Mangrove ecosystems are sites with high biodiversity of benthic fauna, and fiddler crabs(genus Uca) are common benthic fauna in mangroves. The North Sulawesi in Indonesia has a good condition of mangrove while the inf...Mangrove ecosystems are sites with high biodiversity of benthic fauna, and fiddler crabs(genus Uca) are common benthic fauna in mangroves. The North Sulawesi in Indonesia has a good condition of mangrove while the information of the fiddler crabs is still limited. Manual samplings were conducted in wet, dry and transient seasons at a mangrove in Kema, North Sulawesi to investigate the species composition, density and distribution pattern of fiddler crabs. A total of 168 individuals, subjected to eight species of genus Uca crabs were collected at the mangrove, with U. triangularis having the highest abundance and U. annulipes having the lowest abundance.The densities of fiddle crabs were 27.56 ind./m2, 32.89 ind./m2and 14.22 ind./m2at the seaward, middle and landward zones, respectively, and the density was higher in dry and wet seasons than in transient season.展开更多
Kalapi(Kalappia celebica)is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s.Conservation of the species is possible through ex situ culture techniques.Arbuscular my...Kalapi(Kalappia celebica)is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s.Conservation of the species is possible through ex situ culture techniques.Arbuscular mycorrhizal fungi(AMF)can accelerate plant growth which in turn supports the conservation of endangered species.This study aimed to assess the efficacy of local AMF to accelerate the growth of kalapi and increase nutrient uptake in kalapi grown in gold mine tailing media.There were three AMF treatments,Glomus claroideum,Glomus coronatum,and a mixture of both,plus the control.Each treatment was replicated three times,each consisting of five plants.The results show that the highest AMF colony was obtained by kalapi seedlings inoculated with Glomus coronatum and the mixture of AMF.The range of mycorrhizae inoculation effect values was 59.7–71.3%.AMF inoculation increased growth and dry weight of 4-month-old seedlings compared to controls.Dry and total weights of kalapi inoculated with G.coronatum were significantly different from those inoculated with the AMF mixture.However,they are not significantly different from kalapi inoculated with G.claroideum.The results also show that AMF increased nitrogen and phosphorous uptake by the roots,as well as nitrogen,phosphorous,potassium,manganese and iron by the shoots.All AMF treatments decreased potassium uptake in the roots,except in kalapi inoculated with G.coronatum.The AMF mixture decreased iron contents the roots by 15%.AMF can be developed into biofertilizer to support the conservation of kalapi in tropical Indonesia.展开更多
This study was conducted to produce a GIS-based land use/land cover(LULC)balance map for a certain period as a reference for policymakers in planning their future regional development.This study also measures supervis...This study was conducted to produce a GIS-based land use/land cover(LULC)balance map for a certain period as a reference for policymakers in planning their future regional development.This study also measures supervised classification accuracy based on remote sensing and geographic information system(GIS)integration with field conditions.In June 2005 satellite imagery 7 ETM+was used as asset maps to assess land-use changes(LUC).Although in March 2019,the liability maps used satellite imagery 8 OLI/TIRS.Methods analysis consists of pre-image processing,image interpretation,random point,field check,and accuracy assessment.The image processing results were overlaid with an Indonesian topographic map to draw a LULC balance map.The findings indicate that in June 2005 and March 2019,each LULC had an assessment accuracy value of 82%and 86%,with a predicted assessment accuracy value of 18.05%and20.50%,respectively.These findings are checked to determine the suitability performance of field-based imaging approaches based on the Cohen Kappa coefficient criteria of 0.45 and 0.48 for June 2005 and March 2019.Based on these results,the image processing precision and suitability were excellent since they are more than 80%and satisfy the Cohen Kappa performance criterion.Furthermore,geospatial data on the LULC balance map is essential as a guide for planners and decision-makers to plan their regional development.展开更多
Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic po...Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic position among them, as well as several other species accessed from the Genbank. Total DNA extracted from the muscular tissue had been obtained through tail cut sampling using the innuPREP DNA micro kit, and amplified using a pair of universal primer, L14841 and H15149. The size of the cyt b gene sequence amplified was 307 bp long. Sequence aligned using CLUSTAL-X program and diversity analysis were done using version 5.2.2. MEGA5 program. Genetic distance had been calculated by Tamura 3 parameter method and phylogenetic tree had been built using Neighbor-Joining and Maximum Likelihood methods. Genetic distance based on cyt b gene nucleotide was found from 0 to 0.240 with an average of 0.080. The phylogenetic tree constructed by Neighbor Joining and Maximum Likelihood methods indicated that T. tarsier, T. sangirensis and T. tumpara were closely related with Tarsius tarsier-complex, and distantly related with Cephalopachus bancanus and Carlito syrichta. The genetic distance and the phylogenetic tree had been constructed on the base of partial cyt b gene sequence of T. tarsier, T. sangirensis, T. tumpara and 5 other tarsier species and their accession. Those results are consistent with taxonomy based on morphology and vocal acoustic form.展开更多
Hand preference of wild moor monkeys Macaca mounts was investigated in food reaching situations at the KaraentaNature Reserve, South Sulawesi, Indonesia. The frequency picking up sweet-corn grains to take into the mou...Hand preference of wild moor monkeys Macaca mounts was investigated in food reaching situations at the KaraentaNature Reserve, South Sulawesi, Indonesia. The frequency picking up sweet-corn grains to take into the mouth by either hand ofmonkeys was counted directly at the feeding ground where sweet-corn grains were scattered for monkeys. Among the 20 monkeysexamined, 8 were right-handed, 8 were left-handed, and 4 were ambilateral. The results indicated the prevailed hand preferenceon individual level but not either trends of left- or right-hand preference on population level. The trend toward a higher proportionof left-handed monkeys found in Japanese and rhesus monkeys was not found. Some other characteristics found in moormonkeys are discussed in comparison with those previous findings in Japanese and Tibetan macaques in order to evaluate variationswithin the genus展开更多
The Poso Depression provides a record of Plio-Pleistocene environments and palaeogeography of Central Sulawesi.Outcrop-based sedimentological and provenance studies suggest that during the Pliocene the Poso Depression...The Poso Depression provides a record of Plio-Pleistocene environments and palaeogeography of Central Sulawesi.Outcrop-based sedimentological and provenance studies suggest that during the Pliocene the Poso Depression was a sea channel connecting Gorontalo and Bone bays formed in an asymmetric half-graben.The Pliocene history began with deposition of the Puna Formation with fan deltas at the eastern basin margin and channel complexes in the deep-water basin further east.Analyses of light and heavy minerals indicate the main sediment source was ultrabasic rocks in East Sulawesi with minor and intermittent magmatic and metamorphic input from West Sulawesi.Later,in the Middle to Late Pliocene,carbonates of the Poso Formation accumulated on the eastern basin margin.They are unconformably overlain by shallow marine glaucophane-rich siliciclastics of the Pleistocene Lage Formation that are associated with the rapid exhu-mation and uplift of the Pompangeo metamorphic complex.This uplift led to the development of a land bridge connecting western and eastern Sulawesi.The terrane evolution favoured increasing the area of exposed land due to rapid tectonic uplift,which when combined with the tropical climate,contributed to faunal speciation and dispersal in Sulawesi.展开更多
Ultrahigh-temperature(UHT)metamorphism represents an extreme crustal thermal event with peak conditions exceeding 900C at 7–13 kbar.In the modern-style plate tectonic system,records of the UHT metamorphism are relati...Ultrahigh-temperature(UHT)metamorphism represents an extreme crustal thermal event with peak conditions exceeding 900C at 7–13 kbar.In the modern-style plate tectonic system,records of the UHT metamorphism are relatively rare due to the secular cooling of Earth.In the Palu region of Western Sulawesi,we newly discovered a series of HT-UHT metamorphic rocks including amphibolite,granulite,eclogites and gneiss.Of them,two granulite samples(18CS14-2,18CS14-4)with high garnet content(>50 mol%)are chosen for petrographic observation,phase equilibrium modelling,and zircon U-Pb dating.These rocks are characterized by a relic M1 assemblage of Grt+Ky+Bt+Rt and a M2 assemblage of Grt+Sil+Pl+Spl+Crd±Qtz+Ilm+melt.Phase equilibrium modelling based on effective bulk compositions yields UHT conditions of 7.2–8.5 kbar/940–1080C(18CS14-2)and 7.0–7.3 kbar/1000–1040C(18CS14-4).U-Pb analysis reveals two generations of metamorphic zircon with evolving REE content that is intimately related to garnet growth and decomposition.Zircon age of 36–5.3 Ma is ascribed to syn-to post-M1 metamorphism,whereas the young zircon age of 5.1–3.8 Ma is linked to syn-and post-M2 stage.The UHT metamorphism was probably the consequence of the upwelling of asthenospheric mantle triggered by post-collisional delamination of lithosphere in the MiocenePliocene(ca.5 Ma).It could represent the youngest known UHT metamorphism on Earth.展开更多
We report for the first time the geochemistry of rare earth elements(REE) in the weathered crusts of I-type and calc-alkaline to high-K(shoshonitic) granitic rocks at Mamasa and Palu region, Sulawesi Island, Indon...We report for the first time the geochemistry of rare earth elements(REE) in the weathered crusts of I-type and calc-alkaline to high-K(shoshonitic) granitic rocks at Mamasa and Palu region, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A(lateritic profile) and B(weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part(horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated compared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weathering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon.展开更多
The Sulawesi Sea and Sulawesi Island are located in the western Pacific area where volcanic activity,plate subduction,and seismic activity are very active.The Sulawesi basin formed during the Middle Eocene-Late Eocene...The Sulawesi Sea and Sulawesi Island are located in the western Pacific area where volcanic activity,plate subduction,and seismic activity are very active.The Sulawesi basin formed during the Middle Eocene-Late Eocene and nearly half of the Eocene oceanic crust has subducted below the North Sulawesi Trench.The Sulawesi Island was spliced and finalized in the Early Pliocene-Pleistocene during volcanic activity and is recently very active.This area is an optimal location to study volcanic geothermal conditions and subduction initiation mechanisms in the southern part of the western Pacific plate margin,which are important in geothermal and geodynamic research.In this study,we combined 133 heat flow data with gravity and magnetic data to calculate the Moho structure and Curie point depth of the Sulawesi Sea and periphery of the Sulawesi Island,and analyze the distribution characteristics of the geothermal gradient and thermal conductivity.The results show that the average depths of the Moho and Curie surfaces in this area are 18.4 and 14.3 km,respectively,which is consistent with the crustal velocity layer structure in the Sulawesi Basin previously determined by seismic refraction.The average geothermal gradient is 4.96°C(100 m)-1.The oceanic area shows a high geothermal gradient and low thermal conductivity,whereas the land area shows a low geothermal gradient and high thermal conductivity,both of which are consistent with statistical results of the geothermal gradient at the measured heat flow points.The highest geothermal gradient zone occurs in the transition zone from the Sulawesi Sea to Sulawesi Island,corresponding to the spreading ridge of the southward-moving Sulawesi Basin.Comprehensive gravity,magnetic,and geothermal studies have shown a high crustal geothermal gradient in the study area,which is conducive to the subduction initiation.The northern part of the Palu-koro fault on the western side of Sulawesi is likely the location where subduction initiation is occurring.During the process of moving northwest,the northern and eastern branches of Sulawesi Island have different speeds;the former is slow and the latter is fast.These branches also show different deep tectonic dynamic directions;the northern branch tilts north-up and the eastern branch tilts north-down.展开更多
Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant spec...Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant species and the largest distribution areas of seagrass, yet the seagrass macrofauna in this region are poorly understood. To help fill this gap in our knowledge, an ecological survey was conducted to describe the abundance and diversity of benthic macrofauna from tropical seagrass beds and to determine between-station variations within a transect and between-site variations in macrofaunal abundance, taxa richness and community structure. Benthic macrofaunal samples associated with seagrass beds were collected with a core sampler on the east coast of North Sulawesi in May 2014 and on the west coast in October 2015. A total of 149 species from 14 higher taxa was collected. The most species-rich groups were polychaetes(56 species, 26% of total individual numbers), decapods(20 species, 9% of total numbers) and amphipods(18 species, 35% of total numbers). Between-station variations within a transect displayed different patterns between the east coast and the west coast. On the east coast, there were marked variations in abundance between stations within a transect for the macrofauna and amphipod assemblages. Both taxa richness and abundance varied with station for the macrofauna and polychaete assemblages on the west coast, resulting from the heterogeneity of the substrate along a transect. One-way ANOSIM together with MDS ordination indicated that macrofaunal community structure in seagrasses differed significantly between the east coast and the west coast, corresponding with the division of seagrasses into two broad categories of habitats, i.e.,mangrove-seagrass-reef continuum and seagrass-reef continuum. Compared with other studies in tropical areas,the abundance and diversity of benthic macrofauna in the present study were moderate. The reason for the two markedly distinct macrofaunal communities might be attributed to multiple factors, including sediment pattern,seagrass structure and temporal changes.展开更多
Background: The White-faced Cuckoo-dove(Turacoena manadensis) is a poorly-known Wallacean endemic with a limited distribution on Sulawesi and its satellites, including the Togian, Banggai and Sula archipelagoes. In 19...Background: The White-faced Cuckoo-dove(Turacoena manadensis) is a poorly-known Wallacean endemic with a limited distribution on Sulawesi and its satellites, including the Togian, Banggai and Sula archipelagoes. In 1900, populations from the Sula archipelago were awarded subspecies status T. manadensis sulaensis based on smaller size and minor differences in plumage; however, this distinction has not been corroborated subsequently, and T. manadensis is considered by most modern sources to be monotypic across its range.Methods: We conducted vocal analysis of the cuckoo-doves' main song using recordings collected from across the taxon's natural range. Descriptive information on the songs was obtained from the recordings using bioacoustic analysis software, after which several statistical methods were used to investigate differences in vocalizations among populations.Results: We report deep bioacoustic divergences in vocal trait pattern from across the cuckoo-doves' range, with birds from Peleng and Taliabu in the east having a different vocal trait pattern from birds from Sulawesi, Buton, and Togian in the west. These patterns agree with changes in landmass that accompanied the sea level fluctuations caused by Pleistocene glacial cycles, and indicate that eastern and western cuckoo-dove populations are at the level of different biological species.Conclusions: We propose that the eastern taxon be elevated to species level as T. sulaensis. Given the rampant degree of habitat destruction in its limited range, this taxonomic change will have important implications on the conservation status of T. sulaensis.展开更多
基金The China-Indonesia Ecological Station Establishment and Marine Biodiversity Investigation in North Sulawesi Seathe China-ASEAN Marine Protected Area Ecosystem Management Networkthe Public Science and Technology Research Funds Projects of Ocean under contract No.201505009
文摘Mangrove ecosystems are sites with high biodiversity of benthic fauna, and fiddler crabs(genus Uca) are common benthic fauna in mangroves. The North Sulawesi in Indonesia has a good condition of mangrove while the information of the fiddler crabs is still limited. Manual samplings were conducted in wet, dry and transient seasons at a mangrove in Kema, North Sulawesi to investigate the species composition, density and distribution pattern of fiddler crabs. A total of 168 individuals, subjected to eight species of genus Uca crabs were collected at the mangrove, with U. triangularis having the highest abundance and U. annulipes having the lowest abundance.The densities of fiddle crabs were 27.56 ind./m2, 32.89 ind./m2and 14.22 ind./m2at the seaward, middle and landward zones, respectively, and the density was higher in dry and wet seasons than in transient season.
基金supported by the funding support(No.171.SP2H/LT/DRPM/2019)from Directorate General of Resource,Science,Technology,Higher Education,Ministry of Research,Technology of the Republic of Indonesia。
文摘Kalapi(Kalappia celebica)is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s.Conservation of the species is possible through ex situ culture techniques.Arbuscular mycorrhizal fungi(AMF)can accelerate plant growth which in turn supports the conservation of endangered species.This study aimed to assess the efficacy of local AMF to accelerate the growth of kalapi and increase nutrient uptake in kalapi grown in gold mine tailing media.There were three AMF treatments,Glomus claroideum,Glomus coronatum,and a mixture of both,plus the control.Each treatment was replicated three times,each consisting of five plants.The results show that the highest AMF colony was obtained by kalapi seedlings inoculated with Glomus coronatum and the mixture of AMF.The range of mycorrhizae inoculation effect values was 59.7–71.3%.AMF inoculation increased growth and dry weight of 4-month-old seedlings compared to controls.Dry and total weights of kalapi inoculated with G.coronatum were significantly different from those inoculated with the AMF mixture.However,they are not significantly different from kalapi inoculated with G.claroideum.The results also show that AMF increased nitrogen and phosphorous uptake by the roots,as well as nitrogen,phosphorous,potassium,manganese and iron by the shoots.All AMF treatments decreased potassium uptake in the roots,except in kalapi inoculated with G.coronatum.The AMF mixture decreased iron contents the roots by 15%.AMF can be developed into biofertilizer to support the conservation of kalapi in tropical Indonesia.
文摘This study was conducted to produce a GIS-based land use/land cover(LULC)balance map for a certain period as a reference for policymakers in planning their future regional development.This study also measures supervised classification accuracy based on remote sensing and geographic information system(GIS)integration with field conditions.In June 2005 satellite imagery 7 ETM+was used as asset maps to assess land-use changes(LUC).Although in March 2019,the liability maps used satellite imagery 8 OLI/TIRS.Methods analysis consists of pre-image processing,image interpretation,random point,field check,and accuracy assessment.The image processing results were overlaid with an Indonesian topographic map to draw a LULC balance map.The findings indicate that in June 2005 and March 2019,each LULC had an assessment accuracy value of 82%and 86%,with a predicted assessment accuracy value of 18.05%and20.50%,respectively.These findings are checked to determine the suitability performance of field-based imaging approaches based on the Cohen Kappa coefficient criteria of 0.45 and 0.48 for June 2005 and March 2019.Based on these results,the image processing precision and suitability were excellent since they are more than 80%and satisfy the Cohen Kappa performance criterion.Furthermore,geospatial data on the LULC balance map is essential as a guide for planners and decision-makers to plan their regional development.
文摘Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic position among them, as well as several other species accessed from the Genbank. Total DNA extracted from the muscular tissue had been obtained through tail cut sampling using the innuPREP DNA micro kit, and amplified using a pair of universal primer, L14841 and H15149. The size of the cyt b gene sequence amplified was 307 bp long. Sequence aligned using CLUSTAL-X program and diversity analysis were done using version 5.2.2. MEGA5 program. Genetic distance had been calculated by Tamura 3 parameter method and phylogenetic tree had been built using Neighbor-Joining and Maximum Likelihood methods. Genetic distance based on cyt b gene nucleotide was found from 0 to 0.240 with an average of 0.080. The phylogenetic tree constructed by Neighbor Joining and Maximum Likelihood methods indicated that T. tarsier, T. sangirensis and T. tumpara were closely related with Tarsius tarsier-complex, and distantly related with Cephalopachus bancanus and Carlito syrichta. The genetic distance and the phylogenetic tree had been constructed on the base of partial cyt b gene sequence of T. tarsier, T. sangirensis, T. tumpara and 5 other tarsier species and their accession. Those results are consistent with taxonomy based on morphology and vocal acoustic form.
基金sponsored by the Grant for Overseas Field Research Program of the Primate Research Institute, Kyoto University
文摘Hand preference of wild moor monkeys Macaca mounts was investigated in food reaching situations at the KaraentaNature Reserve, South Sulawesi, Indonesia. The frequency picking up sweet-corn grains to take into the mouth by either hand ofmonkeys was counted directly at the feeding ground where sweet-corn grains were scattered for monkeys. Among the 20 monkeysexamined, 8 were right-handed, 8 were left-handed, and 4 were ambilateral. The results indicated the prevailed hand preferenceon individual level but not either trends of left- or right-hand preference on population level. The trend toward a higher proportionof left-handed monkeys found in Japanese and rhesus monkeys was not found. Some other characteristics found in moormonkeys are discussed in comparison with those previous findings in Japanese and Tibetan macaques in order to evaluate variationswithin the genus
基金supported by the SE Asia Research Group of Royal Holloway University of London,United Kingdom,which is backed by a consortium of oil companiessupported by the Earth Observatory of Singapore(EOS),Singapore and comprises EOS contribution number 508
文摘The Poso Depression provides a record of Plio-Pleistocene environments and palaeogeography of Central Sulawesi.Outcrop-based sedimentological and provenance studies suggest that during the Pliocene the Poso Depression was a sea channel connecting Gorontalo and Bone bays formed in an asymmetric half-graben.The Pliocene history began with deposition of the Puna Formation with fan deltas at the eastern basin margin and channel complexes in the deep-water basin further east.Analyses of light and heavy minerals indicate the main sediment source was ultrabasic rocks in East Sulawesi with minor and intermittent magmatic and metamorphic input from West Sulawesi.Later,in the Middle to Late Pliocene,carbonates of the Poso Formation accumulated on the eastern basin margin.They are unconformably overlain by shallow marine glaucophane-rich siliciclastics of the Pleistocene Lage Formation that are associated with the rapid exhu-mation and uplift of the Pompangeo metamorphic complex.This uplift led to the development of a land bridge connecting western and eastern Sulawesi.The terrane evolution favoured increasing the area of exposed land due to rapid tectonic uplift,which when combined with the tropical climate,contributed to faunal speciation and dispersal in Sulawesi.
基金supported by the National Natural Science Foundation of China[42025204,41890831,41803029,41973025 and 92155306]Guangdong Province Introduced Innovative R&D Team of Geological Processes and Natural Disasters around the South China Sea[2016ZT06N331]HKU Seed Fund for Basic Research[201811159089].
文摘Ultrahigh-temperature(UHT)metamorphism represents an extreme crustal thermal event with peak conditions exceeding 900C at 7–13 kbar.In the modern-style plate tectonic system,records of the UHT metamorphism are relatively rare due to the secular cooling of Earth.In the Palu region of Western Sulawesi,we newly discovered a series of HT-UHT metamorphic rocks including amphibolite,granulite,eclogites and gneiss.Of them,two granulite samples(18CS14-2,18CS14-4)with high garnet content(>50 mol%)are chosen for petrographic observation,phase equilibrium modelling,and zircon U-Pb dating.These rocks are characterized by a relic M1 assemblage of Grt+Ky+Bt+Rt and a M2 assemblage of Grt+Sil+Pl+Spl+Crd±Qtz+Ilm+melt.Phase equilibrium modelling based on effective bulk compositions yields UHT conditions of 7.2–8.5 kbar/940–1080C(18CS14-2)and 7.0–7.3 kbar/1000–1040C(18CS14-4).U-Pb analysis reveals two generations of metamorphic zircon with evolving REE content that is intimately related to garnet growth and decomposition.Zircon age of 36–5.3 Ma is ascribed to syn-to post-M1 metamorphism,whereas the young zircon age of 5.1–3.8 Ma is linked to syn-and post-M2 stage.The UHT metamorphism was probably the consequence of the upwelling of asthenospheric mantle triggered by post-collisional delamination of lithosphere in the MiocenePliocene(ca.5 Ma).It could represent the youngest known UHT metamorphism on Earth.
基金Financial support assistance from Global-Centre of Excellent (GCOE) program Kyushu University
文摘We report for the first time the geochemistry of rare earth elements(REE) in the weathered crusts of I-type and calc-alkaline to high-K(shoshonitic) granitic rocks at Mamasa and Palu region, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A(lateritic profile) and B(weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part(horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated compared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weathering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon.
基金supported by the National Natural Science Foundation of China(Grant Nos.91858212,41906056 and U1701245)the Strategic Pilot Science and Technology Project of Chinese Academy of Sciences(Grant No.XDB42020104)。
文摘The Sulawesi Sea and Sulawesi Island are located in the western Pacific area where volcanic activity,plate subduction,and seismic activity are very active.The Sulawesi basin formed during the Middle Eocene-Late Eocene and nearly half of the Eocene oceanic crust has subducted below the North Sulawesi Trench.The Sulawesi Island was spliced and finalized in the Early Pliocene-Pleistocene during volcanic activity and is recently very active.This area is an optimal location to study volcanic geothermal conditions and subduction initiation mechanisms in the southern part of the western Pacific plate margin,which are important in geothermal and geodynamic research.In this study,we combined 133 heat flow data with gravity and magnetic data to calculate the Moho structure and Curie point depth of the Sulawesi Sea and periphery of the Sulawesi Island,and analyze the distribution characteristics of the geothermal gradient and thermal conductivity.The results show that the average depths of the Moho and Curie surfaces in this area are 18.4 and 14.3 km,respectively,which is consistent with the crustal velocity layer structure in the Sulawesi Basin previously determined by seismic refraction.The average geothermal gradient is 4.96°C(100 m)-1.The oceanic area shows a high geothermal gradient and low thermal conductivity,whereas the land area shows a low geothermal gradient and high thermal conductivity,both of which are consistent with statistical results of the geothermal gradient at the measured heat flow points.The highest geothermal gradient zone occurs in the transition zone from the Sulawesi Sea to Sulawesi Island,corresponding to the spreading ridge of the southward-moving Sulawesi Basin.Comprehensive gravity,magnetic,and geothermal studies have shown a high crustal geothermal gradient in the study area,which is conducive to the subduction initiation.The northern part of the Palu-koro fault on the western side of Sulawesi is likely the location where subduction initiation is occurring.During the process of moving northwest,the northern and eastern branches of Sulawesi Island have different speeds;the former is slow and the latter is fast.These branches also show different deep tectonic dynamic directions;the northern branch tilts north-up and the eastern branch tilts north-down.
基金China-Indonesia Maritime Cooperation Fund Project“China-Indonesia Bitung Joint Marine Ecological Station Establishment”the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2011034
文摘Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant species and the largest distribution areas of seagrass, yet the seagrass macrofauna in this region are poorly understood. To help fill this gap in our knowledge, an ecological survey was conducted to describe the abundance and diversity of benthic macrofauna from tropical seagrass beds and to determine between-station variations within a transect and between-site variations in macrofaunal abundance, taxa richness and community structure. Benthic macrofaunal samples associated with seagrass beds were collected with a core sampler on the east coast of North Sulawesi in May 2014 and on the west coast in October 2015. A total of 149 species from 14 higher taxa was collected. The most species-rich groups were polychaetes(56 species, 26% of total individual numbers), decapods(20 species, 9% of total numbers) and amphipods(18 species, 35% of total numbers). Between-station variations within a transect displayed different patterns between the east coast and the west coast. On the east coast, there were marked variations in abundance between stations within a transect for the macrofauna and amphipod assemblages. Both taxa richness and abundance varied with station for the macrofauna and polychaete assemblages on the west coast, resulting from the heterogeneity of the substrate along a transect. One-way ANOSIM together with MDS ordination indicated that macrofaunal community structure in seagrasses differed significantly between the east coast and the west coast, corresponding with the division of seagrasses into two broad categories of habitats, i.e.,mangrove-seagrass-reef continuum and seagrass-reef continuum. Compared with other studies in tropical areas,the abundance and diversity of benthic macrofauna in the present study were moderate. The reason for the two markedly distinct macrofaunal communities might be attributed to multiple factors, including sediment pattern,seagrass structure and temporal changes.
基金funded by National University of Singapore internal Faculty of Sciences Grant WBS R-154-000-570-133Department of Biological Sciences grant WBS R-154-000-583-651
文摘Background: The White-faced Cuckoo-dove(Turacoena manadensis) is a poorly-known Wallacean endemic with a limited distribution on Sulawesi and its satellites, including the Togian, Banggai and Sula archipelagoes. In 1900, populations from the Sula archipelago were awarded subspecies status T. manadensis sulaensis based on smaller size and minor differences in plumage; however, this distinction has not been corroborated subsequently, and T. manadensis is considered by most modern sources to be monotypic across its range.Methods: We conducted vocal analysis of the cuckoo-doves' main song using recordings collected from across the taxon's natural range. Descriptive information on the songs was obtained from the recordings using bioacoustic analysis software, after which several statistical methods were used to investigate differences in vocalizations among populations.Results: We report deep bioacoustic divergences in vocal trait pattern from across the cuckoo-doves' range, with birds from Peleng and Taliabu in the east having a different vocal trait pattern from birds from Sulawesi, Buton, and Togian in the west. These patterns agree with changes in landmass that accompanied the sea level fluctuations caused by Pleistocene glacial cycles, and indicate that eastern and western cuckoo-dove populations are at the level of different biological species.Conclusions: We propose that the eastern taxon be elevated to species level as T. sulaensis. Given the rampant degree of habitat destruction in its limited range, this taxonomic change will have important implications on the conservation status of T. sulaensis.