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Land Use Land Cover (LULC) change is a complex phenomenon driven by various natural and anthropogenic factors, significantly impacting carbon storage potential. By applying integrated models of ANN-CA Markov, GeoDetector, and InVEST model, this study aimed to analyze LULC change, their driving factors, and implications on carbon storage in the Forest Management Unit (FMU) of Ampang Plampang in West Nusa Tenggara, Indonesia. Several data sources were utilized in the modelling approach, including DEM (Digital Elevation Model), topographical map, Landsat imageries (2011, 2016, 2021), measured carbon density (above ground, below ground, soil, dead organic), and socio-economic data (number of populations, farmer, and agricultural land). The dryland forest in the study area constitutes the most extensive LULC that has experienced significant declines due to deforestation, predominantly transforming into agricultural land, and these are predicted to continue until 2031 with different magnitudes. The significant driving factors of LULC change were elevation, population pressure on land, and distance from settlement. The LULC change also greatly influenced the decline of carbon storage historically (2011–2016) and in projected LULC (2026–2031). The conversion of forested areas to non-forest LULCs has released carbon emissions of about 1.89 Mt CO2-eq. The study findings implied that the integration of ANN-CA Markov, GeoDetector, and InVEST models has been helpful for comprehending complicated interactions among LULC change, driving factors, and carbon dynamics. The results also contribute to the scientific knowledge base for land management decision-making and policy formulation. Effective management of LULC changes through low carbon development is suggested to mitigate the loss of carbon storage capacities, foster sustainable development goals (SDGs), support Nationally Determined Contribution (NDC), and improve ecosystem resilience.

Excessive use of chemical insecticides on plants has had a negative impact on the environment and human health. To overcome this, the use of plant-based pesticides is an attractive alternative, but not yet fully optimal in Indonesia. This research aims to study the potential use of neem leaf extract (Azadirachta indica) as a plant insecticide, with a focus on local knowledge of the Samawa tribe on Sumbawa Island. Extraction methods and phytochemical analysis were carried out, as well as insecticidal power tests against several common pest species in the area. The research results show that neem leaf extract has the potential to be an effective natural insecticide in controlling pest populations. Factors such as extract concentration and drying method of neem leaves influence its effectiveness. The use of neem leaf extract at a dose of 80 gr/liter has proven to be more effective than the Dane brand of vegetable pesticide at three times the dose. However, the use of synthetic pesticides at the recommended dosage still shows faster and more effective results in controlling pests. This research contributes to the development of environmentally friendly and effective plant protection materials, and expands understanding of the potential of local natural resources for sustainable agriculture.

The mangrove ecosystems in Labuhan Kuris Village, Lape Subdistrict, Sumbawa Regency are degraded. The area of mangrove ecosystems is categorized as good; it has decreased, potentially impacting the decline in fisheries' productivity, global warming, and other effects. This community service activity aims to rehabilitate mangroves through education and mangrove planting. The stages of this activity include an initial survey of community knowledge (pre-test) regarding mangroves, education and discussion sessions (talk shows), mangrove planting, and monitoring and evaluation. Meanwhile, the target audience for this activity is adult community members. Interviews using questionnaires were conducted to assess the community's initial understanding of mangroves. An educational session on the roles of mangroves was conducted by providing materials and distributing stickers about the roles of mangroves, and sessions. An evaluation of understanding levels was performed through post-tests, while monitoring and evaluation were conducted using direct observation methods in the field. Post-test results showed that 88% of the target audience understand the function of mangroves, 96% stated that mangroves ' role is to protect fish and crabs, while only 60% answered that mangroves have roles in climate mitigation. The number of participants in the educational session was 50 people. The mangrove species planted was Rhizophora sp. On this occasion, 1000 mangrove seedlings were planted, and the number of community members involved in mangrove planting was 220. Monitoring and evaluation results indicated that some plants were damaged due to trampling by livestock. Thus, mitigation was done by fencing around the planting area. Overall, the community actively participated from the beginning to the end of the activities. This condition indicates that the community is highly concerned about mangrove management. However, community participation in mangrove management should be improved. [ABSTRACT FROM AUTHOR]

Abstrak Peristiwa banjir di Kabupaten Sumbawa terjadi hampir setiap tahun. BNBP mencatat telah terjadi sebanyak 80 kali bencana banjir di Kabupaten Sumbawa sejak tahun 2009. Penelitian ini bertujuan untuk menganalisis potensi bencana banjir di Kabupaten Sumbawa berdasarkan data hasil prediksi curah hujan menggunakan metode Artificial Neural Network (ANN) backpropagation. Data historis curah hujan bulanan dari Juni 2009 sampai Mei 2024 digunakan untuk melatih dan menguji model ANN. Hasil prediksi menunjukkan periode kritis terjadi pada Februari 2025 yang mengindikasikan potensi banjir yang tinggi. Penelitian ini mengusulkan strategi mitigasi yang meliputi peningkatan sistem pemantauan cuaca, edukasi publik, reforestasi, dan pembangunan infrastruktur hijau. Kolaborasi antara pemerintah, masyarakat, dan lembaga penelitian ditekankan sebagai kunci untuk mengurangi risiko dan dampak banjir.

This research aims to determine the history of the Cek Bocek indigenous community in Sumbawa and the fundamental differences between the general community in Sumbawa. This research uses the historical method. In this case, all documents considered important in the Cek Bocek traditional community will be used as one discussion narrated by taking the essence or main points. The existence of the Cek Bocek traditional community in Sumbawa began in 1492, and in 1512, the form of government of the Selesek chiefdom led by Dewa Datu Awan Maskuing began. The fundamental difference between the Cek Bocek Selesek Reen Sury indigenous community and other communities in Sumbawa lies in the language used, called the Berco language. The Cek Bocek indigenous communities have traditional institutions and mechanisms for meeting meetings, which are referred to as Rapulun Adat and are led by one traditional leader as tribal head, and have a jointly protected customary area which is outlined in a participatory map approved by the village government, and has different traditional rituals such as NABAR (Tulak Bala), Pungka Inu (customary forest welfare), zakat alms every post-harvest season, Enang Uran (asking for rain) in Tiu Mareng. Also, customary law rules and property are left behind to maintain ancestral traditions

The research reported on a literacy intervention program for 150 early grade learners from low socio-economic background by involving 50 volunteers in 50 different village spots in Sumbawa Regency of Indonesia. The research was emancipatory because it seeks to empower the community to address the local problems of literacy learning loss experienced by the needy early graders. The data were collected through literacy assessment, observation, interviews, and documentation. The findings showed that 90% of the early graders improved their literacy mostly with two and one level progress. Factors contributing to the success were good preparation of volunteers, engaging teaching approaches, relevant materials that suited student levels, and continuous assessment. The last key finding was that the volunteers strongly embodied teaching voluntarism as a soul with six features (affection towards others, action of giving, availability, positive inner feelings, heroism, and divinity). The recommendation from these findings is that multi-stakeholders, including the government, provide support to enhance the program sustainability. This research contributes a model of voluntary teaching for low socio-economic early graders that can be adapted in other locations in Indonesia and overseas. [ABSTRACT FROM AUTHOR]

This study aims to produce an applicable Sumbawa local wisdom-based mathematics module for elementary school students by using the Four-D (4D) development research design from Thiagarajan. However, the development design of this module only includes three steps, namely define, design, and develop. The product feasibility test is only on the aspect of validity. Observation, interviews, and questionnaires were used to collect the data. The defined stage resulted in the formulation of the material, including the KPK, FPB, Fractions, Two-dimensional Shapes, and three-dimensional Geometry. A draft was created by emerging the elements of Sumbawa local wisdom in the materials, which is then validated at the design stage. The average validation results of material experts were 91.678%, linguists 90%, and media experts were 91.15%. The average validation result of the three specs is 90.94%, categorized as very valid, which confirms that the module is valid and suitable for elementary school students. Penelitian ini bertujuan untuk menghasilkan modul matematika berbasis kearifan lokal Sumbawa yang valid untuk siswa sekolah dasar dengan menggunakan desain penelitian pengembangan Four-D (4D) dari Thiagarajan. Namun, desain pengembangan modul ini hanya meliputi tiga langkah yaitu define, design, dan develop. Pada tahap develop, uji kelayakan produk hanya pada aspek kevalidan. Teknik pengambilan data meliputi observasi, wawancara dan angket. Hasil penelitian pada tahap define yaitu perumusan materi yang meliputi KPK, FPB, pecahan, bangun datar dan bangun ruang. Hasil penelitian pada tahap design yaitu memunculkan unsur kearifan lokal Sumbawa pada materi sehingga menghasilkan draf modul matematika berbasis kearifan lokal Sumbawa untuk divalidasi. Hasil validasi diperoleh bahwa rata-rata hasil validasi ahli materi 91.67%, ahli bahasa 90% dan ahli media 91.15%. Rata-rata hasil validasi ketiga spek yaitu 90.94% dan dikategorikan sangat valid, sehingga dapat disimpulkan bahwa modul matematika berbasis kearifan lokal Sumbawa dikatakan sangat valid dan layak digunakan oleh siswa sekolah dasar.

A new cone species, Cylinder feliciae, is described from the Saleh Gulf (Teluk Saleh) of Sumbawa, Nusa Tenggara Islands (Lesser Sunda Islands), Indonesia. The new species is morphologically similar to Cylinder gloriamaris (Chemnitz, 1777) from the southwestern Pacific and represents a geographically-isolated relict of a once widespread molluscan fauna that extended all along the coast of the Middle Pleistocene Sundaland Peninsula. [ABSTRACT FROM AUTHOR]

A new cone species, Cylinder sumbawaensis Verbinnen, 2022, was recently described from the Saleh Gulf (Teluk Saleh) of Sumbawa, Nusa Tenggara Islands (Lesser Sunda Islands), Indonesia. The new species is morphologically very similar to Cylinder bengalensis (Okutani, 1968) from the Gulf of Bengal and Andaman Sea and represents a geographically-isolated relict of a once widespread Indian Ocean-derived molluscan fauna that extended all along the coast of the Middle Pleistocene Sundaland Peninsula. [ABSTRACT FROM AUTHOR]

Pathogenic bacterial contamination was a serious matter due to its capability in reducing food quality and health. This study aimed to select various types of algae in Luk Coast, Sumbawa Regency that have the potential to produce antibacterial compounds for natural food preservatives. Algae on Luk Coast was identified by means of morphological characters, followed by sample preparation and extraction of secondary metabolites (bioactive compounds). Algae extracts were used in antibacterial tests against food spoilage bacteria, such as Escherecia coli, Staphylococcus aureus, Salmonella thypi, Enterobacter cloacae and Pantoea agglomerans. Five types of algae identified were Padina sp., Halimeda opuntia, Sargassum horneri, Sargassum crassifolium and Galaxaura rugose. The five algae have the growth-inhibiting ability toward the tested bacteria. The highest inhibition zone was obtained from the 100% algae extract concentration.

Sumbawa is one area that has the potential to be developed as a center for beef cattle production which is quite competitive in Indonesia. The proportion of cattle in Sumbawa itself is around 21% which is generally dominated by the Bali cattle variety (Bos sondaicus). Therefore, a business that has great potential to support this goal is cattle fattening. Unfortunately, one of the main problems encountered in fattening cattle is the cost of feed. Thus, the management of Bali cattle fattening that utilizes agricultural waste for the manufacture of feed is urgently needed. In addition, the management of fattening cattle must also be complemented by other components, such as the manufacture of medicines to treat diseases of underweight Bali cattle using local plants, the process of bathing, drying, and monitoring the cattle to be fattened. From the research and observations conducted, it is known that the time needed to get the cow display condition with ideal characteristics and optimal weight in the fattening process is 3 months. During this time, the selling price of lean fattened cows increased by about 2-2.3 times. It can be concluded, that the fattening management of lean Bali cattle carried out in Pungka Village, Unter Iwes District, Sumbawa Regency is quite profitable. In addition, this can also be used as part of community waste management that is integrated with community livestock business.

The newly described species Quasimitra houarti Dharma, 2021 from Indonesia is found to be a junior synonym of Quasimitra stossieri (Herrmann, 2016). [ABSTRACT FROM AUTHOR]

A new rainforest tree species of the myrtle family (Myrtaceae), Syzygium nusatenggaraense Sunarti & Y.W.Low is described here based on two collections from the Lesser Sunda Islands. This species is superficially similar to Syzygium arcanum P.S.Ashton, a Bornean endemic tree species, but differs in a suite of morphological characters and geographic distribution. The new species is illustrated, and description is here given. Satu spesies pohon hutan hujan baru dari suku jambu-jambuan atau Myrtaceae, Syzygium nusatenggaraense Sunarti & Y.W.Low diterbitkan disini berdasarkan kepada dua koleksi dari Kepulauan Nusa Tenggara. Spesies ini mirip dengan satu spesies pohon endemik Borneo Syzygium arcanum P.S.Ashton, tetapi berbeda dalam rangkaian karakter morfologi dan distribusi geografisnya. Spesies baru tersebut diilustrasikan dan deskripsi diberikan di sini. [ABSTRACT FROM AUTHOR]

Sumbawa Besar Regency is one of the regencies on Sumbawa Island, West Nusa Tenggara Province. As the regency with the largest area on the island of Sumbawa, Sumbawa Besar Regency has the challenge of being able to provide clean water for all its citizens. The urban area of Sumbawa Besar which consists of 5 sub-districts, namely Sumbawa District, Labuhan Badas District, Unter Iwis District, Moyo Hilir District, and North Moyo District, which actually has a sufficient supply of water sources, but for distribution of clean water from the PDAM piping system uneven and not well connected between water sources and the urban area of Sumbawa Besar. This study aims to analyze the prediction of Unmet (supply shortage) of clean water supply system using the WEAP program. The results showed that in the period 2016 - 2020 there was still a significant unmet (supply shortage) amounting to 21,764,753.1 m3 with the largest supply shortage in Sumbawa District of 11,937,238.7 m3 while the smallest supply shortage in Labuhan Badas Subdistrict amounted to 774,623.3 m3. From the results of this study, it is hoped that in the future PDAM will be able to increase the quantity of water discharge and improve the PDAM's piping system so that it can develop and be well connected so that it can meet the needs of clean water for the community in the study area. [ABSTRACT FROM AUTHOR]

This paper describes a new species of Angaria Röding, 1798 from north-western Sumbawa, Indonesia. In general appearance it resembles some forms of the species Angaria delphinus (Linnaeus, 1758) found in the same area and on neighbouring islands. The new species differs from it in sculptural features and interstitial markings, which it shares with two Vietnamese species, Angaria fratrummonsecourorum Günther, 2013 and Angaria guntheri Thach, 2018. [ABSTRACT FROM AUTHOR]

Several specimens of a new species of Quasimitra Fedosov, Herrmann, Kantor & Bouchet, 2018 were found off Bungin Island, North West of Sumbawa Island in Nusa Tenggara Islands, Indonesia. The shell is different from other species in the family Mitridae Swainson, 1831, and is compared to other species in the genus Quasimitra Fedosov, Herrmann, Kantor & Bouchet, 2018. [ABSTRACT FROM AUTHOR]

This paper describes a new member of the Eugeniconus nobilis (Linnaeus, 1758) complex from Bungin Island in north-western Sumbawa, Indonesia. It shares some of the features of the subspecies found on geographically separated neighbouring islands and the nominate subspecies. To recognize the distinctness of this new population we name it as a new subspecies in honour of Steven Lie's daughter. [ABSTRACT FROM AUTHOR]

This paper describes a new subspecies of Asperitas bimaensis (Mousson, 1849) from Alas District, western Sumbawa in West Nusa Tenggara, Indonesia. Shell coloration, pattern, sculpture, shape and periostracum separate it from the other subspsecies of A. bimaensis, and a similar looking relative from western Sumbawa. [ABSTRACT FROM AUTHOR]

Calamus vitiensis, previously known to occur only in Papua New Guinea, Australia (Queensland), the Solomon Islands, Vanuatu, and Fiji is now also found in the mountainous area of Batudulang, West Sumbawa, Lesser Sunda Islands, Indonesia. This paper presents a complete report of the description, notes, and illustrations of the species.

Indonesia is exposed to earthquakes, volcanic activities, and associated tsunamis. This is particularly the case for Lombok and Sumbawa Islands in West Nusa Tenggara, where evidence of tsunamis is frequently observed in its coastal sedimentary record. If the 1815 CE Tambora eruption on Sumbawa Island generated a tsunami with well-identified traces on the surrounding islands, little is known about the consequences of the 1257 CE tremendous eruption of Samalas on the neighboring islands, and especially about the possible tsunamis generated in reason of a paucity of research on coastal sedimentary records in this area. However, on Lombok Island, the eruption of the Samalas volcano produced significant volumes of pyroclastic flows that entered the sea in the North and East of the island. These phenomena must have produced a tsunami that left their traces, especially on Sumbawa Island, whose western coastline is only 14 km away from Lombok’s eastern shore. Therefore, the main goal of this study is to investigate, find evidence, and determine the age of marine-origin sediments along the shore of the Alas Strait, Indonesia. We collected and analyzed samples of coral and seashells from marine deposits identified along the west coast of Sumbawa, i.e., in Belang Island and abandoned fishponds in Kiantar Village, in order to identify the sources and the occurrence period of these deposits events. Based on the radiocarbon dating of coral and seashell samples, we concluded that none of the identified marine deposits along the western coast of Sumbawa could be related chronologically to the 1257 CE eruption of Samalas. However, possible tsunami deposits located in Belang Island and abandoned fishponds in Kiantar Village yielded 4th century CE, 9th century CE, and 17th century CE. We also conclude that past large earthquakes triggered these tsunamis since no known volcanic eruption occurred near the Alas Strait at that time that may have triggered a tsunami.

Since 2010, we are conducting a survey on the living resources and the living culture of the inhabitants of Lesser Sunda Islands, Indonesia. Indonesia is an island nation rich in natural resources and culture. Because Indonesia is a multicultural country with many languages, tribes and ethnic groups, understanding of Indonesia is essential for understanding the minority languages of each region. There are abundant resources such as timber and oil in the Kalimantan region of Indonesia. It has long been used as a colony of western countries, and resource plunder has occurred. In recent years, KORINDO (Korea-Indonesia Joint companies) have been involved in the illegal logging of wood in East Kalimantan, causing social problems. Indonesia is made up of more than 13,000 islands, and Bali and Lombok have a unique ecosystem and culture for each island, and many tourists are looking for it. Especially the Bali, which is a Hindu, is a very important tourist destination to be visited by tourists from all over Asia including Australia and Germany. Recently, however, environmental problems including marine litter have been raised, showing the limit of environmental capacity of Bali. The Indonesian government is, therefore, developing Islamic Lombok Island, as a tourist destination that is a substitute for Bali. Since most Indonesian islanders are engaged in fishing, they have been able to travel between islands and islands for a long time using vessels. To understand marine culture, life history and eco-cultural studies on the major minority tribes of each island are essential. In particular, it is necessary to understand traditional knowledge about how natural resources are used. [ABSTRACT FROM AUTHOR]

All three genetic groups of ratHEV have been found in Indonesia, suggesting the presence of additional variants of ratHEV in unexamined areas of Indonesia. A total of 242 wild rats were captured in Bali and Sumbawa, Indonesia, during 2014-2016. Among them, 4.1% were seropositive for anti-ratHEV IgG and two (0.8%) had detectable ratHEV RNA: ratESUMBAWA-140L and ratEBali2016D-047L, sharing 84.9-85.4% and 86.9-92.1% nucleotide identity with the reported G2 strains, respectively. The provisional criteria supported the notion that the ratEBali2016D-047L and ratESUMBAWA-140L strains were novel G2 variants. These results suggested the spatial distribution of further divergent ratHEV strains in Indonesia. [ABSTRACT FROM AUTHOR]

As a mega-biodiversity country, Indonesia ratified the United Nations Convention of Biological Diversity in 1994, and by so doing, Indonesia is obliged to meet Aichi Biodiversity Target 11. The target states: ‘by 2020, at least 17 per cent of terrestrial and inland water areas and 10 per cent of coastal and marine areas, especially areas of particular importance for biodiversity and ecosystem services, are conserved through effectively and equitably managed, ecologically representative and well-connected systems of protected areas and other effective area-based conservation measures, and integrated into the wider landscape and seascape’. Indonesia has been committed to set aside 20 million hectares of its coastal and marine waters for biodiversity conservation by 2020, en route to achieving the national target of at least 30 million hectares in the future. Here we demonstrate how the development and expansion of marine protected areas (MPAs) at the local level is crucial if the national government is to achieve the target. Using West Nusa Tenggara (WNT) Province as a case study, we describe the current achievements as well as plans for expanding marine conservation areas in the province by 2020. Despite challenges along the way, by 2016 the province managed to set aside 229,555.36 ha for biodiversity conservation thanks to the district governments’ efforts for establishing MPAs in their respective region. This figure covers approximately 7.87% of the province’s marine waters and contributed 1.25% to the national target of marine conservation areas in 2017. Intelligent preparation of the province’s coastal and small islands zoning plan will provide opportunities to allocate around 100,000 ha more to the WNT coastal and marine waters for conservation areas. With this addition, the total area is estimated to reach around 330,000 ha or approximately 10.29% of the province’s marine waters and would contribute 1.50% to the national target of marine conservation areas by 2020. The related challenges and opportunities for reaching this important target in WNT Province are discussed. [ABSTRACT FROM AUTHOR]

Surveys of pupae and larvae of black flies were carried out in Bali, Lombok, Sumbawa and Flores in the Lesser Sunda Archipelago, Indonesia, where 10 species were known. A total of 14 simuliid species including four new species and five new records of the genus Simulium were collected, bringing the number of species from the Lesser Sunda Archipelago to 19. They are classified into four subgenera: two in Nevermannia , nine in Gomphostilbia , seven in Simulium and one in Wallacellum . One of four new species, Simulium ( Simulium ) baliense , is described based on females, males, pupae and larvae from Bali and Lombok. This new species, which is placed in the Simulium striatum species-group of the subgenus Simulium , is closely related to S . ( S .) argyrocinctum De Meijere from Java and Sumatra, but it is distinguished from the latter species by the smaller number of the male enlarged upper-eye facets and larval abdomen lacking dorsal pairs of conical protuberances. The distribution record of S . ( S .) upikae Takaoka & Davies from Flores is corrected as that of S . ( S .) eximium De Meijere. Some aberrant characters of the pupal gill filaments of S . ( G .) atratum De Meijere, S . ( G .) floresense Takaoka, Hadi & Sigit and S . ( G .) sunapii Takaoka, Sofian-Azirun & Suana are illustrated. Characteristics of the fauna of black flies in this archipelago are briefly noted. Keys to all 19 species are provided for females, males, pupae and larvae. [ABSTRACT FROM AUTHOR]

Labuhan Terata Waters, Sumbawa, West Nusa Tenggara is one of the waters are very important for Labuhan Terata peoples because function for fisheryes especially seaweed cultivation, but asses carrying capacity and site suitability of waters is minus. The research objective was to assess carrying capacity and site suistability in the Labuhan Terata waters at transititions season. This research have been carried out in Mey to June 2015. Current, brightness, temperature, dissolved oxygen (O2), acidity (pH), salinity, phosphate and nitrate parameters was measured directly from a layer surface at five research stations. The degree of temperature was measured thermometer Hg, acidity (pH) was measured with pH meter, dissolved okxygen was measured dissolved oxygen meter (DO meters), measurement of nutriens (phosphate & nitrate) concentration used spectrophotometri method. The result of the analysis showed that the value of site suitability of the five stations are in the category conditional suitable. [ABSTRACT FROM AUTHOR]

Three species belonging to the genus Thalerosphyrus Eaton, 1881 are reported from Java and Sumatra. The nymphs of Th. determinatus (Walker, 1853) from Java, Th. sinuosus (Navás, 1933) from Java and Sumatra and Th. lamuriensis Sartori, 2014 from Sumatra are redescribed. The egg morphology of the three species is also presented for the first time. A key to the nymphs is proposed. General considerations on the composition of the genus Thalerosphyrus in the Oriental Realm are given. The distribution of the genus is greatly expended, and currently ranges over the Himalaya and Sumbawa in the Sunda Islands. [ABSTRACT FROM AUTHOR]

The cataclysmic eruption of Tambora volcano (Sumbawa, Indonesia) in 1815 has long been recognized as one of the largest explosive eruptions in historical time. It yielded extensive pyroclastic deposits from the emptying of a 30–33 km3 trachyandesite (latite)–tephriphonolite (herein referred to as trachyandesite) magma body. The parental trachybasalt magma of the trachyandesite erupted in 1815 can be produced by ∼2% partial melting of a garnet-free, Indian-type mid-ocean ridge basalt (I-MORB)-like mantle source contaminated with ∼3% fluids from altered oceanic crust and <1% sedimentary material, preserving small 238U excesses in the Tambora rocks. Magmatic differentiation from primary trachybasalt to trachyandesite occurred during two-stage, polybaric differentiation at depth(s) around the Moho and in a shallow-level crustal magma reservoir, emplaced at a maximum depth of ∼7·5 km (and, possibly, as shallow as ∼2·3 km). This crustal reservoir grew by influx of basaltic trachyandesite (shoshonite) magma, which originated predominantly by partial crystallization of primary trachybasalt in the inferred deep reservoir. Subsequent magmatic differentiation dominated by fractional crystallization, magma recharge–mixing and convection over timescales of ∼4000–4500 years led to the trachyandesitic (and ultimately phonolitic) melts erupted in 1815. Highly calcic, corroded plagioclase crystals in 226Ra–230Th equilibrium (>8000 years old) provide physical evidence for incorporation of ‘antecrystic’ material into the 1815 magma. Magma accumulation and differentiation at shallow depth prior to the eruption were accompanied by continuous degassing of sulphur (and other volatile species), which is thought not to have accumulated within or towards the top of the magma reservoir to contribute to the volatile budget of the eruption, but to have escaped to the surface passively through the permeable wall rocks. [ABSTRACT FROM PUBLISHER]

Three new species of the genus Irianjaya Koçak & Kemal, 2009 (Diptera: Asilidae: Asilinae) from Indonesia are described and partly illustrated. Irianjaya halmaheraensis spec. nov. from Halmahera (North Moluccas), A. sulaensis spec. nov. from Mangole (Sula Islands) and I. sumbawaensis spec. nov. from Sumbawa (Lesser Sunda Islands). Eccoptopus impiger van der Wulp, 1872, is a new junior synonym of Irianjaya areolaris (Walker, 1860). In addition, the following new combinations are given: Irianjaya areolaris (Walker, 1860), I. impiger (Wulp, 1872), and I. mendax (Walker, 1857), formerly placed in Amphiscolops. [ABSTRACT FROM AUTHOR]

Batu Hijau is a world-class gold-rich porphyry copper deposit, situated in Sumbawa Island, Indonesia. Deep drilling indicates that several intervals of calc-silicate rock were intersected, where they are apparently interbedded with volcaniclastic rocks. The calc-silicate rocks occur at the contact with copper-gold-bearing tonalite porphyries. The rocks are fine-grained and granular with green, reddish-brown and white layers. The green layers consist mostly of fine-grained clinopyroxene (diopside and hedenbergite) and the reddish-brown layers consist mostly of garnet (andradite), whereas the white layers are commonly composed of calcite and zeolite (chabazite). The calc-silicate rocks were formed by contact metasomatism of andesitic volcaniclastic rocks, as it is calcic in composition. Paragenesis study reveals at least two stages of calc-silicate mineralization. Stage 1 (prograde) is characterized by the presence of garnet (andradite), clinopyroxene (diopside and hedenbergite), anorthite and quartz at 340–360 C (high salinity 35–45 NaCl wt percentage eqn.). Stage 2 (retrograde) is characterized by chlorite and rare epidote at 280–300 C (low salinity 1–10 NaCl wt% eqn.). Late calcite ± quartz veinlets and calcite + chabazite veins/veinlets may also be related to this stage and cross cut the oldest mineral assemblages. Mineralization (magnetite, chalcopyrite and pyrite) may occur during the retrograde stage. Clinopyroxene and garnet were modified by Fe-rich hydrothermal fluid (oxidizing condition) indicated by increase of Fe from core to rim of both the cogenetic minerals. The presence of the calc-silicate rocks associated with massive magnetite-chalcopyrite-pyrite assemblage indicates the occurrence of calcic-exoskarn surrounding the Batu Hijau porphyry copper-gold deposit. [ABSTRACT FROM AUTHOR]

Indonesia is exposed to earthquakes, volcanic activities, and associated tsunamis. This is particularly the case for Lombok and Sumbawa Islands in West Nusa Tenggara, where evidence of tsunamis is frequently observed in its coastal sedimentary record. If the 1815 CE Tambora eruption on Sumbawa Island generated a tsunami with well-identified traces on the surrounding islands, little is known about the consequences of the 1257 CE tremendous eruption of Samalas on the neighboring islands, and especially about the possible tsunamis generated in reason of a paucity of research on coastal sedimentary records in this area. However, on Lombok Island, the eruption of the Samalas volcano produced significant volumes of pyroclastic flows that entered the sea in the North and East of the island. These phenomena must have produced a tsunami that left their traces, especially on Sumbawa Island, whose western coastline is only 14 km away from Lombok's eastern shore. Therefore, the main goal of this study is to investigate, find evidence, and determine the age of marine-origin sediments along the shore of the Alas Strait, Indonesia. We collected and analyzed samples of coral and seashells from marine deposits identified along the west coast of Sumbawa, i.e., in Belang Island and abandoned fishponds in Kiantar Village, in order to identify the sources and the occurrence period of these deposits events. Based on the radiocarbon dating of coral and seashell samples, we concluded that none of the identified marine deposits along the western coast of Sumbawa could be related chronologically to the 1257 CE eruption of Samalas. However, possible tsunami deposits located in Belang Island and abandoned fishponds in Kiantar Village yielded 4th century CE, 9th century CE, and 17th century CE. We also conclude that past large earthquakes triggered these tsunamis since no known volcanic eruption occurred near the Alas Strait at that time that may have triggered a tsunami. [ABSTRACT FROM AUTHOR]