Trace elements and accessory minerals in lunar samples

Halogen contents similar to those in meteorites are reported in Apollo 11 samples. Concentrations of 0.6 to 13 parts mercury, 0.2 to 0.8 part uranium, 1 to 17 parts lithium, and 1 to 800 parts osmium per million and 0.5 to 1 percent chromium oxide by weight have been measured. In contrast to meteorites and terrestrial rocks a large mercury release below 110 degrees C is observed. Some implications of these results are presented. Fluorapatite, quartz, tridymite, fayalite, and iron-rich, manganese-poor pyroxmangite, previously unreported, have been identified. The small amount of fluorapatite found does not account for the fluorine contents.     

Abundances of 30 elements in lunar rocks, soil, and core samples

Abundances of 30 elements in seven lunar rocks and soil were determined by instrumental and radiochemical activation analysis. Seven major and minor elements in chips from 27 rocks were determined by instrumental activation analysis. Abundances of ten bulk elements overlap for the breccia rocks and soil samples. All lunar rare earth elements distribution patterns resemble those found in terrestrial abyssal subalkaline basalt, but with Eu depleted by about 60 percent in all lunar samples compared to the adjacent rare earth elements. Precipitation of plagioclase and hypersthene achondritic-like minerals from a melt could account for Eu depletion and the observed distribution of rare earth elements. Abundances of Ti, Al, Ca, Na, and Mn determined by instrumental activation analysis in five core-tube soil samples indicate uniformity for Al and Mn and apparent differences (10 to 20 percent) for Ti, Ca, and Na at 7.8 and 10.5 centimeters as compared to 0to5.2 centimeter depths.     

Pinpointing the source of a lunar meteorite: implications for the evolution of the Moon

The lunar meteorite Sayh al Uhaymir 169 consists of an impact melt breccia extremely enriched with potassium, rare earth elements, and phosphorus [thorium, 32.7 parts per million (ppm); uranium, 8.6 ppm; potassium oxide, 0.54 weight percent], and adherent regolith. The isotope systematics of the meteorite record four lunar impact events at 3909 +/- 13 million years ago (Ma), approximately 2800 Ma, approximately 200 Ma, and <0.34 Ma, and collision with Earth sometime after 9.7 +/- 1.3 thousand years ago. With these data, we can link the impact-melt breccia to Imbrium and pinpoint the source region of the meteorite to the Lalande impact crater.     

Search for magnetite in lunar rocks and fines

Magnetite crystals larger than 2 micrometers are absent from rocks and fines. Smaller opaque spheres in the fines can tentatively be identified as magnetite. Their concentration is not higher than 1 x 10(-6) particle per particle smaller than 1 millimeter. In the fines from the sampling site, the contribution of material similar to type 1 carbonaceous meteorites is insignificant, either because it never existed, or because it was evaporated or comminuted by impact or was diluted by indigenous material. Other magnetite habits typical of carbonaceous meteorites or possibly of cosmic dust or comets were also sought without success-such as rods, platelets, framboids, spherulites, and idiomorphic crystals.     

Major compositional units of the moon: lunar prospector thermal and fast neutrons

Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. There appears to be a smooth transition between the most mafic and feldspathic compositions, which correspond to low and high surface altitudes, respectively. The maria show low thermal and high fast neutron fluxes, consistent with basaltic rocks.     

Petrology of unshocked crystalline rocks and shock effects in lunar rocks and minerals

On the basis of rock modes, textures, and mineralogy, unshocked crystalline rocks are classified into a dominant ilmenite-rich suite (subdivided into intersertal, ophitic, and hornfels types) and a subordinate feldspar-rich suite (subdivided into poikilitic and granular types). Weakly to moderately shocked rocks show high strain-rate deformation and solid-state transformation of minerals to glasses; intensely shocked rocks are converted to rock glasses. Data on an unknown calcium-bearing iron metasilicate are presented.     

Radioactive elements on Mercury's surface from MESSENGER: implications for the planet's formation and evolution

The MESSENGER Gamma-Ray Spectrometer measured the average surface abundances of the radioactive elements potassium (K, 1150 ± 220 parts per million), thorium (Th, 220 ± 60 parts per billion), and uranium (U, 90 ± 20 parts per billion) in Mercury's northern hemisphere. The abundance of the moderately volatile element K, relative to Th and U, is inconsistent with physical models for the formation of Mercury requiring extreme heating of the planet or its precursor materials, and supports formation from volatile-containing material comparable to chondritic meteorites. Abundances of K, Th, and U indicate that internal heat production has declined substantially since Mercury's formation, consistent with widespread volcanism shortly after the end of late heavy bombardment 3.8 billion years ago and limited, isolated volcanic activity since.     

Volatile elements in apollo 16 samples: possible evidence for outgassing of the moon

Several Apollo 16 breccias, including one containing goethite, are strikingly enriched in volatile elements such as bromine, cadmium, germanium, antimony, thallium, and zinc. Similar but smaller enrichments are found in all highland soils. It appears that volcanic processes took place in the lunar highlands, involving the release of volatiles including water. The lunar thallium/uranium ratio is 2 x 10-(4) of the cosmic ratio, which suggests that the moon's original water content could not have exceeded the equivalent of a layer 22 meters deep. The cataclastic anorthosites at the Apollo 16 site may represent deep ejecta from the Nectaris basin.     

Petrographic, mineralogic, and x-ray fluorescence analysis of lunar igneous-type rocks and spherules

Three lunar rocks show almost identical mineralogy but grain sizes that vary from basaltic to gabbroic. Clinopyroxene is zoned from augite to subcalcic ferroaugite compositions and is accompanied by decrease in Cr, Al, and Ti. Plagioclase is zoned from 93 to 78 percent anorthite. Olivine (68 percent forsterite) is present in one rock and apatite is rare. Cristobalite, ilmenite with Ti-rich lamellae, ulv?spinel (often Cr-rich), troilite, and kamacite are low in trace elements. Glassy spherules are of basaltic or feldspathic (92 percent anorthite) composition but contain abundant iron spheres of taenite composition (13 percent Ni). Four rock analyses by x-ray fluorescence show affinity with terrestrial basalts but with anomalous amounts of Ti, Na, Cr, Zr, Y, Rb, Nb, Ni, Cu, and Zn.     

Potassium, rubidium, strontium, barium, and rare-Earth concentrations in lunar rocks and separated phases

Concentrations of potassium, rubidium, strontium, barium, and rareearth elements have been determined by mass spectrometric isotope dilution for eight Apollo 11 lunar samples and for some separated phases. Potassiumn and ritbidium are at chondritic levels, strontium at 15 times, and barium and rare earths at 30 to 100 times chondritic levels. There are trace element similarities between the lunar samples and basaltic achondrites, terrestrial dredge basalts and the bulk earth. The trace element data appear to be consistent with these lunar samples being the result of limited partial fusion of some material similar to the brecciated eucrite meteorites.     

Alpha radioactivity of the lunar surface at the landing sites of surveyors 5,6, and 7

Evidence has been obtained for a radioactive deposit on the lunar surface at Mare Tranquillitatis with a total intensity of 0.09 +/- 0.03 alpha disintegration per second per square centimeter. The presence of polonium-210 in amounts that are close to equilibrium indicates a continuous turnover rate of lunar material at this site of less than 0.1 micrometer per year. The lack of such a deposit at two other lunar sites suggests lower local concentrations of uranium there.     

Very heavy solar cosmic rays: energy spectrum and implications for lunar erosion

The energy spectrum of solar cosmic-ray particles of the iron group has been determined for the first time over the energy range from 1 to 100 million electron volts per nucleon by the use of glass removed from the Surveyor 3 spacecraft. The difference between the observed (energy)(-3) spectrum and the limiting spectrum derived previously from tracks in lunar rocks gives an erosion rate of 0 to 2 angstroms per year. High-energy fission of lead, induced by galactic cosmicray protons and alpha particles, has also been observed.     

Evidence and implications of shock metamorphism in lunar samples

Lunar microbreccias and loose regolith materials contain abundant evidence of shock metamorphism related to crater-forming meteorite impacts. Diagnostic shock effects include (i) planar features in a silica phase and feldspars, and lamellae in clinopyroxene, (ii) thetomorphic feldspar glass, (iii) heterogeneous glasses of rock and mineral composition, (iv) distinctive recrystallization textures, and (v) characteristic changes in crystal structure as indicated by x-ray diffraction analysis and measurements of refractive index. The microbreccias are produced from regolith materials (ejected fromz craters) by shock lithification. Some feldsparrich fragments may represent ejecta introduced from nonlocal sources, such as the lunar highlands.     

Ages, irradiation history, and chemical composition of lunar rocks from the sea of tranquillity

The (87)Rb-(87)Sr internal isochrons for five rocks yield an age of 3.65 +/-0.05 x 10(9) years which presumably dates the formation of the Sea of Tranquillity. Potassium-argon ages are consistent with this result. The soil has a model age of 4.5 x10(9) years, which is best regarded as the time of initial differentiation of the lunar crust. A peculiar rock fragment from the soil gave a model age of 4.44 x 10(9) years. Relative abundances of alkalis do not suggest differential volatilization. The irradiation history of lunar rocks is inferred from isotopic measurements of gadolinium, vanadium, and cosmogenic rare gases. Spallation xenon spectra exhibit a high and variable (131)Xe/(126)Xe ratio. No evidence for (129)I was found. The isotopic composition of solar-wind xenon is distinct from that of the atmosphere and of the average for carbonaceous chondrites, but the krypton composition appears similar to average carbonaceous chondrite krypton.     

云南省景洪市茶园土壤肥力诊断与评价

\t\t\t\t\t目的\t\t\t\t\t研究新平县茶园土壤肥力状况,为新平县茶园高效养分管理提供参考依据。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t通过野外调查和室内分析,应用模糊综合评判法,以9项土壤肥力质量指标为评价依据,对新平县8个主要种植茶园土壤肥力质量进行数值化综合评价。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t新平县茶园土壤pH为4.40~5.83,符合优质高产茶园要求,有机质(OM)、全氮(TN)、全磷(TP)、全钾(TK)、有效氮(AN)、有效磷(AP)、有效钾(AK)平均含量分别为57.1 g/kg、0.269%、0.077%、1.51%、206.3 mg/kg、11.0 mg/kg、154 mg/kg,均为Ⅰ级标准,阳离子交换量(CEC)平均含量为15.95 cmol/kg,属于Ⅱ级标准;茶园土壤肥力指数(IFI)为0.769,为Ⅰ级(高等水平),依次是者竜乡(0.877)>戛洒镇(0.851)>漠沙镇(0.807)>平掌乡(0.799)>水塘镇(0.796)>建兴乡(0.734)>平甸乡(0.647)>新化乡(0.642),Ⅰ级(高等水平)占75%,平甸乡和新化乡属Ⅱ级,处于中上水平;土壤中TP、TN、OM、CEC、AK、AP含量对土壤肥力的影响较大。\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t新平县茶园土壤肥力水平达到I级标准,但AP含量相对偏低,需要有针对性的增施磷肥。\t\t\t\t     

Thermal conductivity of lunar and terrestrial igneous rocks in their melting range

The thermal conductivity of a synthetic lunar rock in its melting range is about half that of a terrestrial basalt. The low conductivity and increased efficiency of insulating crusts on lunar lavas will enable flows to cover great distances without being quenched by high radiant heat losses from the surface. For a given rate of heat production, the thermal gradient of the moon would be significantly steeper than that of the earth.     

Potassium-uranium systematics of apollo 11 and apollo 12 samples: implications for lunar material history

Apollo 11 and Apollo 12 lunar rock suites differ in their potassium-uranium abundance systematics. This difference indicates that relatively little exchange of regolith material has occurred between Mare Tranquillitatis and Oceanus Procellarum. The two suites appear to have been derived from materials of identical potassium and uranium content. It appears unlikely that bulk lunar material has the ratio of potassium to uranium found in chondrites. However, systematic differences in the potassium-uranium ratio between Apollo samples and crustal rocks of the earth do not preclude a common potassium-uranium ratio for bulk earth and lunar material.     

亚热带不同母岩成壤过程中金属元素的迁移和积累特点

为了解不同岩石风化成壤过程中重金属等元素在土壤剖面中的积累特点,在浙江省选择玄武岩、花岗岩、泥页岩、石灰岩和碳质页岩这5类岩石发育的原位土壤剖面,按发生层采集分层土壤样品和基岩样品,分析主要元素全量组成,并以稳定元素Zr为参照,采用质量平衡法分析了成壤过程中土壤重金属等元素的淋失与积累特点。结果表明,石灰岩发育土壤剖面中重金属元素的淋失和积累明显不同于其他母岩,由石灰岩转变为土壤过程中重金属呈现明显的富集,同时成壤过程中发生了大量重金属等元素的淋失。泥页岩和碳质页岩发育土壤重金属富集不明显,其重金属含量与母岩接近或低于母岩;但碳质页岩因母岩中重金属本底较高,其形成的土壤含较高的重金属。玄武岩和花岗岩发育土壤风化程度高于泥页岩和碳质页岩发育土壤,前者在成壤过程中Si、Ca、K、Cr、Cu、Zn、Hg、Ni、Co的淋失高于后者。成壤过程中重金属的平均淋失比例由高至低依次为Hg>As>Cu>Zn>Cd>Ni>Co>Pb>Cr,Cr和Pb的稳定性最高。多数情况下,元素的淋失比例由表土向母质层降低。石灰岩成壤过程中镉的富集和高淋失特点可能是石灰岩分布区土壤镉积累的主要原因。