TALKS BY PROF. J. RICHARD KYLE

Lecturer: Prof. J. Richard Kyle, C. E. Yager Professor of Geology, Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin. 2275 Speedway, C9000 Austin, Texas 78712-0254. E-mail: Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo. . Webpage:  https://www.jsg.utexas.edu/researcher/richard_kyle/

Date: Monday May the 19^th 2014, 15.00-17:00h.

Place: room 4

TALK 1 (15:00-16:00h)

Title:  High Resolution X-ray Computed Tomography Studies for Geological Materials: Emphasis on Contributions to Gold Ore Genesis and Processing

Abstract: High resolution X-ray computed tomography (CT) is the industrial equivalent of medical CAT scanning and provides a mechanism for non-destructive studies of the three-dimensional nature of geological materials.  HRXCT produces two-dimensional images ("slices") that reveal the interior of an object as if it had been sliced open along the image plane for viewing. A CT image is generated by differences in X-ray absorption that arise principally from differences in density within the object.  By acquiring a contiguous set of slices, a density map for all or part of a sample volume can be obtained, allowing three-dimensional inspection and measurement of features of interest. 

CT is particularly effective in the study of metallic ores that commonly contain minerals spanning the range of densities of natural materials. Available software can produce grain shape, size, and orientation data from the scanned volume, which can be particularly useful for oriented samples.  CT precisely defines the in-situ location of mineral grains of interest within a sample, which then can be studied in conventional petrographic sections, and other forms of data collected, e.g. isotope or trace element geochemistry.

This talk will review CT principles and diverse applications in geological sciences, with emphasis on ore deposits genetic and applied studies (Kyle et al., 2008; Kyle and Ketcham, in press). Emphasis will be placed on instrumentation, scanning protocols, and studies conducted at the High Resolution X-ray Computed Tomography facility at the University of Texas at Austin http://www.ctlab.geo.utexas.edu. 

For further information: Kyle, J.R., Mote, A.S., Ketcham, R.A. (2008): High resolution X-ray computed tomography studies of Grasberg porphyry Cu-Au ores, Papua, Indonesia. Mineralium Deposita, 43, 519-532.

TALK 2 (16:00-17:00h)

Title: Giant Pliocene porphyry-skarn Cu-Au deposits, Ertsberg District, Papua, Indonesia: Exploration, production and research in a challenging environment

Abstract: The Ertsberg-Grasberg district in Papua, Indonesia, hosts two giant porphyry and skarn-hosted Cu-Au systems that formed between 3.3 and 2.5 Ma in the Central Range that forms the Highlands of western New Guinea. These Cu-Au systems are associated with two dioritic intrusions, the Grasberg Igneous Complex and the Ertsberg Intrusive Complex, that were emplaced into a deformed sedimentary sequence of Cenozoic carbonate and late Mesozoic siliciclastic strata. Economic mineralization in each of these systems is vertically continuous over at least 1,500 m. Current original ore in place estimations (Leys et al., 2013) indicate that Grasberg-related system contains 7.5 Gt grading 0.70% Cu and 0.64 ppm Au in two deposits, the Grasberg porphyry system and the Kucing Liar skarn. The Ertsberg-related system contains 3.6 Gt grading 0.60% Cu and 0.44 ppm Au in four skarn deposits, the Ertsberg, the Ertsberg East Skarn System, the Dom, and the Big Gossan. All of these deposits represent hypogene mineral concentrations with high complementary gold values, anomalous aspects that makes this district one of the world’s great mineral districts.

This talk will present an overview of the University of Texas at Austin’s long term research in the Ertsberg-Grasberg district, with emphasis on the stockwork and skarn mineralization of the Ertsberg Intrusive Complex.   The challenges to exploration, mining, and research forms an appropriate context to review the region’s geologic, tectonic, and mineralization history.

Biografical summary: Rich Kyle is the C. E. Yager Professor of Geology at the University of Texas at Austin.  Most of his career has focused on strata-controlled metal and industrial mineral resources in sedimentary terranes. Dr. Kyle has conducted field work in more than 40 countries and has supervised more than 50 graduate and post-doctoral students on diverse research projects ranging from sedimentary basins at near surface to deep burial conditions, as well as the interactions of magmatic hydrothermal systems with reactive wallrocks.  He promotes the importance of field experience to complement the traditional classroom education and has led more than 40 major field trips for students, societies, and companies, including last week to Finland and Sweden.

Dr. Kyle’s current interests include the application of high resolution X-ray computed tomography to ore deposit studies, microbial involvement in geological processes, and the role of stratigraphic inheritance in controlling stratabound mineralization.  He has been active in several professional resource geology organizations, particularly the Society of Economic Geologists, for whom he served as an Associate Editor for Economic Geology, as well as the Thayer Lindsley Lecturer.  Dr. Kyle was the Editor-in-Chief for Ore Geology Reviews from 1990 to 2002.