Palaeoproterozoic to Mesoproterozoic Geology of North Queensland

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Deformation & metamorphismGilbert Fold beltRegional studies have suggested the following eventsD1• mainly E-W folds with strong cleavage/foliation• dominant regional structures;• lower greenschist to amphibolite metamorphism• usually thought to be ~1590Ma, based on SHRIMP dates from Dargalong areafarther north.D2• approx N-S folds superimposed on E-W structures,• restricted to E half of outcrop area;• multiple mesoscopic fabrics;• most workers have associated D2 with peak amphibolite facies metamorphismand emplacement of Forsayth Supersuite (S-type anatectic granites) andcommon metamorphic zircon growth at 1550-1560MaD3 - E-W folds, restricted to central part of areaLater open folds, possibly early Palaeozoic
Robertson River areaDeformation & metamorphismHowever, detailed microstructural (FIA analysis of porphyroblasts) & CHIMEdating of monazite from the Robertson River area give a somewhat differentpicture (Cihan & others, JCU)Porphyroblasts containing FIA1 to FIA3, overgrew a S1/S2 matrix foliationFIA1 and FIA2 related to early N-S shortening associated with monazite dated at1625±15 MaFIA3 related to E-W shortening associated with monazite dated at 1586±6 MaThermobarometry indicates pressure increased progressively to 6-7kb duringFA1 to FA3S3 – a flat lying fabric associated with matrix monazite dated at 1564±8 MaProbably related to decompression and exhumationFIA4 related to NW-SE shortening associated with monazite dated at 1542±8 MaAssociated with lower pressure-high temperature metamorphism at 3-4kbS4 younger fabric associated with with monazite dated at 1512±5 Ma
Page 1 and 2: Australian GovernmentGeoscience Aus
Page 3 and 4: Tasman LineCOENINLIERDeep crustalse
Page 5 and 6: 50 kmSurface Geology - Georgetown r
Page 7 and 8: Proterozoic Stratigraphic Units - S
Page 9 and 10: Bernecker Creek Formation• Calcar
Page 11 and 12: Daniel Creek Formation• Very fine
Page 13 and 14: Dead Horse Metabasalt• Aphyric th
Page 15 and 16: Corbett Formation• Predominantly
Page 17 and 18: Lane Creek Formation• Mudstone an
Page 19 and 20: Cobbold Metadolerite• Mostly sill
Page 21 and 22: Cobbold Metadolerite• Mostly sill
Page 23 and 24: Townley Formation• Mudstone, silt
Page 25 and 26: Heliman Formation• Mudstone and s
Page 27 and 28: Langdon River Mudstone• Laminated
Page 31 and 32: Langlovale Group• Malacura Sandst
Page 33 and 34: Palaeoproterozoic-Mesoproterozoic S
Page 35 and 36: Croydon Volcanic Group• Dominated
Page 37 and 38: Inorunie Group• Unconformably ove
Page 41 and 42: Einasleigh Metamorphics• Psammope
Page 43 and 44: Einasleigh Metamorphics• Psammope
Page 45 and 46: Proterozoic solid geology - Georget
Page 47: Proterozoic structural domains & so
Page 51 and 52: Deformation & metamorphismLangloval
Page 53 and 54: Palaeoproterozoic-Mesoproterozoic S
Page 55 and 56: Other Proterozoic Inliers - norther
Page 57 and 58: Tasman LineCOENINLIEROther Proteroz
Page 59 and 60: Other Proterozoic Inliers - Yambo
Page 61 and 62: Other Proterozoic Inliers - Coen•
Page 63 and 64: Correlations between InliersEtherid
Page 65 and 66: Correlating Georgetown and Mt Isa S
Page 67: Correlating Georgetown and Mt Isa S

Palaeoproterozoic to Mesoproterozoic Geology of North Queensland

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