The western Pacific region contains 22 independent island countries and territories spread over an area of 27.8 million km 2 . Pacific peoples have lived here for as long as 50,000 yr, developing isolated cultures with close relationships to the environment. Although food security is adequate, the region suffers from persistent poverty that places many in a precarious position. Beginning in the 1920s, geological surveys conducted pioneering studies geared toward development. Beginning in the mid-1990s, many aid donors shifted their focus away from science, leading to a depletion of geo-science capacity. Lately, regional organizations have made considerable headway in expanding scientific capacity. The Geoscience Division of the Secretariat of the Pacific Community plays a significant role in helping the region attract geoscience-related aid funding and stitching the dispersed geoscience communities together. Universities in the region, assisted by geoscientists abroad and private employers, are also playing a role. This paper describes three examples of how geoscience can contribute to inclusive sustainable development. One example explores deep-sea minerals as a new source of wealth generation and the challenges the region faces in developing capacity and addressing the environmental concerns of this new revenue stream. A second project in Kiribati has moved aggregate extraction from beaches only 3 m above sea level to sediment-rich lagoons, providing new options for the future. Lastly, the promises and benefits of sustainable geothermal and ocean thermal technology are described.

Abstract This paper summarizes some 30 years of more intense recent work and almost 100 years of geological observations in Kohistan. The paper is divided into two section: an earlier factual-based section with minimal interpretation, and a later section summarizing a range of ideas based on the data as well as presenting new thoughts and interpretations. Kohistan is a c. 30 000 km 2 terrane situated in northern Pakistan. The great bulk of Kohistan represents growth and crustal accretion during the Cretaceous at an intra-oceanic island arc dating from c. 134 Ma to c. 90 Ma (Early to Late Cretaceous). This period saw the extrusion of c. 15–20 km of arc volcanic and related sedimentary rocks as well as the intrusion of the oldest parts of the Kohistan batholith, lower crustal pluton intrusion, crustal melting and the accretion of an ultramafic mantle–lower crust sequence. The crust had thickened sufficiently by c. 95 Ma to allow widespread granulite-facies metamorphism to take place within the lower arc. At around 90 Ma Kohistan underwent a c. 5 Ma high-intensity deformation caused by the collision with Eurasia. The collision created crustal-scale folds and shears in the ductile zone and large-scale faults and thrusts in the brittle zone. The whole terrane acquired a strong penetrative foliation fabric. Kohistan, now an Andean margin, was extended and intruded by a diapiric-generated crustal-scale mafic–ultramafic intrusion (the Chilas Complex) with a volume of 0.2×10 6 km 3 that now occupies much of the mid–lower crust of Kohistan and had a profound impact on its thermal structure. The Andean–post-collisonal ( c. 90–26 Ma) period also saw the intrusion of the stage 2 and 3 components of the batholith and the extrusion of the Dir Group and Shamran/Teru volcanic rocks. Collision with India at c. 55–45 Ma saw the rotation, upturning, underplating and whole-scale preservation of the terrane. The seismic structure of Kohistan has some similarities to that of mature arcs such as the Lesser and Greater Antilles and Japan, although Kohistan has a higher proportion of high-velocity granulites in the lower crust. The chemical composition of Kohistan is very different from that of average continental crust, although it is similar to an analogue obducted arc within Alaska (Talkeetna), suggesting that ‘mature’ continental crust undergoes a series of geochemical processes and reworking to transform an initial stage 1 ‘primitive arc crust’. Most of Kohistan is gabbroic in composition, particularly within the lower and middle crust. A high proportion of the ‘basement’ volcanic units is also basaltic to basaltic andesite with smaller proportions of boninite, andesite to rhyolite, ignimbrite and volcaniclastic material. Post Eurasian-collision ‘cover’ volcanic rocks are highly evolved, comprising predominant rhyolites, ignimbrites and related volcaniclastic rocks. Most lithological units throughout the crustal section have an arc-like geochemical composition (e.g. high LREE/HREE and LFSE/HFSE ratios) although some have oceanic (main ocean and back-arc) characteristics. Isotopic compositions indicate that the great bulk of igneous rocks have an ultimate sub-arc mantle source. In broad terms the Kohistan terrane represents a juvenile mantle extract addition to the Phanerozoic continental crust with a total volume of c. 1.2×10 6 km 3 (equivalent to c. 1/50 the volume of the Ontong–Java Plateau or Alaska).

Abstract This paper presents the most complete results yet published of geological surveys in Malaita, north of latitude 9°05′S between 1990 and 1995. The geology of Malaita reflects its position as an obducted part of the Alaska-size Ontong Java Plateau (OJP). The geology comprises a monolithological Cretaceous basalt basement sequence up to 3–4 km thick, termed the Malaita Volcanic Group (MVG), conformably overlain by a 1–2 km-thick Cretaceous–Pliocene pelagic sedimentary cover sequence. Cretaceous–Pliocene pelagic sedimentation was punctuated by alkaline basalt volcanism during the Eocene and by intrusion of alnöites during the Oligocene. Basement and cover sequences were both deformed by an intense, but short, middle Pliocene event. A number of localized, Upper Pliocene–Pleistocene, shallow-marine–subaerial, predominantly clastic formations overlie the middle Pliocene unconformity surface. The MVG comprises a monotonous sequence of pillowed and non-pillowed tholeiitic basalt lavas and sills with a predominant clinopyroxene–plagioclase–glass–opaques ± olivine mineralogy. The basaltic plateau morphology of the MVG is reflected in the presence of trap-like topographic features exposed in numerous river sections. Remarkably little sediment is present between basalt flows (most interlava contacts are basalt–basalt), indicating high to very high effusion rates. When present, inter-lava sediment is laminated pelagic chert or limestone, millimetres to centimetres thick, reflecting emplacement of the basalt in deep water (near or below the calcite compensation depth). Gabbro intrusions, dolerite dykes and an unusual spherulitic dolerite facies are locally present. The deep-water eruptive environment of the MVG probably was defined by the accumulation of voluminous eruptions from a multi-centred, submarine, possibly fissure-fed, volcanic source. The Malaitan cover sequence largely comprises a series of foraminifera-rich, pelagic calcilutites and calcisiltites with chert and, in the younger formations, arc-derived mudstone interbeds at various stratigraphic levels.