Discovering the World’s Largest Caldera: An Interview with Geophysicist Jenny Anne Barretto - Part 2
by Marcelle P. Villegas - April 01, 2021
“I always say that you don’t have to be a genius or a math wizard to pursue a career in STEM [Science, Technology, Engineering, Mathematics]. It may mean working harder, but your love for learning and discovery will sustain you. Never stop being curious and take every opportunity to learn.” (Jenny Anne Barretto)
Last year, Philippine Resources Journal interviewed geologist and marine geophysicist Jenny Anne Barretto during an online talk show and forum in New Zealand titled “NetKapihan”. She shared the story on how she and her team discovered the world’s largest caldera located in Benham Rise (also known as Philippine Rise) – the Apolaki Caldera.
Ms Barretto is a Filipina scientist who works in GNS Science in New Zealand. She graduated with a degree in MSc Geology from the National Institute of Geological Science in University of the Philippines (UP). She was also an instructor in UP for five years.
Since 2007, she has been assisting coastal States like the Philippines and the Sultanate Republic of Oman in delineating their continental shelves as defined in UNCLOS Article 76. Ms Barretto was a key scientist of the technical working group that successfully confirmed the continental shelf of the Philippines in the Benham Rise region.
In 2019, Ms Barretto and two colleagues, Ray Wood and John Milsom, published a paper in Marine Geology Journal titled, “Benham Rise unveiled: Morphology and structure of an Eocene large igneous province in the West Philippine Basin”. In this paper, they reported the discovery of what may be the largest caldera in the world. They named this the Apolaki Caldera, a tribute to the "god of sun and war" in Philippine mythology. How big is this caldera? It has a diameter of ~150 km, which is 90 km bigger than the Yellowstone Caldera in Wyoming, U.S.A.
“My co-authors and I were part of the Benham Rise continental shelf technical working group. Back in 2008, we only analysed the bathymetric, geological and geophysical data for the purpose of proving that Benham Rise is part of the Philippine continental shelf. That is by showing that Benham Rise is physically connected to Luzon,” Ms Barretto said.
On Part 1 of our interview, she also discussed the possible mineral resources available in the area. “With the presence of the caldera, exploration geologists will say that the possible mineral resources are volcanogenic massive sulfide (VMS) deposits which are significant sources of metals (largely Cu, Zn, Pb ± Au).”
She also noted, “The available data supports our interpretation of the existence of the caldera. However, it is not impossible that other scientists or even us (me and my co-authors) may find later evidence refuting it. It’s just how science works.”
For part 2 of this interview, we shall discuss further the features of the Apolaki Caldera, its origins and possible dangers it might pose future. We also asked Ms Barretto about the difference between working as a scientist here in the Philippines and abroad, plus her message for young people who aspire to pursue a career in science.
PRJ: Bathymetric surveys were used to identify the morphology of the caldera. What other data sets (such as seismic or gravimetric surveys) are available to model not only the surface but also the structure of the caldera?
Ms Barretto: Yes, multibeam bathymetry data was the primary data used that led to the identification of the caldera. There is only one existing multichannel seismic reflection profile that crossed the caldera from which we identified ~1km of sediment fill, which is unusual for oceanic plateaus because these submarine features are commonly blanketed by thin sediments. Single channel seismic reflection profiles across Benham Rise show less than 500 m sediment blanket which is supported by drill cores from DSDP Site 292. There was also a 2D gravity model which included a thick pocket of sediments in the same location as that depicted on the seismic profile.
I went through all the data we have from 2008 and availed of other data in the public domain. Reading John Milsom’s previous interpretations of seismic and gravity data in Benham Rise, I realized that a way to explain the relatively thick pocket of sediments on the summit that he pointed out was the presence of a caldera. So that began our work together to prove or disprove the presence of a giant caldera on Benham Rise.
The seismic interpretation and gravity model were made years before we noticed the caldera feature. The presence of the caldera gave sense to the existence of the thick pocket of sediments.
Future work should include deep penetrating 2D multichannel seismic reflection survey complemented by gravity and magnetic studies would help verify the existence of the caldera and associated structures and could also provide insight into magma chamber dimension and geometry. And of course, ultimately drilling within the caldera feature to get rock samples.
PRJ: Apolaki Caldera would be far the largest caldera in the world with 150 km diameter. Circular morphological structures of that size are known from impacts of meteors. Hence, could this not be a large impact structure?
Ms Barretto: Yes, that’s a possibility that’s why in our paper we compared Apolaki’s morphology with both impact craters and known giant calderas. Results of that comparison exercise show that Apolaki exhibit more caldera-like features than impact crater-like features.
PRJ: Such a huge caldera requires a similarly large magma-chamber or call it a huge “hot-spot”. Hot spots in the earth mantle are relatively stable but the earth crust is moving over such a hot-spot and creates a chain of volcanoes (see Hawaii island chain). In the case of Apolaki, the crust was not moving over the hot spot and volcanic activities occurred at stable positions. Could that not be an indication that the volcanic activity was much smaller without forming a caldera? Hence, the structure might be caused by an impact?
Ms Barretto: Yes, huge calderas imply an underlying equally sized magma chamber. In our paper, we suggested that the formation of the Apolaki Caldera (the collapse) may not have been simply caused by magma withdrawal from its magma chamber. Pre-existing large scale structures (i.e. faults and rifts) related to seafloor spreading and rifting most likely facilitated the collapse.
The lithosphere on which Benham Rise (and of course, Apolaki Caldera) was moving over a hot spot. The mantle plume or hot spot supplying the magma chamber that formed Apolaki Caldera is believed (by scientists who have worked in the region) to coincide with a spreading ridge (the now extinct Central Basin Spreading Center). So as spreading was occurring, the lithospheric plates on either side of the spreading ridge were moving away from the ridge. At the same time, the mantle plume underneath was supplying magma in excess of what the spreading ridge would normally produce and therefore create a chain of oceanic plateaus. Each oceanic plateau is split as the lithospheric plates moved away from the spreading ridge creating paired plateaus on either side, like twins. Urdaneta Plateau is interpreted by many ay Benham Rise’s twin. They are equidistant from the Central Basin Spreading Center and have similar ages. Oki-Daito Rise is an older oceanic plateau on the Urdaneta Plateau’s side. It was hypothesized by Ishizuka et al. (2013) that its twin which is supposed to be on Benham Rise’s side has either subducted or accreted with the Philippines.
PRJ: Do you think the presence of the Apolaki Caldera will put the Filipino fishermen in danger in the future?
Ms Barretto: No. Available data show that volcanism ended on Benham Rise (including its spurs) about 26 million years ago. Threat of a volcanic eruption in that area is very low.
PRJ: What are your future projects or current endeavours with regards to marine geophysics and geology?
Ms Barretto: For New Zealand, I’m currently involved in a research programme looking at next generation geothermal resources. I help put together available magnetic data for the Taupo Volcanic Zone which will help find deeper geothermal energy sources.
I’m also leading a science education outreach project funded by the NZ government. My team and I will bring an augmented reality sandbox in different remote North Island primary schools teaching students about land and water interaction.
For the Philippines, I’m currently doing research with John Milsom and Ronaldo Gatchalian of NAMRIA about the gravity variations over the Zambales Ophiolite. There’s also ongoing work to explain the Luzon syntaxis (the bent shape of Luzon).
There’s more work to be done on Benham Rise, but at the moment we are unable to find funds to do them.
PRJ: What are some of the challenges or difficulties you have experienced as a geologist/marine geophysicist in the Philippines? How does it compare pursuing this career in New Zealand?
Ms Barretto: Funding for research is always a challenge for scientists anywhere in the world, but more so in developing countries like the Philippines. Like anywhere, we scientists in NZ need to write proposals and compete for government funding. However, there is more funding for research available here in NZ than in the Philippines. There is more support for scientists.
Working in NZ is also more relaxed with no need to beat the traffic to and from work. Even if government pay in NZ is less compared to industry, it is still enough to have a decent living. Back in PH, I have to do consultancy work in addition to my teaching job at UP to make ends meet.
PRJ: For the young people, what message would you like to impart to them that would encourage them to pursue a career in geology or in any field in science?
Ms Barretto: I always say that you don’t have to be a genius or a math wizard to pursue a career in STEM [Science, Technology, Engineering, Mathematics]. It may mean working harder, but your love for learning and discovery will sustain you. Never stop being curious and take every opportunity to learn.
Thank you, Ms Jenny Anne Barretto for sharing your amazing story, and GNS Science for the opportunity to write about this discovery and study. Thank you, Sir Rene Molina and NetKapihan for inviting me as panelist in your radio show in New Zealand. PRJ would also like to thank Dr Friedrich Bandelow for his contribution in the technical discussion in the interview, and science journalist Angelica Yang for guidance and support.
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Philippine Resources - May 23, 2023
MEMORANDUM OF AGREEMENT SIGNED WITH TVI RESOURCE DEVELOPMENT (PHILS.) INC.
Photo credit: TVI Resource Development The Board of RTG Mining Inc. is pleased to announce that a comprehensive settlement of all outstanding issues with the Villar Family controlled Sage Capital and TVI Resource Development (Phils.) Inc. (“TVIRD”) has been reached and a binding Memorandum of Agreement signed. On execution of the final documents, expected in the next month, all litigation that RTG had launched will be withdrawn as part of an agreed restructuring of the Mabilo Project. The Villar Family is one of the most prominent families in the Philippines and RTG is pleased to partner with them in the development of the Mabilo Project, which is a significant mining project for the country. The key terms of the agreement for RTG include the following: RTG (through SRM Gold Limited) will retain a 40% interest in Mt. Labo Exploration and Development Corporation (“Mt. Labo”) with the project also developed by Mt. Labo, in line with Philippine regulatory requirements, with Sage Capital (which is owned by TVIRD) holding the remaining 60%; RTG will have a 2% net smelter royalty (“NSR”); RTG’s debt together with interest, currently in the order of US$27M (subject to audit) will be repaid out of the proceeds of Stage 1 of the project, the Direct Shipping Operation subject to customary requirements to address liquidity and ongoing operations of Mt. Labo; Funding arrangements for the project as between the major shareholders of Mt. Labo have been successfully renegotiated, (relieving RTG of a sole funding obligation) and replaced with a pro-rata funding obligation, together with a disproportionate funding obligation of Sage Capital, as set out below; With debt repayments in full and the NSR, RTG will be entitled to approximately 57% of the proceeds of Stage 1, the Direct Shipping Operation; RTG will be entitled to 40% of the operating cashflow of the project, together with the 2% NSR and repayment of its debt, which is currently in the order of US$27M; The first US$5M of expenditure for Mt. Labo (or 12 months of expenditure, whichever occurs the earlier), will be funded pro-rata between the two shareholders (ie RTG will provide 40%) and thereafter, Sage Capital/TVIRD will sole fund the next US$5M of expenditure, with all additional funding thereafter to be provided on a pro-rata basis; All parties are required to act in the best interests of the project and not compete; A shareholders’ agreement will be finalised which will provide typical minority interest protection clauses including reserve matters for voting including annual budgets and appointments of key personnel; Any disputes will be resolved by the Singapore International Arbitration Centre; and On completion of final signed documents, all litigation matters will be withdrawn and settled in full. With the restructuring of the Mabilo Project now agreed, over the balance of this year, the remaining permitting matters and financing plans will be finalised, a review of the 2016 Feasibility Study will be completed, together with finalising the acquisition of surface rights, following which, a commitment to development will be formalised by the Board of Mt. Labo. RTG is pleased with the outcome of the discussions and the co-operative and constructive approach adopted by the Villar Family representatives. RTG believes they can be a strong and positive partner to work with to take the Mabilo Project forward, with both a near term development and future exploration activities to expand the project, which will start to unlock the value of the project for all stakeholders, not only the local communities but for the country as a whole.
Philippine Resources - May 22, 2023
Mining Operational Excellence Through Digital Transformation
Part 1: Mining Operation Challenges and Mine Operations Management Domains 1 & 2. By Mae Ann Cabasag, EM Mining companies encounter numerous challenges throughout their operations. However, initiatives to mitigate these challenges and improve efficiency are often limited. Most of these limitations emanated from a common factor: the challenge of “poor visibility” in mining operations. A viable solution is to adopt digital transformation in mining operations by incorporating available real-time data into an integrated system— capable of ensuring automatic updates and reliable source of information. Through this, mining companies not only understand simulations and plans developed but also anticipate potential outcomes. Various mining industry analysts have found that using non-digital methods in the mining operations can lead to a 27% reduction in production time and 25% increase in data inaccuracy. For a mining company to remain competitive in an industry susceptible to operation challenges, i.e. production processes, workers’ and equipment performances, ore quality and quantity, compliance to regulations, and inter-departmental collaboration, it needs to embrace digital transformation. Dassault Systèmes Mine Operations Management provides transformative digital solution for mining companies to achieve excellence in their operations. Mine Operations Management (MOM) equips mining companies with an integrated system for their mining operations, enabling them to achieve efficient plan and schedule. This system integrates entire operation data into a single repository source of information, known as the “single source of truth”, ensuring complete transparency of the company’s processes from mine to port. By leveraging MOM, we can address the following global mining industry challenges: Maintaining competitiveness amidst market volatility. Eliminating waste materials, poor communication, and error duplication. Improving site productivity and efficiency. Utilizing assets and sharing best practices across the value chain. Ensuring an utmost level of safety. Reducing environmental impacts and achieving sustainable operations. The transformative digital solution, Mine Operations Management, is composed of eight work packages, split across four domains, namely: Data Management, Material Reconciliation, Operational Control, and Assets Performance. These domains help generate valuable insights from integrated operational data for rapid and informed strategic decision-making. The Data Management consists of Master Data Model and Integration Framework packages essential for material tracking, stockpile management, task and workforce management, machine performance, and asset maintenance. It enables users to manage master data objects such as Site, Material, Location, Equipment, and Operator through manual data entry or third-party source systems. With this, mining companies can ensure efficient and integrated management of critical data required for seamless operations. Material Reconciliation, on the other hand, consists of Material Tracking and Stockpile Management packages. Material Tracking enables us to track material movements across different stages, i.e. from the least accurate grade estimated in geological model to the most precise information on shipped material quantity and quality, to account for any inaccuracies. While in the Stockpile Management, users not only can calculate daily stockpile balance, add Survey or Sampling data, analyze inventory levels and trends, create graphical representation of the stockpile balances and movements, calibrate stockpile using volumetric survey and sampling, enables comparison of different models, track movement genealogy and review stockpile slices for stockpiles with LIFO and FIFO calculation type but can create a different type of analysis such as actual vs plan vs model. In the upcoming article, we will explore the two remaining domains of Mine Operations Management to where assigning operational tasks, tracking compliance to plan, monitoring equipment down to workers’ performance are feasible in the mining operations. To know more about MOM, mining innovations and solutions, contact Dassault Systèmes Value Solutions Partner: Paramina Earth Technologies Inc. through firstname.lastname@example.org References: Make it happen for mine execution excellence: Dassault Systèmes®. MEGATrends. (n.d.). https://events.3ds.com/make-it-happen-for-mine-execution-excellence Dassault Systèmes. (2021, August 12). Digging deeper: The virtual solution for Mining Operational Excellence. Dassault Systèmes. https://discover.3ds.com/virtual-mining-operational excellence dassault3ds. (2022, June 16). The mining industry needs to adapt, but how? Dassault Systèmes blog. https://blog.3ds.com/brands/delmia/the-mining-industry-needs-to-adapt-but-how/
Philippine Resources - May 22, 2023
Customer’s First Choice: Sandvik Philippines Delivers 11th and 12th Pantera DP1500i Drills to Filminera Resources Corporation
Sandvik Philippines has successfully commissioned and delivered to loyal customer Filminera Resources Corporation (“Filminera”) their 11th and 12th Pantera DP1500i Top-hammer Surface Drills last 25 January 2023 at the Masbate Gold Project (MGP) located in Masbate Island, Philippines. Photo shows Sandvik Technician Larry Lugnas (second from left) and Service Operations Manager Jorge Cabello (third from left) handing over the drills to MGP representatives. Located 360 km southeast of Manila, the Masbate Mine is operated by Filminera, the Philippine subsidiary of TSX- and NYSE-listed B2Gold with headquarters in Vancouver. In 2022, the mine produced a record-setting 212,728 oz of gold out of 7.93M tonnes of ore milled at an average grade of 1.11 g/t. B2Gold also operates the Fekola Mine in Mali and the Otjikoto Mine in Namibia. Their projects under development include the Anaconda Area in Mali and the Gramalote JV Project in Colombia. The Masbate Mine started operating in 2008 initially using 4 x Atlas Copco ECM660 Drills owned and operated by the erstwhile mining contractor, Leighton. When the opportunity for re-fleeting came about in 2012, Sandvik succeeded in winning the tender which came packaged with a full maintenance contract for 24,000 service meter hours of five years. Ironically, the said maintenance contract almost led to the cancellation of the order for the first 4 x DP1500i due to a dispute with the rates. Eventually, both Leighton and Sandvik were able to arrive at a mutually acceptable arrangement, and Sandvik ran the service contract for five years without incurring penalties in the availability guarantees. The contract was so profitable, Sandvik even had to share some of the residual profit at the end with Filminera under the pain-and-gain proviso of the contract. The next re-fleeting opportunity came in 2017, with the Masbate Mine. This time, there was no service contract attached to the equipment and Leighton was no longer the mining contractor; the mine has shifted to owner-miner operation. Sandvik managed to secure the repeat order for another batch of 4x DP1500i, banking on the proven performance and reliability of the first four. That brings the total to 8 units. Drill numbers 9 and 10 were ordered in July 2020 and delivered in 2021. Numbers 11 and 12 in the photo above were ordered in January 2022 and are now handed over to the customer. Filminera ordered two more DP1500i’s in November 2022; these machines are now awaiting completion in Tampere, for delivery later this year. That should bring the total to 14 x DP1500i units spread over 11 years for our most loyal Pantera DP1500i customer in the Philippines – Filminera Resources Corporation!
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