Petro-Structural Study of the Paleoproterozoic Formations of the Faboula Gold Deposit (Bougouni-Kékoro Basin, Leo-Man Shield)

Recent petro-structural investigations on the Faboula gold deposit located in the Bougouni-Kékoro basin, in southern Mali, north-west of the Leo-Man Shield, have provided new data on the nature and spatial organization of the lithostratigraphic units as well as their deformation style. The deposit is covered by a thick lateritic layer and is hosted by a metavolcano-sedimentary sequence of Paleoproterozoic age intersected by intrusive bodies and filled fractures of various shapes and types. The lithostratigraphic units consist of metagreywackes, metasiltstones, meta-argillites, slates and schists. Metagreywackes and metasiltstones are generally feldspathic, both may contain biotite and locally amphibole, just as slates may contain andalusite which is locally stretched. Plutonic units most often occur as stocks or as dikes on the drill core, up to 1 m. The metavolcano-sedimentary rocks are schistose and deformed under greenschist facies conditions, and locally they reach the epidote-amphibolite facies. The structural study revealed that the deposit is affected by several stages of deformation evolving from a ductile type to a brittle type via a ductile-brittle type. The dominant ductile and brittle-ductile deformations show a combination of isoclinal folding and strike-slip faults. Both the isoclinal folding and the strike-slip faults whose sigmoidal en-echelon tension gashes indicate a dextral movement in the NNE-SSW direction are the result of the same ENE-WSW regional shortening. Consequently, they highlight a transpressive deformation. This deformation noted here D2Fb, could be equivalent to the regional D2 or D3 deformations identified at the scale of the Leo-Man Shield if we refer to the style of deformation. There is an abundance of quartz veins networks. Their relation within the structural features indicates that the mineralization is structurally controlled during a hydrothermal event linked certainly to the circulations of fluids during the transpressive event D2Fb.

Petrographic and Geochemical Characteristics of the Granitoids in the South of Godé (North of the Square Degree of Léo-Burkina Faso, West Africa)

South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the REE spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones.

利比里亚金矿成矿地质背景与资源潜力

西非地区比里姆(Birimian)岩系经历了伊本尼(Eburnean)造山运动,成为全球金矿商业投资的主要含矿岩系之一,该岩系在利比里亚覆盖约36%国土面积。通过对西非尤其是利比里亚地质背景分析,初步建立了利比里亚区域地质构造格架,梳理出比里姆岩系中33处重要意义的岩金矿点,其分布与比里姆绿岩带、区域剪切构造带密切相关。综合全国266处金矿化点及密切相关的Au、Ag、Hg、Cu元素异常,在利比里亚划定了比-克波、杜格贝、塞斯托斯、鲍特洛-祖亚-皮菲吉、邦-托托-宁巴、杜贝、朱亚松、托迪8个金成矿带,显示出良好的成矿潜力,并对不同开发程度下矿化前景区进一步找矿方面提出了初步建议。

利用重复使用地月转移级往返近地轨道空间站的载人月球探测飞行模式

为提高中国月球探测的安全性和效费比,提出了一种利用重复使用地月转移级往返近地轨道空间站进行载人月球探测的任务模式,分析了任务往返的轨道和窗口,通过多方案对比分析给出2种构型重复使用地月转移级方案建议,估算对比了重复使用地月转移级效益,得出对于长期多次载人月球探测任务,采用重复使用地月转移级方案将具有更低的任务成本。

LEO大型载人航天器主动电位控制技术进展

LEO大型载人航天器主动电位控制技术可以有效的防护空间等离子体充放电效应对于航天器造成的安全隐患,确保航天员出舱和航天器空间对接作业的顺利完成。通过研究LEO大型载人航天器与空间等离子体的相互作用,从原理上认识空间等离子体对于航天器的危害程度。分析回顾国外主动电位控制技术在LEO大型载人航天器上的成功应用及发展情况,得出启示和初步的主动电位控制系统设计设想。对比国内外主动电位控制领域的核心技术,对主动电位控制技术的发展和应用提出了建议。

一种基于互联网星座的载人飞船测控模式构想

在总结神舟载人飞船测控模式发展演进规律的基础上,基于当前国内外低轨卫星星座蓬勃发展的趋势,文章提出了一种基于低轨互联网星座进行载人飞船测控的模式构想,通过对初步互联网星座方案构想下开展神舟载人飞船测控能力的仿真分析,得出该测控模式可将飞船最长站外时间降低至2 min,大幅提升应急处理能力和测控系统冗余,减少传统地面测站和中继资源占用,从而降低测控成本,提高测控效益,是未来测控模式演进的选择之一。

莱奥波尔德的大地伦理思想及启示

随着生态危机的加剧,人们环境保护意识的提高,人与自然的关系重新被审视。美国著名的生态伦理学家莱奥波尔德是环境保护主义思想的先驱,他所创立的大地伦理学是当今生态伦理学中主要流派。大地伦理思想把人与自然当作一个整体来思考,改变了传统的认知观念,确立了新的价值尺度,旨在构建一个和谐、美丽和稳定的大地共同体,为我们当代社会提供了理论指南与行动指导。通过分析莱奥波尔德的大地伦理思想,分析了大地伦理学对构建生态文明的启示,呼吁人们应重视生态问题,并加强对这一问题的研究,促进这一问题的解决,实现人与自然的和谐相处。

施特劳斯论霍布斯政治哲学的基础

一般认为,施特劳斯对霍布斯政治哲学基础的解读,重点在其早期著作《霍布斯的政治哲学》(1936)。实际上,《论霍布斯政治哲学的基础》(1954)一文才是最终的真正解读。其中,施特劳斯重新阐释了霍布斯政治哲学的基础。首先,霍布斯不再从自然欲望与自然理性的区分而是从具有因果判断这种特殊官能来定义人的特性。其次,霍布斯的政治哲学不是独立于而是依赖其对自然科学的理解。最后,霍布斯的不信仰是其政治哲学的必要前提。总而言之,霍布斯政治哲学的基础并不是霍布斯的人生观,而是霍布斯的整全观——霍布斯关于人、自然和神的全部观念。