Andrew Wetherelt

Correlation between geology and concentration-volume fractal models: significance for Cu and Mo mineralized zones separation in the Kahang porphyry deposit (Central Iran)

Abstract This study identifies the major mineralized zones including supergene enrichment and hypogene enrichment in the Kahang Cu-Mo porphyry deposit which is located in Central Iran based on subsurface data and utilization of the concentration-volume (C-V) fractal model. Additionally, a correlation between results achieved from a C-V fractal model and geological models consisting of zonation, mineralography and alteration have been conducted in order to have an accurate recognition and modification of the main mineralized zones. Log-log plots indicate five geochemical populations for Cu and Mo in the deposit which means that mineralization commences with 0.075 % and 13 ppm for Cu and Mo (as the first thresholds) respectively. The main mineralization began for Cu ≥ 0.42 % and Mo ≥ 100 ppm and also enriched mineralization containing Cu ≥1.8 % and Mo ≥ 645 ppm which is located in the central part of the deposit. According to the C-V model, the main Cu-Mo mineralized zones occur in the hypogene zone, especially in the central, NW and NE parts of the Kahang deposit. The supergene enrichment zone derived via the C-V model is smaller than that in the geological model and is located in the central and eastern parts of the deposit. Results analysed by the C-V fractal model certify that the interpreted zones based on the fractal model are accurate. To certify this, a logratio matrix has been employed to validate the C-V fractal model for the Cu and Mo main mineralized zones

Visualising Sea-Level Rise at a Coastal Heritage Site: Participatory Process and Creative Communication

Abstract This paper describes a research project that aimed to translate complex spatial and scientific data about coastal change into accessible digital formats for general audiences. The project used fine-scale remote sensing techniques including airborne and terrestrial laser scanning to produce spatially accurate and realistic 3D digital visualisations of projected sea level rise at Cotehele Quay, a site on the River Tamar in Cornwall owned and managed by the National Trust. Area residents and stakeholders were involved in a series of focus groups which provided guidance on the integration of the spatial models into a short film. The paper focuses on how the participatory, iterative process adopted in the project shaped the content and design of the film. The paper concludes with a discussion of how this process enhanced the viability of the film as a communication tool for use in wider engagement activities.

Large-scale mine visualization using VRML

Traditionally, mine plans and sections in 2D stored 3D information. We show that using VRML to model this information leads to new, interactive methods of data visualization. With the demise of the last working tin mine in Cornwall (South Crofty), perhaps the end has arrived for a way of life that saw the rise of Cornish miners and the engineering know-how they brought to the world. Using the Virtual Reality Modeling Language (VRML) is the latest in a series of attempts to view the complex arrangement of tunnels and stopes at South Crofty. VRML has many advantages, especially in rendering speed, ease of creating geometry, and the added bonus of Internet capability. This permits viewing interactive mine models by almost any interested party at almost any location if they have an Internet connection and can access a location where the model is stored. To construct a 3D model, we must first obtain coordinate information. In the case of South Crofty, this information came from three sources: electronic digital data, paper plans and miscellaneous plans and reports. Because the South Crofty survey department used a commercial mine survey package called Surpac, we used that format ourselves. Once all the information was in Surpac format, relatively painless editing could take place within Surpac using a graphical editor. Next, we used a conversion utility written in Java to convert the coordinate data into a suitable VRML format.

Evaluation of automated underground mapping solutions for mining and civil engineering applications

Abstract. The extractive and construction industries rely heavily on accurate geospatial data to control position, location, alignment, and orientation of planned excavations. Recent advancements in the survey industry, through the use of terrestrial laser scanning, can now provide engineering teams with three-dimensional (3-D) data in unprecedented detail via georeferenced point clouds. Furthermore, equipment is now available that provides fully mobile automated mapping solutions, independent of satellite positioning, utilizing simultaneous localization and mapping. This paper evaluates the surveying capability of three fully mobile automated mapping solutions against a benchmark laser scanning survey undertaken at the underground Camborne School of Mines Test Mine facility. The study highlights that handheld automated mapping solutions, in which closed-loops can be formed, have the potential to provide quicker data collection and processing time, as well as the required accuracy for underground surveying applications. However, the automated solution was unable to produce the necessary point cloud density to identify low-angled discontinuities that may have a major safety implication, leading to potential rockfall.

Determination of optimised cut-off grade utilising non-linear programming

One of the most fundamental problems in a mining operation is how to recognise an optimum cut-off grade, which defines the grade for discriminating between ore and waste in an ore body, including ore that is extracted at different periods over a mine life period. Therefore, the identification of an optimised cut-off grade (COG) is a crucial function which has to be monitored during the mine life. The main aim of this study is to propose a modified optimum COG model in order to maximise the profit value (PV) for mining projects. Maximising the PV of a mining operation, which is a non-linear programming, is subject to different constraints involving a general grade distribution within a deposit and three stages of production namely mining, concentrating and refining. The proposed computer-based model is more effective in long-term planning of the open pit mines. To provide a better understanding of the algorithm efficiency, a numerical example is given and subsequently solved based on the Lane algorithm. In order to achieve this, the LINGO software was employed.

Morgawr: an experimental Bronze Age-type sewn-plank craft based on the Ferriby boats

This paper reports on the construction of a full-scale Bronze Age-type sewn-plank boat based on the Ferriby boats. The boat, which was named Morgawr, was constructed in the National Maritime Museum Cornwall in Falmouth, England, during 2012 and the first months of 2013, as part of a larger exhibition in the museum. This paper provides the background and context of the project, describes the process of building the craft, and reflects in particular on differences between Morgawr and the ‘hypothetical reconstruction of a complete sewn-plank boat’ published in 1990 by Ted Wright and John Coates which formed the basis for this project.

AN IMPROVED TAPE ZERO GYRO-THEODOLITE CALCULATION TECHNIQUE

Abstract The tape zero or unknown equilibrium position of a suspended gyro has, in the past, been relatively difficult to determine accurately. Frequently, existing methods of tape zero determination have not accounted precisely for the influence of damping factors. This paper presents a new iterative method to establish estimates of the parameters for a damped oscillation model and locate its equilibrium position. Results have proved to be consistent with those obtained by more traditional methods and more reliable. Consideration is given to the possibility of applying similar techniques to the spun mode of operation of the gyro, and utilisation of automated timing.

From Boatyard to Museum: 3D laser scanning and digital modelling of the Qatar Museums watercraft collection, Doha, Qatar: J. P. COOPER ET AL.: 3D LASER SCANNING FOR WATERCRAFT RECORDING AND MODELLING

This article presents the results of a project to 3D laser scan and digitally model 14 watercraft from theQatarMuseums collection, comprising a range of regional vessels: most had not been surveyed previously. The project used the resulting point clouds generated 2D naval lines and orthographic records of the vessels in their current condition, and photorealistic 3D digital models for gallery display. This case study provides illustrative examples of the intermediate stages and final outputs. It assesses the pros and cons of 3D laser scanning as a survey technology for nautical scholars in terms of the time, cost, and skillset, as well as logistical considerations. It also compares the accuracy of traditional hand survey methods.

Determination of an optimum voxel size based on statistical methods in the Kahang Cu porphyry deposit, Central Iran

The aim of this study is to determine an optimum voxel size in the Kahang Cu porphyry deposit (Central Iran) using statistical parameters and vector analysis based on the 26 drilled boreholes. The mean, median and Median Absolute Deviation (MAD) were calculated for total distances between 14 pairs of closest boreholes in terms of X and Y directions. Based on the results, three block models were determined with 3 x 3 x 10 m3, 4 x 4 x 10 m3 and 5 x 5 x 10 m3 of voxel volumes for Cu distribution utilising inverse distance weighted (IDW) method. According to calculation of Non-Zero voxel numbers and decreasing of standard deviations and Cu average values, the block model with 4 x 4 x 10 m3 voxel sizes determined as an optimum block model.

3D laser scanning and modelling of the Dhow heritage for the Qatar National Museum

Curating boats can be difficult. They are complex structures, often demanding to conserve whether in or out of the water; they are usually large, difficult to move on land, and demanding of gallery space. Communicating life on board to a visiting public in the terra firma context of a museum can be difficult. Boats in their native environment are inherently dynamic artifacts. In a museum they can be static and divorced from the maritime context that might inspire engagement. New technologies offer new approaches to these problems. 3D laser scanning and digital modeling offers museums a multifaceted means of recording, monitoring, studying and communicating watercraft in their care. In this paper we describe the application of 3D laser scanning and subsequent digital modeling. Laser scans were further developed using computer-generated imagery (CGI) modeling techniques to produce photorealistic 3D digital models for development into interactive, media-based museum displays. The scans were also used to generate 2D naval lines and orthographic drawings as a lasting curatorial record of the dhows held by the National Museum of Qatar.