Andrew Gleadow

University of Melbourne, School of Earth Sciences, Faculty Member

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Papers by Andrew Gleadow

Uplift and thermal history of the Papuan Fold Belt, Papua New Guinea: Apatite fission track analysis

by Kevin C Hill and Andrew Gleadow

Australian Journal of Earth Sciences, 1989

Apatite fission track analysis of 44 surface and borehole samples indicates that the Papuan Fold ... more Apatite fission track analysis of 44 surface and borehole samples indicates that the Papuan Fold Belt was uplifted, eroded and cooled from the earliest Pliocene (5 Ma) to the present day. Uplift and cooling of basement in the Kubor and Muller Anticlines, 250 km apart, took place at 4.0±0.5 Ma, but thrusting of the large anticlines at the mountain front

A reappraisal of low-temperature thermochronology of the eastern Fennoscandia Shield and radiation-enhanced apatite fission-track annealing

by P. Sorjonen-Ward and Andrew Gleadow

Geological Society, London, Special Publications, 2009

... 1994; Harman et al. 1998). ... 1988; Nikishin et al. 1996; Samuelsson &amp; Middleton 199... more ... 1994; Harman et al. 1998). ... 1988; Nikishin et al. 1996; Samuelsson &amp; Middleton 1998; Larson &amp; Tullborg 1998; Larson et al. 1999, 2006; Cederbom et al. 2000; Cederbom 2001; Lorencak 2003; Huigen &amp; Andriessen 2004; Murrell &amp; Andriessen 2004; Kohonen &amp; Rämö 2005). ...

Late-stage evolution of the Chemehuevi and Sacramento detachment faults from apatite (U-Th)/He thermochronometry--Evidence for mid-Miocene accelerated slip

by Andrew Gleadow, Jon Woodhead, and Barry Kohn

Bulletin of the …, Jan 1, 2006

Quick Search: All GSW Journals, GSW + GeoRef. advanced search. ...

Comparison through fission-track analysis of portions of Australia and Antarctica adjacent prior to continental drift

International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1990

ABSTRACT Australia and Antarctica have been reconstructed by the matching of three terranes in we... more ABSTRACT Australia and Antarctica have been reconstructed by the matching of three terranes in western Victoria (Glenelg River, Grampians-Stavely, Stawell) with three terranes in northern Victoria Land (Wilson, Bowers, Robertson Bay). Apparent fission-track ages from granitic rocks of these matched regions are compared. In western Victoria, Australia, data reflect a history of slow cooling following intrusion in early to middle Paleozoic time. In northern Victoria Land, Antarctica, a complex history of cooling and uplift is indicated, with uplift of the present-day mountains commencing approximately 50 Ma. Fission tracks in apatites from most samples from northern Victoria Land were completely re-set to zero by the thermal effects of Jurassic tholeiitic magmatism. Apatite in three samples from the western margin of the Wilson Terrane, however, predate the Jurassic and were only partially re-set by this event. Apparent sphene fission-track ages indicate that the three terranes in northern Victoria Land have shared a common thermal history since the Devonian. With the exception of one small area adjacent to the Cretaceous-Tertiary Otway Basin in western Victoria, neither western Victoria nor northern Victoria Land data show a clear influence of rifting and breakup in the late Cretaceous.Overall, the data indicate that once the breakup of Australia and Antarctica had occurred, their thermal and tectonic histories evolved independently along differing paths. It is suggested that during extension northern Victoria Land, Antarctica, was flanked by two upper plate margins, whereas southeastern Australia was flanked by an upper plate and a lower plate margin, thus accounting for the present-day geomorphic differences between the two regions.

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New approaches in fission track geochronology as a tectonic tool: Examples from the transantarctic mountains

International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1990

Stratigraphy and 40 Ar/ 39 Ar geochronology of the Santa Rosa basin, Baja California: Dynamic evolution of a constrictional rift basin during oblique extension in the Gulf of California

Basin Research, 2013

The Santa Rosa basin of northeastern Baja California is one of several transtensional basins that... more The Santa Rosa basin of northeastern Baja California is one of several transtensional basins that formed during Neogene oblique opening of the Gulf of California. The basin comprises Late Miocene to Pleistocene sedimentary and volcanic strata that define an asymmetric half-graben above the Santa Rosa detachment, a low-angle normal fault with ca. 4-5 km of SE-directed displacement. Stratigraphic analysis reveals systematic basin-scale facies variations both parallel and across the basin. The basin-fill exhibits an overall fining-upward cycle, from conglomerate and breccia at the base to alternating sandstone-mudstone in the depocentre, which interfingers with the fault-scarp facies of the detachment. Sediment dispersal was transverse-dominated and occurred through coalescing alluvial fans from the immediate hanging wall and/or footwall of the detachment. Different stratigraphic sections reveal important lateral facies variations that correlate with major corrugations of the detachment fault. The latter represent extension-parallel folds that formed largely in response to the ca. N-S constrictional strain regime of the transtensional plate boundary. The upward vertical deflection associated with antiformal folding dampened subsidence in the northeastern Santa Rosa basin, and resulted in steep topographic gradients with a high influx of coarse conglomerate here. By contrast, the downward motion in the synform hinge resulted in increased subsidence, and led to a southwestward migration of the depocentre with time. Thus, the Santa Rosa basin represents a new type of transtensional rift basin in which oblique extension is partitioned between diffuse constriction and discrete normal faulting. 40 Ar/ 39 Ar geochronology of intercalated volcanic rocks suggests that transtensional deformation began during the Late Miocene, between 9.36 ± 0.14 Ma and 6.78 ± 0.12 Ma, and confirms previous results from low-temperature thermochronology . Two other volcanic units that appear to be part of a conformable syn-rift sequence are, in fact, duplicates of pre-rift volcanics and represent allochthonous, gravity-driven slide blocks that originated from the hanging wall. = Santa Rosa basin section 1, SRb2 = Santa Rosa basin section 2, SRb3 = Santa Rosa basin section 3, SRb4 = Santa Rosa basin section 4, SRb4(W)=Informal section west of SRb4 where detailed orientation measurements are available for the purpose of Fig. 9, Hb1 = Huatamote basin section 1.

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A thermochronological perspective on the morphotectonic evolution of the southeastern Tibetan Plateau

Journal of Geophysical Research: Solid Earth, 2014

A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at ... more A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at high elevations (>3.5 km). The origin of these landscapes and their geodynamic implications with regard to evolution of the southeastern TP has been the subject of considerable debate. Focusing on this topic, this study utilizes fission track and (U-Th)/He thermochronology to reconstruct the thermal history of the Late Triassic Daocheng granite, on which a low-relief high-elevation landscape has developed. Results suggest that the plateau surface experienced widespread Late Jurassic to Early Cretaceous cooling (at a rate of~1-2°C/Ma), followed by minimal regional cooling (~0.3°C/Ma) and Early Miocene enhanced cooling (~2-3°C/Ma) along deep valleys at the southern edge of the landscape. Given the subdued Late Jurassic to Early Cretaceous crustal deformation in the study area, we relate the coeval cooling to crustal refrigeration and exhumation triggered by northward subduction of the Meso-Tethys Ocean along the Bangong suture. Subsequent Late Cretaceous to Cenozoic minimal cooling supports arguments for the formation of a low-elevation landform prior to uplift of the southeastern TP. The enhanced cooling commenced at the Early Miocene (~15-22 Ma) along deep valleys and heralded the onset of river incision and surface uplift of the southeastern TP. This finding does not support previous proposals claiming that high elevations of the southeastern TP were formed in Late Miocene time resulting from lower crustal flow but rather supports a model highlighting continental subduction and extrusion along the large Tanggula-Yushu-Batang-Red River fault system. TIAN ET AL.

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Synchronous fluvial response to surface uplift in the eastern Tibetan Plateau: Implications for crustal dynamics

Geophysical Research Letters, 2015

Synchronous response of river erosion to surface uplift is often assumed by studies using thermoc... more Synchronous response of river erosion to surface uplift is often assumed by studies using thermochronometer-constrained erosion histories to estimate changes in landscape and tectonics. We have tested this assumption by studying river incision histories at two sites (Heishui and Lianghekou) located in the westernmost inland part of the deeply incised eastern Tibetan Plateau. Apatite fission track age-elevation plots for the two sites show clear late Miocene inflection points, marking the time when apparent erosion rates increased fourfold to eightfold to 300-800 m/Myr. This timing is further refined as 10-12 Ma by thermal history modeling and overlaps within analytical uncertainties with that recorded from the eastern Tibetan Plateau margin~150-200 km to the east, demonstrating that river incision propagated rapidly from the margin to the interior in less than~2 Ma. Such synchronous regional river incision is consistent with regional surface uplift generated by crustal extrusion along a detachment at depth.

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Workshop on Antarctic geology 17–18 May 1979

Journal of the Geological Society of Australia, 1979

... Authors: Tingey, RJ; Black, LP; James, PR; Collerson, KD; Arriens, PA; Lovering, JF; Oliver, ... more

Intracontinental deformation in southern Africa during the Late Cretaceous

Journal of African Earth Sciences, 2014

Intracontinental deformation accommodated along major lithospheric scale shear zone systems and w... more Intracontinental deformation accommodated along major lithospheric scale shear zone systems and within associated extensional basins has been well documented within West, Central and East Africa during the Late Cretaceous. The nature of this deformation has been established by studies of the tectonic architecture of sedimentary basins preserved in this part of Africa. In southern Africa, where the post break-up history has been dominated by major erosion, little evidence for post-break-up tectonics has been preserved in the onshore geology. Here we present the results of 38 new apatite fission track analyses from the Damara region of northern Namibia and integrate these new data with our previous results that were focused on specific regions or sections only to comprehensively document the thermo-tectonic history of this region since continental break-up in the Early Cretaceous. The apatite fission track ages range from 449 ± 20 Ma to 59 ± 3 Ma, with mean confined track lengths between 14.61 ± 0.1 lm (SD 0.95 lm) to 10.83 ± 0.33 lm (SD 2.84 lm). The youngest ages (c. 80-60 Ma) yield the longest mean track lengths, and combined with their spatial distribution, indicate major cooling during the latest Cretaceous. A simple numerical thermal model is used to demonstrate that this cooling is consistent with the combined effects of heating caused by magmatic underplating, related to the Paraná-Etendeka continental flood volcanism associated with rifting and the opening of the South Atlantic, and enhanced erosion caused by major reactivation of major lithospheric structures within southern Africa during a key period of plate kinematic change that occurred in the South Atlantic and SW Indian ocean basins between 87 and 56 Ma. This phase of intraplate tectonism in northern Namibia, focused in discrete structurally defined zones, is coeval with similar phases elsewhere in Africa and suggests some form of trans-continental linkage between these lithospheric zones.

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An early cretaceous phase of accelerated erosion on the south-western margin of Africa: Evidence from apatite fission track analysis and the offshore sedimentary record

International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1990

Abstraet--Apatite fission track ages and confined track length distributions have been determined... more Abstraet--Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of ~ 14/~m with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (< 10/am). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early Cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin.

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Apatite fission track stratigraphy-profiles of fission track age and track length in the crust

Dating fluid flow in developing passive margins using low-temperature thermochronology

Strain Localisation at Rift Segment Boundaries: An Example from the Bocana Transfer Zone in Central Baja California, Mexico

Structural inheritance versus magmatic weakening: What controls the style of deformation at rift segment boundaries in the Gulf of California, Mexico?

ABSTRACT Rifts are commonly segmented into several hundred kilometre long zones of opposing upper... more ABSTRACT Rifts are commonly segmented into several hundred kilometre long zones of opposing upper-plate transport direction with boundaries defined by accommodation and transfer zones. A number of such rift segments have been recognized in the Gulf of California, a youthful oceanic basin that is currently undergoing the rift-drift transition. However, detailed field studies have so far failed to identify suitable structures that could accommodate the obvious deformation gradients between different rift segments, and the nature of strain transfer at segment boundaries remains enigmatic. The Bocana transfer zone (BTZ) in central Baja California is a linear, WNW striking structural discontinuity separating two rift segments with different magnitudes and styles of extensional deformation. North of the BTZ, the Libertad fault is part of the Main Gulf Escarpment, which represents the breakaway fault that separates the Gulf of California rift to the east from the relatively stable western portion of the Baja peninsula. The N-striking Libertad escarpment developed during the Late Miocene (~10-8Ma) and exhibits a topographic relief of ca. 1,000m along a strike-length of ca. 50km. Finite displacement decreases from ~1000m in the central fault segment to ~500m further south, where the fault bends SE and merges with the BTZ. In the hanging wall of the Libertad fault, a series of W-tilted horsts are bound along their eastern margins by two moderate-displacement E-dipping normal faults. South of the BTZ, extension was much less than further north, which explains the comparatively subdued relief and generally shallower tilt of pre-rift strata in this area. The BTZ itself is characterized by two en echelon WNW-ESE striking dextral-oblique transfer faults with a significant down-to-the-NNE extensional component. Strain is transferred from the Libertad breakaway fault onto the transfer faults over a distance of &gt;20km through a network of interacting normal, oblique and strike-slip faults. The shape, location and orientation of the main faults were strongly influenced by pre-existing rheological heterogeneities. Major normal faults are parallel to either the Mesozoic metamorphic foliation or Cretaceous intrusive contacts, and developed where the foliation was at a high angle to the extension direction. In contrast, the oblique-slip faults of the BTZ formed parallel to the metamorphic foliation where formlines are at a small angle to the regional extension direction. Compared to the BTZ, deformation in other known accommodation zones of the Gulf of California rift occurred distributed across a much wider zone, and appropriate transfer faults are either lacking or minor. In these cases, however, the accommodation zones coincide with the locations of significant pre- and synrift volcanism, suggesting that thermal weakening associated with magmatic activity may have promoted the distribution of strain across a wider region instead of localising it into discrete transfer faults.

Structure and thermal annealing of latent fission tracks in apatite and zircon

Apatite fission track dating by LA-ICP-MS and External Detector Method: How do they stack up?

Fission track length distributions in multi-system thermochronology

Continental extension tectonics in the Gulf Extensional Province, northern Baja California, Mexico: evidence from low-temperature thermochronology

ASEG Extended Abstracts, 2006

... Page 3. Thermochronology and Extension, Baja California Gleadow, Kohn, Fletcher and Raza peni... more

$Research paper thumbnail of Identification of reactivated crustal anistropies and controls on the development of oceanic fracture zones from apatite fission-track thermochronology$

Identification of reactivated crustal anistropies and controls on the development of oceanic fracture zones from apatite fission-track thermochronology

Nuclear Tracks and Radiation Measurements, 1993

Andrew Gleadow

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