Catchment-based gold prospectivity analysis combining geochemical, geophysical and geological data across northern Australia

The results of a pilot study into the application of an unsupervised clustering approach to the analysis of catchment-based National Geochemical Survey of Australia (NGSA) geochemical data combined with geophysical and geological data across northern Australia are documented. NGSA Mobile Metal Ion (R) (MMI) element concentrations and first and second order statistical summaries across catchments of geophysical data and geological data are integrated and analysed using Self-Organizing Maps (SOM). Input features that contribute significantly to the separation of catchment clusters are objectively identified and assessed. A case study of the application of SOM for assessing the spatial relationships between Au mines and mineral occurrences in catchment clusters is presented. Catchments with high mean Au code-vector concentrations are found downstream of areas known to host Au mineralization. This knowledge is used to identify upstream catchments exhibiting geophysical and geological features that indicate likely Au mineralization. The approach documented here suggests that catchment-based geochemical data and summaries of geophysical and geological data can be combined to highlight areas that potentially host previously unrecognised Au mineralization.The NGSA project was part of the Australian Government’s Onshore Energy Security Program 2006 – 2011, from which funding support is gratefully acknowledged

Reflections on undertaking the Probation Qualifying Framework scheme during the transforming rehabilitation changes

This article reflects upon the author’s experience of undertaking the PQF (Probation Qualifying Framework) training scheme during the chaotic period of Transforming Rehabilitation. The author asserts that the uncertainty and precarious nature of the changes were detrimental to an effective learning environment, which ultimately promoted a practice culture of punitiveness and control and did not allow learners the space to be skilful and confident practitioners, comfortable working autonomously. Furthermore, the author contends there is an emerging culture within the NPS (National Probation Service) increasingly fostered on ‘risk management’, which is reflected in the vocational nature of PQF training and is contributing towards a widening cultural gap that is emerging between the community rehabilitation companies and NPS

Strengthening the Magnetic Interactions in Pseudobinary First-Row Transition Metal Thiocyanates, M(NCS)2.

Understanding the effect of chemical composition on the strength of magnetic interactions is key to the design of magnets with high operating temperatures. The magnetic divalent first-row transition metal (TM) thiocyanates are a class of chemically simple layered molecular frameworks. Here, we report two new members of the family, manganese(II) thiocyanate, Mn(NCS)2, and iron(II) thiocyanate, Fe(NCS)2. Using magnetic susceptibility measurements on these materials and on cobalt(II) thiocyanate and nickel(II) thiocyanate, Co(NCS)2 and Ni(NCS)2, respectively, we identify significantly stronger net antiferromagnetic interactions between the earlier TM ions-a decrease in the Weiss constant, θ, from 29 K for Ni(NCS)2 to -115 K for Mn(NCS)2-a consequence of more diffuse 3d orbitals, increased orbital overlap, and increasing numbers of unpaired t2g electrons. We elucidate the magnetic structures of these materials: Mn(NCS)2, Fe(NCS)2, and Co(NCS)2 order into the same antiferromagnetic commensurate ground state, while Ni(NCS)2 adopts a ground state structure consisting of ferromagnetically ordered layers stacked antiferromagnetically. We show that significantly stronger exchange interactions can be realized in these thiocyanate frameworks by using earlier TMs.EPSRC NPIF 2018 fund Laboratory Directed Research and Development Program of Oak Ridge National Laboratory NSERC of Canada PGSD fund Trinity College, Cambridge School of Chemistry, University of Nottingham Hobday Fellowship EPSRC Strategic Equipment Grant EP/M000524/

Post-release reforms for short prison sentences: re-legitimising and widening the net of punishment

Transforming Rehabilitation (TR) promised a ‘revolution’ in the way offenders are managed, providing a renewed focus on short sentence prisoners. The TR reforms extends mandatory post-release supervision and tailored through-the-gate resettlement provisions to a group that has predominately faced a ‘history of neglect’ yet often present with the most acute needs within the criminal justice system. However, existing literature underlines that serving short sentences lack ‘utility’ and can be counter-productive to facilitating effective rehabilitation. This article explores the purposes of providing post release supervision for short sentences, firstly exploring a previous attempt to reform short sentences; (the now defunct) ‘Custody Plus’ within the 2003 Criminal Justice Act and then the Offender Rehabilitation Act 2014 within the TR reforms. This article contends that both post release reforms have sought to re-affirm and re-legitimise prison as the dominant form of punishment in society- or what Carlen refers to as ‘carceral clawback’. This article will also use Cohen’s analysis on social control to establish that post release supervision will serve to ‘widen the net’ extend the period of punishment and oversight and will only reinforce a form of enforced ‘state obligated rehabilitation’ that will undermine efforts made to resettle short sentence prisoners

Automated Acid Rock Drainage Indexing from Drill Core Imagery

The automated classification of acid rock drainage (ARD) potential developed in this study is based on a manual ARD Index (ARDI) logging code. Several components of the ARDI require accurate identification of sulfide minerals that hyperspectral drill core scanning technologies cannot yet report. To overcome this, a new methodology was developed that uses red⁻green⁻blue (RGB) true color images generated by Corescan® to determine the presence or absence of sulfides using supervised classification. The output images were then recombined with Corescan® visible to near infrared-shortwave infrared (VNIR-SWIR) mineral classifications to obtain information that allowed an automated ARDI (A-ARDI) assessment to be performed. To test this, A-ARDI estimations and the resulting acid-forming potential classifications for 22 drill core samples obtained from a porphyry Cu⁻Au deposit were compared to ARDI classifications made from manual observations and geochemical and mineralogical analyses. Results indicated overall agreement between automated and manual ARD potential classifications and those from geochemical and mineralogical analyses. Major differences between manual and automated ARDI results were a function of differences in estimates of sulfide and neutralizer mineral concentrations, likely due to the subjective nature of manual estimates of mineral content and automated classification image resolution limitations. The automated approach presented here for the classification of ARD potential offers rapid and repeatable outcomes that complement manual and analyses derived classifications. Methods for automated ARD classification from digital drill core data represent a step-change for geoenvironmental management practices in the mining industry

Geoenvironmental characterisation of the King River Delta: a combined geophysical, geochemical and mineralogical approach

The Mount Lyell Mining and Railway company discharged nearly 95 Mt of tailings and 1.4 Mt of slag from its copper, gold and silver production into the Queen River from 1916 to 1994. Approximately 87.4 Mt of tailings has accumulated at the King River Delta. This research presents a geoenvironmental characterisation of the King River Delta that combines geophysical, geochemical and mineralogical data. Apparent resistivity and shear wave (Vs) profiles suggest the baseline of the tailings at 3-5 m depth. Low resistivity values (i.e., < 2 Omega.m) characterise the salt water intrusion, while resistivity values between roughly 5 to 12 Omega.m, below 15 m depth, suggests bedrock boundaries. Scanning electron microscope (SEM) analysis of sediments identifies pyrite, chalcopyrite, muscovite, quartz, chlorite, barite, and iron oxides in the tailings. Additionally, chemical analysis indicates high content of S and heavy metals (e.g., Fe, Cu, Co, Ni and Zn), which contribute to rapid acid formation and risk of metal leaching into the surrounded environment, confirmed by geochemical static tests