Structural cross-section based on the Mt Isa deep seismic transect

MacCready, Tyler C

doi:10.1080/08120090500431415

Cited by 21 publications

(26 citation statements)

References 15 publications

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“…At the onset of the Mesoproterozoic large tracts of central and eastern Australia underwent a period of orogenesis (circa 1620 and 1580 Ma) (Figure 10). The orogenic history is preserved in the Arunta Inlier (Chewings Orogeny), Curnamona Province (Olarian Orogeny), Gawler Craton (Kararan Orogeny), Mount Isa Inlier (Isan Orogeny) and Georgetown Inlier (Jana Orogeny) [ Betts et al , 2006; Blenkinsop et al , 2008; Cihan et al , 2006; Cihan and Parsons , 2005; Collins et al , 1995; Daly et al , 1998; Forbes et al , 2004, 2007; Gibson et al , 2008; Giles et al , 2006b; Hand et al , 2007; MacCready , 2006a; O'Dea et al , 1997b, 2006; Potma and Betts , 2006; Rubatto et al , 2001; Vry et al , 1996] (Figures 1 and 10). The circa 1610–1560 Ma Chewings Orogeny [ Collins and Shaw , 1995] is characterized by early thin‐skinned deformation and nappe emplacement during north directed thrusting [ Teyssier et al , 1988], followed by the development of upright, shallowly plunging folds with ∼east‐west trending axial traces [ Collins and Shaw , 1995].…”

Section: End‐member Tectonic Modelsmentioning

confidence: 99%

Mesoproterozoic plume‐modified orogenesis in eastern Precambrian Australia

et al. 2009

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Tectonic models for the latest Paleoproterozoic to earliest Mesoproterozoic evolution of eastern Australia (circa 1620–1500 Ma) are diverse and either emphasize plume or plate margin activity, neither of which satisfactorily explains all geological observations. The dichotomy is largely attributed to geochemical, spatial and temporal data that suggest voluminous A‐type felsic magmas are plume related, whereas distribution of arc‐related magmas and intense orogenic overprint suggest plate margin activity. The salient geological events include arc‐related magmatism at circa 1620–1610 Ma followed by a magmatic hiatus coincident with north‐south crustal shortening (1610–1590 Ma) and a magmatic flare‐up of A‐type felsic magmas throughout the Gawler Craton (circa 1595–1575 Ma). These magmas form the oldest component of a northward younging hot spot track that extends to the Mount Isa Inlier. At circa 1590–1550 Ma, arc magmatism resumed along the northern margin of the Gawler Craton and the rest of eastern Australia records a 90° shift in the regional shortening direction related to activity along the eastern margin of the Australian continent. A plume‐modified orogenic setting satisfies all of the spatial and temporal relationships between magma generation and orogenic activity. In this model, the Gawler Craton and the adjacent subduction zone migrated over a mantle plume (circa 1620–1610 Ma). Resultant flat subduction caused transient orogenesis (1610–1595 Ma) in the overriding plate. Slab delamination and thermal assimilation of the plume and the subducting slab caused a switch to crustal extension in the overriding plate, resulting in extensive mantle‐derived and crustal melting in the Gawler Craton (1595–1575 Ma).

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Section: End‐member Tectonic Modelsmentioning

confidence: 99%

Mesoproterozoic plume‐modified orogenesis in eastern Precambrian Australia

et al. 2009

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“…However, major uncertainties remain regarding the pre-1.8 Ga crustal architecture and nature of the basement in each of the three belts, and the nature of the tectonic setting that led to and prevailed during the amalgamation of the fold belts. Previous studies have highlighted differences in crustal architecture between the Western and Eastern Fold Belts, and various models to explain these differences have been proposed MacCready et al 1998;MacCready 2006). These include (i) the presence of a mafic underplate, or subduction of oceanic crust, beneath the Western Fold Belt, (ii) the presence of thick basaltic horizons within the supracrustal succession in the Eastern Fold Belt, or (iii) the emplacement of mafic intrusions along a decollement that once separated the Western from the Eastern Fold Belt.…”

Section: Introductionmentioning

confidence: 99%

Pre-1.8 Ga tectono-magmatic evolution of the Kalkadoon–Leichhardt Belt: implications for the crustal architecture and metallogeny of the Mount Isa Inlier, northwest Queensland, Australia

Bierlein

Maas

Woodhead

2011

Australian Journal of Earth Sciences

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“…The Mount Isa terrane (Figures 1, 12) forms a crustal fragment amalgamated with the North Australian Craton during the Paleoproterozoic (Spikings et al 2001;Bierlein & Betts 2004;Betts et al 2006;Giles et al 2006;MacCready 2006). Some authors suggested that a crust of Precambrian age lies in the sub-surface of the Thomson Orogen (Henderson 1980;Murray 1990;Wellman 1990;Glen 2005;Glen et al 2006;Fergusson et al 2007aFergusson et al , 2009.…”

Section: Thomson Orogen Vs Mount Isa Terranementioning

confidence: 92%

“…The Eastern Fold Belt accommodated W-directed tectonic transport above the crystalline basement rock during the Mesoproterozoic, whereas the Western Fold Belt shows E-directed deformations that affect the basement crust (O'Dea et al 1997b;Betts et al 2006;MacCready 2006). The Thomson Orogen instead is characterised by prominent W-and Sdipping structures that affect the entire crust.…”

Section: Thomson Orogen Vs Mount Isa Terranementioning

confidence: 96%

“…The Mount Isa terrane can be divided in two broad tectonic domains showing contrasting tectonic styles and heterogeneous depositional sequences (Blake 1987;Wellman 1992;O'Dea et al 1997a, b;Betts et al 2006;MacCready 2006;Foster & Austin 2008). The Eastern Fold Belt accommodated W-directed tectonic transport above the crystalline basement rock during the Mesoproterozoic, whereas the Western Fold Belt shows E-directed deformations that affect the basement crust (O'Dea et al 1997b;Betts et al 2006;MacCready 2006).…”

Section: Thomson Orogen Vs Mount Isa Terranementioning

confidence: 96%

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Crustal architecture of the Thomson Orogen in Queensland inferred from potential field forward modelling

Spampinato

Aillères

Betts

et al. 2015

Australian Journal of Earth Sciences

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The basement rocks of the poorly understood Thomson Orogen are concealed by mid-Paleozoic to Upper Cretaceous intra-continental basins and direct information about the orogen is gleaned from sparse geological data. Constrained potential field forward modelling has been undertaken to highlight key features and resolve deeply sourced anomalies within the Thomson Orogen. The Thomson Orogen is characterised by long-wavelength and low-amplitude geophysical anomalies when compared with the northern and western Precambrian terranes of the Australian continent. Prominent NE-and NW-trending gravity anomalies reflect the fault architecture of the region. High-intensity Bouguer gravity anomalies correlate with shallow basement rocks. Bouguer gravity anomalies below À300 mm/s 2 define the distribution of the Devonian Adavale Basin and associated troughs. The magnetic grid shows smooth textures, punctuated by short-wavelength, high-intensity anomalies that indicate magnetic contribution at different crustal levels. It is interpreted that meta-sedimentary basement rocks of the Thomson Orogen, intersected in several drill holes, are representative of a seismically non-reflective and non-magnetic upper basement. Short-wavelength, high-intensity magnetic source bodies and colocated negative Bouguer gravity responses are interpreted to represent shallow granitic intrusions. Long-wavelength magnetic anomalies are inferred to reflect the topography of a seismically reflective and magnetic lower basement. Potential field forward modelling indicates that the Thomson Orogen might be a single terrane. We interpret that the lower basement consists of attenuated Precambrian and mafic enriched continental crust, which differs from the oceanic crust of the Lachlan Orogen further south.

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Structural cross-section based on the Mt Isa deep seismic transect

Cited by 21 publications

References 15 publications

Mesoproterozoic plume‐modified orogenesis in eastern Precambrian Australia

Mesoproterozoic plume‐modified orogenesis in eastern Precambrian Australia

Pre-1.8 Ga tectono-magmatic evolution of the Kalkadoon–Leichhardt Belt: implications for the crustal architecture and metallogeny of the Mount Isa Inlier, northwest Queensland, Australia

Crustal architecture of the Thomson Orogen in Queensland inferred from potential field forward modelling

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