Journal articles on the topic 'Diamonds – Africa, Southern'

Abstract The morphological, chemical impurities and carbon isotope properties of diamonds may reveal subtle details of their mantle source and growth characteristics, supporting efforts towards identifying their original place of harvesting. Here we investigate the mantle carbon and nitrogen sources and growth patterns from selected diamonds mined from four kimberlites: macro-sized diamonds from River Ranch kimberlite in Zimbabwe and the Swartruggens and Klipspringer kimberlitic deposits from South Africa, and micro-sized diamonds from the Klipspringer and Premier kimberlite intrusions in South Africa. Type IaAB diamonds are found in all the samples; Type IaB diamonds only occur in samples from the Swartruggens, River Ranch and Premier kimberlites. A single Type II diamond (nitrogen below the detection limit) was also observed in the River Ranch and Premier kimberlites. Both the micro- and macro-sized diamonds from Klipspringer have similar nitrogen contents. Based on the % B-defect, the diamonds from Klipspringer are grouped into low- and high-nitrogen aggregates (i.e. % of B-defect <40% and >56%, respectively) that likely represent two different diamond forming episodes. Time averaged mantle storage temperatures for Type IaAB diamonds are calculated to have been: 1060°C for Swartruggens; 1190°C for River Ranch; 1100°C (low aggregated); and 1170°C (highly aggregated) for Klipspringer, and 1210°C for Premier diamonds. The CL-images of the River Ranch, Klipspringer and Premier diamonds reveal multi-oscillatory growth zones. The carbon isotopic analyses on the diamonds reveal an average δ13CVPDB value of: -4.5‰ for Swartruggens; -4.7‰ for River Ranch; -4.5‰ for Klipspringer; and -3‰ for Premier. With the exception of the diamond from Premier, the average δ13C value of the diamonds are similar to the average δ13C value of the mantle (-5‰), which is similar to the occurrence of diamonds in the other kimberlites. The internal carbon isotopic variation of individual diamonds from Swartruggens, Klipspringer and Premier are less than 4‰, which is similar to the variability of most other diamond occurrences reported from elsewhere in the world. Up to 6.7‰ internal carbon isotopic variation was observed in a single diamond from River Ranch. The internal carbon isotopic studies of the diamonds reveal that the primary carbon in the Swartruggens and Klipspringer was derived from an oxidation of CH4-bearing fluid, whereas in the River Ranch the primary carbon was derived from the reduction of carbonate-or CO2-bearing fluids. The Swartruggens diamonds also reveal a secondary carbon sourced from a reduction of CO2- or carbonate-rich fluid or melt. Diamonds from Klipspringer exhibit a cyclic change in δ13C values that reflects fluctuation in a complex mantle perturbation system or periodic change in fugacity of the mantle. Based on this study, we conclude that, in principle, a selected range of diamond signatures might be used to fingerprint their origins; especially when linked to their other physical properties such as a low temperature magnetic signature.

Ultramafic dyke rocks with kimberlitic megacrysts and mantle nodules have been known for decades from the northern part of the Archaean block and adjacent Proterozoic terranes in southern West Greenland (Fig. 1; Escher & Watterson 1973; Goff 1973; Scott 1981; Larsen & Rex 1992; Mitchell et al. 1999). Some of the dykes have proved to be diamondiferous (see Jensen et al. 2004a, b, for exploration results, diamond contents, and references). The c. 600 Ma old dykes werecalled ‘kimberlitic’ by Larsen & Rex (1992), but Mitchell et al. (1999) concluded that they were best referred to a ‘carbonatiteultramafic lamprophyre’ suite (aillikites or melnoites). Mitchell et al. (1999) further suggested that the West Greenland province represents “one of the few bona fide examples of ultramafic lamprophyre which contain diamonds”. Reports on indicator mineral assemblages (Jensen et al. 2004b) and diamond contents (e.g. Hudson Resources Inc. 2005) have re-opened the discussion on the classification of the dykes. The results of an investigation of the Majuagaa dyke (Nielsen & Jensen 2005) are summarised below, together with the preliminary results of a regional investigation of the groundmass minerals of the dykes. It is concluded that dykes in the Maniitsoq region are similar to archetypal, South African, on-craton, Type 1 kimberlites, and that all regions of the West Greenland province of ultramafic magmatism are favourable for diamond exploration.

IN KING SOLOMON'S MINES(1885), H. Rider Haggard describes the journey of three robust English men who successfully penetrate a sexualized landscape in southern Africa, depicted as both the body of the long-dead Queen of Sheba and that of her contemporary, King Solomon. The three English adventurers, led by the narrator Allan Quatermain, climb “Sheba's breasts” (26; ch. 2), traverse her torso, and arrive finally at the location where diamonds are stored inside her cavernous body, in the space Haggard calls “King Solomon's treasure chamber” (27; ch. 2). Narrative desire and the mystery of the Jewish patriarch's ancient empire propel these men through a series of male bonding adventures that lead to their arrival and conquest of the famed mines, where they pocket diamonds “as large as pigeon-eggs” (225; ch. 17) and plot their escape from what they fear may be a sealed cave.

The southern part of the African continent has, for nearly a hundred and fifty years, been witness to a set of epic struggles to create within it a single unified state and, within that, forms of citizenship that are both identifiably “South African” and more or less collectively owned. The never-ending nature of these twinned tasks has echoes in contemporary mantras about the healthiness of “nation-building,” just as surely as the underlying anemia remains manifest in the name of a place and a people that are, arguably, still more of an expression of geography than a reflection of a collectively lived experience. Perhaps it is significant that it was only a decade after the discovery of diamonds, in the late 1860s, that these struggles first took on recognizably modern political forms. An early attempt to promote federation among the dominant white settlers was, however, thwarted by the still largely separate identities of the two British coastal colonies (the Cape and Natal) and two inland Afrikaner-Dutch or “Boer” republics (the Orange Free State and the Zuid Afrikaansche Republiek) that sprawled over southern Africa—enveloping, albeit imperfectly, their distinctive and very different indigenous African, imported Asian, and Colored (people of mixed descent) laboring populations.

This article presents an overview of palaeofluvial geomorphology research in southern Africa. For the purposes of this article this includes South Africa, Zimbabwe, Namibia, Lesotho, Swaziland and Botswana. Although interest in fluvial systems has a long history in southern Africa, the scientific study of rivers was initiated by the discovery of the first alluvial diamond along the banks of the Orange River in 1867. Since then, significant progress has been made in unravelling the fluvial history of southern Africa from the early Archaean Ventersdorp Contact Reef River to modern channel process studies. The development of an understanding of palaeofluvial systems has occurred along two main lines. The first was alluvial diamond exploration work undertaken by the large mining houses. The second line was of a more ‘academic’ interest and included determining the impact of superimposition, tectonics, base level and climate changes. The review suggests that southern Africa fluvial systems have shown large-scale changes in drainage pattern, discharge and sediment yield and that these can be related to a complex set of causative factors including the geological template, the Jurassic rifting of Gondwana, tectonic episodes and climate change.

This paper studies the evolution of the Southern African Customs Union (SACU), tracing it from its inception in 1889 as the Customs Union Convention, the worlds first customs union, to its current status. While the union has operated under different agreements, which have been negotiated and renegotiated with changing circumstances, the study identifies the agreements of 1889, 1910, 1969 and 2002 as key to the unions transformation. It is observed that SACU has evolved from a geopolitical organisation with a repressive colonial foundation to a well-integrated regional trading bloc that is perceived as a possible springboard for larger regional trading blocs in Africa. The study further explores evidence of declining SACU revenue and investigates its implications on government expenditures in the small members of the union; namely, Botswana, Lesotho, Namibia and Swaziland (BLNS countries). It is found that among the members of the union, Lesotho and Swaziland are the most dependent on SACU transfers and, consequently, the most vulnerable to the current downward trend in SACU revenue. While Namibia has traditionally relied on diamond exports, it has also been receiving large SACU transfers relative to its GDP. In addition, the study observes that the present SACU revenue sharing formula adopted in 2002 exposes the BLNS countries to instabilities arising from global business cycles more than it does South Africa.

AbstractA suite of ultramafic-mafic alkaline igneous rocks in the Damodar Valley, eastern India, contains carbonate, phosphate and titanate minerals that are not characteristic or common in minettes or lamproites, but are typical of orangeites (Group II kimberlite) from southern Africa. Phlogopite grains from the Damodar alkaline rocks yield mean 40Ar/39Ar ages of 116.6±0.8 Ma, 113.5±0.5 Ma and 109.1±0.7 Ma (1σ errors) using laser dating techniques. These ages are similar to the Rb-Sr ages of African orangeites, which lie mostly in the range 121 to 114 Ma. Prior to this study, only one possible occurrence of orangeite (the ∼820 m.y.-old Aries pipe, Western Australia) was known outside the Kaapvaal craton and its environs. If the Damodar alkaline rocks are bona fide orangeites, it is likely that they were generated at depths of >150 km, within the stability field of diamond.

<p>Analysis of production systems allows scientists to identify their weaknesses, particularly concerning production practices which require improvements at economic, social, and environmental levels. The present study aimed to characterise rabbit farms in the urban and peri-urban areas of South Benin and assess their sustainability using the DIAMOND method, a multicriteria sustainability assessment tool. Ninety-eight farmers were surveyed and individually interviewed. Categorical principal component and twostep cluster analyses were performed on information collected for a typology of farms. Sustainability scores were generated using the scoring scale of the DIAMOND tool. Five types of rabbit farms were identified as follows: modern extensive polyculture, traditional extensive monoculture, modern extensive monoculture, semi-intensive polyculture, and traditional extensive polyculture. Overall, all the rabbit farms had good scores for the economic sustainability pillar but were socially limited. They were all similar in their economic and environmental performances. In particular, semi-intensive farms were the most socially sustainable, whereas traditional farms (either in polyculture or monoculture) showed the lowest social performances. Furthermore, there were significant differences between farms for criteria relating to consumers’ demands and resource use. Semi-intensive farms responded best to consumers’ demands, whereas the traditional polyculture farm type was the most resource use efficient. Overall, in the urban and peri-urban areas of South Benin, the most sustainable rabbit farms were semi-intensive. Irrespective of farm type, positive coefficients of correlations were recorded among the three pillars of sustainability, being significant between the social and economic pillars on one hand, and between the social and environmental pillars on the other hand. These results suggest that efforts to improve farm social performance would also positively affect their economic and environmental performances and improve overall farm sustainability.</p>

AbstractThe mid-Cretaceous weevil fossils from the Orapa Diamond Mine in Botswana are studied, and a new genus and species, Orapaeus cretaceus Kuschel & Oberprieler, is described. This fossil genus is placed in the tribe Eurhynchini of Brentidae and compared with the two extant genera of the tribe. With the discovery of Orapaeus, the family Brentidae can, for the first time, be traced back to Cretaceous times, and there is evidence that the brentid subfamilies and perhaps also the tribes were already differentiated by the Middle Cretaceous. By contrast, the modern families of angiosperm plants were evidently not yet established by then. In consideration of the palaeoflora of Orapa, it is concluded that the environment probably was tropical and the area well vegetated, but that no clues are present as to the likely hostplant(s) of Orapaeus. The differences between Orapaeus and the extant Eurhynchini suggest that the fossil insect fauna of Orapa is generally assignable to extinct forms, and these differences do not support a hypothesis of prolonged evolutionary stasis.

The popular film The Gods Must Be Crazy (1980) remains, despite its age, the primary reference point for Westerners with regard to the San people of southern Africa (commonly known outside Africa as the Bushmen). It is a catalyst for tourist interest in the people since many tourists, as this paper demonstrates, credulously accept the mythology that the San people live now as (and where) they do in the film. Indeed, a Lonely Planet ‘coffee-table’ publication of 2010 cites the film as mandatory viewing for tourists prior to visiting Botswana. The San’s lifestyle is depicted in the film as one of Garden-of-Eden tranquility, although the landscape is somewhat more arid than the Genesis idyll. The San had been driven out of the Kalahari by the Botswana government in the interests of diamond mining, big-game hunting and high-end tourism. Meanwhile, tourist ephemera in-country extols the lifestyle of the Bushmen esoterically, producing imagery that suggests they are still living as they did for millennia, omitting any mention of their modern realities and perpetuating a lie about their ongoing relationship with lands to which they no longer have access. The film is explored here via some thematic distinctions of Spurr (1993). This paper transcribes these distinctions (or tropes) of colonialist thought and action as neo-colonialist which are ubiquitously in operation within the modern tourism industry, perpetuating disempowerment to a significant extent

AbstractThe radiocarbon ages of mollusc shells from the Bogenfels Pan on the hyper arid southern coast of Namibia provide constraints on the Holocene evolution of sea level and in particular, the mid-Holocene highstand. The Bogenfels Pan was flooded to depths of 3 m above mean sea level (amsl) to form a large subtidal lagoon from 7300 to 6500 calibrated radiocarbon years before present (cal yr BP). The mollusc assemblage of the wave sheltered lagoon includes Nassarius plicatellus, Lutraria lutraria, and the bivalves Solen capensis and Gastrana matadoa, both of which no longer live along the wave-dominated southern Namibian coast. The radiocarbon ages of mollusc shell from a gravely beach deposit exposed in a diamond exploration trench indicate that sea level fell to near or 1 m below its present-day position between 6500 and 4900 cal yr BP. The rapid emergence of the pan between 6500 and 4900 cal yr BP exceeds that predicted by glacio-isostatic models and may indicate a 3-m eustatic lowering of sea level. The beach deposits at Bogenfels indicate that sea level rose to 1 m amsl between 4800 and 4600 cal yr BP and then fell briefly between 4600 and 4200 cal yr BP before returning to 1 m amsl. Since 4200 cal yr BP sea level has remained within one meter of the present-day level and the beach at Bogenfels has prograded seaward from the delayed arrival of sand by longshore drift from the Orange River. A 6200 cal yr BP coastal midden and a 600 cal yr BP midden 1.7 km from the coast indicate sporadic human utilization of the area. The results of this study are consistent with previous studies and help to refine the Holocene sea-level record for southern Africa.

The HIV and AIDS pandemic has been characterised as the greatest health and development challenge ever to confront humanity, and is one of the great moral curses of our time. The pandemic has hit sub-Saharan Africa, and Namibia is one of the countries which are badly affected. In Namibia, the focus has been on the population aged 15 to 49 years. Hence, this study looks at older men in terms of it being a neglected population.A descriptive, cross-sectional survey utilizing a quantitative research approach was applied. Data were collected through face-to-face interviewing 105 randomly selected male employees aged 50 years and older. Data were captured in MS Excel and then imported into SPSS version 16.0. The level of statistical significance was set at 0.05.This study revealed that respondents’ knowledge about male condoms appeared to be moderate (52.4%). About 92.4% stated that correct and consistent use of male condoms prevents HIV transmission. A larger percentage (85.1%) of respondents disagreed that older men do not need to learn how to use a condom. A high percentage of respondents suggested that HIV-positive individuals should use condoms every time they have sexual intercourse.Men aged 50 years and older are not at risk of contracting HIV due to lack of knowledge of male condom use. Thus, to minimize the likelihood of HIV infection, targeted interventions including peer education programmes were suggested in order to strengthen the practice and attitudes.

AbstractThe widespread occurrence of pyrope garnet in Archean lithospheric mantle remains one of the 'holy grails' of mantle petrology. Most garnets found in peridotitic mantle equilibrated with incompatible-trace-element enriched melts or fluids and are the products of metasomatism. Less common are macroscopic intergrowths of pyrope garnet formed by exsolution from orthopyroxene. Spectacular examples of these are preserved in both mantle xenoliths and large, isolated crystals (megacrysts) from the Kaapvaal craton of southern Africa, and provide direct evidence that some garnet inthe sub-continental lithospheric mantle formed initially by isochemical rather than metasomatic processes. The orthopyroxene hosts are enstatites and fully equilibrated with their exsolved phases (low-Cr pyrope garnet ± Cr-diopside). Significantly, P-T estimates of the postexsolution orthopyroxenes plot along an unperturbed conductive Kaapvaal craton geotherm and reveal that they were entrained from a large continuous depth interval (85 to 175 km). They therefore represent snapshots of processes operating throughout almost the entire thickness of the sub-cratonic lithosphericmantle.New rare-earth element (REE) analyses show that the exsolved garnets occupy the full spectrum recorded by garnets in mantle peridotites and also diamond inclusions. A key finding is that a few low-temperature exsolved garnets, derived from depths of ∼90 km, are more depleted in light rare-earth elements (LREEs) than previously observed in any other mantle sample. Importantly, the REE patterns of these strongly LREE-depleted garnets resemble the hypothetical composition proposed for pre-metasomatic garnets that are thought to pre-date major enrichment events in the sub-continental lithospheric mantle, including those associated with diamond formation. The recalculated compositions of pre-exsolution orthopyroxenes have higher Al2O3 and CaO contents than their post-exsolution counterparts and most probably formed as shallow residues of large amounts of adiabatic decompression melting in the spinel-stability field. It is inferred that exsolution of garnet from Kaapvaal orthopyroxenes may have been widespread, and perhaps accompanied cratonization at ∼2.9 to 2.75 Ga. Such a process would considerably increase the density and stability of the continental lithosphere.

Historians of colonial Brazil have conventionally located the conclusion of the great era of bandeira-led conquest somewhere near the end of the seventeenth century. The onset of the colony's gold cycle, corresponding with a series of major inland mineral strikes, reoriented those most actively engaged in the bandeira enterprise. Concentrated in the southern coastal captaincy of São Vicente, later, São Paulo, these wilderness adventurers had explored Portuguese America's immense interior and hunted its indigenous inhabitants. When their accompanying search for alluvial riches finally had born fruit, the Paulista backwoodsmen remade themselves into miners and merchants. The bandeirantes had first discovered gold in 1693 in Brazil's southeastern interior, the region that would soon acquire the name Minas Gerais or the General Mines; they made secondary strikes far to the west in Mato Grosso and Goiás in 1718 and 1725. Many then found themselves quickly displaced by the tide of Portuguese fortune-seekers and their African slaves who followed the paths now opened to the mining zones. As gold and then diamonds flooded the Atlantic world in unprecedented quantities, the colony's subsequent historical legacy would accrue not to São Paulo's peripatetic rustics but to those who consolidated control over the flow of riches. During the second half of the eighteenth century, with the mineral washings already in decline, attention would shift still further away from wilderness exploits, supposed to reflect a bygone era, back toward the coastal agricultural export enclaves that had traditionally preoccupied the Portuguese crown. The scholarly concerns of a later era would generally follow suit. As a consequence, the persistence of armed expeditions of exploration and conquest, which continued to roam the unmapped interior of Portuguese America, would go all but unnoticed as a critical feature of the late colonial period.

China Shale-Gas Field Sets Production Record Sinopec recorded China’s highest daily output of shale gas at 20.62 million cubic meters (Mcm) at its Fuling shale-gas field in Chongqing, China, a key gas source for the Sichuan-East gas pipeline. The first major commercial shale-gas project in China, Fuling has continuously broken records for the shortest gasfield drilling cycle while significantly increasing the drilling of high-quality reservoirs covering more than 3 million m, according to Sinopec. Gasfield production construction was also expanded to raise production capacity. The company said the field maintains a daily output of 20 Mcm, producing an estimated 6.7 Bcm per year. Apache and Total Plan Suriname Appraisals Apache filed appraisal plans for its Maka and Sapakara oil discoveries in block 58 offshore Suriname. The company said another submission is expected for Kwaskwasi, the largest find in the block, by the end of the year. Operations continue for Keskesi, the fourth exploration target. There are plans to drill a fifth prospect at Bonboni in the North-Central portion of the concession. Partner company Total is assuming operatorship of the block ahead of next year’s campaigns. BP Emerges as Sole Bid for Offshore Canada Parcels BP was the only operator to place a bid in the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) Call for Bids NL20-CFB01, which offered 17 parcels (4,170,509 hectares) in the eastern Newfoundland region. The successful bid was for Parcel 9 (covering 264,500 hectares) for $27 million in work commitments from BP Canada Energy Group. Subject to BP satisfying specified requirements and receiving government approval, the exploration license will be issued in January 2021. No bids were received for the remaining 16 parcels, which may be reposted in a future Call for Bids. Criteria for selecting a winning bid is the total amount the bidder commits to spend on exploration of the parcel during the first period of a 9-year license, with a minimum acceptable bid of $10 million in work commitments for each parcel. Beach Energy To Drill Otway Basin Well Beach Energy plans to drill at its Artisan-1 well about 32 km offshore Victoria, Australia, in the Otway basin, before the end of 2021. The well, located on Block Vic/P43, was to be spudded in 1H 2020 but was delayed due to COVID-19. The timeframe for drilling was confirmed by the National Offshore Petroleum Safety and Environmental Management Authority, which also said Beach is keeping open the option to suspend the well and develop it, pending reservoir analysis. Anchors, mooring chains, and surface buoys have already been laid for the well, which is in a water depth of approximately 71 m. The well is expected to take approximately 35–55 days to drill, depending on the final work program and potential operational delays. Diamond Offshore’s semisubmersible Ocean Onyx was contracted for the drilling program. Artisan is the first of Beach’s planned multiwell campaigns, which also include development wells at the Geographe and Thylacine fields. Hess Completes Sale of Interest in Gulf of Mexico Field Hess completed the sale of its 28% working interest in the Shenzi Field in the deepwater Gulf of Mexico (GOM) to BHP, the field’s operator, for $505 million. Shenzi is a six-lease development structured as a joint ownership: BHP (operator, 44%), Hess (28%), and Repsol (28%). The acquisition would bring BHP’s working interest to 72%, adding approximately 11,000 BOE/D of production (90% oil). The sale is expected to close by December 2020. Hess CEO John Hess said proceeds from the sale will help fund the company’s investment in Guyana. Greenland Opens New Offshore Areas Greenland opened three new offshore areas for application of oil and gas exploitation licenses off West Greenland. The areas are Baffin Bay, Disko West, and Davis Strait. The country also said it is working on an oil strategy to reduce geological uncertainty by offering an investment package to companies that engage in its Open Door Procedures. The procedures are a first-mover advantage to remove national oil company Nunaoil, as a carried partner, reducing turnover and surplus royalties. It is estimated to reduce the government take by 51.3% to 40.6%. Shell and Impact Oil & Gas Agree to South Africa Farmout Africa Oil announced Impact Oil & Gas entered into two agreements for exploration areas offshore South Africa. The company has a 31.10% share-holding in Impact, a privately owned exploration company. Impact entered into an agreement with BG International, a Shell subsidiary, for the farm-out of a 50% working interest and operatorship in the Transkei and Algoa exploration rights. Shell was also granted the option to acquire an additional 5% working interest should the joint venture (JV) elect to move into the third renewal period, expected in 2024. Algoa is located in the South Outeniqua Basin, east of Block 11B/12B, containing the Brulpadda gas condensate discovery and where Total recently discovered gas condensate. The Transkei block is northeast of Algoa in the Natal Trough Basin where Impact has identified highly material prospectivity associated with several large submarine fan bodies, which the JV will explore with 3D seismic data and then potential exploratory drilling. Impact and Shell plan to acquire over 6,000 km² of 3D seismic data during the first available seismic window following completion of the transaction. This window is expected to be in the Q1 2022. After the closing of the deal, Shell will hold a 50% interest as the operator and Impact will hold 50%. Impact also entered into an agreement with Silver Wave Energy for the farm-in of a 90% working interest and operatorship of Area 2, offshore South Africa. East and adjacent to Impact’s Transkei and Algoa blocks, Area 2 complements Impact’s existing position by extending the entire length of the ultradeepwater part of the Transkei margin. Together, the Transkei and Algoa Blocks and Area 2 cover over 124,000 km2. Area 2 has been opened by the Brulpadda and Luiperd discoveries in the Outeniqua Basin and will be further tested during 2021 by the well on the giant Venus prospect in ultradeepwater Namibia, where Impact is a partner. Impact believes there is good evidence for this Southern African Aptian play to have a common world-class Lower Cretaceous source rock, similar excellent-quality Apto-Albian reservoir sands, and a geological setting suitable for the formation of large stratigraphic traps. Following completion of the farm-in, Impact will hold 90% interest and serve as the operator; Silver Wave will hold 10%. Petronas Awards Sarawak Contract to Seismic Consortium The seismic consortium comprising PGS, TGS, and WesternGeco was awarded a multiyear contract by Petronas to acquire and process up to 105,000 km2 of multisensor, multiclient 3D data in the Sarawak Basin, offshore Malaysia. The contract award follows an ongoing campaign by the consortium in the Sabah offshore region, awarded in 2016, in which over 50,000 km2 of high-quality 3D seismic data have been acquired and licensed to the oil and gas industry to support Malaysia license round and exploration activity. The Sarawak award will allow for a multiphase program to promote exploration efforts in the prolific Sarawak East Natuna Basin (Deepwater North Luconia and West Luconia Province). The consortium is planning the initial phases and is engaging with the oil and gas industry to secure prefunding ahead of planned acquisition, covering both open blocks and areas of existing farm-in opportunities. Total Discovers Second Gas Condensate in South Africa Total made a significant second gas condensate discovery on the Luiperd prospect, located on Block 11B/12B in the Outeniqua Basin, 175 km off the southern coast of South Africa. The discovery follows the adjacent play-opening Brulpadda discovery in 2019. The Luiperd-1X well was drilled to a total depth of about 3,400 m and encountered 73 m of net gas condensate pay in well-developed, good-quality Lower Cretaceous reservoirs. Following a coring and logging program, the well will be tested to assess the dynamic reservoir characteristics and deliverability. The Block 11B/12B covers an area of 19,000 km2, with water depths ranging from 200 to 1800 m. It is operated by Total with a 45% working interest, alongside Qatar Petroleum (25%), CNR International (20%), and Main Street, a South African consortium (10%). The Luiperd prospect is the second to be drilled in a series of five large submarine fan prospects with direct hydrocarbon indicators defined utilizing 2D and 3D seismic data. BP Gas Field Offshore Egypt Begins Production BP started gas production from its Qattameya gasfield development ‎offshore Egypt in the North Damietta offshore concession. Through BP’s joint venture Pharaonic Petroleum Company working with state-owned Egyptian Natural Gas Holding Co., the field, which is ‎expected to produce up to 50 MMcf/D, was developed through a one-well subsea development and tieback to existing infrastructure.‎ Qattameya, whose discovery was announced in 2017, is located approximately 45 km west ‎of the Ha’py platform, in 108 m of water. It is tied back to the Ha’py and Tuart field ‎development via a new 50-km pipeline and connected to existing subsea ‎utilities via a 50-km umbilical. ‎BP holds 100% equity in the North Damietta offshore concession in the East Nile Delta. ‎Gas production from the field is directed to Egypt’s national grid.

Abstract The Kasai alluvial field in southern Democratic Republic of Congo (DRC) is part of central Africa’s largest diamond placer that has produced more than 200 million carats, mainly derived from Quaternary deposits. A small part of these deposits, along and within the Longatshimo River, is the subject of this study providing a glimpse into the alluvial history of the Kasai diamond placer. This work documents their sedimentological and diamond mineralization attributes, as well as their emplacement processes, which can inform future exploration models. The key controls of this placer formation, notably Quaternary climatic variations, fluvial landscape evolution and bedrock conditions are also evaluated. A consequence of the interplay among these processes is that diamond supply (from Cretaceous alluvial sources), recycling and concentration were most pronounced and consistent, in the Late Quaternary. Alluvial diamond mineralization in this central African region thus evolved differently to those in southern Africa. Based on exploration results in the Longatshimo Valley, diamond concentration improves but diamond size diminishes with decreasing deposit age, and thus the modern river sediments contain the highest abundance but smallest diamonds. This is opposite to the grade and diamond size trend that characterises southern African fluvial diamond placers. The Longatshimo River study offers insight into the Kasai alluvial field, and its placer model is expected to be applicable to the exploration of other central African diamond placers.

SYNOPSIS Because of their high degree of geological complexity, kimberlite-hosted diamond deposits are exceedingly difficult to evaluate for economic viability. Accordingly, standard mineral asset evaluation protocols (e.g., the Cost-, Market-, and Income Approaches defined in the SAMREC Code) may not hold sufficient predictive abilities for these deposit types, especially at the early stages of exploration. Here we present a novel tool, a cost filter approach towards preliminary evaluation of economic viability of southern African kimberlite-hosted diamond deposits, using the AK6 and BK11 diamond deposits from the Orapa diamond field as case studies. The development of this cost filter is underpinned by elements of both the Market Approach (i.e., comparisons to similar deposits) and the Income Approach (i.e., use of net present value (NPV) calculations) for mineral asset evaluation. Importantly, the cost filter is constrained through modification of only two primary variables (the average diamond value and the diamond grade) and thus differs significantly from other cost filters that rely on estimation and assumptions for every parameter input into an NPV calculation. The cost filter correctly predicts the sub-economic status of the BK11 diamond pipe, and is thus presented as a useful geo-economic tool for early stage kimberlite evaluation within the local southern African context. The approach and its theoretical underpinning foreseeably hold vast potential for use in the economic evaluation of other ore commodities, particularly where socio-economic and political risk factors can be negated by employing a geographic constraint. Keywords: diamond, economic viability, kimberlites, southern Africa, cost models filter.

Abstract At least four spatially overlapping Large Igneous Provinces, each of which generated ∼1 x 106 km3 or more of basaltic magmas over short time intervals (&lt;5 m.y.), were emplaced onto and into the Kaapvaal Craton between 2.7 and 0.18 Ga: Ventersdorp (2 720 Ma, ∼0.7 x 106 km3), Bushveld (2 056 Ma, ∼1.5 x 106 km3), Umkondo (1 105 Ma, ∼2 x 106 km3) and Karoo (182 Ma, ∼3 x 106 km3). Each of these has been suggested to have been derived from melting of sub-continental lithospheric mantle (SCLM) sources, but this is precluded because: (1) each widespread heating event sufficient to generate 1 to 2 x 106 km3 of basalt from the Kaapvaal SCLM (volume = 122 to 152 x 106 km3) would increase residual Mg# by 0.5 to 2 units, depending on degree of melting, and source and melt composition, causing significant depletion in already-depleted mantle, (2) repeated refertilization of the Kaapvaal SCLM would necessarily increase its bulk density, compromising its long-term buoyancy and stability, and (3) raising SCLM temperatures to the peridotite solidus would also have repeatedly destroyed lithospheric diamonds by heating and oxidation, which clearly did not happen. It is far more likely, therefore, that the Kaapvaal LIPs were generated from sub-lithospheric sources, and that their diverse geochemical and isotopic signatures represent variable assimilation of continental crustal components. Combined Sr and Nd isotopic data (n = 641) for the vast volumetric majority of Karoo low-Ti tholeiitic magmatic products can be successfully modelled as an AFC mixing array between a plume-derived parental basalt, with &lt;10% of a granitic component derived from 1.1 Ga Namaqua-Natal crust. Archaean crustal materials are far too evolved (εNd ∼ -35) to represent viable contaminants. However, a very minor volume of geographically-restricted (and over-analysed) Karoo magmas, including picrites, nephelinites, meimechites and other unusual rocks may represent low-degree melting products of small, ancient, enriched domains in the Kaapvaal SCLM, generated locally during the ascent of large-volume, plume-derived melts. The SCLM-derived rocks comprise the well-known high-Ti (&gt;2 to 3 wt.% TiO2) magma group, have εNd, 182 values between +10.5 and -20.9, and are characteristically enriched in Sr (up to 1 500 ppm), suggesting a possible connection to kimberlite, lamproite and carbonatite magmatism. These arguments may apply to continental LIPs in general, although at present, there are insufficient combined Sr + Nd isotopic data with which to robustly assess the genesis of other southern African LIPs, including Ventersdorp (n = 0), Bushveld (n = 55) and Umkondo (n = 18).