Tectonic feedback, intraplate orogeny and the geochemical structure of the crust: a central Australian perspective

Sandiford, Mike; Hand, Martin; McLaren, Sandra

doi:10.1144/gsl.sp.2001.184.01.10

Cited by 59 publications

(49 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sites of intracontinental subsidence are sites of thermal and/or rheological weakening that can be reactivated during compression, often in response to far-field stresses (see Sandiford et al 2001). Examples include the late Mesoproterozoic to early Neoproterozoic successions in the North Atlantic , and the Neoproterozoic Centralian Supergroup of Central Australia, which was deformed during the late Neoproterozoic Peterman and Palaeozoic Alice Springs orogenies (Collins & Teyssier 1989;Walter et al 1995;Sandiford & Hand 1998;Hand & Sandiford 1999;Cawood & Korsch 2008).…”

Section: Classification Of Orogens In Space and Timementioning

confidence: 99%

Accretionary orogens through Earth history

et al. 2009

View full text Add to dashboard Cite

Accretionary orogens form at intraoceanic and continental margin convergent plate boundaries. They include the supra-subduction zone forearc, magmatic arc and back-arc components. Accretionary orogens can be grouped into retreating and advancing types, based on their kinematic framework and resulting geological character. Retreating orogens (e.g. modern western Pacific) are undergoing long-term extension in response to the site of subduction of the lower plate retreating with respect to the overriding plate and are characterized by back-arc basins. Advancing orogens (e.g. Andes) develop in an environment in which the overriding plate is advancing towards the downgoing plate, resulting in the development of foreland fold and thrust belts and crustal thickening. Cratonization of accretionary orogens occurs during continuing plate convergence and requires transient coupling across the plate boundary with strain concentrated in zones of mechanical and thermal weakening such as the magmatic arc and back-arc region. Potential driving mechanisms for coupling include accretion of buoyant lithosphere (terrane accretion), flat-slab subduction, and rapid absolute upper plate motion overriding the downgoing plate. Accretionary orogens have been active throughout Earth history, extending back until at least 3.2 Ga, and potentially earlier, and provide an important constraint on the initiation of horizontal motion of lithospheric plates on Earth. They have been responsible for major growth of the continental lithosphere through the addition of juvenile magmatic products but are also major sites of consumption and reworking of continental crust through time, through sediment subduction and subduction erosion. It is probable that the rates of crustal growth and destruction are roughly equal, implying that net growth since the Archaean is effectively zero.Classic models of orogens involve a Wilson cycle of ocean opening and closing with orogenesis related to continent-continent collision. These imply that mountain building occurs at the end of a cycle of ocean opening and closing, and marks the termination of subduction, and that the mountain belt should occupy an internal location within an assembled continent (supercontinent). The modern Alpine -Himalayan chain exemplifies the features of this model, lying between the Eurasian and colliding African and Indian plates (Fig.

show abstract

Section: Classification Of Orogens In Space and Timementioning

confidence: 99%

Accretionary orogens through Earth history

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Subsidiary, milder extensional episodes are reflected in changes in the depocentres up until the early Ordovician (e.g., Shaw et al 1991). Relatively new data from sediment provenance studies (Comacho et al 2002) shed important further light on the original extent of these extensional Sandiford et al (2001). Within the basement inliers we can distinguish two distinct types of terrane: (1) gneissic granite terranes that form the peripheral regions of the inliers and which are unconformably overlain by the sediments in the basins; (2) depleted granulite terranes that define the cores of the inliers and which are tectonically juxtaposed with the gneissic granite terranes.…”

Section: Styles Of Inversion In Naturementioning

confidence: 99%

Lower crustal rheological expression in inverted basins

Sandiford

Hansen

McLaren

2006

View full text Add to dashboard Cite

Although lithospheric modelling has provided extraordinary insights into the processes that shape the continental crust, considerable uncertainty surrounds the basic rheology that governs behaviour at geological timescales. In part, this is because it has proved difficult to identify the geological observations that might discriminate, or unify, models of lithospheric rheology. In particular, the relative strength of lower crust and upper mantle remains a contentious aspect of continental lithospheric rheology. We show that various models for lower crustal rheology may produce distinct patterns of inversion in extensional sedimentary basins, consistent with some of the observed natural variability of inversion styles. Inversion of basin interiors, as is common in European Mesozoic basins, is favoured by a lithospheric rheology more sensitive to lateral thermal structure than to changes in the depth of the Moho, consistent with there being little strength contrast between the lower crust and upper mantle in these settings. In contrast, inversion of basin margins, particularly involving basinward verging structures, is consistent with a rheological sensitivity to the depth of Moho as would apply for a lower crust much weaker than the upper mantle. We use an example from central Australia to demonstrate this later response, together with thermochronologic data that suggests that a relatively weak lower crust in this setting may reflect abnormally high geothermal gradients.

show abstract

“…One consequence of this denudation was the exhumation of an orogenic core comprising older, higher-grade metamorphic rocks. This high-grade core comprises both ma¢c and felsic granulites that are readily distinguished from mid-crustal granite-dominated terranes that immediately underlie the Centralian Superbasin sediments along the margin of the Arunta Inlier in terms of their radioelement concentrations ( [10], Fig. 4).…”

Section: The Asomentioning

confidence: 99%

“…4). Typical heat production rates for the highgrade core are 6 1^1.5 WW m 33 whereas the marginal granitic terranes have characteristic heat production rates of 3^5 WW m 33 , with some individual granites having heat production rates in excess of 10 WW m 33 [10]. This granitic layer has been estimated to contribute approx.…”

Section: The Asomentioning

confidence: 99%

“…The proposed mechanism relates to the way deformation and associated denudation has redistributed crustal radiogenic heat sources, thereby leading to changes in lithospheric thermal regimes. This mechanism is only likely to provide a viable mechanism for locking-in the extraordinary gravity anomalies if the thermal structure of the orogen was able to adapt to the redistribution of heat sources during the deformation [10]; as would apply if it were deformed at a low Pe T (Pe T 6 1). This paper reviews evidence for the time-integrated deformation rates associated with the ASO, suggesting that it did indeed evolve as a low-Pe T orogen, and brie£y explores the implications of this hypothesis for the notions of lithospheric strength.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation