The development of the pinnacles (Lena pillars) along Middle Lena (Sakha Republic,Siberia, Russia)

The study deals with the Lena Pillars (Sakha Republic, Russia, Siberia). The Lena Pillars are pinnacle features which are characteristic on karsts. The importance of these features is that they are extremely large and occur on very large areas. Their occurrence is interesting because they do not appear on tundra karst. We investigated the veneers of cliffs, the fracture density of the building rock, the distribution and dispersion of the fracture directions, direction distribution and dispersion of the giant grikes between the pillars, the layer thickness of the building rock, the size and dispersion of debris. We distinguished pillar types, and then we classified the features on the area of the pillars from a morphogenetical point of view. According to investigations and morphological analyses, the pillars developed from palaeokarsts. During the former karstification grikes and caverns developed close to the surface. These features coalesced into each other. The giant grikes of great size became filled and the pillars were covered. After the cut of the Lena River these features were revealed and became exhumed. Now the pillars are destroyed and continue developing by frost weathering.     

Seasonal change in the deep atmosphere of Uranus

We present high-resolution radio maps of Uranus, made from data collected in 1994 at wavelengths of 2 and 6 cm, which show large-scale changes occurring deep and rapidly in the troposphere. Brightness features in these maps are significantly different from those observed throughout the 1980's. These differences are not due to the changing viewing geometry, but result from atmospheric changes in the 5 to 50 bar region. All the observations show strong latitudinal variations in absorber abundance and/or temperature, causing the South Pole to appear brighter than lower latitudes. The transition between bright pole and darker latitudes is always near −45°, but between 1989 and 1994 the contrast between the regions increased significantly. This suggests that the large-scale circulation in the upper 50 bars of the uranian Southern Hemisphere changed. Older, disk-averaged microwave observations have suggested that seasonal variability occurs, but these new maps are the first to provide detailed timing and location information which can be used to test dynamical models.     

四川省同德石墨矿床地质特征及成因研究

四川省同德石墨矿床是近年来在扬子板块西缘发现的大型中-大鳞片晶质石墨矿之一。为研究同德石墨矿地质特征及矿床成因,本文采用系统的野外地质调查、地球物理与地球化学等方法,并开展山地取样工程、岩矿测试研究工作。研究认为：同德石墨矿产于古元古代前震旦系康定岩群冷竹关组变质岩层中,赋矿岩石为云母石英片岩。矿体主要呈层状、似层状近南北向展布。矿石矿物为石墨,脉石矿物主要为石英、白云母、黑云母、斜长石及少量铁质矿物等。矿石自然类型为云母石英片岩型,工业类型为中-大鳞片晶质石墨矿。其原岩为一套含碳质泥岩、泥质粉砂岩、砂岩;碳质主要来源为有机物。物探自然电位梯度呈正负相伴,最低电位和梯度值为零的位置往往指示了石墨矿体的顶面中心;音频大地电磁测深呈带状向深部延伸的低阻异常指示了石墨矿体的深部赋存形态。矿床的形成经历了沉积成岩-区域变质阶段,属沉积变质型矿床。     

Haitaite-(La), LaU4+Fe3+2(Ti13Fe2+4Fe3+)Σ18O38, a New Member of the Crichtonite Group

Haitaite-(La), (La, Ce)(U4+, U6+, Fe2+)(Fe3+, Al)2(Ti, Fe2+, Fe3+)18O38, is a new member of the crichtonite group. It is named after the Haita Village in the Miyi County of Sichuan Province, China, where the mineral was discovered. The mineral occurs as black opaque centimeter-sized aggregates in the external contact zone between the Neoproterozoic (~800 Ma) alkali feldspar granite and the Mesoproterozoic (~1700 Ma) micaschist. In the studied sample, haitaite-(La) is associated with other minerals, including ilmenite, magnetite, rutile, zircon, brannerite and uraninite. The new mineral is a black, metallic phase and has a Mohs hardness of 6, with a density of 4.99 g/cm3 (calculated) and 5.03 g/cm3 (measured). Haitaite-(La) is opaque in transmitted light and grayish-white under reflected light, with a reflectivity between 22.5% and 16.42% in the 400–700 nm band (SiC, in the air). The compositions of the mineral were measured by EPMA, the U4+/U6+ ratio was determined by X-ray photoelectron spectroscopy and the Fe2+/Fe3+ ratio was determined by M?ssbauer spectroscopy. Haitaite-(La) is trigonal, belongs to R3ˉ and has unit-cell parameters a = 10.3678(5) ?, c = 20.8390(11) ?, V = 1939.9(2) ?3, Z = 3. The crystalline structure is composed of octahedra with 9 layers of close-packed octahedra (M1, M3, M4, M5), tetrahedra (M2) and contains large 12-coordinated M0 sites.     

Relationships between radium and radon occurrence and hydrochemistry in fresh groundwater from fractured crystalline rocks, North Carolina (USA)

Naturally-occurring radionuclides (uranium, radium, and radon), major dissolved constituents, and trace elements were investigated in fresh groundwater in 117 wells in fractured crystalline rocks from the Piedmont region (North Carolina, USA). Chemical variations show a general transition between two water types: (1) slightly acidic (pH 5.0–6.0), oxic, low-total dissolved solids (TDS) waters, and (2) near neutral, oxic to anoxic, higher-TDS waters. The uranium, radium, and radon levels in groundwater associated with granite (Rolesville Granite) are systematically higher than other rock types (gneiss, metasedimentary, and metavolcanic rocks). Water chemistry plays a secondary role on radium and radon distributions as the ²²²Rn/²²⁶Ra activity ratio is correlated with redox-sensitive solutes such as dissolved oxygen and Mn concentrations, as well as overall dissolved solids content including major divalent cations and Ba. Since ²²⁴Ra/²²⁸Ra activity ratios in groundwater are close to 1, we suggest that mobilization of Ra and Rn is controlled by alpha recoil processes from parent nuclides on fracture surfaces, ruling out Ra sources from mineral dissolution or significant long-distance Ra transport. Alpha recoil is balanced by Ra adsorption that is influenced by redox conditions and/or ion concentrations, resulting in an approximately one order of magnitude decrease (~ 20,000 to ~ 2000) in the apparent Ra distribution coefficient between oxygen-saturated and anoxic conditions and also across the range of dissolved ion concentrations (up to ~ 7 mM). Thus, the U and Th content of rocks is the primary control on observed Ra and Rn activities in groundwater in fractured crystalline rocks, and in addition, linked dissolved solids concentrations and redox conditions impart a secondary control.     

Interpretation of the carbon abundance in Saturn measured by Cassini

Spectral observations of Saturn from the far infrared spectrometer aboard the Cassini spacecraft [Flasar, F.M., et al., 2005. Temperatures, winds, and composition in the Saturnian system. Science 307, 1247-1251] have revealed that the C/H ratio in the planet is in fact about twice higher than previously derived from ground based observations and in agreement with the C/H value derived from Voyager IRIS by Courtin et al. [1984. The composition of Saturn's atmosphere at northern temperate latitudes from Voyager IRIS spectra - NH₃, PH₃, C₂H₂, C₂H₆, CH₃D, CH₄, and the Saturnian D/H isotopic ratio. Astrophys. J. 287, 899-916]. The implications of this measurement are reanalyzed in the present report on the basis that volatiles observed in cometary atmospheres, namely CO₂, CH₄, NH₃ and H₂S may have been trapped as solids in the feeding zone of the planet. CH₄ and H₂S may have been in the form of clathrate hydrates while CO₂ presumably condensed in the cooling solar nebula. Carbon may also have been incorporated in organics. Conditions of temperature and pressure ease the hydratation of NH₃. Such icy grains were included in planetesimals which subsequently collapsed into the hydrogen envelope of the planet, then resulting in C, N and S enrichments with respect to the solar abundance. Our calculations are consistent, within error bars, with observed elemental abundances on Saturn provided that the carbon trapped in planetesimals was mainly in the form of CH₄ clathrate and CO₂ ice (and maybe as organics) while nitrogen was in the form of NH₃ hydrate. Our approach has implications on the possible pattern of noble gases in Saturn, since we predict that contrary to what is observed in Jupiter, Ar and Kr should be in solar abundance while Xe might be strongly oversolar. The only way to verify this scenario is to send a probe making in situ mass spectrometer measurements. Our scenario also predicts that the ¹⁴N/¹⁵N ratio should be somewhat smaller in Saturn than measured in Jupiter by Galileo.     

哈大巨型城市带要素集聚程度与生态环境水平关系演变

基于耦合模型和象限图法,从整体和内部分异2个角度对2000~2012年哈大巨型城市带要素集聚程度与生态环境水平演变及其关系进行分析,结果表明：哈大巨型城市带要素集聚程度呈波动上升的演变特征,生态环境则“先波动上升,后缓慢下降”,城市带整体要素集聚程度与生态环境水平间关系趋于协调,产业结构演变、资源消耗水平、经济密度是导致城市带要素集聚程度与生态环境水平协调度提高的主要驱动因子,其中产业结构演变的影响作用更加明显。城市带内部要素集聚的“四城市”格局已经形成,呈现出“核心-边缘”结构,要素集聚程度与生态环境水平可分为高级协调、要素集聚滞后、低级协调、生态环境滞后4种类型。4个区域中心城市要素集聚程度与生态环境水平关系趋向不协调,中心城市周边地区主要向要素集聚滞后型转变,资源型城市和重工业城市要素集聚程度与生态环境水平多表现为低级协调。     

哈大巨型城市带空间开发-经济发展-环境演变的耦合分异机制

通过构建空间开发、经济发展、资源环境水平的评价指标体系,引入耦合度概念,并应用变异系数、趋势面分析、回归分析等定量模型研究2000~2014年哈大巨型城市带空间开发-经济发展-环境演变的耦合分异特征及其影响机制,主要得到以下结论：① 2000年以来哈大巨型城市带各城市空间开发-经济发展-环境演变的耦合度均处在不同程度失调状态,且整体表现为“西高东低-南高北低”的空间格局,但耦合度水平总体趋于上升。哈长次区域和辽中南次区域以及哈大巨型城市带整体的耦合度波动性均先升高后下降,总体趋势不断向好;② 政府投入强度是2000年影响哈大巨型城市带各城市耦合度差异的重要作用因素,资本投入强度与科技投入规模是2007年、2014年2个阶段的主导影响因素,且城市发展能级差异与2007年各城市间的耦合度差异表现出一致性;③ 在政府投入强度、科技投入规模、资本投入强度等因素的共同作用下,哈长次区域空间开发-经济发展-环境演变的耦合程度出现空间分异。辽中南次区域耦合度分异的影响因素由人力资本效率和行政等级逐渐演变为以资本投入强度主导。