The NW–SE-trending Nagavali–Vamsadhara Shear Zone (NVSZ) in the central Eastern Ghats Mobile Belt (EGMB) is a discrete transverse structure that cuts across the regional EGMB fabric along India’s east coast and is interpreted as a major crustal discontinuity with counterparts in East Antarctica. We use both regional and detailed gravity and magnetic datasets (including approximately 1000 newly collected data points) to understand the scale and subsurface crustal architecture beneath the NVSZ and surrounding areas. We have modelled the crust across the NVSZ using joint gravity and magnetic modelling along three selected profiles to better understand the subsurface crustal architecture below the NVSZ. The jointly interpreted gravity and magnetic maps reveal that: (1) the NVSZ is characterised by subdued magnetic signatures, while gravity anomalies closely align with the exposed lithological units; (2) The relatively subdued magnetic response of the Nagavali Shear Zone (NSZ) and Vamsadhara Shear Zone (VSZ) contrasts other shear zones within the EGMB, which exhibit distinct magnetic anomalies, indicating fundamental differences in their magnetic properties and/or structural evolution; (3) The geophysical anomaly patterns suggest that the younger granitoid gneisses overprint the pre-existing charnockite and khondalite rocks; and (4) The NSZ and VSZ are interpreted as mid-crustal faults, while the lower crust beneath them behaves as a coherent single layer in the modelled profiles. Their geometry, together with the arcuate charnockite belts flanking granitoid gneiss, indicates development under an extensional regime that bent these belts, with subsequent repeated reactivation across multiple supercontinent cycles.

In the passive margin of southeast Australia, a mosaic of tectonic structures of the Otway Basin records the protracted Cretaceous to Eocene break-up evolution of Australia and Antarctica. Here, we use an innovative approach that combines Euler deconvolution and DBSCAN clustering of global magnetic data and drill-hole-constrained interpretations of deep 2D seismic traverse to image deep-rooted, pre-rifting basement crustal structures now covered by passive margin basins. The method is used to identify the complex network of Early Paleozoic faults that were reactivated and transformed into major basing-bounding listric faults during Cretaceous rifting. Major faults identified include the Bambra, Avoca, Yarramyljup, and Moyston faults. The Yarramyljup and Moyston faults segmented the Cretaceous Otway Basin, demonstrating how basement lithospheric heterogeneities can influence basin development. Our analysis also redefines the northwest margin of the Proterozoic VanDieland microcontinent. This microcontinent acted as a rigid crustal block during the Cretaceous extension and influenced the geometries of the passive margin basin depocenters. These insights transform our understanding of the crustal architecture and structural inheritance in the tectonic evolution of southeast Australia and establish a template for imagining deep crustal structures elsewhere.

Pranhita-Godavari (PG) Basin is an inter-cratonic failed rift basin between the Dharwar and Bastar cratons in the Southern Indian Shield. Previous studies reveal an unusually thick crust beneath it with high surface heat flow, a characteristic uncommon in inter-cratonic failed rift basins. To understand this uncommon phenomena, we carry out the aeromagnetic and Bouguer gravity data interpretation of the PG Basin constrained by seismic and seismological data. The Bouguer gravity anomaly highs on either side of the basin reflect crustal extension of the Karimnagar Granulite Belt (KGB) and Bhopalpatnam Granulite Belt (BGB). The Moho depth map, derived from constrained 3-D gravity inversion, shows depth variations between 35 and 47 km in the region. Additionally, the estimated Curie depths from aeromagnetic anomaly data vary between 22 and 30 km, with shallower depths (similar to 22-26 km) beneath the basin, and reconcile with the observed higher heat flow in the region. The crustal model reveals: i) a normal crustal thickness below the PG Basin; ii) a high-density lower crustal body (similar to 3.05 gm/cc) within the basin; iii) high-density, upper-mid crustal bodies interpreted as granulitic rocks (KGB and BGB) exhibit increased magnetisation at the margins of the PG basin. Both the KGB and BGB thicken with depth beneath the PG Basin before rapidly thinning-resembling boudinage beneath the basin depocenter. Both KGB and BGB represent once continuous package of granulite rocks. The thinning of granulite package is related to crustal thinning associated with rift formation and the development of PG Basin.

The Mesoproterozoic rocks of the Krishna Province in the Eastern Ghats Mobile Belt are situated at the edge of the Indian interior cratons and the mobile belts along the edge. We use newly acquired high-resolution gravity and magnetic along with the regional geophysical data to delineate the faults, lineaments, and subsurface boundaries between the various domains of the Krishna Province. We use this data to forward model the crustal architecture below these terranes. Our analysis shows that the Ongole domain rocks are continuing further southwards up to the Nellore and below the K–G Basin on the north side at subsurface levels. The Vinjamur and Udayagiri domains of the Krishna Province are merged into a single narrow belt known as the Nellore–Khammam Schist Belt. The joint 2D modelling of the gravity and magnetic data across these domains reveals two easterly dipping parallel thrusts separating the Dharwar–Nellore–Khammam Schist Belt and Nellore–Khammam Schist Belt–Eastern Ghats Mobile Belt, respectively. The interpreted suture between the Nellore–Khammam Schist Belt and Ongole domain of EGMB is characterized by the ophiolite and alkaline complexes of Mesoproterozoic ages. We propose that the collision between the Krishna Province and Indian Cratons occurred during the Nuna amalgamation.

We present a novel approach that determines the location and dip of geologic structures by clustering Euler deconvolution depth solutions using Density-Based Spatial Clustering Applications with Noise (DBSCAN). This method and workflow rely on the association of changes in the location and relationships between Euler depth clusters and cluster boundaries with changes in rock susceptibility. We applied our method to global magnetic and high-resolution aeromagnetic datasets over Phanerozoic-Precambrian zone-bounding faults in west and central Victoria. The architecture of these structures at different scales from this imaging technique is comparable to interpreted 2D seismic reflection data. The results from the global magnetic data resolved the architecture of these structures below 5 km, while the aeromagnetic data used were limited to structural information of faults above 2 km depth. Therefore, this method shows the structural relationship of the west-dipping Avoca Fault that soles into the east-dipping Moyston Fault at a depth of similar to 22 km in central Victoria and at a shallower depth of similar to 15 km southward beneath the Quaternary basaltic rocks of the Newer Volcanic Province. In the vicinity of the Heathcote Zone, the method resolves the location, dip, and overprinting relationship between faults and extrusive rocks, such as the relationship between the Heathcote and Mount William Faults and the granitic Cobaw Batholith. We show how combining magnetic data at various scales can track faults from the near-surface to deeper roots while avoiding possible over-interpretation. We demonstrate how to optimise the DBSCAN parameters and a sensitivity analysis of how to determine clusters and cluster boundaries that are geologically relevant in the absence of geological constraints. Our technique provides an effective and rapid tool for imaging structures and can supplement complex and expensive imaging techniques to resolve the architecture of structures in complex geologic terrains.

The Pacific Plate underwent a significant change in motion during the early Eocene. This change has been linked to plate boundary reconfiguration, particularly in relation to subduction margins. The reconfiguration also resulted in a new Pacific-Australian plate boundary section transecting Zealandia. Following the Eocene transition, the relative rotation axis was located within continental Zealandia, and it has been hypothesized that this region acted as a pivot point. Here we investigate the extent to which collision resistance along the intra-continental Zealandia margin (length similar to 1,000 km) might have impacted the motion of the Pacific Plate, which is characterized by trench lengths more than an order of magnitude greater. We first highlight the relatively large radial component in the Pacific Plate absolute rotation during the period ca. 47 and 32 Ma (i.e., the spin around the plate centroid axis). We then consider how parameterized plate boundary forces impact the tangential and radial components of the net torque (i.e., the fictitious and true torque components). We show that during this period, both the Zealandia and Izu-Bonin-Marianas (IBM) margins of the Pacific Plate were well-oriented in terms of partitioning boundary normal forces into counter-clockwise (CCW) radial torques. This analysis is supported by results from recent global-scale numerical models. The role of Zealandia cannot be established unambiguously, based on our analysis, but effects can be quantified under different assumptions. Collision resistance along the Zealandia margin could plausibly constitute a "first order" effect on Eocene Pacific Plate rotation, albeit only on the radial component. During the Eocene tectonic reorganization, the Pacific Plate rotation vector developed increased radial component (spin around the centroid) The geometry of both the Zealandia and Izu-Bonin-Marianas (IBM) margins would have facilitated strong radial torque partitioning of plate boundary normal forces Global-scale numerical models support our geometric analysis, particularly in terms of the role of theIBM margin

This review aims to bridge the knowledge gap between geological and geophysical communities by elucidating the interpretation of aeromagnetic data. Aeromagnetic surveys measure the Earth's magnetic field variations and provide critical insights into subsurface geology, including basins, stratigraphy, igneous rocks and structural geology. The magnetic properties of rocks make these datasets valuable for identifying anomalies associated with various rock types and their magnetic responses. However, interpreting aeromagnetic data is complex due to the diverse geological processes that influence the formation and distribution of magnetic minerals, which must then be correlated with geological phenomena and features. Despite improved data accessibility and processing, many geoscientists still find interpreting aeromagnetic data challenging, resulting in a shortage of skilled expertise for research and industry applications. Accurate interpretation necessitates a thorough understanding of data collection and processing, recognising both the insights and limitations of the methods used and understanding how data resolution impacts the scale of interpretable geological features. This review is intended to assist those grappling with these challenges and to aid the geophysical community in interpreting complex geological features.Data treatment is explained with a focus on the reasons for specific processing methods rather than their mathematical foundations. Emphasis is placed on rock properties and their influence on aeromagnetic data expressions. The aeromagnetic expressions of common geological elements, including sedimentary, igneous, and metamorphic rocks, and their structures, such as stratigraphy and structural geometries related to folding and faulting, are explored. The discussion covers how these responses arise and how to identify them. Our explanations aim to bolster confidence in data interpretation for geologists new to aeromagnetic data and geophysicists who may not regularly interpret geological information from such data.Finally, we present strategies and pitfalls for interpreting aeromagnetic data, discuss automated interpretation methods, and offer practical guidance to improve interpretation skills and outcomes.

Continuous Proterozoic plate reconstructions consistent with plate geodynamics were designed to reconcile data, conceptual models, and human imagination as applied to the assembly of the Australian craton. The reconstructions were created using GPlates and considered available magmatic and metamorphic UPb zircon data. Two tectonic scenarios for the Paleo- to Mesoproterozoic assembly of the cratonic lithosphere of Australia were tested for their geodynamic and geochronological viability. The scenarios are founded on tectonic events that are relatively well -established and well -supported by data, but also with several periods and areas that are disputed mostly due to scarcity of data. For these scenarios, we test geodynamic criteria to explore a) which possibilities are better supported by our geodynamic criteria, and b) the implications of those models for the larger -scale plate tectonic setting. The time frame in this model set includes assembling two supercontinents, Nuna (1900-1800 Ma) and Rodinia (1300-900 Ma), and the transition between them. Model 1 presents a progressive assembly of the Australian continent between 2000 Ma and 1300 Ma, showing events in the West Australian Craton (WAC), the convergence of the WAC and the North Australian Craton (NAC), and then accretion at the margin of the South Australian Craton and NAC until collision in the Albany -Fraser Orogen (AFO). Model 2 suggests WAC was separate from the rest of the Australian Craton until 1300 Ma and all combined in one orogenic cycle. It proposes Andean -type subduction along the E and NE margins of the WAC for 40-60 million years as the means of final assembly. Both models are geodynamically plausible, yet each lacks sufficient data support to conclusively resolve the differences and deepen our understanding of the Proterozoic assembly of Australia. (c) 2024 The Author(s). Published by Elsevier B.V. on behalf of International Association for Gondwana Research. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

Geophysical interpretation and modelling of the poorly exposed Proterozoic basement rocks of the Tennant Creek Block in the North Australian Craton elucidated the distribution, location, connectivity, and overprinting relationships of regional faults. The prominent structural grain within the basement comprises west-northwest-striking faults that commonly bound geophysically defined domains of the Warramunga Formation and felsic plutons of the Tennant Creek Supersuite. Constrained by seismic reflection data, forward models of gravity and magnetic data identified several faults as major structures that link into a shallow south-dipping structure at approximately 20 km depth. The modelling also reveals a 20 km wide and 14 km southward deepening half-graben bounded by a northeast dipping normal fault. The half-graben forms a sub-basin filled with the Ooradidgee Group at the top of the basement stratigraphy. The west-northwest-trending structural grain of the basement is not reflected in the Tomkinson Creek Group in the overlying younger basin. The younger basin has dominant north-oriented faults and basement highs. This suggests basement structures had limited influence in controlling the evolution of younger basins in this region. Our approach has wider relevance, addressing similar challenges encountered in other cratonic areas globally, such as India and Africa, where sedimentary cover obscures critical aspects of basement architecture and tectonic evolution. This underscores the broader significance of our methodology in advancing the understanding of Precambrian terranes.

<p>The inversion of rift basins is commonly associated with the reactivation of normal, basin-bounding faults or shear zones. Analogue models have shown how the reverse reactivation of these pre-existing structures facilitates the uplift of a basin’s sedimentary infill. However, few of these models examine the viscous processes occurring beneath the brittle crust, which may or may not drive basin inversion. In our study, we use lithospheric-scale analogue experiments of orthogonal extension followed by shortening to simulate rifting followed by inversion and orogenesis. Here we explore how the flow behaviours of ductile layers underneath rift basins promote or suppress basin inversion.</p> <p>In our experiments, we simulate rifting by extending a multi-layer, brittle-ductile lithosphere which floats on a fluid asthenosphere, creating a system of distributed basins. This extension is followed by shortening of the model, during which strain is accommodated by the reactivation of basin-bounding faults and folding or upwelling of the ductile layers. These experiments reveal that the rheology of the ductile lower crust and lithospheric mantle, modulated by the imposed bulk strain rate, determine: (1) how rift basins are distributed during extension and (2) whether all or only some of these basins are inverted during shortening. We interpret that this selective basin inversion is related to the superposition of crustal-scale and lithospheric-scale boudinage during the basin-forming extensional phase. Our findings demonstrate that lithospheric-scale analogue models can be a powerful tool for investigating the interaction between brittle and viscous deformation during basin inversion.</p>

Abstract. Basin inversion is commonly attributed to the reverse reactivation of basin-bounding normal faults. This association implies that basin uplift and inversion-related structures are mainly controlled by the frictional behaviour of pre-existing faults and associated damage zones. In this study, we use lithospheric-scale analogue experiments of orthogonal extension followed by shortening to explore how the flow behaviour of ductile layers underneath rift basins promote or suppress basin inversion. Our experiments show that the rheology of the ductile lower crust and lithospheric mantle, modulated by the imposed bulk strain rate, determine (1) basin distribution in a wide rift setting and (2) strain accommodation by fault reactivation and basin uplift during subsequent shortening. When the ductile layers deform uniformly during extension (i.e. stretching) and shortening (i.e. thickening), all of the basins are inverted. When deformation in the ductile layers is localised during extension (i.e. necking) and shortening (i.e. folding), only some basins – which are evenly spaced apart – are inverted. We interpret the latter as selective basin inversion, which may be related to the superposition of crustal-scale and lithospheric-scale boudinage during the previous basin-forming extensional phase and/or folding of the ductile layers during shortening.

Craton margins undergo intense deformation influenced by the pre-existing crustal and lithospheric architecture, rheology, and far-field kinematics. The role of rheological contrasts and weak zones at the edge of the craton has been discussed, but it is unclear whether deformation in the upper crust is influenced by the geometry of the craton margin itself (i.e., whether the margin dips towards or away from the interior of the craton). Our analogue experiments are aimed at studying the influence of craton margin geometry on structures formed during rifting and inversion, as craton margins are prone to reworking and reactivation during superimposed tectonic events.The experiments are designed based on the geometries of the eastern and southern margins of the North Australian Craton which has experienced multiple stages of extension and shortening. The inward vs. outward dipping craton margins in these areas were interpreted from crustal-scale seismic reflection data. In our experiments, we see that strain and deformation style varies with proximity to the craton margin. During the extensional phase of both inward and outward dipping experiments, we observe that rifts are mainly formed by boudinage and necking in the lower crust. The inward dipping model prevents the propagation of a major normal fault at the margin, resulting in a number of smaller faults. Subsequent shortening of the inward dipping model results in modest basin inversion above the craton margin, suggesting that the majority of strain is accommodated by reactivation of normal faults away from the margin. In contrast, the outward dipping model shows the propagation of a single major normal fault along the craton margins, leading to significant thinning of the lower crust. A major rift is also being formed away from the craton margin in this model. Inversion of the outward dipping craton margin model shows more intense inversion at the margin compared to the inward dipping model, with lower strain and smaller reactivation of normal faults away from the margin. We can therefore conclude that the geometry of a craton margin exerts a first-order control on the deformation of the upper crust during rifting and subsequent inversion.

The North Australian Craton is a significant crustal element of the Australian continent. In this review, we focus on the internal architecture of the North Australian Craton by reviewing the tectonic evolution of basement exposures in the Pine Creek, Tanami, Tennant Creek, Arnhem, and Mount Isa blocks, which we refer to as the proto-North Australian Craton. These sparsely exposed basement blocks are extensively overlain by Late Paleoproterozoic to Mesoproterozoic sedimentary basins. We assess the differences and similarities in magmatism, basin systems, and deformation events of pre-1800 Ma rocks. We reviewed UPb inherited zircon ages older than 1900 Ma together with Nd geochemical data for pre-1800 Ma magmatic rocks which show that the interior of proto-North Australian Craton is largely homogenous with indistinguishable isotopic and geochemical characteristics of ca 1870–1840 Ma magmatic rocks and similar ca 2050–1870 Ma structural patterns. There are notable differences in deformation styles, metamorphism, and structure trends in the interior of North Australian Craton highlighting the presence of some localized crustal-scale discontinuities and evidence of crustal reworking. We identify several crustal boundaries within individual terranes, whose continuity across the proto-North Australian Craton is often masked by overlying basins.

East Antarctica along with Greater India played a vital role in the accretion and breakup of the Indo-Antarctic landmasses during the supercontinents Nuna, Rodinia and Gondwana. Without geophysical potential field methods, interpreting the architecture of the ice-covered geological provinces of Antarctica is impossible. We present here a crustal element map of East Antarctica between Enderby Land and Princess Elizabeth Land (Indo-Antarctica tectonic element) using aerogeophysical data interpretation. The data reveal distinct anastomosing geophysical provinces that correlate with sparse geological data. Our crustal element map shows the Oygarden Province and the Northern and Southern Rayner provinces are arcuate belts that wrap around the Archean Napier Province. These provinces represent the remnants of an accretionary tectonic margin, which evolved between ca 1300 Ma and 900 Ma. The arcuate geometry of these Meso- to Neoproterozoic provinces formed during the collision with the Napier Province, which represents a microcontinent. This collision triggered widespread extension and ultra-high temperature metamorphism in the Northern and Southern Rayner provinces. The southernmost provinces include the Fisher Province, Lambert Province and a transition zone. The provinces are truncated by a suture zone with the Archean Ruker Province, following north-dipping subduction during the Meso- to Neoproterozoic. Our interpretation provides a template upon which to correlate geological provinces with the terranes on the conjugate eastern Indian margin.

The Red Sea provides an opportunity to study the processes during the transition from continental rifting to early-stage seafloor spreading during ocean initiation. We delineate variations of lithospheric architecture and the nature of extension along the Red Sea region through joint interpretation of gravity and geoid anomalies and gravity-topography transfer functions. We use lithospheric-scale models to compare stretching factors with upper mantle gravity anomaly, residual mantle Bouguer anomaly, and effective elastic thickness. Based on our observations, the Red Sea is divided into four segments; each having distinct lithospheric characteristics and stretching styles. These are: (i) southernmost Red Sea and Danakil having regionally weak and stretched lithosphere, (ii) southern Red Sea with fully developed seafloor spreading and asymmetric lithospheric architecture, (iii) central Red Sea having discontinuous magma accretion with newly formed seafloor spreading, and (iv) northern Red sea with a stronger lithosphere and limited stretching revealing a stage of continental rifting. In these segments, lithospheric stretching correlates with regions of weak lithosphere, including a regime of sublithospheric plume channel beneath the southern Red Sea. The Zabargad fracture zone between the central and northern segments is revealed as a major lithosphere-scale boundary that may act as a barrier to the propagation of seafloor spreading into the northern Red Sea. The weak and highly stretched lithosphere in this region may indicate the onset of a new spreading cell. Our results conclude that the evolution of the Red Sea is more complex than the previously suggested kinematic models of simple "unzipping" and illustrate that several extensional styles can exist within different segments during the initial stages of ocean formation.

V. S. Gokul 1,2,3., K. M. Sreejith4., G. Srinivasa Rao 5., M. Radhakrishna 1*., P. G. Betts 21 Department of Earth Sciences, Indian Institute of Technology Bombay, Mumbai 400 076, India.2 School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria 3800, Australia.3 IITB-Monash Research Academy, Indian Institute of Technology Bombay, Mumbai 400 076, India.4 Geosciences Division, Space Applications Centre, Ahmedabad 380 015, India.5 Department of Applied Geophysics, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad 826 004, India (*Corresponding author:gokul.vs@monash.edu)AbstractThe Indian Ocean has the largest geoid anomaly, known as the Indian Ocean Geoid Low (IOGL). This long wavelength geoid depression has a magnitude of negative 106 m, and is centered south of India. The nature and depth of the sources causing this characteristic low are poorly constrained and has been the subject of debate. In this abstract, we focus on understanding the density contributions to the geoid low from the crust and upper mantle using joint analysis of geoid and gravity data along with published tomographic models in the region. Decomposition of geoid anomalies in the spectral domain indicate that mass anomalies below the upper mantle (> 700 km) contribute to 90% of the total geoid anomaly. In order to compute the upper mantle contribution to the IOGL, we used the Moho geometry and the crustal density structure from the 3-D gravity inversion, and the SL2013sv tomography model for the upper mantle density structure. The presence of density sources, which was not resolved in the modeling within the sub-lithospheric mantle is confirmed upon comparing the crustal and upper mantle (up to 700 km) geoid response below the IOGL with n=10 residual geoid anomaly. Integrated gravity-geoid 2-D modeling of the geometries of the anomalous sources located at the base of LAB and at a depth of 320-340 km, respectively, confirms that the contribution of density structures up to 700 km explains only the ten percent of the IOGL which matches well with the spectral decomposition results. This suggests that the lower mantle sources, such as paleo-subducted slabs or plume sources from the core-mantle boundary significantly contributes to the IOGL.

The Afar region presents a unique example of a juvenile R‐R‐R triple junction with the arms evolved to various stages of maturity. The lithosphere in this area has been modified heterogeneously by the nearby Afar mantle plume. To gain a comprehensive and consistent understanding of the link between crustal geometry and geodynamics of the region and facilitate comparisons across different tectonic elements, we developed a high‐resolution crustal thickness map of the region that resolves major tectonic features. The calculation involved a well‐constrained 3‐D inversion of upper mantle‐corrected crustal Bouguer gravity anomalies computed with the help of tomography‐derived densities. Our results match earlier localized crustal thickness estimates, illustrating the method's efficacy. A thinner crust (∼20–26 km) is revealed in the Afar compared to adjacent continental regions. The Main Ethiopian Rift has the thickest crust in the central part of the rift (∼38–40 km) and thinner to the north (∼30 km) and south (∼35 km). The crustal thickness along the Gulf of Aden changes from east (∼5 km) to west (∼17 km) in the west, consistent with a westward transition from seafloor spreading to continental rifting. The southern Red Sea is characterized by asymmetric crustal thickness, with a thicker crust (∼17 km) on the eastern flank compared to the western flank (∼11 km), which we attribute to the influence of a sub‐lithospheric channel from the Afar mantle plume. We propose a model describing the channel leading to asymmetric features of the southern Red Sea, such as crustal accretion, marginal topography, and volcanism.

Analogue models are powerful tools for investigating extensional and convergent tectonic processes in 4D and at multiple scales. However, rarely do we introduce two successive phases of tectonism in a single analogue experiment to study the interaction between structures from two kinematically distinct tectonic events. Here we showcase a series of analogue experiments in which lithospheric-scale models are extended and subsequently shortened, simulating rifting followed by inversion and mountain building. In our experiments, we simulate rifting by extending a multi-layer, brittle-ductile model lithosphere; this initial model is analogous to a hot, thickened lithosphere immediately after orogenesis. We demonstrate that the absence or presence of a narrow, pre-existing weakness in the lithospheric mantle results in end-member models of either wide or narrow rifting, respectively. Extension is immediately followed by shortening of the model, where we observe that contractional structures are localised along pre-existing rift basins. Analyses of particle imaging velocimetry (PIV) data reveal that shortening is accommodated by several mechanisms, including reverse reactivation of normal faults and buckling and/or inversion within pre-existing basins. We also show that these findings are consistent with field and geophysical observations from northern Australia as well as previous numerical experiments.