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1.
The Ningbo iron meteorite fell near Ningbo, Chekiang province, on October 4,1975. 103 days later, γ-ray spectrum of the meteorite, was undestructively measured by a low-level γ-ray spectrometer. It is shown that the specific activity of Mn^34 present in the Ningbo iron meteorite is ap proximately close to that of Mn^34 in the Bogou and Aroos meteorites, while the specific activity of Co^37 seems to be higher in the Bogou and Aroos than in the Ningbo.  相似文献   

2.
Preliminary results of our study an ancient meteorite records by the end of the Ching dynasty are presented in the present paper. Early in 645 B.C. there were formal records on meteorite falls and cosmoganesis of meteorites. The utinization of iron meteorites for making weapons alloyed with bronze has a history of more than 3000 years (in the Shang and Zhou dynasties). By the time of 1064 (in the Sung dynasty) iron meteorites were well doeum anted. The geographical distribution and falling time of meteorites are also mentioned. The maximum number of meteorite falls was recorded in May and June against the minimum number in December in a year.33 serious calamities caused by meteorite f alls themselves, and several interesting records on meteorite falls are also described in this paper.  相似文献   

3.
广西南丹铁陨石雨的发现   总被引：1，自引：0，他引：1  
The distribution and exterior characters of each individual meteorite are presented for the iron meteorite shower in Nantan County, Kwangsi Chuang Autonomous Regiou,China. Nineteen iron meteorites have been found up to date, umounting approximately to 9,500 kg in total weight and spreading over an area of about 30 square kilometers. As compared with other iron meteorites known in China, they are much larger in size and contuin much more mineral species. It is also interesting to note that a complete sample of various parts of a primitive meteorite can be expected. The discovery of this meteorite shower is considered to be of significant value in science.  相似文献   

4.
Glass and gas inclusions have been observed in olivine and other minerals in 30 doubly polished tin sections of Jilin meteorites, indicating that there must have been melting And condensation stages during the process of meteorite formation. Temperatures of formation have been determined by homogenization and quenching runs,giving 1050-200℃ and 502℃ for glass and gas inclusions respectively, Meanwhile,the fibrous radial crystals of pyroxene have been notieed to grow when heated over 800℃. These observations are in general agreement with the available experimental data and theoretical calculations regarding meteorite.  相似文献   

5.
Amino acids have been separated from and identified in the Jilin meteorite No.Ⅰ and Ⅱ by gas-liquid chromatography. Eight kinds of amino acid, i.e., α-alanine,valine, glycine, isoleucine, β-alanine, leucine, proline, and threonine are observed in meteorite No. Ⅰ Ten varieties of amino acids including serine, hydroproline, lysine and etc. are noticed from meteorite No. Ⅱ. A brief diseussion is given to the origin of these acids.  相似文献   

6.
The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed.Low cosmogenic(~(22)Ne/~(21)Ne)_c ratio is consistent with irradiation in a large body.Cosmogenic noble gases indicate that Sulagiri has a 4πcosmic-ray exposure(CRE) age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of IX chondrites.Radiogenic ~4He and ~(40)Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and4.56 Ca,indicating the loss of He from the meteorite.Xenon and krypton are mixture of Q and spallogenic components.  相似文献   

7.
Iron meteorites from Nandan, Guangxi ; Wushike, Xinjiang; Shangdu, Hebei and Huangling, Hubei are investigated with a spark souree mass speetrometer for their Cr, Ni, Co, Cu, Zn, Ga, Ge, As, Mo, Ru, Rh, Pd, Os and Ir contents. The accuracy of the results and the factors affecting it are discussed. It is preliminarily concluded,while textural evidences of these meteorites are also taken into account, that the Nandan, Wushike and Shangdu meteorites belong to IA, Ⅲ .4 and ⅢE groups respectively. The Ni, Ga and Ge contents in the Huangling iron meteorite come close to that of mesosiderites.  相似文献   

8.
Based on structural observations and the concentrations of Cr, Co, Ni, Cu, Ga, Ge,As, Sb， Re, Ir and Au by neutron-activation analysis we have classified 14 Chinese iron meteorites. Thirteen are members of the large groups IAB, IIICD, IIICD,IIIAB and IVA.Leshan is an ungrouped iron meteorite that falls within the IIE field on some elementNi diagrams, but is distinctly outside this .fiel on plots of Cu, W, and Ir vs. Ni; it is very similar in Composition to Techado,another ungrouped iron. The high Cu content of Leshan is consistent with other evidence indicating that Cu is a valuable parameter for classifying, iron meteorites. IIICD Dongling appears not to be a new meteorite, but to be paired with Nantan; Dongling was recovered about 50 km from the location of the Nantan shower. Yungning is highly oxidized; we assign it to group LAB but cannot rule out IIICD. IVA-An Longchang has many characteristics of IVA irons, but has been remelted, prebably in a terrestrial setting, Five irons belong to group IVA, a remarkably large number. Three are identical in Composition, and we suspect that the two from Hubei, Guanghua and Huangling, are paired. Thus this set of 14 irons ineludes 12 independent fall.  相似文献   

9.
This paper discribes the extraction of porphyrin compounds and related pigments from Jilin meteorite with 9:1 (v/v) benzene and methanol mixture. After removal of sulfur and asphalts the hexane solution of the extract is eluted through a silica jel chromatographic column with hexane, benzene, and acetone successively.Nickel porphyrin, vanadium porphyrin and chlorins are found in the benzene eluate and their content are estimated to be 0.008 ppm, 0.006 ppm and 0.002 ppm respectively.The aliphatie hydrocarbons in the meteorite are estimated to be approximately 74pp.The results are summarized and discussed.  相似文献   

10.
Petrography and mineral chemistry of 24 ordinary chondrites from the Grove Mountains, Antarctica, have been studied in order to identify their chemical-petrographic types. These samples were selected from a total of 4448 Grove Mountains (GRV) meteorites collected during the 19th Chinese Antarctic Research Expedition so as to make an estimation of the large GRV meteorite collection. The chemical-petrographic types of these meteorites are presented below: 1 H3,2 H4, 4 H5, 2 H6, 1 L4, 7 L5, 5 L6, 1 LL4 and 1 LL6. The new data weaken the previous report that unequilibrated ordinary chondrites are unusually abundant in the Grove Mountains region. However, this work confirms significant differences in distribution patterns of chemical-petrographic types between the Grove Mountains and other  相似文献   

11.
Isoprenoid compounds in the Jilin meteorite are isolated and identified by a combined chromatography-mass spectrometry. In the chromatographic part of this instrumentation, the open glass capillary is coated with SE^30 carrier. Chromatographic and mass spectrometric evidence of the existance of pristane and phytane in the Jilin meteorite has been presented and the possible origin of these compounds briefly discussed  相似文献   

12.
Abstract: Heterogeneity of permeability in fractured media is a hot research topic in hydrogeology. Numerous approaches have been proposed to characterize heterogeneity in the last several decades. However, little attention has been paid to correlate permeability heterogeneity with geological information. In the present study, several causes of permeability heterogeneity, that is, lithology, tectonism, and depth, are identified. The unit absorption values (denoted as ω), which are results obtained from the packer test, are employed to represent permeability. The variability of permeability in sandstone–mudstone is so significant that the value of unit absorptions span 3–4 orders of magnitude at any depth with several test sections. By declustering, it has been found that under a similar tectonic history, the means of permeability differ greatly at different formations as a result of different mudrock contents. It has also been found that in the same formation, permeability can be significantly increased as a result of faulting. The well-known phenomenon, the decrease in permeability with depth, is found to be caused by the fractures in the rock mass, and the relationship between permeability and depth can be established in the form of logω–logd. After subtracting the trend of ω with absolute depth, the mean of the residual value at each relative depth can be well correlated with the distribution of mudstone. The methods proposed in this paper can be utilized to research in similar study areas.  相似文献   

13.
The Lunan stony meteorite recovered from Yunnan Province is an ordinary chondrite of high-iron Hs type. Thirteen kinds of minerals have been identified, of which natural copper contains 88--96% Cu. Compared with other meteorites of the same type,the Lunan meteorite has mere FeO and Ni.  相似文献   

14.
Some current methods for the calculation of the geogenetic depth are based on the hydrostatic model, it is induced that the depth in certain underground place is equal to the pressure divided by the specific weight of rock, on the assumption that the rock is hydrostatic and overlain by no other force but gravity. However, most of rock is in a deformation environment and non-hydrostatic state, especially in an orogenic belt, so that the calculated depth may be exaggerated in comparison with the actual depth according to the hydrostatic formula. In the finite slight deformation and elastic model, the relative actual depth value from the 3-axis strain data was obtained with the measurement of strain including that of superimposed tectonic forces but excluding that of time factor for the strain. If some data on the strain speed are obtained, the depth would be more realistically calculated according to the rheologicai model because the geological body often experiences long-term creep strains.  相似文献   

15.
A New Martian Meteorite from Antarctica:Grove Mountains (GRV) 020090   总被引：15，自引：0，他引：15  
Reported in this paper are the petrology and mineral chemistry of GRV 020090, the second Martian meteorite collected from the Grove Mountains, Antarctica. This meteorite, with a mass of 7.54 g, is completely covered by a black and glazy fusion crust. It has two distinct textural regions. The interstitial region is composed of euhedral grains of olivine, pigeonite, and anhedral interstitial maskelynite, with minor chromite, augite, phosphates and troilite. The poikilitic region consists of three clasts of pyroxenes, each of which has a pigeonite core and an augite rim. A few grains of subhedral to rounded olivine and euhedral chromite are enclosed in the pyroxene oikocrysts. GRV 020090 is classified as a new member of lherzolitic shergottites based on the modal composition and mineral chemistry. This work will shed light on the composition of Martian crust and magmatism on the Mars.  相似文献   

16.
The 3-D P- and S-wave velocity models of the upper crust beneath Southwest Iberia are determined by inverting arrival time data from local earthquakes using a seismic tomo~raphy method. We used a total of 3085 P- and 2780 S-wave high quality arrival times from 886 local earthquakes recorded by a per- manent seismic network, which is operated by the Institute of Meteorology （IM）, Lisbon, Portugal. The computed P- and S-wave velocities are used to determine the 3-D distributions of Vp/Vs ratio. The 3-D velocity and Vp/Vs ratio images display clear lateral heterogeneities in the study area. Significant veloc- ity variations up to ~6% are revealed in the upper crust beneath Southwest lberia, At 4 km depth, both P- and S-wave velocity take average to high values relative to the initial velocity model, while at 12 km, low P-wave velocities are clearly visible along the coast and in the southern parts. High S-wave velocities at 12 km depth are imaged in the central parts, and average values along the coast; although some scattered patches of low and high S-wave velocities are also revealed. The Vp/Vs rztio is generally high at depths of 4 and 12 km along the coastal parts with some regions of high Vp/Vs ratio in the north at 4 km depth, and low Vp/Vs ratio in the central southern parts at a depth of 12 km, The imaged low velocity and high Vp/Vs ratios are related to the thick saturated and unconsolidated sediments covering the region; whereas the high velocity regions are generally associated with the Mesozoic basement rocks.  相似文献   

17.
Five stages can be recognized with respeet to the evolution of the Jilin meteorite in the light of preliminary results available: (1) The stage of birth, fractionation and condensation of the solar nebula disc; (2) Formation of the parent body and thermal metamorphism; (3) Cooling of parent body and breaking up by impact; (4) Formation and orbiting of the Jilin meteor; (5) The falling of the meteor and the emergence of the meteorite shower. The process and characteristics are discussed at some length for each of these stages,  相似文献   

18.
The discovery of unconventional hydrocarbon resources since the late 20 th century changed geologists' understanding of hydrocarbon migration and accumulations and provides a solution to energy shortage.In 2016,unconventional oil production in the USA accounted for 41% of the total oil production;and unconventional natural gas production in China accounted for 35% of total gas production,showing strong growth momentum of unconventional hydrocarbons explorations.Unconventional hydrocarbons generally coexist with conventional petroleum resources;they sometimes distribute in a separate system,not coexisting with a conventional system.Identification and prediction of unconventional resources and their potentials are prominent challenges for geologists.This study analyzed the results of 12,237 drilling wells in six representative petroliferous basins in China and studied the correlations and differences between conventional and unconventional hydrocarbons by comparing their geological features.Migration and accumulation of conventional hydrocarbon are caused dominantly by buoyance.We propose a concept of buoyance-driven hydrocarbon accumulation depth to describe the deepest hydrocarbon accumulation depth driven dominantly by buoyance;beyond this depth the buoyance becomes unimportant for hydrocarbon accumulation.We found that the buoyance-driven hydrocarbon accumulation depth in petroliferous basins controls the different oil/gas reservoirs distribution and resource potentials.Hydrocarbon migration and accumulations above this depth is dominated by buoyancy,forming conventional reservoirs in traps with high porosity and permeability,while hydrocarbon migration and accumulation below this depth is dominated by non-buoyancy forces(mainly refers to capillary force,hydrocarbon volume expansion force,etc.),forming unconventional reservoirs in tight layers.The buoyance-driven hydrocarbon accumulation depths in six basins in China range from 1200 m to 4200 m,which become shallower with increasing geothermal gradient,decreasing particle size of sandstone reservoir layers,or an uplift in the whole petroliferous basin.The predicted unconventional resource potential below the buoyance-driven hydrocarbon accumulation depth in six basins in China is more than 15.71 × 109 t oil equivalent,among them 4.71× 109 t reserves have been proved.Worldwide,94% of 52,926 oil and gas reservoirs in 1186 basins are conventional reservoirs and only 6% of them are unconventional reservoirs.These 94% conventional reservoirs show promising exploration prospects in the deep area below buoyance-driven hydrocarbon accumulation depth.  相似文献   

19.
The measurements are present in the paper of cosmogenic radionuclides in various types of meteorites falling recently in China. In particular, a full diseussion is also given to the provenance of the Qingzhen enstatite condrite. Based upon the measored Al^26 specific activity, an estimation has been made of the aphelion of the Qingzhen orbit (q‘≤1.9 AU). It is, therefore, concluded that the provenance of enstatite chondrites may be much closer to the sun as compared with ether types of meteorites.  相似文献   

20.
Taking the Second Songhua River which lies in the northeast of China as a study area, this paper firstly designs the improved BP neural network water evaluating and forecasting model of which 13 water evaluating items are selected as nodes in input layer; 6 classes of evaluating results are selected as nodes of output layer; then, with the ＂0, 1＂ identified pattern and continually practiced comparisons, ＂13-9-5-6＂ double hidden layers with optimized training structure are confirmed; on the basis of this work, the water quality of the Second Songhua River was evaluated and forecasted at the end. The results showed that in the six classes of predefined water quality in 157 stations, none of them belongs to class Ⅰ, and classes Ⅱ, Ⅲ, Ⅳ and Ⅴ are as follows： 8.91%, 58.59%, 18.47%, 1.91% and 12.1%, respectively; the precision of these evaluating and forecasting results is 82.8%.  相似文献   

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