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Nicolas Mazzella Josiane Molinet Agung Dhamar Syakti Jean-Claude Bertrand Pierre Doumenq 《Marine Chemistry》2007,103(3-4):304-317
This in situ study reports on the relevance of intact phospholipids as new biomarkers and highlights the limits of the classical fatty acid analysis after the hydrolysis of the polar lipid fraction. The analysis of polar lipid fractions revealed significant contributions of marine macrophytes with either non-phospholipid compounds (sulfoquinovosyl diacylglycerol) or with both non-bacterial phospholipid classes (phosphatidylcholine) and non-bacterial phospholipid molecular species (some molecular species of phosphatidylglycerol). The analysis of intact phospholipids showed also the predominance of gram-negative bacteria in sediments whereas the analysis of fatty acids alone cannot confirm such information. Lastly, as regard to the effects of petroleum hydrocarbons on the sedimentary bacterial communities, we observed a higher degree of saturation of the fatty acyl chains of the phospholipids extracted from sediment exposed to a massive and chronic crude oil contamination. Such a result was interpreted as an adaptive response resulting in higher membrane rigidity of the bacterial communities. 相似文献
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GeoJournal - Gamalama is an active stratovolcano on Ternate, a small volcanic island in Maluku Utara, Indonesia. Since 1510, a total of 77 eruptions have been recorded, with various impacts on the... 相似文献
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Following the Yogyakarta earthquake on May 27th, 2006, the subsequent eruption of a mud volcano has been closely observed and analyzed by the geological community. The mud volcano, known as LUSI, began erupting near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia. LUSI offers a unique opportunity to study the genesis and development of a mud volcano. 相似文献
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Agung Dhamar Syakti Nuning Vita Hidayati Endang Hilmi Anne Piram Pierre Doumenq 《Marine pollution bulletin》2013
The study aimed to determine the spatial distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Segara Anakan nature reserve and their potential origins using gas chromatography–mass spectrometry. Total alkane concentrations ranged from 3755 to 129,027 μg kg−1, and the concentrations of 16 PAHs ranged from 375 to 29,517 μg kg−1. The ratios of specific n-alkanes (e.g., CPI24–34, WaxCn, and Paq), including a new proposed index, terrestrial–marine discriminant (TMD), as well as the ratios of selected PAHs (e.g., Ant/∑178, Fl/∑202, BaAnt/∑228, and IPyr/∑276), showed that the sources of hydrocarbons in the sediments were generally biogenic, including both terrigenous and marine, with an anthropogenic pyrolytic contribution (petrogenic and biogenic combustion). For the environmental risk assessment, a sediment quality guideline (SQGs) comparison indicated that the station risk levels ranged from low to medium-low, except for R6, which has a greater impact on the ecological risk for marine organisms. 相似文献
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Spatial and temporal variation of upwelling along the southern coast of Bali and in the Nusa Tenggara waters — Indonesia was studied by using satellite image data of sea surface temperatures and chlorophyll-a from September 1997 to December 2008. This study clearly reveals annual upwelling in the regions from June to October, associated with the southeast monsoon cycle, with the sea surface temperature (chlorophyll-a concentration) being colder (higher) than that during the northwest monsoon. In addition, this study also shows that the upwelling strength is controlled remotely by ENSO and IOD climate phenomena. During El Niño/positive IOD (La Niña/negative IOD) periods, the Bali — Nusa Tenggara upwelling strength increases (decreases). 相似文献
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Agung Harijoko Kenzo Sanematsu Robert A. Duncan Sukmandaru Prihatmoko Koichiro Watanabe 《Resource Geology》2004,54(2):187-195
Abstract. The Cibaliung deposit is a low-sulfidation type epithermal gold deposit situated about 70 km west of the Bayah dome complex. The gold-bearing quartz veins are hosted by basaltic andesite of the Honje Formation, which is comparable to the host rock of gold deposits at the Bayah dome complex.
In order to clarify the timing of the mineralization and the volcanism at the Cibaliung area, two radiometric dating methods were applied. First,40 Ar/39 Ar dating was conducted on six adularia samples to elucidate the age of mineralization. Second, K-Ar method was applied to two samples of the host rock, andesite and the Cibaliung tuff, in order to reveal the timing of volcanism.
The40 Ar/39 Ar dating determined mineralization ages in the range from 11.18 to 10.65 Ma while the K-Ar dating indicated the age of the andesite and the Cibaliung tuff to be 11.4±0.8 Ma and 4.9±0.6 Ma, respectively. These results imply that the epithermal gold mineralization in the Cibaliung area is related to the volcanic activity that produced the Honje Formation, while the Cibaliung tuff played an important role in the preservation of the Cibaliung deposit. The Cibaliung deposit is the oldest epithermal gold deposit yet discovered in western Java. 相似文献
In order to clarify the timing of the mineralization and the volcanism at the Cibaliung area, two radiometric dating methods were applied. First,
The
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Agung Harijoko Yukiko Ohbuchi Yoshinobu Motomura Akira Imai Koichiro Watanabe 《Resource Geology》2007,57(2):114-123
Middle Miocene (11.18–10.65 Ma) low sulfidation‐type epithermal gold mineralization occurred in the Cibaliung area, southwestern part of Java Island, Indonesia. It is hosted by andesitic to basaltic andesitic lavas of the Middle Miocene Honje Formation (11.4 Ma) and is covered by Pliocene Cibaliung tuff (4.9 Ma). The exploration estimates mineral resource of approximately 1.3 million tonnes at 10.42 g/t gold and 60.7 g/t silver at a 3 g/t Au cut‐off. This equates to approximately 435,000 ounces of gold and 2.54 million ounces of silver. That resource resulted from two ore shoots: Cibitung and Cikoneng. Studies on ore mineralogy, hydrothermal alteration, geology, fluid inclusion, stable isotopes and age dating were conducted in order to characterize the deposit and to understand a possible mechanism of preservation of the deposit. The ore mineral assemblage of the deposit consists of electrum, naumannite, Ag‐Se‐Te sulfide minerals, chalcopyrite, pyrite, sphalerite and galena. Those ore minerals occur in quartz veins showing colloform–crustiform texture. They are enveloped by mixed layer clay illite/smectite zone, which grades into smectite zone outward. The temperature of mineralization revealed by fluid inclusion study on quartz in the veins ranges from 170 and 220°C at shallow and deep level, respectively. The temperature range is in agreement with the temperature deduced from the hydrothermal alteration mineral assemblage including mixed layered illite/smectite and laumontite. The mineralizing fluid is dilute, with a salinity <1 wt% NaCl equivalent and has stable isotopes of oxygen and hydrogen composition indicating a meteoric water origin. Although the deposit is old enough that it would have been eroded in a tropical island arc setting, the coverage by younger volcanic deposits such as the Citeluk tuff and the Cibaliung tuff most probably prevented this erosion. 相似文献
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Indonesia has turned its alleged role as global leader of land-based carbon emissions into a role as a global trailblazer exploring modalities for Reducing Emissions from Deforestation and Forest Degradation (REDD+). REDD+ readiness is largely about improving forest governance, but this itself is a multilayered concept. This article analyses how the processes and practices of REDD+ readiness are leading to various forest governance reforms in Indonesia. We analysed six dimensions of REDD+ readiness progress over the past six years and the way these interact with land tenure reform and land-use planning. We found evidence that (1) tenure issues are taken more seriously, as evidenced by the development of social safeguard mechanisms and efforts to accelerate the gazettement of forest boundaries, although a constitutional court recognition in 2013 for customary forest management is, however, yet to be operationalized; (2) spatial planning relates forests more clearly to other parts of the landscape in terms of compliance with Nationally Appropriate Mitigation Actions (NAMAs) commitments; and (3) the forest and peatland conversion moratorium initiative led to a revamping of forest management. Despite progress, there are still major obstacles to full REDD+ implementation in Indonesia. The discussion focuses on the weaker part of readiness and possible ways forward. 相似文献