Despite the upsurge in hydrocarbon exploration in the Lake Albert Rift Basin(LARB)over the past three decades,systematic characterization of hydrocarbon compositions remains lacking,leading to uncertainties in source ...Despite the upsurge in hydrocarbon exploration in the Lake Albert Rift Basin(LARB)over the past three decades,systematic characterization of hydrocarbon compositions remains lacking,leading to uncertainties in source rock and oil generation determination.We characterized crude oil compositions and oil sand samples in the northern and southern subbasins of LARB.The relative abundance of normal and branched linear alkanes,hopanes,steranes,and aromatic hydrocarbon suggest that northern and southern hydrocarbons were deposited in anoxic to suboxic lacustrine environments and share similar biological source compositions(i.e.,a mixture of plants and aquatic algae and bacteria).Relative to southern samples,northern samples show more negative δ^(13)C values for oils,saturates and aromatics,indicating longer migration paths,and exhibit higher MPI-1,DNR-1 and 4-/1-MDBT ratios,indicating higher maturity.Between the two possible sets of source rocks(upper Miocene and Jurassic strata),the positive δ^(13)C values of saturated hydrocarbons(average=-20.5‰)suggest that the upper Miocene lacustrine shale is the most likely candidate.Oleanane index(<5% in our samples)does not exclude either source rock possibility,and C_(28)/C_(29) regular sterane(average=0.63)may be biased by high terrestrial inputs in a lacustrine setting.Together,our data show that northern and southern oils originate from the same source rocks but different oil kitchens.Given the similar geochemical characteristics of southern and northern oils,previous exploration successes in the northern subbasin likely suggest similar potential in the southern sector,while other elements influencing exploration success must be also evaluated.展开更多
Goats are globally very important domestic small ruminants being kept for meat, milk, skin, byproducts and several socio-cultural purposes. Goat farmers in the Lake Albert Crescent Zone (LACZ) of Uganda identified dry...Goats are globally very important domestic small ruminants being kept for meat, milk, skin, byproducts and several socio-cultural purposes. Goat farmers in the Lake Albert Crescent Zone (LACZ) of Uganda identified dry-season feed scarcity, poor breeds, diseases, informal marketing and theft as major constraints which underscore the scarcity of information on improved management technologies and the need for targeted decisions. At BuZARDI goat farm, a semi-intensive farm that is also experiencing similar challenges, we documented management practices and collected production related data for 2 years. We computed flock dynamics and mortality rates purposely to influence decisions aimed at increasing the farm’s productivity. Data were collected using pens and books, validated and analyzed using MS office 2013 and SPSS version 22. The flock size increased from 37 goats in July 2020 to 175 goats in June 2022. One hundred twenty-five goats were introduced into the farm as breeding stock, 89 kids were born on the farm and 61 goats died due to various causes. The average number of goats in the farm per month was 109.2 (SEM = 13.7), female 79.8 (SEM = 10.8) and male 29.4, (SEM = 9.9). Average population of goats at risk of death was 95 and the Mortality rate was 27 goats per 1000 goat months. The disaggregated mortality rate of 5 goats per 1000 goat months and 39 goats per 1000 goat months were obtained for the period FY 2020-2021 and FY2021-2022 respectively. The main contributors to the mortality of goats were worm infestation (33%), fracture and injuries arising from stampedes (18%), Ticks and tick borne diseases (18%), respiratory tract infections (11%) and malnutrition (10%). We recommend strict adherence to the flock health program;improved parasite management, separation & improved care for kids, vaccinations, safer feeding, and evidence based disease management, adoption of digital data collection tools and development of an appropriate app for more accurate determination of mortality rates.展开更多
基于地质、地震和钻井资料,对东非阿尔伯特盆地(Lake Albert Basin)的形成演化及构造—沉积地层特征进行了研究,深入分析了盆地石油地质特征,总结其成藏模式及油气富集条件。盆地主要受东非裂谷期构造运动的影响,形成两侧以深大断裂为...基于地质、地震和钻井资料,对东非阿尔伯特盆地(Lake Albert Basin)的形成演化及构造—沉积地层特征进行了研究,深入分析了盆地石油地质特征,总结其成藏模式及油气富集条件。盆地主要受东非裂谷期构造运动的影响,形成两侧以深大断裂为界、狭长(半)地堑的构造格局。沉积地层以新近系碎屑岩为主,岩性多为泥岩、砂岩和砾岩。河流—(扇)三角洲—湖泊沉积体系发育,主要烃源岩为中新统上部富有机质页岩,中新统—上新统河流相、(扇)三角洲相砂岩为主要储层,与细粒湖相泥岩在纵向上形成良好的生储盖匹配。盆地发育大量断块、断背斜等构造圈闭。盆地成藏模式为"凹陷供烃、侧向与垂向复合运移、下生上储",生储盖匹配良好控制垂向上形成多套成藏组合,优质砂体与垂向断层控制油气有效运移,断层控制的构造圈闭是油气聚集的主要场所。展开更多
基金funded by National Natural Science Foundation of China(Grant No.42072149)support of US National Science Foundation grant(Grant No.EAR-1255724)。
文摘Despite the upsurge in hydrocarbon exploration in the Lake Albert Rift Basin(LARB)over the past three decades,systematic characterization of hydrocarbon compositions remains lacking,leading to uncertainties in source rock and oil generation determination.We characterized crude oil compositions and oil sand samples in the northern and southern subbasins of LARB.The relative abundance of normal and branched linear alkanes,hopanes,steranes,and aromatic hydrocarbon suggest that northern and southern hydrocarbons were deposited in anoxic to suboxic lacustrine environments and share similar biological source compositions(i.e.,a mixture of plants and aquatic algae and bacteria).Relative to southern samples,northern samples show more negative δ^(13)C values for oils,saturates and aromatics,indicating longer migration paths,and exhibit higher MPI-1,DNR-1 and 4-/1-MDBT ratios,indicating higher maturity.Between the two possible sets of source rocks(upper Miocene and Jurassic strata),the positive δ^(13)C values of saturated hydrocarbons(average=-20.5‰)suggest that the upper Miocene lacustrine shale is the most likely candidate.Oleanane index(<5% in our samples)does not exclude either source rock possibility,and C_(28)/C_(29) regular sterane(average=0.63)may be biased by high terrestrial inputs in a lacustrine setting.Together,our data show that northern and southern oils originate from the same source rocks but different oil kitchens.Given the similar geochemical characteristics of southern and northern oils,previous exploration successes in the northern subbasin likely suggest similar potential in the southern sector,while other elements influencing exploration success must be also evaluated.
文摘Goats are globally very important domestic small ruminants being kept for meat, milk, skin, byproducts and several socio-cultural purposes. Goat farmers in the Lake Albert Crescent Zone (LACZ) of Uganda identified dry-season feed scarcity, poor breeds, diseases, informal marketing and theft as major constraints which underscore the scarcity of information on improved management technologies and the need for targeted decisions. At BuZARDI goat farm, a semi-intensive farm that is also experiencing similar challenges, we documented management practices and collected production related data for 2 years. We computed flock dynamics and mortality rates purposely to influence decisions aimed at increasing the farm’s productivity. Data were collected using pens and books, validated and analyzed using MS office 2013 and SPSS version 22. The flock size increased from 37 goats in July 2020 to 175 goats in June 2022. One hundred twenty-five goats were introduced into the farm as breeding stock, 89 kids were born on the farm and 61 goats died due to various causes. The average number of goats in the farm per month was 109.2 (SEM = 13.7), female 79.8 (SEM = 10.8) and male 29.4, (SEM = 9.9). Average population of goats at risk of death was 95 and the Mortality rate was 27 goats per 1000 goat months. The disaggregated mortality rate of 5 goats per 1000 goat months and 39 goats per 1000 goat months were obtained for the period FY 2020-2021 and FY2021-2022 respectively. The main contributors to the mortality of goats were worm infestation (33%), fracture and injuries arising from stampedes (18%), Ticks and tick borne diseases (18%), respiratory tract infections (11%) and malnutrition (10%). We recommend strict adherence to the flock health program;improved parasite management, separation & improved care for kids, vaccinations, safer feeding, and evidence based disease management, adoption of digital data collection tools and development of an appropriate app for more accurate determination of mortality rates.
文摘基于地质、地震和钻井资料,对东非阿尔伯特盆地(Lake Albert Basin)的形成演化及构造—沉积地层特征进行了研究,深入分析了盆地石油地质特征,总结其成藏模式及油气富集条件。盆地主要受东非裂谷期构造运动的影响,形成两侧以深大断裂为界、狭长(半)地堑的构造格局。沉积地层以新近系碎屑岩为主,岩性多为泥岩、砂岩和砾岩。河流—(扇)三角洲—湖泊沉积体系发育,主要烃源岩为中新统上部富有机质页岩,中新统—上新统河流相、(扇)三角洲相砂岩为主要储层,与细粒湖相泥岩在纵向上形成良好的生储盖匹配。盆地发育大量断块、断背斜等构造圈闭。盆地成藏模式为"凹陷供烃、侧向与垂向复合运移、下生上储",生储盖匹配良好控制垂向上形成多套成藏组合,优质砂体与垂向断层控制油气有效运移,断层控制的构造圈闭是油气聚集的主要场所。
