mz11-2 mz11-3 Gnt3 mz12-1 mz12-2 mz12-3 Gnt4 mz13-1 mz13-2 Gnt5 mz14-1 mz14-2 mz14-3 mz14-4 mz15-1 mz15-2 mz15-3 Gnt6 mz16-1 mz16-2 Gnt7 mz17-1 mz17-2 mz17-3. 79 80. Analysed spots. Age (Ma). Error (2σ). 1601 1662 1648 1638. 47 61 61 39. 1619 1635. 30 49. 1647 1614 1633 1613 1596 1664 1672 1682 1672 1617 1679 1700 1656. 75 75 64 95 98 86 91 101 114 105 88 120 57. 1623 1565. 55 86. 1624 1618 1637 1601 1634 1536 1633 1592. 65 79 66 74 65 65 65 71. 1637 1580 1582 1546 1592 1563 1629 1612. 55 85 86 96 61 57 59 65. 1660 1607. 81 55. (c) Textural setting: FIA 2 1 2. N17 Gnt1 mz1-1 mz1-2. 1549 1559. 48 50. 23 24. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22. mz2-1 Gnt2 mz3-1 mz3-2 mz3-3 mz3-4 mz3-5 Gnt3 mz4-1 mz4-2 mz5-1 mz5-2 mz6-1 mz6-2 Gnt4 mz7-1 mz8-1 Gnt5 mz9-1 mz9-2 Gnt6 mz10-1 mz11-1 mz11-2 mz11-3. 1600 1611 1616 1623 1581 1574 1556 1567 1602 1607 1529 1559 1597 1583 1541 1556 1566 1610 1572 1578. 92 92 51 71 93 98 60 95 66 78 75 82 71 47 61 75 73 93 68 84. 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42. Table 4.. mz3-1 St2 mz4-1 mz4-2 mz4-3 mz5-1 mz5-2 mz5-3 mz5-4 D434 St1 mz1-1 St2 mz2-1 mz2-2 mz2-3 mz2-4 mz2-5 mz2-6 mz2-7 CC6 Gnt1 mz1-1 mz1-2.
(20) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Table 4. Electron microprobe monazite weighted mean ages for each spot in monazite grains recorded in structural domains represented by porphyroblasts preserving FIA set 00 (a), FIA set 1 (b) and FIA set 2 (c). (Mineral abbreviation symbols after Kretz, 1983).. 79.
(21) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 5. (a-c) Weighted mean and probability density plotsof monazite grain inclusions within porphyroblasts preserving NW–SE, W–E and N–S trending FIAs (‘a’ after Rubenach, 2008).. 80.
(22) box heights are 2σ 1840 1800. 10. Mean = 1649±12 [0.72%] 2 σ Wtd by data-pt errs only, 0 of 36 rej. MSWD = 0.52, probability = 0.992. 9. FIA SET 00. 8. 1760. Number. 1680. Relative probability. 7. 1720. 6 5. 1640. 4. 1600. 3. 1560. 2. 1520. 1. 1480. 0 1450 box heights are 2σ. 1900. Mean = 1645.1±7.0 [0.42%] 2σ Wtd by data-pt errs only, 0 of 93 rej. MSWD = 0.80, probability = 0.92. 1550. 1650. 1750. 1850. (a). 1950. 20. c. FIA SET 1. 18 16. 1800. Relative probability. 14. Number. 12 1700. 10 8. 1600. 6. (b). 4. 1500. 2 0. 1400. 1400 box heights are 2σ. 1780 1740. Mean = 1591±10 [0.65%] 2σ Wtd by data-pt errs only, 0 of 42 rej. MSWD = 0.94, probability = 0.57. 1500. 1600. 1700. 1800. 1900. 2000. 10. e. 9. f. FIA SET 2. 8. 1700. Relative probability. 7 1660. 1580. Number. 6 1620. 5 4. 1540. 2100. 3. 1500. 2. 1460. 1. 1420. 0 1400 1400. Figure 5. 1450. 1500. 1550 1550. 1600. 1650. 1700. 1750 1750. 1800 1800. 1850 1850. (c).
(23) Sample No. Mineral SiO2 TiO2 Al2O3 Cr FeO MnO MgO CaO Na2O K2O Total Oxygens Si ti Al Cr Fe Mn Mg Ca na k total. O92 Bt 33.89 1.54 18.53 0.65 22.00 0.03 8.58 0.02 0.16 8.92 94.30. Ms 46.55 0.20 36.60. St Ilm 27.21 0.21 58.57 53.62. 1.47 0.01 0.37 0.02 0.61 7.77 93.61. 14.37 34.38 0.09 1.19 1.38 0.02. 22 5.30 0.18 3.42 0.08 2.88. 22 6.19 0.02 5.74. 46 6 7.64 0.05 2.24 17.76. 0.16. 2.00. 0.07. 3.38 0.02 0.58 0.01. 96.92 94.89. 1.46 0.05. 0.05 0.16 1.78 1.32 15.69 13.66 29.43 3.76. L5 Bt 34.52 0.96 18.76 0.34 21.16 0.02 8.72. Ms 46.74 0.16 37.63. St Ilm 27.10 0.41 51.14 53.51. 0.90 0.01 0.33 0.02 0.19 1.23 8.45 7.24 93.11 94.25. 14.50 43.02 0.08 1.47 1.45 0.01. 22 5.41 0.11 3.47 0.04 2.77. 22 6.14 0.02 5.83. 46 6 7.61 0.09 2.02 17.71. 0.10. 2.04. 0.06. 3.40 0.02 0.61. 97.09 95.76. 1.89 0.07. 0.06 0.31 1.69 1.21 15.60 13.69 29.45 3.98. Table 5.. C66 Bt 34.20 1.05 18.64 0.17 22.25 0.03 7.85 0.03 0.31 8.64 93.16. Ms Ilm 46.60 0.25 49.72 36.35 1.38. 46.17 0.40. 0.40 0.01 0.77 7.42 93.18 96.40. 22 5.40 0.12 3.47 0.02 2.94. 22 6.21 0.02 5.71. 6. 0.15. 2.04 0.02. 1.85. 0.08. 1.97. 0.09 0.20 1.74 1.26 15.65 13.64 4.03. N17 Chl 23.43 0.06 23.11 0.03 27.82 0.02 11.91 0.02 0.02 0.01 86.42 36 6.54 0.01 7.61 0.01 6.50 0.01 4.95 0.01 0.01. Ilm 50.29. 44.66 0.80. 95.81 6 2.00. 1.97 0.04. 25.64 4.00.
(24) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Table 5. Representative microprobe chemical analyses of biotite, muscovite, staurolite, chlorite and ilmenite.. 81.
(25) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 6. X-ray compositional maps of two garnet porphyroblasts preserving W–E (a-d) and N–S (e-h) trending FIAsand showing compositional variation from core to rim.. 82.
(26) Mg. Fe. a. 1 mm. Ca. c. 1 mm. d. 1 mm. Mg. 1 mm. Ca. g. 1 mm. Mn. Fe. e. b. f. 1 mm. Mn. 1 mm. h. Figure 6. 1 mm.
(27) 9. (Qz+H2O+Ms in excess). 8. Grt. St Ky Bt Grt. t Ky B. Sample L5 MnNcKFMASH. Ctd Bt Grt St Bt Grt. 6. 5. Ctd Bt Zo. rt it Zo G C td B. 7. St Bt Grt Ctd. St Sill Bt Grt. XFe XCa. 4. XMn. t Gr t dB. An St. And. 3. And Bt Grt Ctd. 450. 470. d Grt C. Bt Grt Cd. Ctd Bt Grt Zo 430. t S ill B. rt Bt G. t Cd t Gr B And. And Zo Bt Grt Ctd 2. Sill Bt Grt. 490. 510. 530. 550. (a). Figure 7. 570. 590. 610. 630. 650. 670.
(28) Sample L5 MnNcKFMASH. Grt Ky Bt. 9. (Qz+H2O+Ms in excess). 8. St Ky Bt Grt Ctd Bt Grt St Bt Grt. 6. 5. Ctd Bt Zo. rt it Zo G C td B. 7. St Bt Grt Ctd. St Sill Bt Grt Sill Bt Grt t Gr t dB. XFe XMn. 4. An St. XCa. And. 3. And Bt Grt Ctd. Bt Grt Cd. Ctd Bt Grt Zo 430. 450. 470. d Grt C. d rt C G t B And. And Zo Bt Grt Ctd 2. t S ill B. rt Bt G. 490. 510. 530. 550. 570. (b). Figure 7 (continued). 590. 610. 630. 650. 670.
(29) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 7. MnNCKFMASH P-T pseudosection modeled for sample L5 using THERMOCALC software.The intersection of the thick lines close to the St-And-Bt-Grt stability fieldshows the XFe, XMn and XCa isopleths for garnet core nucleation of samples N17 (a) and CC6 (b).. 83.
(30) PhD Thesis. Section D. A.S.A. Ahmed (Abu Sharib). Figure 8. (a) The matrix foliation in this sample is sub-vertical and strikes N–S and varies from steep to gently SW pitching in this vertical slide striking at 30° as it wraps around the cordierite and andalusite porphyroblasts in the centre. This low angle to the matrix foliation section orientation was chosen because it shows every phase of porphyroblast growth. The cordierite porphyroblast in centre contains very fine-grained inclusions and formed first. Within the right side of the andalusite (AND1) is a staurolite porphyroblast (ST1), the left inclusion rich portion of which predates the andalusite. Both grew prior to the matrix foliation SN-S which wraps around both them and the cordierite. A second generation of staurolite St2 overgrew this foliation. A second generation andalusite (AND2) partially replaces the St2 staurolite (top right). (b) Cordierite porphyroblast locally surrounded by second generation staurolite that overgrew the N–S-striking matrix foliation that also wraps around a first generation andalusite porphyroblast.Vertical thin section with single barbed arrow showing strike and way up. Plane polarized light.. 84.
(31) 30. Crd. L38 160. And2 St2 SN. -S. St1. St2 And1. Sil. Crd. St2. St2 Sil 2 mm. a. Figure 8.
(32)
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