夏季副高数值产品的集成预报研究

本文使用１９９５年和１９９６年６－８月欧洲中期天气预报中心和我国Ｔ６３Ｌ１６的５００ｈＰａ４８＾ｈ－１４４＾ｈ五个时效平均预报场，以及相应的Ｔ６３５０００ｈＰａ五天平均场资料，根据１００－１４０°Ｅ、２－５０°Ｎ范围内西北太平洋副热带高压的南北位置分为四类副高。对比分析ＥＣ和Ｔ６３两个模式的各类副高特征参数的预报误差特点，发现当ＥＣ预报的副高强度强于或接近Ｔ６３预报时，ＥＣ预报副高的数值产品精度优     

潞安矿区屯留井田断裂构造研究

屯留井田以逆断层发育为特色，本文讨论了了井田断层形态特征和断层展布规律，指出基底构造格局是控制本区煤田构造变形的基本因素，由此推断井田西部同样发育南北走向的逆断层。     

Geothermal observations in east Liaoning and haicheng seismic area

We have obtained altogether heat flux data of 23 drill holes including 2 observational holes of thermal flow in the Haicheng seismic area. These data show roughly thermal structure of the crust in eastern Liaoning and in the Haicheng seismic area. The results indicate that there is higher value of heat flow in the belt north by east from Liaoyang to Xiongyue, the average thermal flux being 8.29× 10⁻²J/m²·s (2.0 hfu). The average thermal fulx in the Haicheng seismic area is 9.22×10²J/m²·s (2.2 hfu). Comparing with other known geophysical data of the Haicheng seismic area, we give a geophysical section of comprehensive interpretation. We suppose the low-velocity layer in the lower crust of the Haicheng seismic area is a result from intrusion of large-scale uper mantle substance. High temperature and low velocity mean that the layer has the nature of plastic mechanics. The focal region of the Haicheng earthquake is situated right in the upper part of that plastic layer. Obviously, this result is significant for studying the seismogenic process of the Haicheng earthquake and other intra-plate earthquakes. We attempt to emphasize that observation of heat flow is necessary for earthquake study. Gu Haoding did the actual writing.     

我国发现的硅灰石膏

本文硅灰石膏发现于我国河北省的符山,固镇和坡山等矿山。它以脉体穿入钙镁橄榄石夕卡岩中,呈纤维状集合体,有时形成六方针状晶体。平均粒度为0.05×0.05×2mm~3,No=1.513(±0.0015),Ne=1.471(±0.0015),比重为1.92(±0.02)。根据化学分析计算晶体化学式为:(Ca_(2.73)Mg_(0.23) Na_(0.03))[Si_(1.0)Al_(0.03)(OH)_(6.18)](CO_3)_(1.067)(SO_4)_(0.952)·10.86H_2O。红外光谱有17个吸收频带,其中1394,1100和756-672cm~(-1)分别指派给CO_3、SO_4和SiO_6的伸缩振动。DTA曲线表现有186℃及784℃两个吸热峰及804℃的放热峰。本区的硅灰石膏是低温下钙镁橄榄石的热液蚀变产物     

Seismicity simulation with a rate- and state-dependent friction law

The dynamic motions and stabilities of a single-degree-of-freedom elastic system controlled by different friction laws are compared. The system consists of a sliding block connected to an elastic spring, driven at a constant velocity. The friction laws are a laboratory-inferred friction law called the rate-and-state-dependent friction law, proposed by Dieterich and Ruina, and a simple friction law described by dynamic and static frictions. We further extend the solution to a one-dimensional mass-spring model which is an analog of a fault controlled by the rate-and-state-dependent friction law. This model predicts non uniform slip and stress drop along the rupture length of a heterogeneous fault. This result is very different from some earlier modelings based on the simple friction law and a slip weakening friction law. In those earlier modelings the stress and slip functions become smoother with time along the length of the fault rupture, owing to the interactions between fault segments during slip. Because of this smoothing process the number of small events will decrease with time, and the universilly observed stationary magnitude-frequency relation cannot be explained. The interaction between a fault segment and its neighboring segments can be measured when the post-slip stress on this segment is compared with the stress on an identical segment (represented by a block in this modeling) without neighboring segments. If the post-slip stress of the former is much higher than that of the latter, strong interaction exists; if the two are close, only weak interaction exists. The interaction is determined by the relative motion between fault segments and the time duration of interaction. Our new modeling with the rate-and-state-dependent friction law appears to show no such smoothing effect and provides a physical mechanism for the roughening process in the difference between the fault strength and stress that is necessary to explain the observed stationary magnitude-frequency relation. The noninstantaneous healing predicted by the rate-and-state-dependent friction law may be repsonsible for the recurring nonuniform slip and stress drop, and may be explained by the reduction of interaction among fault segments due to the low frictional strength during the fault stopping. The very low friction during slip stopping allows much longer times than does the higher friction due to instantaneous healing for the fault segments to adjust their motions from an upper-limit slip velocity to almost rest. According to newton's second law, a process with fixed masses and constant velocity changes involves low forces and weak interactions if it is accomplished in a long time period, and vice versa. Our modeling also indicates that the existence of strong patches with higher effective stress on a fault is needed for the occurrence of major events. The creeping section of a fault, such as the one along the San Andreas fault in central California, on the other hand, can be simulated with the rate-and-state-dependent friction law by certain model parameters, which, however, must not include strong patches. In this case small earthquakes and aseismic creep relieve the accumulating strain without any large events.     

Experimental studies to 10 kb of the bulk composition tremolite50-tschermakite50+excess H2O

Phase relations for the magnesio-hornblende bulk composition, 2 CaO·4 MgO·Al₂O₃·7 SiO₂+ excess H₂O, have been investigated to 10 kb employing hydrothermal and piston-cylinder techniques. The low-temperature limit of amphibole in this system lies at 519° C, 1,000 bars, 541° C, 2,000 bars, and 718° C, 10 kb. The low-T assemblage consists of an+chl+di+tc(+f), and is related to the adjacent high-T equilibrium assemblage, amph+an+chl+f, by the solid-solid reaction (A): 2 di+tc=tr. Small amounts of aluminum, hypothesized to be preferentially dissolved in the cpx (and in the tc) relative to amph, may account for the broad P-T stability range of the di+tc assemblage in the synthetic work relative to systems involving stoichiometric tr, Ca₂Mg₅Si₈O₂₂(OH)₂, such as are common in natural, Al-poor calc-silicate parageneses. Alternatively, the low-temperature assemblage produced in the experiments may be metastable. For the investigated bulk composition, synthetic tremolitic-cummingtonitic amphibole contains relatively modest amounts of ts, Ca₂Mg₃Al₂ ^IVSi₆-Al₂ ^IVO₂₂(OH)₂; at pressures of 1,000–3,000 bars, solid solution extends from near tremolite only to about cu₁₁tr₆₉ts₂₀, analogous to most analyzed natural magnesio-hornblendic specimens. At 10 kb fluid pressure, the solid solution reaches approximately cu₀₆tr₅₃ts₄₁ for the investigated bulk composition, and appears to be virtually independent of temperature. Amphibole and 14 Å chl react within the amphibole stability field, along curve (B), at about 704° C and 2,000 bars, to produce an, en, fo and f (H=40.9 kcal/ mole); at pressures greater than approximately 7kb, due to the incompatibility of an and fo, the higher temperature assemblage consists of amph, an, en, sp and f. Above P _fluid– T curve (B), the amphibole coexists with an+en+fo+f at low pressures; at higher pressures, the amphibole, which is in equilibrium with an+en+sp+f, is relatively more aluminous. The high-T stability limit of aluminous tr+fo lies approximately 20–25° C below the dehydration curve for stoichiometric tremolite on its own bulk composition. Reaction (C), tr+fo=2 di+5 en+f (H = 39.4 kcal/mole), produces an+di+en+f, the highest temperature subsolidus assemblage investigated for the tr₅₀ts₅₀ bulk composition. Hydrous melt is encountered at temperatures at least as low as 900° C at 10 kb, and at that fluid pressure coexists with amphibole over an interval of more than 60° C. Limited solid solution observed between tr and ts in nature (tr_100-70) is accounted for by the restricted range of amphibole compositions produced in the present study. Such amphiboles, moreover, appear to have both high- and low-temperature stability limits, as demonstrated by the experimental results.Institute of Geophysics and Planetary Physics Publication No. 2811     

湘南经向构造带北段环形影象的判译及铀找矿方向的探讨

本文通过对湘南经向构造带北段的遥感地质解译,发现了具有环形影象特征的古盆、古盆盆缘及其附近爆花点状影象的古岩溶,并阐述了它们在空间分布上与铀矿化有着较为密切的关系。文章在分析该区经向构造紧密褶断带和新华夏系构造强烈活动的基础上,强调了构造体系的复合。从而展示了古盆、古岩溶空间分布上的构造有利部位。华南多数大、中型铀矿床、在空间分布上显示了与NNE向中、新生代断拗红盆有着某种内在联系,作者就断拗红盆对铀成矿的机理进行了探索。并提出在该区一定的标高和距断拗红盆的一定范围内为理想的找矿区域。     

JCXA-733型电子探针快速、综合应用程序

为JCXA-733型电子探针新编写的综合应用程序,兼顾了谱仪特性测量、四道波谱定性分析、金属和氧化物定量分析.应用一个小的正文区执行较大的程序.测试内容按顺序号排列,调用灵活,提高了分析测试速度.在定量分析中对较轻元素的定量分析作了初步的偿试.     

胶东河西金矿控矿断裂及矿体预测

本文以野外地质观察为基础,运用显微构造、岩组、构造地球化学等多种手段,对河西金矿断裂构造及其控矿作用进行了探讨,并进行了矿体预测,得到了证实,取得了可喜的经济效益。     

第四纪气候旋回孢粉植被动态组合探讨

通过对中纬区完全孢粉植被动态组合规律的分析,可以推导出某一地区沉积剖面中第四纪冷暖气候旋回的孢粉植被动态组合,其方式是:冷期孢粉动态组合,以比该区更北(平原)或更高位(山地)的孢粉植被为中间层,其上下依次对称出现比中间层更南(平原)或更低位(山地)的孢粉植被组合;暖期孢粉植被动态组合,以比该区更南(平原)或更低位(山地)的孢粉植被为中间层,其上下依次对称出现比中间层更北(平原)或更高位(山地)孢粉植被组合。