A sky survey at 102.5 MHz: Radio sources at declinations 27.5°–33.5° and 67.5°–70.5°

The results of observations on the Large Phased Array of the Lebedev Physical Institute made as part of a survey of the northern sky at 102.5 MHz are reported. Survey source lists for the declination ranges 27.5°–33.5° and 67.5°–70.5° are given, together with their coordinates, flux densities, and identifications with 4C objects. In total, there are 920 sources with flux densities S _102.5≥3.0 Jy in the two zones, which cover 0.73 star. The observing and data-reduction methods are described, and the reliability and completeness of the catalog are estimated.     

THE COLANGUIL BATHOLITH (29-31° S), CORDILLERA FRONTAL,ARGENTINA: STRUCTURE AND TECTONIC ENVIRONMENT

This paper assesses chemical-mineralogical changes resulting from hydrothermal alteration associated with granite-hosted gold mineralization in southern Salamanca province, Spain. Within the mineralized veins, along planes of quartz growth, two types of fluid inclusions were observed. One type is rich in CH₄ with minor CO₂, the other is rich in H₂O with CO₂ (± CH₄). These are interpreted as reflecting the immiscibility of an initial fluid rich in H₂O-CH₄ and some CO₂. Inclusions with similar composition are seen at the silicification formed at the granite contact with host rocks. However, differences in P-T conditions and immiscibility of fluids are indicated by the microthermometric study and relation of the inclusions. These are consistent with the temperatures calculated from the arsenopyrite-pyrite geothermometer. Formation temperatures of 445 ± 15° C were deduced for the mineralization at the granite contact and temperatures not exceeding 386° C for the vein mineralization.

Metasomatically altered granites are depleted in Na and K in comparison to fresh granites. A gain in CO₂ has been measured in the altered rocks. No correlation was found between gold contents and any of the major or trace elements analyzed.

δ³⁴S arsenopyrite values suggest a variable source of sulfur. Calculated δD_fluid values show significant variability (?66 to ?37%₀ SMOW), whereas δ¹⁸O fluid values show small variation (from +7.6 to +8.4%_o SMOW). These values for the fluids are consistent with interaction between magmatic fluids and metamorphic rocks. Gold deposition in quartz veins could be explained by the loss of H₂S during fluid immiscibility.     

THE NUMERICAL SIMULATE OF THE UPLIFT PROCESS OF THE QINGHAI—TIBET PLATEAU

THE NUMERICAL SIMULATE OF THE UPLIFT PROCESS OF THE QINGHAI—TIBET PLATEAU     

中国北方地区(33°～41°N,108°～115°E)过去500年夏季降水量的周期成分分析

利用连续小波分析和经验模态分解方法,对我国北方地区(33°～41°N,108°～115°E)1470 ～2002年每年夏季降水量指数的时间序列进行了周期成分分析,探索全球气候变暖下的该地区降水量的多尺度变化特征.小波分析表明,降水量指数的可能周期有2.57a,4.83a,10.65a,23.25a,48.56a,68.30a和105.90a的周期,在95％置信水平有统计意义的周期是2.57a和23.25a的周期.这些周期和自然因素导致的周期相联系,不仅包含了气候系统内部(平流层准2a振荡和厄尔尼诺/南方涛动)的非线性作用,还包含了气候系统外(主要是太阳活动)受强迫的周期变化,且二者在原始降水量中所在比重相当,共同反映了原始降水量的绝大部分变化.降水量不只是在百年尺度上受太阳活动的驱动,在数十年尺度上也受到太阳活动的影响.我国北方地区的夏季降水量指数和夏季温度指数同相位反相关,全球增温并没有明显地改变二者之间的反相关关系.近百年来全球变暖期间,夏季降水量出现明显的新特征:短周期成分(小于30a的周期)的振幅比以往要显著大,而长周期成分的振幅比以往要显著小,同时呈现降水量逐年减少的长期变化趋势.     

Giant radio-galaxy candidates at declinations from 3.5° to 12°

A search for extended radio sources with peak flux densities higher than 10 Jy at 110.6 MHz has been carried out, and two giant radio-galaxy candidates found. Data from a 24-hour survey in an area spanning ～8° in declination were used for the search.     

Sediment thickness map of the Indian region 79°E–86°E, 2°S–8°S based on satellite gravity interpretation

Satellite free air gravity anomalies over the Indian ocean region 79°E–86°E, 2°S–8°S were obtained from the website http://topex.ucsd.edu and a contour map was compiled. Five profiles of the anomaly have been interpreted in terms of two-dimensional structures in the ocean. Thickness of sediments lying on the oceanic crust determined from the interpretation of gravity profiles were used to compile an isopach map of the region 79°E–86°E, 2°S–8°S. This map in combination with one of the isopach maps compiled by previous workers, provides information regarding the thickness of sediments up to 6° S. According to this map sediment thickness varies from ～600 m over the middle part of the region to ～800 m further south, indicating that thinning of sediments in the middle part of the region is only localized. Information provided by this gravity study may be useful in planning detailed seismological studies to delimit the outer edge of the continental margin of Sri Lanka, defined according to the United Nations Convention of the Law of the Sea (UNCLOS).     

90°—75°勘探钻孔用的金属轻便钻塔

吉尔吉兹加盟共和国部长会议所属地质保矿管理局的地质勘探队1959年10月钻进90°—75°角的斜孔时,利用了由作者设计的金属轻便钻塔。     

THE CENOZOIC GEORECORDS IN THE NORTHWEST OF YUNNAN AND THE EVOLUTION OF QING—ZANG PLATEAU

THE CENOZOIC GEORECORDS IN THE NORTHWEST OF YUNNAN AND THE EVOLUTION OF QING—ZANG PLATEAU     

THE OCCURRENCE OF CERCIS ASSOCIATED WITH THE REMAINS OF SINANTHROPUS

In a short paper entitled "Evidences of the Use of Fire by Sinanthropus",Dr.Davidson Black has discussed the occurrence of burned bone fragments andcharcoal debris in association with the remains of Sinanthropus at Chou KouTien,and has concluded that Sina     

THE TERTIARY STRATIGRAPHIC SEQUENCE OF YANYUAN BASIN IN THE SOUTHEASTERN MARGIN OF THE QINGHAI—TIBET PLATEAU

THE TERTIARY STRATIGRAPHIC SEQUENCE OF YANYUAN BASIN IN THE SOUTHEASTERN MARGIN OF THE QINGHAI—TIBET PLATEAUYoungGeologistofGMR(Qn979816 )andNSFCGeneralProjects(4980 2 0 13)     

QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAU

QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAUgrants 49732 0 90and 496 0 2 0 36fromtheNSFofChina     

西南印度洋中脊48.6°~51.7°E沉积物地球化学特征

为了深入了解西南印度洋中脊调查区表层沉积物的物质来源和沉积环境,对大洋第30航次在该区域获取的21个表层沉积物样品进行了物相鉴定和主量元素、微量元素及稀土元素含量测试,分析结果显示,样品可分为Si质沉积物和Ca质沉积物两类,其中Si质沉积物富含Si、Mg、Fe、Al,稀土元素含量特征、轻重稀土元素分馏特征,以及稀土元素的北美页岩归一化曲线均表明沉积物保留了N-MORB的特征,主要为基性岩、超基性岩的风化产物;而Ca质沉积物富Ca、LOI、Sr,稀土元素以及微量元素之间的分配均指示沉积物物源为生源主导;所有站位均显示了两类沉积物不同程度的混杂,表明物质来源具有一定的多样性,调查区总体为稳定的偏氧化环境。     

Search for Dispersed Pulses at Declinations from +56° to +87°

Astronomy Reports - A survey of the northern hemisphere at the frequency 111 MHz is carried out. The total accumulation time for each point of the survey area was at least one hour. When searching...     

CLASSIFICATION AND CORRELATION BASED ON THE DISTRIBUTION OF THE FUSULINA LIMESTONES

In view of the extensive distribution of the "Fusulina Limestone" in North China it was formerly suggested~1 that a careful study of the Fusulina might throw some light upon the vexed problem of the age of the Palaeozoic     

ON THE GOBI PLANE OF DEFLATION—THE GOBI EROSION PLANE

Anyone Who travels in Mongolia cannot help being struck by a remarkable feature in the topography. Between the mountainous lands and the recently dissected basins the vast country of Mongolia is covered by a great number of separated or more or less continuous smooth surfaces at an inter-     

CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN

The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extension     

西南印度洋中脊45.3°E~56°E蚀变玄武岩地球化学

<正>大洋21航次第七航段在西南印度洋中脊45.3°E~56°E洋脊段采集了20个站位的玄武岩和橄榄岩等岩石样品。本文选择了10件新鲜的和发生不同程度蚀变的玄武岩进行岩石地球化学研究,探讨热液     

APPLICATION OF THE DC RESISTIVITY METHODS TO THE STUDY OF GROUNWATER IN THE WESTERN PART OF AMMAN BASIN, JORDAN

1. Introduction In many parts of the world, the technique of electrical sounding has been used effectively for solving subsurface water problems in order to minimize drilling costs (e.g. Breusse 1963; Zohdy and Jackson, 1969; Zohdy, 1969; Zohdy et. al. 1984). During June 1999, resistivity surveys was made at the western Amman basin to provide some information about the thickness, lithology and tectonics of the subsurface layers and then to locate suitable drilling sites for water wells. T…     

OIL-GASPROSPECTING MODELS BASED ON THE PERMIAN SEQUENCE FRAMEWORK OF THE SICHUAN-YUNNAN-GUIZHUO-GUANGXI REGION

ＯＩＬＧＡＳＰＲＯＳＰＥＣＴＩＮＧＭＯＤＥＬＳＢＡＳＥＤＯＮＴＨＥＰＥＲＭＩＡＮＳＥＱＵＥＮＣＥＦＲＡＭＥＷＯＲＫＯＦＴＨＥＳＩＣＨＵＡＮＹＵＮＮＡＮＧＵＩＺＨＵＯＧＵＡＮＧＸＩＲＥＧＩＯＮＯｉａｎＹｉｚｈｏｎｇ，ＳｈａｏＪｉａｎｆｅｎｇａｎ...