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1.
ＩＮＴＲＯＤＵＣＴＩＯＮＱｕａｎｔｉｔａｔｉｖｅｅｘｔｒａｃｔｉｏｎｏｆｐａｓｔｃｌｉｍａｔｉｃｅｎｖｉｒｏｎｍｅｎｔｉｎｆｏｒｍａｔｉｏｎｉｓａｎｅｗｆｏｃｕｓｏｆａｔｔｅｎｔｉｏｎｉｎｔｈｅｆｉｅｌｄｏｆｇｌｏｂａｌｅｎｖｉｒｏｎｍｅｎｔａｌｃｈａｎｇｅｓ.Ｉｎｔｈｅｒｅｃｅｎｔ 1 0ｙｅａｒｓ,ａｓｅｒｉｅｓｏｆａｃｈｉｅｖｅｍｅｎｔｓｉｎｒｅ ｂｕｉｌｄｉｎｇｔｈｅｓｅｑｕｅｎｃｅｓｏｆｃｌｉｍａｔｉｃａｎｄｅｎｖｉｒｏｎｍｅｎｔａｌｅｖｏｌｕｔｉｏｎｓｉｎｖａｒｉｏｕｓｓｃａｌｅｓｈａｖｅ…  相似文献   

2.
To investigate the relationship between volcanic activity and sediment record on regional and temporal scales, 158 surface sediment samples were collected from the East China Sea Shelf to the northern Okinawa Trough (OT), and two cores recovered in the northern and southern OT, respectively. Mineralogy, grain-size, and geochemical analyses of those samples show that: 1) volcanic glass, volcanic-type pyroxene, hypersthenes, and magnetite increase in sediment influenced by volcanic activity; 2) sediment grain sizes (and also silt content) increase in ash layers; and 3) the contents of Na2O and Zr are higher, while terrigenous elements, e.g., TFe2O3 and K2O, and biogenous compositions, e.g., CaO and Sr, are relatively lower in ash layers than those of non-ash layers. The distribution of volcanic ash has three distinguishing characteristics: 1) volcanic ash is more abundant in the northern and central OT than the southern OT; 2) volcanic ash increases from continental shelf to the trough; 3) the sediment during the last 12 000 a suggests stronger volcanic events than during 15 000–12 000 a. The eruptive locations, frequency, and volume of calderas are among the most important factors controlling the distributions of volcanic ash. In addition, the main Kuroshio warm current that extends northward probably impeded the diffusion of volcanic ash to the west and south in the OT. However, a southward current probably carried some volcanic ash toward southern OT.  相似文献   

3.
This article deals with the interaction of zinc with δ−MnO2, γ−MnOOH and manganite existing in natural water systems. The mechanism of the reaction has been studied in detail. From the fact that the “ratio of ion exchange(%)-pH” graph is an “S shaped” curve, it is possible to deduce that the chemical reaction is of the nature of cation exchange. And since the pH range of ion exchange=4, it is possible to further deduce that the reaction can be explained by the mechanism of monovalence cation exchange. The main result of this article is the discovery of a new type of isotherm which has not been mentioned in previous literature here and abroad. This isotherm cannot be represented by any presently available adsorption isotherm equations in marine chemistry. The characteristics of this new type of isotherm are as follows: the isotherm has two “knees” and three “plateaus”, the heights of these three “plateaus” are in the ratio 1:2:3. In order to explain theoretically our new isotherm, this article suggests the application of the principle of interfacial stepwise ion exchange for liquid-solid distribution of minor elements on suspended particulate matter. The corresponding isotherm equation was derived from this theory. The results obtained in this article will be of theoretical guiding significance in the study of the marine geochemistry of zinc. Projects supported by the Science Fund of the Chinese Academy of Sciences.  相似文献   

4.
ImODUcrION'Watervaporchenhatry"asanewsdencewasestablisedbyGu'slaboratorybasedontheirdiscoveryoftheruleof'witCr-watervaporconstanttransferoftracemetalionsinthenaturalwaterCyde';andwasprovedbyamodelexperimntofsea-airtransfer(Gu,l988,l99l,Gueta1.,l982,l986).Thertilehasnotorreationwiththethermody-nawhrsofthetracephySicochdricalsyStem(Gu,l99l,Guetal.,l984).ThispaperpresentSthefuflctionrelating'witCfvaporchedtry"ionconamtrationtothe'huantumchedtry"bondparametCr.FUimONThedatausedinthecurvea…  相似文献   

5.
This paper deals with the infrared spectra of “amino acid-clay, calcium carbonate and γ-AlOOH” and “Cu(II)-clay-amino acid” model systems, and shows that the model of the ternary surface complex is M-OHLCu (L=amino acid) for marine solid particle-Cu (II)-amino acid. Study of the formation mechanism of the ternary surface complex shows that the specific surface area, and especially the intrinsic acidity constant, determine whether the ternary surface complex is easily formed, and that factor,F TSC, quantifies the relationship between the promoting effect of organics on Mt-marine solid particle ion exchange and the intrinsic acidity constant and specific surface area.  相似文献   

6.
The authors studied zircon LA-ICP-MS U-Pb dating,the zircon Hf isotope and geochemistry of acidic volcanic rocks in Baiyingaolao Formation of Keyouzhongqi area,Inner Mongolia,and discussed the chronology, source region and tectonic setting of the volcanic rocks in the studied area． The clear oscillatory zoning of zir- cons indicates a typical magmatic origin,and the results of dating show that the volcanic rocks of Baiyingaolao Formation were formed in Early Cretaceous (121.5 ±1.0 Ma)． The features of major and trace elements show that the rocks are alkali-rich,poor in calcium and magnesium with enrichment in LILEs like Th,U,K and Gd and depletion in HFSEs,e.g. Nb,Ta,Sr and Ti． The fact implies that they were the products of partial melting of the crust． εHf(t) = ( +6.30--+9.06) and TDM2=600--835 Ma,suggest the magma originated from par- tial melting of the young crust． Combined with the evolution of regional tectonic structure,the authors conclude that the acidic volcanic rocks of Baiyingaolao Formation may be formed under the extensional environment relat- ed to the subduction of Paleo-Pacific Plate．  相似文献   

7.
Determination of the concentrations of, 15 rare earth elements (REE) in China continental shelf sediments by X-ray fluorescent spectral analysis of selected representative sediment samples showed that REE concentration in the sediments is 156 ppm, similar to that in China loess and Fujian granite, but different from that in Pacific sediments. The shelf REE have the characteristic distribution pattern of typical continental crust REE and evidently philo-continental property. The above findings suggest that weathered materials transported from the China continent are the main source of the REE in China continental shelf sediments. Experiments show that REE exist mainly in the crystal lattices of clay minerals (<2μ) as isomorphs and that REE have close relation with most elements (Al, Ti, K, Rb, Fe, etc.) related with clay minerals, but have negative correlation with the biophile elements Ca and Sr. Contribution No. 1520 from the Institute of Oceanology, Academia Sinica.  相似文献   

8.
Early Cretaceous A-type rhyolites of the Shangkuli Formation in the Hailar Basin of NE China exhibit geochemical characteristics of high silicon, alkali, Fe/Mg, Ga/Al, Zr, Pb, HFSEs, and REE contents but low Ca, Ba, Sr and Eu, which meet the criteria of typical reduced A-type granite.The A-type rhyolites are most probably derived from magmatic underplating and partial melting of quartz-feldspathic lower crust, with the lithospheric mantle material involved, due to the extensional deformation of the Erguna-Hulun Fault.Although the A-type rhyolites show A1-type trace elements characteristics, they were formed in a post-orogenic extension-al background together with the coeval widespread bimodal volcanic rocks, metamorphic core complexes, vol-canic fault basins and metallogenic province in the Sino-Russia-Mongolia border tract.This extension event was related to the collapse of thickened region of the continental crust after the closure of the Mongol-Okhotsk Ocean.  相似文献   

9.
河南省嵩箕地区登封群变质杂岩，原岩为一套造山带和岛弧的中基性、少部分为酸性的火山岩组合。其中郭家窑组为基性，常窑组、石牌河组逐渐向酸性火山岩过渡，石梯沟组属正常沉积岩系列。该群微量元素丰度值与地壳克拉克值相比，普遍偏低，其中Ｒｂ、Ｓｒ、Ｂａ、Ｆ、Ｌｉ等元素明显偏低。  相似文献   

10.
It is well known that there are two patterns of potash deposition in lacustrine facies: “tear drop pattern” (the Dabsan saline lake is a typical example) and “bull's eye pattern”. Potash-forming in tear drop pattern is still continuing. The 2,678 m A. S. L. lake in the middle of the Qarhan playa in the Qaidam Basin covers an area of 210 km2, and has an average depth of 0.39 m. Its MgCl2 type surface brine is 280–340 g/l in salinity and mainly consists of Na, K, Mg and Cl. As a rule, the potash deposits occur as evaporite distributed in tear drop pattern at the northern and northeastern lakeshore zones. They mostly consist of carnallite and halite, occasionally sylvite. The deposition is very unstable and controlled principally by the varying supply of deposit materials from the Golmud River in the south. The potash deposits were formed when concentration of the surface brine reached a certain degree in the main evaporating season. Their forming process followed some crystalization paths in the phase diagram for the Na, K, Mg/Cl H2O equilibrium system. Such a sedimentary model of potash deposits in the lacustrine facies is relatively common in nature. Under the extremely arid climate, differential concentration of the nonhomogeneous potassium-rich surface brine produced the potash deposits. Qarhan Salt Lake also had the same pattern of potash depositions and so, in a sense, the Dabsan saline lake is the continuation of the Qarhan salt lake in terms of potash formation. Schmalz (1970) put forward two distributive patterns for evaporite: “tear drop pattern” and “bull's eye pattern”. These patterns exist in both marine and continental salt-bearing basins (including recent salt lakes), and are controlled by the conditions of physical geography, hydrogeology, sedimentology and climatology of each basin. In his works (Sun, 1981; 1984; 1986; 1988) on the origins of potash deposits, the author always referred to them as two models of potash formation. The “tear drop pattern” is one of the salt-forming models and also an important potash-forming model. This paper deals with the formative mechanism of the tear drop pattern potash deposition by presenting the Dabsan saline lake as an example and elucidates on the distributive characteristics and formative processes of potash deposits in the lake.  相似文献   

11.
Based on a new idea for research on cycling of marine biogenic elements, this study showed that only the leachable form phosphorus in natural grain sizes manne sediments constitutes the transferable phosphorous in the sediments. The transferable phosphorus content in the natural grain sizes surface sediments in the Huanghe River estuary adjacent waters ranges from 58.5-69.8 μg/g, accounting for only 9.1%-11.0% of the total phosphorus content, whereas the leachable form (“transferable” )phosphorus content in the sediment after it was totally ground into powder was found to be 454.8-529.2μg/g, accounting for 73.4%-89.1% of the total phosphorus. Analysis of the correlation between thebill,ass of benthos and the leachable form (“transferable” ) phosphorus showed that most of the leachableform (“transferable”) phosphorus in the totally ground sediment did not participate in the marine biogeo chemical cycling. Furthermore, a synchronous survey on benthos showed that the biornass of meio-and maero-benthos exhibited good positive correlation with the leachable form of phosphorus in the naturalgrain sizes sediment, but peorer correlation with the leachable form (“transferable”) phosphorus in the totally ground sediment, indicating that transferable phosphorus in marine sediment is the leachable form of phosphorus in the natural grain sizes sediments, and is not the previously known leachable form(“transferable”) phosphorus obtained from the totally ground sediment.  相似文献   

12.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｗｏｒｌｄ’ｓｓｈｒｉｍｐｃｕｌｔｕｒｅｉｎｄｕｓｔｒｙｈａｓｂｅｅｎｓｕｆｆｅｒｉｎｇｆｒｏｍｖｉｒａｌｅｐｉｄｅｍｉｃｄｉｓｅａｓｅｓａｎｄｆｅｌｌｉｎｔｏａｄｉｆ ｆｉｃｕｌｔｐｏｓｉｔｉｏｎｆｏｒｙｅａｒｓ.Ｉｔｉｓｇｅｎｅｒａｌｌｙａｃｃｅｐｔｅｄｔｏｄａｙｔｈａｔｔｈｅｄｉｓｅａｓｅｓｗｅｒｅｃａｕｓｅｄｍａｉｎｌｙｂｙｗａｔｅｒｐｏｌｌｕ ｔｉｏｎｃｒｅａｔｅｄｂｙｓｈｒｉｍｐｃｕｌｔｕｒｅｉｔｓｅｌｆ,ｂｏｔｈｉｎｓｈｒｉｍｐｐｏｎｄｓａｎｄｉｎｃｏａｓ…  相似文献   

13.
A 2-year study onKappaphycus alvarezii (Doty) Doty introduced to Hainan Island from the Philippines in 1985 showed promising results. The average daily growth in weight reached 10% at a favourable temperature of about 26°C. Experimental results showed that timely cutting of the plant was an effective way to obtain new cuttings for cultivation and accelerate growth. New cuttings 0.05 kg in weight are suggested to be used as “seeds” and the old plant should be harvested. At present, artificial cultivation with a type of underwater raft applicable in places where there is strong wind will expand cultivation to more regions in Hainan Province. This paper was originally published in Chinese inOceanologia et Limnologia Sinica 19(5): 410–418, 1988. The plant under discussion wasEucheuma alvarezii Doty which was previously calledE. striatum in the article, and which now becomesKappaphycus alvarezii (Doty) Doty. To the original title, “in China” was added. Only the essence of the original article was presented.  相似文献   

14.
A dynamic box model of bioactive elements in the southern Taiwan Strait   总被引：3，自引：0，他引：3  
A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO_4-P,NO_3-N,AOU,POC and PON in the southern Taiwan Strait region based on field data of the"Minnan Taiwan Bank Fishing Ground Upwelling Ecosystem Study" during the period of Dec.1987-Nov.1988.According to the unique hydrological and topographical features of the region,six boxesand three layers were considered in the model.The variation rates and fluxes of elements induced by hor-izontal current,upwelling,by diffusion,sinking of particles and biogeochemical processes were estimatedrespectively.Results further confirmed that upwellings had important effects in this region.Thenearshore upwelling areas had net input fluxes of nutrients brought by upwelling water,also had high de-pletion rates of nutrients and production rates of particulate organic matter and dissolved oxygen.Theabnormal net production of nutrients in the middle layer(10-30m) indicated the important role of bacte-ria in this high production region.Th  相似文献   

15.
The present paper is an introduction of a universal model of cluster and discrimination in the field of fisheries science. The mathematical principle and algorithm are described and the application results analysed. This model is called “weighted generalized distance” method, based on the principle of “minimum distance”. For different types of data, different methods are put forward. The quantitative attributes are standarized by “norm” method and the qualitative attributes are quantified by indicative value based on Shannon's information theory to locate the specimen in the coordinates. An approach by progressive readjustment of pivotal points is employed for the cluster rational. Finally, any new specimen can be discriminated by the principle of “minimum distance”, too.  相似文献   

16.
The Chinese “Yangtze” alligator is a rare reptile that has been listed as an “endangered species” by the United Nations, so its preservation has become an urgent task. A study of its habitats through analysis of their Landsat images will provide a scientific basis for the government departments concerned to select the best locations for its breeding. The Chinese alligator is a subtropical reptile of freshwater rivers, lakes and ponds. Found only in China, it is now distributed only in the border region between the three provinces of Anhui, Zhejiang and Jiangsu. On the basis of previous investigations by Chinese scientists, and from an analysis and interpretation of their Landsat images, we made a special study, review, and classification of the natural environment of the alligator’s present habitats (and the modern changes in the natural background of these hatitats) so that the government departments concerned with the preservation of the reptiles may have a scientific basis for determining the best locations for the breeding and propagation of the alligator. This paper was published in Chinese inOcean. Linn. Sin. 16(1): 35–41, 1985.  相似文献   

17.
The densities of 36 water samples from the Huanghe River estuary and Bohai Bay were determinedby a magnetic float densimcter under three temperatures from 15℃ to 25℃.All the measured densities ofsamples were greater than that of the values calculated from the International Equation of State of Seawater.The differences between the measured and calculated densities increased with the decrease of salinities.The dif-ferences appeared exponentially correlated with[Ca~(2+)]/s,[Mg~(2+)]/s and[SO_4~(2-)]/s,and had"s"type curverelationship with the alkalinity in all salinity range.But in the salinity ranging from 25.72 to 31.57,therelationships were all linear.The density difference can be estimated from the equation △ρ（10~3kg·m~(-3)）=（-2.79+236.5([Ca~(2+)]/s)/(-9.7464×10~（-3）+[Ca~(2+)]/s).It was the high alkalinity and[Ca~(2+)]/s that resulted in the measured densi-ties of seawaters being higher than the calculated densities in the Huanghe estuary and Bohai Bay.  相似文献   

18.
Results of neutron activation analysis (NAA) ofSargassum thumbergii samples collected from the Qingdao Taipingjiao coast on March 20, 1996 showed that (1)Sargassum thunbergii can to some extent accumulate potassium and calcium (the accumulation coefficient was 10); (2) it can accumulate almost all trace elements, especially iron, managanese and zinc; (3) it can accumulate strontium, aluminium thorium, and rare earth elements. Contribution No.3308 from the Institute of Oceanology, Chinese Academy of Sciences. The study supported by the National Ninth-Five-Year Key Project “96-916-04-01”.  相似文献   

19.
The condensates from the Yacheng Gas Field, Ying-Qiong Basins, have unusual chemical characteristics, with distribution dominated by terpanes and steranes derived from higher-plants. Pr/Ph ratios (6- 11 ) are very high. Drimane, cadinanes and homocadinanes exist in high concentration. Anomalously abundant 18α(H)-oleanane and remarkably abundant bicadinanes are present in Yacheng condensates, while 17α( H)-hopanes are in extremely low concentration. Taraxastane and significantlyabundant 17α(H)-diabopanes occur in the condensates. In addition, a number of C29 and C30 unknown pentacyclic triterpanes were monitored in the condensates, some of which are abundant. The unknown compounds may be terrestrial biomarkers or their occurrence may suggest a sub-oxic (dyacrobic) clay-rich depositional environment. C29 homologues are relatively predominant in regular and rearranged steranes. The concentration of diasteranes is markedly higher than that of regular steranes. The characteristics of Yacheng condensates are indicative of terrestrial source input. Based on condensate-condensate and con-densate-rock correlations, combined with results of studies on sedimentary facies. Yacheng condensates may be sourced from Yacheng and Lingshui Formations in the Qiongdongnan Basin. The maturity of Yacheng condensate is relatively high, at late oil window stage ( corresponding to 0.9 % - 1.3 % R0 ),based on sterane and terpane maturity parameters.  相似文献   

20.
Based on high-resolution tree-ring data from Dulan area of Qinghai Province, five spells have been divided: the warm period before 230’s A. D., the cold period between 240’s A. D. and 800’s A. D., the significantly warm period between 810’s A. D. and 1070’s, i. e. “Medieval Warm Period”, the cold period including the “Little Ice Age” 1420’ – 1870’s and the warming period since 1880’s. All the eleven coldest or warmest decades and several great abrupt changes took place before the Middle Ages, indicating that climatic system operated in great instability during the period 150’s – 1100’s A. D., Comparison of the tree-ring data with other temperature proxy data from East China, Guliya ice core as well as the south of Qinghai-Xizang Plateau shows that such great climatic events as Eastern Han warm period between the beginning of the 1st century and the previous fifty years of the third century, the cold period covering the span of the Wei, the Jin, and the Southern and Northern dynasties, the well-known “Medieval Warm Period” as well as the “Little Ice Age” appeared in these series such as East China and Dulan area. Only the first two climatic events were recorded conspicuously in Guliya ice core while the “Medieval Warm Period” and “Little Ice Age” is far weaker. Also, the well-defined “Medieval Warm Period” didn’t occurred in the south of Qinghai-Xizang Plateau. The warming since the 20th century is the warmest in the last 2000 years Guliya ice core, the second in Dulan area and East China, but it scarcely seems pronounced in the eastern part of Qinghai-Xizang Plateau. Foundation item: Under the auspices of the projects of the Chinese Academy of Sciences (KZ951-A1-204-02 and KZ951-A1 402-03). Biography: YANG Bao(1971–), male, a native of Yanggao County, Shanxi Province, Ph. D. His research interestinclude global change.  相似文献   

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