Methodology for quantitative rock characterisation using multiple imaging systems and random particles generation.

The characterisation technologies have advanced rapidly in the last decade. From a qualitative observation of minerals with optical microscopy, more quantitative techniques have emerged. Examples are the SEM-based technologies that focus on mineralogical identification at the microscale and the X-ray microtomography systems that allow identifying rock features in three dimensions. Features such as rock texture and mineralogy have a degree of control on how the rock behaves in the processing plant and thus can affect the project's economic feasibility. None of the available measurement devices is currently capable of identifying all the aspects of rock characteristics that are of interest in linking mineralogy and texture to process response in a single measurement. However, through the integrated use of the techniques in a complementary approach is possible to generate the required suite of information about the mineralogical composition and mineral grain size and shape in a given sample. A multisource method for rock characterisation has been developed in this work. This method includes: • A multistage imaging process that uses 2D and 3D microscopes • An object-segmentation technique to separate mineral grains in the photomicrographs for the quantification of mineralogical and textural properties. • A segmentation technique was developed to create particles of different sizes from a larger image.

Rapid, long-distance dispersal by pumice rafting.

Pumice is an extremely effective rafting agent that can dramatically increase the dispersal range of a variety of marine organisms and connect isolated shallow marine and coastal ecosystems. Here we report on a significant recent pumice rafting and long-distance dispersal event that occurred across the southwest Pacific following the 2006 explosive eruption of Home Reef Volcano in Tonga. We have constrained the trajectory, and rate, biomass and biodiversity of transfer, discovering more than 80 species and a substantial biomass underwent a >5000 km journey in 7-8 months. Differing microenvironmental conditions on the pumice, caused by relative stability of clasts at the sea surface, promoted diversity in biotic recruitment. Our findings emphasise pumice rafting as an important process facilitating the distribution of marine life, which have implications for colonisation processes and success, the management of sensitive marine environments, and invasive pest species.