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Yanacocha high-sulfidation epithermal deposit, Peru
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My CV

Zhaoshan Chang's CV

PDF document icon Resume_20180117_Zhaoshan Chang.pdf — PDF document, 355 KB (363888 bytes)

Honours Projects - 2012

1. Geological characteristics and ore genesis of the Welcome gold Prospect, Mingela, Queensland, Australia

Honours student: Greg Clapin


2. Paragenesis and alteration zonation of the Candelabro porphyry Cu-Mo project, Chile

Honours student: Adam Wilson


3. Study of the Ben Lomond uranium and molybdenum deposit, Hervey Range, Queensland, Australia

Honours student: Bill Andrews


4. Zonation, paragenesis, and origin of the Iron Glen Fe skarn, Queensland, Australia

Honours student: Aaron Wilhelmsen

PDF document icon 2013 Honours_Thengkham_Sepon.docx.pdf — PDF document, 70 KB (71839 bytes)

PDF document icon 2013 Honours_Houay Yeng_Sepon.docx.pdf — PDF document, 74 KB (75840 bytes)

PDF document icon 2013_Honours_TennantCreek.pdf — PDF document, 76 KB (78663 bytes)

Available PhD projects - Steam heated alteration

Steam-heated alteration: Identification, genesis, and application in exploration for epithermal deposits [pdf]

 

Supervisor: Dr. Zhaoshan Chang, Prof. Noel White, and Prof. Tom Blenkinsop

 

Introduction/background

Steam-heated alteration consists of a blanket of altered rocks near present-day or paleo-surface. Around the water table it is typically composed of fine-grained porous to massive silicic rocks whereas the upper part is typically friable, consisting mainly of fine-grained alunite, kaolinite and quartz. Ancient steam-heated blankets typically have their friable upper parts weathered away, leaving behind only the siliceous layer.

Steam-heated blankets formed from acid water produced by condensation of vapors boiled from geothermal waters in the vadose zone (e.g, Hedenquist et al., 2000). Steam-heated blankets may occur above high-sulfidation epithermal deposits (HS), and intermediate- or low-sulfidation epithermal deposits (IS/LS; e.g., Hedenquist et al., 2000). If there were fluctuating levels of the water table and multiple epithermal mineralisation events, e.g., at Yanacocha, Peru (Longo et al., 2010), there may be multiple levels of steam-heated blankets.

Stream-heated blankets cause difficulties in exploration for several reasons: 1) Steam-heated blankets may overlie altered rocks related to epithermal deposits, and so prevent ore-related alteration from being detected; 2) the very fine-grained silicic rocks may appear similar to massive silicic rocks closely associated with mineralisation in high-sulfidation epithermal deposits (e.g., Chang et al., 2011), or to silica sinter, thereby causing confusion in interpretation; and 3) they may occur above epithermal deposits of any type, making it difficult to discriminate the potential for different types of epithermal mineralisation.

Most of the difficulties arise because of difficulties discriminating massive silicic rocks related to different epithermal deposit types. However in the recent years, there has been significant progress in technology, such as cathodoluminescence imaging (CL) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), that allow us to examine steam-heated blankets with better methods and lower detection limits for trace elements (e.g., Gotez et al., 2005; Landtwing et al., 2005; Rusk et al., 2006; Rusk et al., 2008; Breiter and Muller, 2009; Jourdan et al., 2009; Muller et al., 2009). With the new technologies we will be able to investigate more primary rock features, particularly cryptic textures and trace element compositions that are related to physicochemical parameters such as temperature, pressure, pH and redox state, thereby helping tackle the problems.

Aims and Objectives

In this study we aim to:

  1. Find reliable ways to identify steam-heated silicic rocks, and to distinguish them from silicic rocks associated with different types of epithermal systems (both productive and barren)
  2. Evaluate the potential to use steam-heated blankets to vector towards mineralisation beneath them
  3. Improve the understanding of the genesis of steam-heated alteration based on new data obtained during the project.

Implications

This study will develop criteria to help explorers to distinguish massive silicic rocks from various epithermal environments, thereby helping the industry to recognise covered targets. The project will also endeavour to define vectors in steam-heated blankets to identify mineralised areas beneath the blanket. If successful, these will enhance exploration efficiency and success rates. The data obtained will also help to constrain hypotheses about the formation of steam-heated blankets, thereby refining and improving our understanding of their genesis.

References

Breiter and Müller. 2009. Evolution of rare-metal granitic magmas documented by quartz chemistry: Eur. J. Mineral., v. 21, p. 335-346.

Chang, Z., Hedenquist, J.W., White, N.C., Cooke, D.R., Roach, M., Deyell, C.L., Garcia, J. Jr., Gemmell, J.B., McKnight, S., and Cuison, A.L., 2011, Exploration tools for linked porphyry and epithermal deposits: Example from the Mankayan intrusion-centered Cu-Au district, Luzon, Philippines: Economic Geology, p. 1365-1398.

Gotze, et al., 2005. Structure and luminescence characteristics of quartz from pegmatites: American Mineralogist, v. 90, p. 13-21.

Hedenquist, J.W., Arribas, A., and Gonzalez-Urien, E., 2000, Exploration for epithermal gold deposits: Reviews in Economic Geology, v. 13, p. 245–277.

Jourdan A et al., 2009. Evidence of growth and sector zoning in hydrothermal quartz from Alpine veins: Eur. J. Mineral., v. 21, p. 219-231.

Landtwing et al., 2005. Relationships between SEM-cathodoluminescence response and trace-element composition of hydrothermal vein quartz: American Mineralogist, v. 90, p. 122-131.

Longo, A.A., Dilles, J.H., Grunder, A.L., and Duncan, R., 2010, Evolution of calc-alkaline volcanism and associated hydrothermal gold deposits at Yanacocha, Peru: Economic Geology, v. 105, p. 1191-1241.

Müller et al., 2010. Trace elements and cathodoluminescence of quartz in stockwork veins of Mongolian porphyry-style deposits: Miner Deposita, v. 45, p. 707-727.

Rusk et al., 2006, Intensity of quartz cathodoluminescence and trace-element content in quartz from the porphyry copper deposit at Butte, Montana: American Mineralogist, v. 91, p. 1300-1312.

Rusk et al., 2008, Trace elements in hydrothermal quartz: Relationships to cathodoluminescent textures and insights into vein formation: Geology, v. 36, p. 547-550.

PDF document icon Proposal_SteamHeated_Web.pdf — PDF document, 95 KB (98291 bytes)

PDF document icon Project description_Antamina_20121119.pdf — PDF document, 52 KB (53860 bytes)

Available PhD projects - Antamina, Peru

Uplift history, intrusive sequence, and skarn mineralisation at the giant Antamina deposit, Peru [pdf]

 

Supervisor: Zhaoshan Chang


Introduction and background

Antamina is one of the world’s giant ore deposits and the largest known skarn deposit. The current resources are 1934 Mt of ore averaging 0.84% Cu, 0.54% Zn, 9.8 g/t Ag and 0.019% Mo (proven and probable ore reserves plus measured, indicated and inferred resources; based on Antamina announcement on March 16, 2011; http://www.antamina.com/en/content.php?825/news_and_publications/compa_ia_minera_antamina_s_a__announces_updated_mineral_resource_and_ore_reserve_estimates.html). The mineralisation is still open at depth. The mine design indicated that it would be the world’s 3rd largest producer of concentrates, with 3rd largest annual production of Zn and 7th largest annual production of Cu (Redwood, 1999).

There are abundant endoskarns and exoskarns at Antamina. The skarns occur above, surrounding and in an intrusion complex mainly composed of porphyritic, monzogranitic rocks (Love et al., 2004). Numerous intrusions have been noticed during logging, indicated by sharp contact boundaries and chilled margins, but the exact phases and intrusive sequence are yet to be documented. Recent deep drilling has shown that the skarns extend for at least 2 km to the depth, and grade/mineralisation is generally stable over the ~2 km vertical internal. In most of the drilled, upper part of the intrusion complex, there are minor porphyry-style quartz veins but with almost no mineralisation (Larry Meinert and Steve Windle, 2012, personal communication). Recent deep drill holes exposed more breccias with chalcopyrite mineralisation in the intrusive complex at the end of the holes, which was suspected to indicate a transition to porphyry-style mineralisation (Steve Windle, 2012, personal communication).

Aims and key questions to address

Why the Antamina skarn is so big? There must have some unusually favourable conditions working together to make this giant deposit. This study will try to decode the secret ingredient of the abundant mineralisation. In particular, the project will address:

1)   What made the vertical extension of skarn mineralisation so long, up to 2 km?

2)   What are the intrusive phases and what is the intrusive sequence? Which phase(s) caused skarn formation and mineralisation?

3)   The uplift and erosion history during the formation of the skarns, and its relationship with skarn mineralisation

4)   The transition from skarn to potential porphyry mineralisation

5)   The reason of the unusual proximal Zn mineralisation. Typically Zn is distal and Cu is proximal. But at Antamina Zn mineralisation occurs together with Cu mineralisation. Chang and Meinert (2004, 2008) proposed that similar proximal Zn mineralisation at Empire skarn, Idaho, was perhaps related to high F activities. Is F also the reason at Antamina? Could F also have contributed to the abundance of mineralisation?

The project will improve the understanding of the formation processes, and thereby help exploration to further depth, in the peripheral areas around Antamina, and elsewhere in the world.

References

Chang, Z., and Meinert, L.D., 2004, The magmatic-hydrothermal transition - Evidence from quartz phenocryst textures and endoskarn abundance in Cu-Zn skarns at the Empire Mine, Idaho, USA: Chemical Geology, v. 210, p. 149-171.

Chang, Z., and Meinert, L.D., 2008, The Empire Cu-Zn Mine, Idaho, USA: Exploration implications of unusual skarn features related to high fluorine activity: Economic Geology, v. 103, p. 909-938.

Love, D.A., Clark, A.H., and Glover, J.K., 2005, The lithologic, stratigraphic, and structural setting of the giant Antamina copper-zinc skarn deposit, Ancash, Peru: Economic Geology, v. 99, p. 887-916.

Redwood, S.D., 1999, The geology of the Antamina copper-zinc skarn deposit, Peru: The Gangue, Nesletter of the Mineral Deposits Division, Geological Association of Canada, issue 60, p. 1-7.

Facilities at EGRU / JCU

PDF document icon EGRU_Facilities.pdf — PDF document, 2.59 MB (2714903 bytes)

EGRU analytical capacities

PDF document icon EGRU_Analytical capacity.pdf — PDF document, 52 KB (53419 bytes)

投资澳洲矿业研修班:课程介绍和报名表

Investing in Australia's Minerals Industry: Short course information and registration form

PDF document icon 投资澳洲矿业研修班_课程介绍和报名表-2013.pdf — PDF document, 895 KB (916581 bytes)

PDF document icon Hongshan_PhD_Project.pdf — PDF document, 79 KB (81656 bytes)

PhD project: Zonation and genesis of the Red Mountain – Red Bull skarns, Shangri-la (Zhongdian), Yunnan Province, China, and the implications to exploration

 

Supervisor: Dr. Zhaoshan Chang

July 2013

 

Background

 

The Red Mountain – Red Bull (RMRB) Cu skarn is located ~40 km NE of the Shangri-la (Zhongdian) city in NW Yunnan Province, China. It is in the middle part of the Pulang Mineral District (PMD) that is rich in porphyry-skarn mineralisation. The geographical range of the PMD is E 99°43’34’’-100°13’58’’,N 27°41’00’’-28°32’00’’. The PMD is 30-40 km wide (W-E) and ~ 100 km long (N-S), covering an area of ~3500 km2.

 

The PMD is one of the most significant porphyry-skarn districts in China. It contains numerous porphyry-style and skarn deposits and prospects. The larger ones include the Pulang porphyry deposit (~5 Mt Cu metal averaging ~1% Cu), the Xuejiping porphyry deposit (~2 Mt of Cu metal) and the RMRB skarns. The Red Mountain Cu skarn contains ~ 230,000 tonnes of Cu metal (Yunnan Bureau No. 7 Geological Team, 1971), and the Red Bull Cu skarn nearby and likely to be of the same system contains ~350,000 tonnes of Cu metal (Yunnan Copper, 2011). These are Large (>0.5 Mt Cu metal) and Super-Large (>2.5 Mt Cu metal) deposits in Chinese standard.

 

The PMD is located in the southern part of the Yidun Island Arc (YIA; Zhang Zhimeng, 1979), which in turn is in the Three River Tectonomagmatic Belt (Hou Zengqian et al., 1991, 1993, 1995; Mo Xuanxue et al., 1993), a belt rich in magma-related hydrothermal mineral deposits. The YIA is within the Tethys tectonic domain, and has gone through Indosinian subduction, late Yanshanian collision and Himalayan strike-slip orogeny (Hou Zengqian et al., 1991, 1993, 1995; Mo Xuanxue et al., 1993).

 

The project

 

Despite the large size of the deposit, there has been little systematic research on the RMRB skarns. This project will document the geological and geochemical features, investigate the zoning patterns and paragenesis, infer the genesis, and find out the major controls on mineralization to help with further exploration. The project will focus on:

 

  1. Intrusive sequences and the causative intrusion features
  2. Features of wall rocks, alteration, and mineralization
  3. Zoning patterns and controlling factors (e.g., Meinert, 1997; Chang and Meinert, 2008) in mineralogy, texture, Short Wave Length Infra-Red (SWIR) spectral features (e.g., Chang and Yang, 2012, and references therein), mineral chemistry (major and trace, e.g., Chang et al., 2011), and isotopic signatures.
  4. Paragenesis of alteration, mineralization and other events
  5. Evolution of the hydrothermal fluids in physicochemical conditions (P, T), in composition (salinity, single fluid compositions) and fluid nature (magmatic, meteoric, mixed), and its relationship with mineralization.

 

This project will use the following techniques: mapping, drill core logging, SWIR spectral techniques, BSE, CL, microprobe, XRD, fluid inclusion thermometric techniques, LA-ICP-MS analysis of minerals and single fluid inclusions, trace element mapping using microprobe, PIXE or LA-ICP-MS, dating, and stable isotopes (O, H, S, C, Cu, Fe, Zn).

 

The project will be supported by James Cook University, a China Geological Survey project at China University of Geosciences, Beijing, and the State Key Laboratory of Ore Deposit Geochemistry (Guiyang) open research fund.

 

Application

 

International students whose native language is not English need to meet the JCU English requirements (http://www.jcu.edu.au/international/apply/entry/JCUPRD1_073732.html) to be eligible to apply.

 

The application deadlines for the JCU Postgraduate Research Scholarship (JPRS; provides living allowance) and the International Postgraduate Research Scholarship (IPRS; covers international student tuition fees and medical insurance) is 30 August. Please see details at http://www.jcu.edu.au/international/scholarships/JCUPRD_016792.html.

 

Chinese students may also apply for CSC (Chinese Scholarship Council) scholarship. The deadline is 9 February each year. Results will be announced by 30 May. Students are expected to start in September or later the same year. For details, please see http://www.jcu.edu.au/grs/scholarships/JCUDEV_015568.html

 

Please send CV, informal transcripts, statement of research interests and career goals, English test results, and publications or thesis for initial evaluation before submitting scholarship applications.

PDF document icon Honours_201308_ErnestHenry_v2.pdf — PDF document, 66 KB (67846 bytes)

PhD project - FSE, Philippines

PDF document icon PhD Ad_FSE_Final.pdf — PDF document, 64 KB (65708 bytes)