Academic literature on the topic 'Petermann Ranges'

The age of stratigraphic units within the Neoproterozoic of the Centralian Super-Basin caii be constrained by using major sequence bounding unconformities. The Officer Basin is redefined to include the Yeneena, Karara, and Savory Basins.Correlation of structural and stratigraphic relationships apparent in surface geological maps to seismic and borehole data leads to the conclusion that the Petermann Ranges Orogeny and the Paterson Orogeny are the same event. The name Petermann Ranges Orogeny has been used extensively in the Centralian Super-basin. It is considered for this publication, to be correlated with and hence to replace the term 'Paterson Orogeny'. This Tectonic event occurred at 540 to 570 Ma and postdated deposition of the Boondawari, Lupton, Pertatataka and Julie Formations and Rodda Beds. These Formations are correlated as part of the same depositional episode; which is separated from the younger Babbagoola Formation and lateral equivalents by a regional unconformity resulting from the Petermann Ranges Orogeny. The Babbagoola Formation is correlated with the Tchukardine and McFadden Formations of the Savory Sub-basin and the Relief Sandstone of the eastern Officer Basin.The Petermann Ranges Orogeny produced a central uplift which includes the Rudall and Musgrave Complexes, forming the north-eastern boundary of the Officer Basin. The Musgrave Complex advanced further south in comparison to the Rudall Complex, with accommodation along numerous north and northeast trending faults. Initial movement along these faults probably started as early as Cambrian and was repeatedly reactivated till post Miocene.Extensive reverse faulting, folding and initiation of diapiric movement of the Upper Proterozoic section began in late Neoproterozoic to Early Cambrian. Reactivation of diapiric movement and folding occurred after and before extrusion of the Table Hill Volcanics. Salt movement continued during the post-Permian and post-Early Cretaceous periods. The evolution of salt structures in the basin from Neoproterozoic to post-Cretaceous provides many different aged traps for migrating hydrocarbons.

On 21 May 2016, an Mwp 6.1 earthquake occurred along the Petermann Ranges in Central Australia. Such a seismic event can be classified as a rare intraplate earthquake because the affected area presents low seismicity, being at the center of the Indo-Australian plate. Also, the architecture and kinematics of shear zones in the Petermann Orogen are largely unknown. We used Sentinel-1 C-band descending data and ALOS-2 L-band ascending data to constrain the causative fault. Our analysis revealed that the earthquake nucleated along an unmapped secondary back-thrust of the main feature of the area, namely the Woodroffe thrust.

ABSTRACT The 20 May 2016 surface-rupturing intraplate earthquake in the Petermann Ranges is the largest onshore earthquake to occur in the Australian continent in 19 yr. We use in situ and Interferometric Synthetic Aperture Radar surface observations, aftershock distribution, and the fitting of P-wave source spectra to determine source properties of the Petermann earthquake. Surface observations reveal a 21-km-long surface rupture trace (strike=294°±29°) with heterogeneous vertical displacements (<0.1–0.96 m). Aftershock arrays suggest a triangular-shaped rupture plane (dip ≈ 30°) that intersects the subsurface projection of the major geophysical structure (Woodroffe thrust [WT]) proximal to the preferred location of the mainshock hypocenter, suggesting the mainshock nucleated at a fault junction. Footwall seismicity includes apparent southwest-dipping Riedel-type alignments, including possible activation of the deep segment of the WT. We estimate a moment magnitude (Mw) of 6.0 and a corner frequency (fc) of 0.2 Hz, respectively, from spectral fitting of source spectra in the 0.02–2 Hz frequency band. These translate into a fault area of 124 km2 and an average slip of 0.36 m. The estimated stress drop of 2.2 MPa is low for an intraplate earthquake; we attribute this to low-frictional slip (effective coefficient of friction >0.015) along rupture-parallel phyllosilicate-rich surfaces within the host rock fabric with possible additional contributions from elevated pore-fluid pressures.

We examined the diet of the barn owl in three bioregions of arid Northern Territory; two in upland areas, the other on the Barkly Tableland. Owls from the MacDonnell and Petermann Ranges fed predominantly on rodents. At both sites, Mus musculus was the dominant prey both in terms of frequency and prey units, with Pseudomys hermannsburgensis an important secondary item. Notomys alexis was an important secondary item in the MacDonnell Ranges. These results support previous research in highlighting the importance of plague rodents in the diet of barn owls in arid Australia. In contrast to the samples from the upland sites, the Barkly Tableland sample was composed mostly of the dasyurid marsupial Sminthopsis macroura, with only one rodent captured. The absence of the long-haired rat, Rattus villosissimus, from the sample, despite the species being a favoured prey item of the barn owl that undergoes population irruptions at the collection site, suggests that the sample was collected during a non-plague period. Our study is the first to record a marsupial species as the major prey of the barn owl. This finding suggests that barn owls can switch to other prey when populations of rodents crash.

AbstractThe standing crop of the epilithic foliose lichen Mastodia tesselata and some other species, the nutrient status (chloride, phosphate, nitrate and ammonium) of the substratum, slope and moisture availability were studied in 29 sample plots on Petermann Island (65°10'S, 66°30'W), Antarctica. The observed standing crop values for Mastodia ranged from 49 to 614 g m 2, with an average of 310 g m 2 (17 sample plots), and were 542 g m−2 for Rinodina petermannii (one sample plot) and 314 g m−2 for the alga Prasiola crispa in two meltwater pools. A regression equation with log-transformed ammonium and phosphate concentrations as predictors explained 75% of the observed variance in Mastodia standing crop. No significant influence of chloride or nitrate concentration on the Mastodia standing crop was detected, indicating that Mastodia is a salt-tolerant lichen species, but is not an obligate halophyte. The maximal standing crop of Mastodia on Petermann Island proved to be lower than maximal values found for fruticose macrolichen vegetation in maritime and continental Antarctic. The Mastodia standing crop on Petermann Island was similar to the standing crop of this species on subantarctic Marion Island.

The Amadeus Basin is divided into a number of structural provinces that developed during the Palaeozoic Alice Springs Orogeny, the course of which is described in terms of: Early Palaeozoic preorogenic crustal extension and basin development; Late Ordovician-Carboniferous NE-SW compressional orogenesis; and Late Carboniferous-(?)Early Permian NW-SE compression.The Southern Province is composed largely of Proterozoic formations that had been deformed during the Petermann Ranges Orogeny. The Central Anticlinal Province is a shear zone of four en echelon trends. The Parana Hills and Mereenie trends have a left lateral orientation to each other and formed during the first phase of orogenesis; the Gardiner Range and James Range trends are right lateral and formed during the second stage. Structures in the Northern Province were created by decollement within the evaporite-bearing Bitter Springs Formation and, to a lesser extent, in the Cambrian Chandler Formation, and by collapse of the basin fill under the burden of the Brewer Conglomerate in a style similar to the formation of diapirs along the northern front of the Pyrenees. The MacDonnell Homocline is a mountain front tip line that resembles the Triangle Zone of the Canadian Rocky Mountains. The Allambi Thrust Zone separates the Northern Province from the Camel Flat Platform that bears diapiric salt walls derived from the Chandler Formation.The varying stress field and revised time scale for orogeny may be of significance to evaluation of reservoir fracture patterns and source rock maturation curves.

The intracratonic Officer Basin of central Australia was formed during the Neoproterozoic, approximately 820 m.y. ago. The eastern third of the Officer Basin is in South Australia and contains nine unconformity-bounded sequence sets (super-sequences), from Neoproterozoic to Tertiary in age. Burial history is interpreted from a series of diagrams generated from well data in structurally diverse settings. These enable comparison between the stable shelf and co-existing deep troughs. During the Neoproterozoic, subsidence in the north (Munyarai Trough) was much higher than in either the south (Giles area) or northeast (Manya Trough). This subsidence was related to tectonic as well as sediment loading. During the Cambrian, subsidence was much higher in the northeast and was probably due to tectonic and sediment loading (carbonates over siliciclastics). During the Early Ordovician, subsidence in the north created more accommodation space for the last marine transgression from the northeast. The high subsidence rate of Late Devonian rocks in the Munyarai Trough was probably related to rapid deposition of fine-grained siliciclastic sediments prior to the Alice Springs Orogeny. Rates of subsidence were very low during the Early Permian and Late Jurassic to Early Cretaceous, probably due to sediment loading rather than tectonic sinking. Potential Neoproterozoic source rocks were buried enough to reach initial maturity at the time of the terminal Proterozoic Petermann Ranges Orogeny. Early Cambrian potential source rocks in the Manya Trough were initially mature prior to the Delamerian Orogeny (Middle Cambrian) and fully mature on the Murnaroo Platform at the culmination of the Alice Springs Orogeny (Devonian).

This study investigates the ecology of one of the best known Australian marsupials, the Common Brushtail Possum Trichosurus vulpecula, in central Australia. Trichosurus vulpecula is one of few medium-sized mammal species that persist in arid Australia today. Its distribution within the arid zone has declined markedly since European settlement. Two populations, one within the East MacDonnell Ranges along the Hale River and the other on Irving Creek, a River Red Gum creek in the Petermann Ranges, were studied in the southern Northern Territory. Others locations in the region were visited opportunistically. Trie central Australian Trichosurus is not distinct genetically from populations elsewhere in Australia. The diet of T. vulpecula consisted of a range of leaves, flowers and fruits of perennial dicotyledonous species as well as some ephemeral herbs. Grasses were absent from the diet. Variation in the diet reflected seasonal availability in flowers and fruits. The species preferentially consumed at each site had significantly higher moisture content and dry matter digestibility than species not consumed. Preferred species included Amyema maidenii leaves (a mistletoe), Acacia spp. flowers and fruits, Santalum lanceolatum leaves (a shrub), Marsdenia australis leaves (a vine), Solarium quadriloculatum fruit (shrub) and Euphorbia spp. leaves (herb). Small amounts of invertebrate material were consumed throughout the year. Other non-plant material consumed included honeycomb and unfledged birds eg. Budgerigars. There were no significant differences in the diet between the sexes. Trichosurus vulpecula were found in six main habitats: Acacia aneura/Callitris glaucophylla on rocky hills; E. camaldulensis sandy creek-lines; mixed Acacia rocky hills, Rocky Eucalyptus creek-lines; Degraded drainage lines; and Wet gullies. Logistic regression modelling revealed a significant correlation between mistletoe species richness, higher levels of soil nitrogen and the presence of T. vulpecula. In habitats occupied by T. vulpecula species richness of mistletoes was associated with the absence of fire and the presence of reliable ground water supplies. Trichosurus vulpecula were highly mobile with mean home ranges at Hale River of 44.21 � 22.76 ha and considerably higher than those recorded in previous studies in Australia. Mean home ranges at Irving Creek were much smaller, at 4.99 � 1.46 ha and VII similar to that recorded in other studies in Australia. At both sites, males had larger home ranges and there was a high degree of overlap with other males and females. At the Hale River study site, T. vulpecula predominantly denned in caves or cavities in rocks, whereas at Irving Creek all den sites were in large Eucalyptus camaldulensis on the drainage line. Adult and pouch young sex ratios were at parity. During this study, T. vulpecula was found to breed continuously, with births recorded in almost all months. Growth of the young were more rapid than previously recorded for Trichosurus in Australia. This is interpreted as an adaptation for living in an arid environment, enabling the young to achieve independence before quality food supplies diminish. No single exotic predator or competitor was solely responsible for the decline of T. vulpecula in arid Australia, implying an interactive impact. Prey switching by dingoes from rabbits to T. vulpecula, macropods and echidnas followed the crash of rabbit populations at Hale River. Predation by dingoes on T. vulpecula was only recorded once, at the Irving Creek study site, where numbers of rabbits remained stable throughout the study. The impact of exotic herbivores occurred through habitat degradation rather than competition. Evaluation of the ecological data collected during this study generally supports current models of decline and extinction in medium-sized mammals in arid Australia, integrating the effects of predators, competitors, drought and fire. However, the importance of each factor on populations of T. vulpecula was found to vary depending on their location in the landscape. This study suggests two separate models to explain the decline of T. vulpecula in arid Australia after the arrival of Europeans. The first operates in the riparian lowlands and the second on the rocky ranges. In both models, prior to European settlement, T. vulpecula occupied refuge habitats characterised by readily available moisture for plant growth (run on areas and/or shallow water tables) and soils with higher soil nutrient concentrations. The impact of fires on these refugia was minimal, as Aboriginal burning practices protected them with mosaic burning generally preventing large-scale fires from developing. Following European settlement, the forces impacting on populations were different in the riparian lowlands from those affecting rocky ranges. In the riparian lowlands, the effects of rabbits and livestock together with predation were found to have the major impact on T. vulpecula populations. Fire was not a significant factor in these areas. In the rocky ranges, fire was the most significant factor affecting T. vulpecula populations. Introduced herbivores did not degrade these habitats as they did in the riparian lowlands because the rugged and steep nature of the ranges acted as a physical barrier. Similarly, predator numbers were lower because of the relative difficulty in moving over rough ground and the generally lower relative abundance of preferred prey such as rabbits. An adaptive management strategy needs to be implemented to determine the effects of different management regimes on T. vulpecula population viability. The key elements of a management strategy in the riparian lowlands involves the manipulation and monitoring of predators, rabbits and livestock numbers. In the rocky ranges, the key management strategy involves the implementation of a patch burning to prevent fires entering habitats occupied by T. vulpecula. Importantly, any management strategies should involve Aboriginal people. Trichosurus vulpecula is an important part of Aboriginal culture. Its decline is of great concern to many people and several of the remaining populations and potential reintroduction locations are on Aboriginal land. Because of their relationship with the land and the animals, people have both the knowledge of the animal and the skills (such as patch burning) to provide information to managers which will assist with management. To achieve these management directions a coordinated national education programme is required to inform and convince the Australian community that conservation of T. vulpecula is deserving of attention in arid and semi-arid Australia. This is particularly important given the perception that T. vulpecula is a common species throughout Australia, despite its massive decline in arid Australia since European settlement.