Diatom data of 192 surface sediment samples from the marginal seas in the western Pacific together with modern summer and winter sea surface temperature and salinity data were analyzed.The results of canonical correspondence analysis show that summer sea-surface salinity(SSS) is highly positively correlated with winter SSS and so is summer sea-surface temperature(SST) with winter SST.The correlations between SSSs and SSTs are less positively correlated,which may be due to interactions of regional current pa... 相似文献
Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir, the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area. Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian. Two kinds of oil cracking gas geological models at least, namely well Mandong-1’s early rapid generation model (Middle Ordovician-end Silurian) and peak cracking model (with the natural gas conversion rate >90%), namely well Yingnan-2’s two-stage generation model of oil cracking gas, have been set up. The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area. The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage. The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage, with strong sealing ability, so that natural gas dissipates mainly by diffusion. According to the above investigations, the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope, Tadong low uplift and Yingjisu depression in the Tadong area prospects well.
The new concept and analysis method for the rainfall peak are introduced in this paper,and an obser-vational study of a heavy rain case in the Meiyu front has been made with finer radiosonde and precipitationdata.It has found in this case that there are a lot of meso-β scale systems associated with the rainfall peaksin the Meiyu front.Meso-β scale systems can be divided into two kinds,i.e.,the moving and standing types.The moving type is characterized by the unstable gravity wave and has a path corresponding to the meso-α scalerain belts in the direction.The discussion about the meso-β systems is made by using the symmetric andtransversal wave instability theory. 相似文献
The Qinghai-Xizang Plateau is an area where a large number of salt lakes are distributed. We have collected several hundred
samples of natural waters over the Plateau since 1976 and carried out researches on their hydrogen and oxygen isotopes. The
results indicate that theδD and δ18O values of the salt lake waters over the Plateau range from −64.1 to +12.4‰ and from −11.19 to +8.62‰, respectively.
From the different types of surfaces, ground and lake waters of various salinities it is inferred that the compositions of
H and O isotopes in the initial water of Qinghai Lake areδD=−55.0‰ and {ie336-1}; and those in the original water from the lakes in northern Xizang, areδD=−116.0‰ and {ie336-2}. Brines in the salt lakes are derived from rain water through prolonged circulation. Oilfield water
also makes some contribution to the salt lakes in the Qaidam Basin. Similar slopes of evaporation lines of water isotopes
are noticed for the Qinghai Lake area and northern Xizang. This is attributed to the evolution of the isotopes in these water
bodies in an environment of middle latitude and high elevation. 相似文献