Biography:

In the past J.J. Veevers has collaborated on articles with W.D. Roots and D.A. Falvey. One of their most recent publications is Lithospheric model with thick oceanic crust at the continental boundary: A mechanism for shallow spreading ridges in young oceans. Which was published in journal Earth and Planetary Science Letters.

More information about J.J. Veevers research including statistics on their citations can be found on their Copernicus Academic profile page.

J.J. Veevers's Articles: (12)

Lithospheric model with thick oceanic crust at the continental boundary: A mechanism for shallow spreading ridges in young oceans

AbstractIn a general lithospheric model of a simple divergent ocean and continental margin that satisfies the constraints of isostasy and gravity anomalies, the free-air gravity anomaly at the margin is modelled by an oceanic crust that thickens exponentially toward the margin from its common value of 6.4 km about 600 km from the margin to 17.7 km at the margin; this postulated thickening is supported empirically by seismic refraction measurements made near continental margins. The thickness of the oceanic crust matches that of the continental lithosphere at breakup, as observed today in Afar and East Africa, and is interpreted as the initial oceanic surface layer chilled against the continental lithosphere. With continued plate accretion, the chilled oceanic crust thins exponentially to a steadystate thickness, which is achieved about 40 m.y. after breakup. These findings contrast with the generally held view that the oceanic crust has a uniform thickness.During the first 40 m.y. of spreading, the thicker oceanic crust, of density 2.86 g/cm3, displaces the denser (3.32 g/cm3) subjacent material; by isostasy, the spreading ridge and the rest of the seafloor thus stand higher in younger( <40m.y.) oceans than they do in older(>40m.y.) oceans. This is postulated to be the cause of the empirical relationship between the crestal depth of spreading ridges and the age (or half-width) of ocean basins.

Physiography of the Exmouth and Scott Plateaus, Western Australia, and adjacent northeast Wharton Basin

AbstractThe continental margin of Western Australia is a rifted or “Atlantic”-type margin, with a complex physiography. The margin comprises a shelf, an upper and lower continental slope, marginal plateaus, a continental rise, and rise or lower slope foothills. Notches or terraces on the shelf reflect pre-Holocene deposition of prograded sediment, whose seaward limit was determined by variations in relative sea level, wave energy, and sediment size and volume. The upper continental slope has four physiographic forms: convex, due to sediment outbuilding (progradation) over a subsiding marginal plateau; scarped, due to erosion of convex slopes; stepped, due to deposition at the base of a scarped slope; and smooth, due to progradation of an upper slope in the absence of a marginal plateau. Lying at the same level as the upper/lower slope boundary are two extensive marginal plateaus: Exmouth and Scott. They represent continental crust which subsided after continental rupture by sea-floor spreading. Differential subsidence, probably along faults, gave rise to the various physiographic features of the plateaus. The deep lower continental slope is broken into straight northeasterly-trending segments, that parallel the Upper Jurassic/Lower Cretaceous rift axis, and northwesterly-trending segments that parallel the transform direction. The trends of the slope foothills are subparallel to the rift direction. The four abyssal plains of the region (Perth, Cuvier, Gascoyne and Argo) indicate a long history of subsidence and sedimentation on Upper Jurassic/Lower Cretaceous oceanic crust.

Short communicationTimor trough and australia: Facies show topographic wave migrated 80 km during the past 3 m.y.

AbstractCorrelation of seismic profiles with the Pliocene and Quaternary facies at DSDP Site 262 in the axis of the 3 km deep Timor Trough shows that Australia and the lateral facies sequence of the Timor Trough foredeep that defines a topographic wave have approached each other by 80 km during the past 3 m.y. The Timor Trough and the island of Timor have the form of a wave of amplitude 6 km and half-wavelength of 100 km; the implied uplifting of Timor as this wave and Australia approached each other is confirmed by the present elevation of autochthonous bathyal deposits on Timor. The time-transgressive depositional and deformational facies of the Timor Trough foredeep resemble those of deep-sea trenches, so that foredeeps and trenches cannot be discriminated by the surface processes that operate in them.

A revised fit of East and West Gondwanaland

AbstractRecently available evidence provides the basis for a revised fit between East and West Gondwanaland before break-up in the Late Jurassic: deep-sea drilling shows that the entire Falkland Plateau is probably underlain by continental crust, marine geophysical studies off southeast Africa indicate large areas of thinned continental or transitional crust; palaeomagnetic studies show that the western side of Madagascar lay alongside equatorial East Africa; and from the pattern of sea-floor spreading between Madagascar and India we deduce that the southern half of the western margin of India cannot have lain, as customarily shown, alongside the eastern margin of Madagascar, but must have lain farther south. This information about Madagascar provides the crucial link between East (Antarctica, Australia, India) and West (South America, Africa) Gondwanaland. The rest of East and West Gondwanaland is brought into contact so that the Falkland Plateau opposes the margin of Antarctica between 10° and 15°E and the southern part of South America fits without deformation into the Weddell Sea re-entrant of Antarctica.In terms of the continuity of geological features and the cluster of pre-break-up palaeomagnetic poles, the revised fit is at least as favourable as that of Smith and Hallam (1970). In its close match of the continental outlines and its harmony with the pattern of subsequent sea-floor spreading, the revised fit is superior to previous reconstructions.

Gondwanaland from 650–500 Ma assembly through 320 Ma merger in Pangea to 185–100 Ma breakup: supercontinental tectonics via stratigraphy and radiometric dating

AbstractGondwanaland lasted from the 650–500 Ma (late Neoproterozoic-Cambrian) amalgamation of African and South American terranes to Antarctica–Australia–India through 320 Ma (mid-Carboniferous) merging with Laurussia in Pangea to breakup from 185 to 100 Ma (Jurassic and Early Cretaceous). Gondwanaland straddled the equator at 540 Ma, lay wholly in the Southern Hemisphere by 350 Ma, and then rotated clockwise so that at 250 Ma Australia reached the S pole and Africa the equator. By initial breakup of Pangea at 185 Ma, Gondwanaland had moved northward such that North Africa reached 35°N.The first clear picture of Gondwanaland, in the Cambrian, shows the assembly of continents with later Laurentian, European and Asian terranes along the “northern” margin, and with a trench along the “western” and “southern” margins, reflected by a 10,000-km-long chain of 530–500 Ma granites. The interior was crossed by the Prydz–Leeuwin and Mozambique Orogenic Belts. The shoreline lapped the flanks of uplifts generated during this complex terminal Pan-Gondwanaland (650–500 Ma) deformation, which endowed Gondwanaland with a thick, buoyant crust and lithosphere and a nonmarine siliciclastic facies. During the Ordovician, terranes drifted from Africa as the first of many transfers of material to the “northern” continents. Central Australia was crossed by the sea, and the eastern margin and ocean floor were flooded by grains of quartz (and 600–500 Ma zircon) from Antarctica. Ice centres in North Africa and southern South America/Africa waxed and waned in the latest Ordovician, Early Silurian, latest Devonian, and Early Carboniferous.In the mid-Carboniferous, Laurussia and Gondwanaland merged in the composite called Pangea by definitive right-lateral contact along the Variscan suture, with collisional stress and subsequent uplift felt as far afield as Australia. Ice sheets developed on the tectonic uplands of Gondwanaland south of 30°S. In the Early Permian, the self-induced heat beneath Pangea drove the first stage of differential subsidence of the Gondwanaland platform to intercept sediment from the melting ice, then to accumulate coal measures with Glossopteris, and subsequently Early Triassic redbeds. An orogenic zone along the Panthalassan margin propagated from South America to Australia and was terminally deformed in the mid-Triassic. Coal deposition resumed during Late Triassic relaxation in the second stage of Pangean extension. In the Early Jurassic, the vast ∼200 Ma Central Atlantic magmatic province of tholeiite anticipated the 185 Ma breakup in the Central Atlantic. Another magmatic province was erupted at this time between southern Africa and southeastern Australia. The northeastern Indian Ocean opened from 156 Ma, and the western Indian Ocean from 150 Ma.By the 100 Ma mid-Cretaceous, the Gondwanaland province of Pangea had split into its five constituents, and the Earth had entered the thalassocratic state of dispersed continents.The 650–500 Ma “Pan-Gondwanaland” events (? by mafic underplating) rendered Gondwanaland permanently geocratic. Pangean (320–185 Ma) tectonics, driven by pulses of self-induced heat, promoted widespread subsidence at 300 Ma Early Permian and 230 Ma Late Triassic. Pangea initially broke up at 185 Ma and the five continental pieces of Gondwanaland had broken apart by the 100 Ma mid-Cretaceous.Another long-lasting feature of Gondwanaland was subduction beneath the “southern” margin and export of terranes from the “northern” and “northwestern” margins. Export of terranes was promoted by Gondwanaland-induced heat, and internal breakup by Pangea-induced heat.

U–Pb ages and source composition by Hf-isotope and trace-element analysis of detrital zircons in Permian sandstone and modern sand from southwestern Australia and a review of the paleogeographical and denudational history of the Yilgarn Craton☆

AbstractDetrital zircons from the Permian Collie Coal Measures and modern sands on the northern part of the Albany Province have been analysed for U–Pb ages by a laser ablation microprobe-inductively coupled plasma mass spectrometer (LAM-ICPMS) and for Hf-isotope compositions by a laser ablation microprobe multi-collector inductively coupled plasma mass spectrometer (LAM-MC-ICPMS). Trace elements were determined by analysis on the electron microprobe (EMP) and the ICPMS's. This combination of techniques makes it possible to determine for each grain not only the age but the nature and source of the host magma, whether crustal or juvenile mantle, and a model age (TDM) based on a depleted-mantle source, which gives a minimum age for the source material of the magma from which the zircon crystallised. The integrated analysis, applied to suites of detrital zircon, gives a more distinctive, and more easily interpreted, picture of crustal evolution in the provenance area than age data alone. Zircons from Permian and Triassic sediments already analysed for U–Pb ages by a sensitive high-resolution ion microprobe (SHRIMP) were also analysed for Hf isotopes and trace elements.Zircons from Collie and Permian and Early Triassic rocks of the northern Perth Basin have an age spectrum with a peak at about 1200 Ma that can be traced to the Albany Province. Differences, however, in Hf-isotope composition indicate that the Collie Coal Measures and the northern Perth Basin sandstones were not derived from the northern part of the Albany Province or from the coastal strip of felsic granitoids. The Perth Basin samples have a second peak age of 600–500 Ma that can be traced to the Leeuwin Block. One of the modern sands has a major peak at 2616 Ma that can be traced to the Yilgarn Craton.Compiled with previously published U–Pb zircon age spectra, the analyses provide insights into the paleogeographical history. The Yilgarn Craton sloped from the north at 1700 Ma, from the southeast at 1350–1140 and 490 Ma, its eastern part to the east at 300 Ma, and the southern part to the northwest from the Albany Province at 300–255 Ma. Denudational data from apatite fission-track analysis and vitrinite-reflectance studies suggest that the Yilgarn Craton was covered by a ∼5-km-thick blanket of Permian and Mesozoic sedimentary rock that was almost entirely removed by the Cenozoic, possibly because the craton was situated between the shoulders of rift systems that grew into the eastern and southeastern Indian Ocean.Ordovician, Permian, Early Triassic, and Quaternary sediment of the Perth Basin came from Proterozoic orogens. Only the Late Permian sample contains significant populations of Archean (Yilgarn) zircons but whether they came direct from the craton or were recycled from the postulated sedimentary cover is not known. The increased influx of sediment during the Jurassic matched by a peak in the denudation rate would seem to require a primary supply from the craton. This question could be resolved by dating zircon from the rapidly accumulated Jurassic formations.

Reconstructions before rifting and drifting reveal the geological connections between Antarctica and its conjugates in Gondwanaland

AbstractThe initial (200–175 Ma) breakup of Pangea was marked by the emplacement of the Large Igneous Provinces (LIPs) of Karoo–Ferrar-SE Australia (KFS) in the back-arc of Panthalassan subduction and by the Central Atlantic Magmatic Province (CAMP) between Africa and the Americas. Seafloor spreading 190–180 Ma (Stage 1) about the CAMP split Pangea into northern (Laurasia) and southern (Gondwanaland) parts. Subsequent stages at 167 Ma (2), 147 Ma (3), 130 Ma (4), 118 Ma (5), and 83 Ma (6) split conjugate Africa, South America, India, Australia, and Zealandia from Antarctica. Here I review the reconstruction of Antarctica in Gondwanaland. First, seafloor spreading is unwound to re-unite the continent–ocean boundaries (COBs), then the extended (rifted) crust about the suture is restored to its original thickness. A comprehensive review of the U–Pb zircon geochronology of the reconstructed margins of Antarctica and its conjugates shows that certain coeval structures are aligned across the suture. Cross structures of high-order spatial continuity and age correlation are the Lambert–Mahanadi Rift, Pranhita–Godavari-Robert Glacier trend, Gawler–Adélie Craton, and western part of the Gondwanide Fold Belt. Cross structures of high-order age correlation but low structural continuity or alignment are, from Africa to Antarctica, the East African–Antarctic Orogen, the Natal and Maud Belts, the Umkondo Group–Ritscherflya Supergroup and LIP, and the Kalahari–Grunehogna Craton; from Antarctica to Zealandia, the Ross-Western and Amundsen-Eastern Provinces; and from Africa through Antarctica to Australia the KFS LIP.

West Gondwanaland during and after the Pan-African and Brasiliano orogenies: Downslope vectors and detrital-zircon U–Pb and TDM ages and εHf/Nd pinpoint the provenances of the Ediacaran–Paleozoic molasse

AbstractThe Pan-African and Brasiliano orogenies endowed West Gondwanaland with U–Pb 700–500 Ma zircons, which, together with 1200–1000 Ma zircons from Rodinian collisions, are scattered in the Ediacaran–Paleozoic syn- and post-tectonic molassic outflow from the orogens. A more complete (TDM, εHf) isotopic signature in places narrows the search for provenance but exclusive use of the signature is of limited value given the ubiquity of primary and secondary 700–500 Ma and 1200–1000 Ma zircons. To overcome this shortcoming, I link the detrital-zircon signature with paleogeographical indicators of downslope preserved in minor sedimentary structures generated by gravity currents: the cross-dip azimuth in fluvial sediments, flute marks and other vectorial markings in turbidites.The prominent East African-Antarctic Orogen (EA-AO) trends through Africa-Arabia southward through East Africa/Madagascar to Dronning Maud Land in Antarctica. Squire et al. (Squire et al., 2006. Did the Transgondwanan Supermountain trigger the explosive radiation of animals on Earth? Earth and Planetary Science Letters 250, 116–133) postulated > 8000-km-long and > 1000-km-wide Transgondwanan Supermountains (TGSM) atop the EA-AO that resulted in extreme erosion and sedimentation rates; super-fans of quartz sand spread across continental North Africa-Arabia and oceanic crust offshore East Gondwanaland, as seawater 87Sr/86Sr rose to a maximum. Downslope indicators and the isotopic signature confirm the suggested deposition of the enormous North African-Arabian Super-fan from the Oubanguides Orogen-TGSM (Burke et al., 2003. Africa's petroleum systems: four tectonic ‘Aces’ in the past 600 million years. Geological Society of London Special Publications 207, 21–60), and the Cape Group from the TGSM. Other major provenance → sink relations are the Oubanguides Orogen → Congo Basin and the Damara Orogen and Dom Feliciano Orogens → Nama Basin. Minor and proximal provenance → sink relations are the Tuareg Shield and the Dahomeyides-Nigerian Shield → Volta Basin, and the Paraguay Orogen → Puncoviscana Basin. The voluminous primary sediment deposited during the Ediacaran, Cambrian, and Ordovician was recycled many times up to its present-day appearance in river and beach sand in Africa and in Australia.Compared with 60–0 Ma (~ Cenozoic) collisional Himalaya-Tibet and Mongolian Plateaus and related sediment fans of East Asia, the 700–500 Ma (Ediacaran–Cambrian) collisional continental super-fan in North Africa and Arabia and the deep-sea super-fan off East Gondwanaland are larger in extent and in their impact on seawater 87Sr/86Sr, probably because West Gondwanaland underwent crustal shortening over a much longer span; furthermore, the ancient morphotectonic regime lasted to the Carboniferous/Permian (~ 300 Ma) merger of Gondwanaland and Laurussia in Pangea, which instituted widespread Pangean-induced subsidence in broad basins that overlapped the planed-off orogens.

Central Antarctic provenance of Permian sandstones in Dronning Maud Land and the Karoo Basin: Integration of U–Pb and TDM ages and host-rock affinity from detrital zircons

AbstractIn conjugate SE Africa and Antarctica, Early Permian sandstones of the Swartrant Formation of the Ellisras Basin, Vryheid Formation of the Karoo Basin, and Amelang Plateau Formation of Dronning Maud Land (DML) were deposited after Gondwanan glaciation on a westward paleoslope. We analysed detrital zircons for U–Pb ages by a laser ablation microprobe-inductively coupled plasma mass spectrometer (LAM-ICPMS) and attached age significance only to clusters of three or more overlapping analyses. We analysed Hf-isotope compositions by a multi-collector spectrometer (LAM-MC-ICPMS) and trace elements by electron microprobe (EMP) and ICPMS. These analyses indicate the rock type and source (whether crustal or juvenile mantle) of the host magma, and a “crustal” model age (TDMC). The integrated analysis gives a more distinctive, and more easily interpreted, picture of crustal evolution in the provenance area than age data alone.Zircons from the Ellisras Basin are aged 2700–2540 Ma with minor populations about 2815 Ma and 2040 Ma, which correspond with the ages of the upslope parts of the proximal Kaapvaal Craton and Limpopo Belt. Mafic rock is the dominant host rock, and it reflects the Archean granite–greenstone terrane of the Kaapvaal Craton.The three Karoo Basin samples and the two DML samples have zircons with these common properties: (1) 1160–880 Ma, host magma mafic granitoid (< 65% SiO2) derived from juvenile depleted mantle sources (εHf positive) at 1.65 Ga and 1.35 Ga, with TDMC of 2.0–0.9 Ga; (2) 760 to 480 Ma, host magma granitoid and low-heavy rare earth element rock (?alkaline rock–carbonatite), derived from mixed crustal and juvenile depleted mantle sources (εHf positive and negative) at 1.50 Ga and 1.35 Ga, with TDMC of 2.0–0.9 Ga.Together with similar detrital zircons in Triassic sandstone of SE Australia, these properties reflect those in upslope central Antarctica, indicating a provenance of ∼ 1000 Ma (Grenville) cratons embedded in 700–500 Ma (Pan-Gondwanaland) fold belts. Detrital zircons in Cambrian sediments of the Ellsworth–Whitmore Mountains block and Cambrian metasediments of the Welch Mountains with comparable properties suggest that the central Antarctic provenance operated also in the ∼ 500 Ma Cambrian.

Provenance of the Gamburtsev Subglacial Mountains from U–Pb and Hf analysis of detrital zircons in Cretaceous to Quaternary sediments in Prydz Bay and beneath the Amery Ice Shelf

AbstractIn central Antarctica, drainage today and earlier back to the Paleozoic radiates from the Gamburtsev Subglacial Mountains (GSM). Proximal to the GSM past the Permian–Triassic fluvial sandstones in the Prince Charles Mountains (PCM) are Cretaceous, Eocene, and Pleistocene sediment in Prydz Bay (ODP741, 1166, and 1167) and pre-Holocene sediment in AM04 beneath the Amery Ice Shelf. We analysed detrital zircons for U–Pb ages, Hf-isotope compositions, and trace elements to determine the age, rock type, source of the host magma, and “crustal” model age (TDMC). These samples, together with others downslope from the GSM and the Vostok Subglacial Highlands (VSH), define major clusters of detrital zircons interpreted as coming from (1) 700 to 460 Ma mafic granitoids and alkaline rock, εHf 9 to − 28, signifying derivation 2.5 to 1.3 Ga from fertile and recycled crust, and (2) 1200–900 Ma mafic granitoids and alkaline rock, εHf 11 to − 28, signifying derivation 1.8 to 1.3 Ga from fertile and recycled crust. Minor clusters extend to 3350 Ma. Similar detrital zircons in Permian–Triassic, Ordovician, Cambrian, and Neoproterozoic sandstones located along the PaleoPacific margin of East Antarctica and southeast Australia further downslope from central Antarctica reflect the upslope GSM–VSH nucleus of the central Antarctic provenance as a complex of 1200–900 Ma (Grenville) mafic granitoids and alkaline rocks and older rocks embedded in 700–460 Ma (Pan-Gondwanaland) fold belts. The wider central Antarctic provenance (CAP) is tentatively divided into a central sector with negative εHf in its 1200–900 Ma rocks bounded on either side by positive εHf.The high ground of the GSM–VSH in the Permian and later to the present day is attributed to crustal shortening by far-field stress during the 320 Ma mid-Carboniferous collision of Gondwanaland and Laurussia. Earlier uplifts in the ∼ 500 Ma Cambrian possibly followed the 700–500 Ma assembly of Gondwanaland, and in the Neoproterozoic the 1000–900 Ma collisional events in the Eastern Ghats–Rayner Province at the end of the 1300–1000 Ma assembly of Rodinia.

GR FocusUpdated Gondwana (Permian–Cretaceous) earth history of Australia

AbstractPermo-Carboniferous glaciation, confined to icecaps and mountain glaciers, was followed by Permian coal measures and Early Triassic barren measures and redbeds, in the east terminally deformed in the mid-Triassic. Coal deposition resumed during the Late Triassic, and tholeiite was erupted in the southeast. After rifting, the western margin was formed by the opening of the Indian Ocean at 156 and 132 Ma. At 140 Ma, a brief glaciation affected central Australia. By the 99 Ma mid-Cretaceous, the southern margin was finally shaped by the opening of the southeastern Indian Ocean, the shoreline retreated to the present coast from the maximum Aptian shoreline of an epeiric sea, and the Eastern highlands were uplifted to produce the present morphology of Australia.New data relate to the Permo-Carboniferous and Early Cretaceous glaciations, the Kiaman Reversed Paleomagnetic Interval, events about the Permian–Triassic boundary, including possible impact craters, advances in palynology, invertebrate paleontology, macrofloral paleontology, and paleobiogeography, the provenance of sediments by U–Pb ages and host-rock affinity of zircons, stable-isotopes and biomarkers in petroleum systems, coal environments, calibrating the time scale with U–Pb ages of zircons, fission-track thermotectonic imaging, geothermal energy, and terranes split off the western margin.

Permian–Jurassic Mahanadi and Pranhita–Godavari Rifts of Gondwana India: Provenance from regional paleoslope and U–Pb/Hf analysis of detrital zircons

AbstractThe Permian–Jurassic Mahanadi and Pranhita–Godavari Rifts are part of a drainage system that radiated from the Gamburtsev Subglacial Mountains in central Antarctica. From 12 samples we analysed detrital zircons for U–Pb ages, Hf-isotopes, and trace elements to determine the age, rock type and source of the host magma, and TDM model age. Clusters, in decreasing order of abundance, are (1) 820–1000 Ma, host magmas felsic granitoids with alkaline rock, (2) 1500–1700 Ma felsic granitoids, (3) 500 to 700 Ma mafic granitoids with alkaline rock, (4) 2400–2550 Ma granitoids, and (5) 1000–1200 Ma felsic and mafic granitoids, mafic rock, and alkaline rock. TDM ranges from 1.5 to 3.5 Ga. Joint paleoslope measurements and zircon ages indicate that the Eastern Ghats Mobile Belt (EGMB) and lateral belts and conjugate Antarctica are potential provenances. Zircons from the Gondwana Rifts differ from those in other Gondwanaland sandstones in their predominant 820–1000 Ma and 1500–1700 Ma ages (from the EGMB and conjugate Rayner–MacRobertson Belt) that dilute the 500–700 Ma (Pan-Gondwanaland) ages. The 1000–1200 Ma zircons reflect the assembly of Rodinia, the 500–700 Ma ones that of Gondwanaland; the other ages reflect collisions in the region.

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