Joseph Espi

Prof. Dr. Joseph Espi

School of Natural & Physical Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
29 November 2023 in Geosciences
Verified
Journal Article
Open access
PDF file
NMNathan Mosusu
Nathan Mosusu
GMGideon Maim
Gideon Maim
Michael PettersonMichael Petterson
Michael Petterson
RHRobert John Holm
Robert John Holm
ALArnold Lakamanga
Arnold Lakamanga
JEJoseph Espi
Joseph Espi
Geoscientists are involved in both the upstream and downstream side of the extractive industries. As explorationists and field geologists, they are often the first technical people related to extractive industries that communities meet. It is imperative in an increasingly globalized and holistic world that geoscientists gain greater awareness of the socio-economic impact of extractive industries and become a more proactive part of improving outcomes for all with respect to extractive industries. When Jigme Singye Wangchuk, the King of Bhutan, first suggested the concept of ‘Gross National Happiness’ (GNH) in 1972, it was met with widespread cynicism and puzzlement. Was the concept meaningful in a hard, economically competitive world? A series of measures, including the Human Development Index (HDI), the Gini Coefficient (GC), and the now annual World Happiness Report (WHR), are evolutionary responses to the 1972 GNH and are widely accepted as proxy measures of holistic human progress. These measures go beyond the narrow confines of Gross Domestic Product and similar economic proxies, placing economic parameters alongside the social, environmental, spiritual, human rights, health, and holistic societal issues. The broad conclusions of the plethora of metrics are that ‘happiness’ links to issues and ideas such as equity, minimal economic inequality, excellent governance, human rights, individual freedom, and so forth. We ask the question: what is the relationship between extractive industries (EIs) and GNH? We present a wide range of data and analytical diagrams/text examining potential correlations and associations between GNH and EIs. We examine potential relationships using global data and case studies for Papua New Guinea, Mongolia, the DRC, and Jamaica. The conclusions of this analysis of course suggest a complex relationship between EIs and GNH. We acknowledge that in situations of weak governance and institutions, EIs struggle to make any tangible difference with respect to GNH. A counter conclusion that EIs may even be a major cause of weak governance, which in turn suppresses happiness, must be seriously considered. We document examples where EIs have made a definitive positive improvement to GNH. Data suggest that hydrocarbon-rich countries have made better progress with respect to GNH than mineral-rich countries. However, the main conclusion is that the link between EIs and GNH remains a work in progress, and that a narrow focus on profit and shareholder return is an antithetical approach to the GNH paradigm. A key recommendation is that industry must adopt a far more active role (rather than merely a passive role) with respect to translating the many potential benefits of EIs into GNH than has hitherto been the case.

24 August 2023 in Geosciences
Verified
Journal Article
Open access
PDF file
OPOlive L Ponyalou
Olive L Ponyalou
Michael PettersonMichael Petterson
Michael Petterson
JEJoseph Espi
Joseph Espi
Feni is located at the southeastern end of the NW-trending Tabar–Lihir–Tanga–Feni (TLTF) volcanic island chain, in northeastern Papua New Guinea. This island chain is renowned for hosting alkaline volcanics, geothermal activity, copper–gold mineralization, and mining. There is no agreed consensus on the tectonic and petrogenetic evolution of Feni. Thus, the purpose of our paper is to present the geology of Feni within the context of the regional tectonic evolution of the TLTF chain and offer a succinct and generic geodynamic model that sets the stage for our next paper. The methodologies used in this study include a critical review of published and unpublished literature in conjunction with our geological observations on Feni. The Pliocene-to-Holocene TLTF chain is a younger arc situated within the greater Eocene-to-Oligocene Melanesian Arc bounded by New Ireland to the west, the Kilinailau Trench and Ontong Java Plateau in the east, and the New Britain Trench to the south. The geological units mapped on Feni include a large volume of basaltic lava flow and trachyandesite stocks intruding a limestone and siltstone basement. Younger units include the trachyte domes, pyroclastic flow, and ash fall deposits. The major structures on Feni are normal or extensional faults such as the Niffin Graben. Feni magmatism is attributed to the petrogenetic processes of polybaric or decompression melting and crystal fractionation of magmas previously influenced by sediment assimilation, mantle wedge metasomatism, slab tears, slab melts, and subduction. Deep lithospheric normal faults provide the fluid pathways for the Feni alkaline magmas.

6 November 2023 in Geosciences
Verified
Journal Article
Open access
PDF file
OPOlive L Ponyalou
Olive L Ponyalou
Michael PettersonMichael Petterson
Michael Petterson
JEJoseph Espi
Joseph Espi
Ambitle in the Feni Island Group is located within the NW trending Tabar–Lihir–Tanga–Feni (TLTF) volcanic island chain, Melanesian Arc, northeastern Papua New Guinea. The TLTF chain is renowned for its alkaline magmatism, geothermal activity, copper–gold mineralization, and world-class gold mining. Although its geochemical patterns indicate island arc signatures (i.e., high LILE and depleted HFSE), TLTF volcanism is not directly related to the older Melanesian Arc subduction system. However, it may have been influenced by source mantle metasomatism linked to the older subduction. The purpose of this study is to (1) present and interpret the petrographic, mineralogical, and geochemical data from Feni within the context of the tectonic evolution of the TLTF and (2) propose a geodynamic, petrogenetic model for the Feni volcanic rocks. The key methodologies used in this study are field mapping and sampling, petrographic analysis using the optical microscope, whole-rock geochemical analysis via XRF and ICP MS, and mineralogical analysis using an electron microprobe. The main rock types sampled in this study include feldspathoid-bearing basalt, trachybasalt, phonotephrite, trachyandesite, and trachydacite. Minerals identified include forsteritic olivine, diopside, augite, labradorite, andesine, anorthitic plagioclase, nepheline, and leucite in the primitive mafic suites, whereas the more evolved intermediate and felsic hypabyssal suites contain amphibole, albite, orthoclase, biotite, and either rare quartz or feldspathoids. Amphibole composition is primarily magnesiohastingsite with minor pargasite formed under polybaric conditions. Accessory minerals include apatite, titanite, and Ti-magnetite. We propose that limestone assimilation followed by fractional crystallization are plausible dominant processes in the geochemical evolution of the Ambitle volcanics. Clinopyroxene fractionation is dominant in the mafic volcanics whereas hornblende fractionation is a major petrologic process within the intermediate suites proven by the enrichment of LREE and depletions in MREE and HREE. Feni magmas are also highly enriched in REEs relative to neighboring arcs. This study is globally significant as alkaline magmas are important sources of Cu, Au, and REE as critical elements for green energy and modern technology.

9 August 2021 in Geosciences
Verified
Journal Article
Open access
PDF file
MLMoira Lunge
Moira Lunge
JEJoseph Espi
Joseph Espi
Studying elemental geochemistry of hypogene sulphides can discriminate the hydrothermal fluids responsible for ore formation. To determine whether Golpu porphyry Cu-Au deposits are related to the Nambonga North porphyry system which is located 2.5 km apart in the Wafi-Golpu Mineral District, Papua New Guinea, we compare the trace element compositions of drill core chalcopyrites and pyrites analysed using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). The results for the Golpu chalcopyrites revealed high concentrations of Au, As, Se, Mo, Sb, Te and Bi and lower concentrations of Ag and Zn compared to those from Nambonga. Pd and Pt were below the detection limit in chalcopyrites for both deposits. The results for the Golpu pyrites indicated high concentrations of Pt, Au, Se, Mo, Sb, and Te and lower concentrations of Cu, Zn, As, Ag, Pb, Pd and Bi compared to those from Nambonga North. Au concentrations in the pyrites from both the porphyry deposits were higher compared to chalcopyrites, which mean that pyrite is the Au-bearing sulphide responsible for the higher Au content. In contrast, Cu values in pyrites from Nambonga North are higher than those from Golpu. Overall, it is envisaged that the ore fluids were exsolved at different times during the evolution of both porphyry deposits, although these porphyry centres may be related in space and time.

14 June 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
OPOlive L Ponyalou
Olive L Ponyalou
Michael PettersonMichael Petterson
Michael Petterson
JEJoseph Espi
Joseph Espi
Ambitle in the Feni Island group is located at the southeastern end of the NW trending Ta-bar-Lihir-Tanga-Feni (TLTF) island chain, northeastern Papua New Guinea. This island chain is known for the presence of alkaline magmas, geothermal activity, copper-gold mineralization, and mining. The purpose of this study is to present and interpret the petrographic, mineralogical, and geochemical data of the subaerial volcanic rocks from Feni within the context of the tectonic evolution of the TLTF. The TLTF arc is a younger arc situated within the Greater Melanesian Arc, specifically the New Ireland Basin bounded by New Ireland and the extinct Kilinailau Trench. The formation of the TLTF is attributed to post-subduction extensional tectonics relating to the opening of the Manus Basin and the magma is potentially sourced from subduction-modified upper mantle. The main rock types sampled in this study are alkalic and include feldspath-oid-bearing basalt, trachybasalt, phonotephrite, trachyandesite, and trachydacite or quartz-trachyte. Minerals identified include forsteritic olivine, diopside, augite, andesine, anor-thitic plagioclase, nepheline and leucite in the primitive mafic suites whereas the more evolved intermediate and felsic hypabyssal suites contain amphibole, albite, orthoclase, biotite, and either rare quartz or feldspathoids. Amphibole composition is primarily magnesiohastingsite with minor pargasite formed under polybaric conditions. Accessory minerals include apatite, ti-tanite, and Ti-magnetite. Feni magmas are highly enriched in REEs relative to neighboring arcs. Fractional crystallization is the dominant process in the geochemical evolution of the Ambitle lavas. Pyroxene fractionation is dominant in the mafic lavas whereas hornblende fractionation is a major petrologic process within the intermediate suites proven by the presence of LREE enrichment and depletions in MREE and HREE.

13 June 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
OPOlive L Ponyalou
Olive L Ponyalou
Michael PettersonMichael Petterson
Michael Petterson
JEJoseph Espi
Joseph Espi
The Feni Island group is located at the southeastern end of the NW trending Ta-bar-Lihir-Tanga-Feni (TLTF) island chain, northeastern Papua New Guinea. This island chain is renowned for hosting alkaline magmas, geothermal activity, copper-gold mineralization and mining. The purpose of this paper is to present the geological observations of Feni Island within the context of the regional tectonic setting and evolution of the TLTF. The TLTF arc is a younger arc situated within the Greater Melanesian Arc, specifically within the New Ireland Basin bounded by New Ireland to the west and the extinct Kilinailau Trench in the east. The formation of the TLTF is attributed to post-subduction extensional tectonics relating to the opening of the Manus Basin and the magma is sourced from subduction-modified upper mantle. Normal, ex-tensional faulting is observed throughout the TLTF.