WA
Type of resources
Keywords
Publication year
Scale
Topics
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Canning Basin (Yampi, Pender, Broome) WA, Magnetic 1988/89 survey were acquired in 1989 by the WA Government, and consisted of 27060 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Canning Basin (Yampi, Pender, Broome) WA, Magnetic 1988/89 (P537), radiometric line data, AWAGS levelled were acquired in 1989 by the WA Government, and consisted of 27060 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Canning Basin (McLarty Hills, Mt Anderson, Derby), WA, 1988/89 survey were acquired in 1988 by the WA Government, and consisted of 44880 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Canning Basin (McLarty Hills, Mt Anderson, Derby), WA, 1988/89 (P538), radiometric line data, AWAGS levelled were acquired in 1988 by the WA Government, and consisted of 44880 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
Whether rift basins form as a consequence of pure shear or simple shear stretching of the lithosphere or a hybrid of these two end members has long been the focus of debate (McKenzie, 1978; Wernicke, 1985; Rosenbaum et al., 2008). It is generally accepted that under low strain pure shear dominates yet the debate rages with respect to highly extended continental margins. The key dataset to resolve this debate is the spatial distribution of syn-rift and post-rift basin subsidence resulting from mechanical thinning of the lithosphere and subsequent thermal re-thickening of the lithospheric mantle to its pre-rift thickness. An often-overlooked element of this debate is what lithospheric template is being stretched (Crosby et al., 2010). Most geodynamic models simply assume a standard lithospheric thickness of 100120 km, yet in the last decade teleseismic tomography has revealed that much of the Earth's continental land mass is underlain by lithosphere over double this thickness (Priestley and McKenzie, 2013). Here, we kinematically model the subsidence history of the Canning basin following Crosby et al. (2010). This intracratonic rift basin putatively overlies lithosphere 180 km thick, imaged using shear wave tomography (Kennett et al., 2013). The entire subsidence history of the, < 300 km wide and < 6 km thick, western Canning Basin is adequately explained by Ordovician rifting of pre-existing 100120 km thick lithosphere followed by post-rift thermal subsidence as described by the established pure shear model. In contrast, the < 150 km wide and 15 km thick Fitzroy Trough of the eastern Canning Basin reveals an almost continuous phase of normal faulting between Ordovician and Carboniferous Periods followed by negligible post-rift thermal subsidence. This pattern cannot be accounted for by a simple shear model (c.f. Drummond et al., 1991), as there is no record of excess post-rift subsidence in the basin, nor does the data fit the standard pure shear model. We attribute this difference in subsidence to a sharp change in mantle lithospheric thickness between the west and eastern Canning Basin. The presence of ~20 Ma diamond bearing lamproites intruded into the basin depocentre indicate that the present lithospheric thickness exceeds ~180 km (Evans et al., 2012). In order to account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted by 5070 kg m3. The actual depletion of the lowermost lithospheric mantle was assessed by modeling REE concentrations of the ~20 Ma lamproites along with other ultrapotassic rocks from the Kimberley, Yilgarn and Pilbara blocks following the method of Tainton and McKenzie (1994) which reveal a depletion of 4070 kg m3. This result suggests that thermal re-thickening of the lithospheric mantle did not occur following rifting, as it is unlikely that such a strongly depleted mantle source was available in the Phanerozoic to be frozen into the lowermost lithospheric mantle. Therefore, we conclude that thinning of thick lithosphere to thicknesses > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. The discrepancy between estimates of lithospheric thickness derived from subsidence data in the Western Canning and that derived from shear wave tomography suggests that the latter technique cannot resolve lithospheric thickness variations on < 300 km half wavelengths.
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Canning Basin (Charnley,Lennard R,Noonkanbah,Crossland), WA, 1989 survey were acquired in 1989 by the WA Government, and consisted of 51022 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Canning Basin, WA, 1988 survey were acquired in 1988 by the WA Government, and consisted of 60775 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Canning Basin (Charnley,Lennard R,Noonkanbah,Crossland), WA, 1989 (P539), radiometric line data, AWAGS levelled were acquired in 1989 by the WA Government, and consisted of 51022 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Canning Basin, WA, 1988 (P540), radiometric line data, AWAGS levelled were acquired in 1988 by the WA Government, and consisted of 60775 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.
-
Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the SW Canning Basin (Yarrie, Anketell), WA, 1991 survey were acquired in 1991 by the WA Government, and consisted of 21782 line-kilometres of data at 1600m line spacing and 60m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.