On the origin and age of the Steep Rock buckshot, Ontario, Canada

The Steep Rock buckshot is a brecciated pisolithic ferruginous bauxite found in the Errington iron mine, Steep Rock Lake, Ontario, Canada. It occurs within the almost vertical ore zone included in the Archean Steep Rock Group, reaching a depth in excess of 1100 ft. (335 m). Successive authors considered its age as Precambrian. The biological observations now presented deny this supposed Precambrian age. Treatment of the concretions by HCI, followed by staining, put in evidence abundant microscopic figurate animal and vegetal remains, namely shreds of insect integument and varied fragments of vascular plant material. Comparable results were obtained by casting and by scanning electron miscroscopy (SEM) of the surface of the concretions and by thin sections. All these remains are Phanerozoic and one of them is probably not anterior to the Late Cretaceous. The macro- and micromorphology of the concretions obey models of termite constructions and the spectrum of organic remains is identical to the one found in tubulo-alveolar laterites and in termite constructions. The presence in the matrix of canaliculi attributable to thin roots gives force to the idea that the buckshot was originated near the soil surface.     

In situ thermal conductivity and equilibrium formation temperature from circulation flow rate variations

A temperature-transient method to estimatein situ formation thermal conductivity and equilibrium formation temperature using circulation fluid flow-rate pulses is described. Flow-rate changes induce temperature variations in the well and the time from when the flow alters to the subsequent maximum or minimum temperature of the drilling fluid can be used to determine these two formation parameters. Some examples are presented to illustrate the method.     

上海地区台风倒槽暴雨分析

本文通过五次个例的对比分析,指出边界层东北急流对长江三角洲台风倒槽的重要作用.同时还得出,那里存在两种类型的台风倒槽暴雨,它们在一些方面有明显的不同.     

Anomalies in rare earth distributions in seawater: Gd and Tb

We have measured profiles of the rare earth elements (REE) in Atlantic and Pacific Ocean waters. The data, normalized versus shales, exhibit a pronounced anomaly in Gd relative to its neighbors Eu and Tb in the REE series such that the Gd concentrations are high by 30–50%. Closer inspection reveals that the anomaly is made up of both elevated Gd and depressed Tb concentrations, likely associated with solution chemistry shifts in the transition from an exactly half filled 4f electron shell. Anomalies in Gd and Tb solution complexation are also indicated by the Turner-Whitfield-Dickson speciation model. The overall trend of heavy REE(III) enrichment in seawater and the $\text{Gd}\text{Tb}$ anomaly described here tend to support scavenging as an important removal mechanism for the REE from seawater.     

Seismic sources and attenuation properties at the Campi Flegrei volcanic area

Microearthquake digital data collected at Campi Flegrei during the recent (1982–1985) ground uplift episode have been analyzed in order to infer source and medium seismic properties. The main results obtained from these analyses are:

1. Hypocenter distribution and the size of the seismic zone do not change with time and do not depend on the ground uplift rate. Events occurred clustered in time with no simple causal relations between the cluster occurrences and their energy.
2. Anelastic attenuation does not depend strongly on frequency, showing a constant pattern at high frequencies. The observed values of low and high frequency attenuation, due to the short source receiver distances, do not seriously affect the spectral content of signals radiated by the sources.
3. A constant Brune stress drop pattern (～4–5 bars) as a function of seismic moment is observed. This indicates that the manner of fracturing is almost independent on magnitude of earthquakes (hypothesis of self-similarity (Aki, 1967)). Seismic processes in a prefractured medium can explain the observed small stress drop values.
4. Focal mechanisms from moment tensor estimates show that radiation patterns are mostly well interpreted in terms of double couple source models.
5. The scaling of peak ground motion parameters (A _max andV _max vs seismic moment) can be explained by an ω² source model (constant stress drop) multiplied by an exponential function with a small decay parameter, which takes into account the measured attenuation.

These results support the hypothesis of earthquakes generated by simple shear fractures along prefractured structures as a response to changes in the stress field due to the ground deformation.     

Friction velocity scaling in wind wave generation

This note is devoted to the problem of the appropriate scaling of parameters relevant for sea waves, such as wave height, peak frequency, duration, and fetch. In the past, the growth of sea waves has often been analysed in terms of the wind velocity at a fixed height, despite the fact that many authors have stressed the importance of scaling with the friction velocity. This problem would be immaterial if the ratio between the friction velocity and the wind speed at a fixed height were a constant. There is, however, ample evidence that this ratio increases with wind speed (Smith and Banke, 1975; Smith, 1980), in agreement with dimensional considerations by Charnock (1955) on the friction height. As a result, the scaling problem is an important one. In this note we conjecture that the correct procedure is to scale wave parameters with friction velocity, and we discuss experimental evidence for the correctness of this conjecture. Comparing two independent datasets (JONSWAP and KNMI), we find some evidence supporting our ideas. Further confirmation remains desirable, however, and suggestions are made as to how this might be obtained.     

Statistical analysis of weather-type runoff phenomena in an Alpine environment

In order to get a better insight into the role of hydrologic regime components in an Alpine environment, runoff characteristics were analysed in relation to atmospheric circulation types over a 23-yr. period. For this purpose, atmospheric circulation types were classified into hydrologically relevant classes of weather types using Schüepp's classification which was developed for the European Alpine region. It is found that the magnitude of runoff during each particular class of weather types is largely governed by autocorrelation (related to the characteristic times of the systems active during preceding classes and thus related to the preceding weather types) and by antecedent conditions, rather than by the weather types themselves. The influence of a weather class displays a distinct dependency of the time elapsed since the start of the particular class. This influence does not become manifest until after a 2–3-day period on the average.     

Anorthite,andesine, wollastonite,diopside, cordierite and pyrope: thermodynamics of melting,glass transitions,and properties of the amorphous phases

Drop calorimetry measurements between 900 and 1850 K are reported for amorphous anorthite, andesine, wollastonite, diopside, cordierite and pyrope. The isobaric heat capacities of the glassy and liquid phases of these materials, and the enthalpies of fusion of the minerals have been derived. The calorimetric entropies of fusion of these substances and of other oxide minerals are generally consistent with the calculated volume changes on melting and with the observed pressure dependences of the melting points. The thermodynamics of mixing of liquid plagioclases have been examined, and it is concluded that their enthalpies of mixing are markedly different from the values derived directly from solution calorimetry measurements at 985 K.