Mg-enriched erythrite from Bou Azzer,Anti-Atlas Mountains,Morocco: geochemical and spectroscopic characteristics

Mineralogy and Petrology - Supergene Mg-enriched erythrite, with an average composition (Co2.25Mg0.58Ni0.14Fe0.04Mn0.02 Zn0.02) (As1.97P<0.01O8)·8H2O, accompanied by skutterudite,...     

1980年以来中国高等地理教育机构的发展：类型、增长与分布演变

为了厘清中国高等地理教育机构发展脉络,论文基于多种类型资料,梳理了1980—2021年中国高等地理教育机构的专业、沿革、停办数据,从类型、增长、分布3个层面讨论其发展过程,并探讨其当前主要问题。研究发现,近40余年中国高等地理教育机构发展有如下特征：① 主要分布在科研机构和高校中,且高校涉及综合、师范、工程与矿业等11类高校;② 地理学专业数量及其在机构中地位的差异使之有必要区分学科机构与专业机构;③ 数量增长包括1980—1998年稳定增长、1999—2009年快速增长、2010—2021年波动增长3个阶段,并主要受高校地理院系增长的影响,不同阶段不同类型高校地理院系增长又有差异;④ 分布演变可分为与数量增长时段相一致的省级稳定扩展、省级与地市级双轨快速扩展、省级与地市级双轨缓慢扩展3个阶段,不同类型机构空间分布及扩展态势也存在差异。当前中国高等地理教育机构已形成学科机构为主体、专业机构为扩展翼的发展态势,但有必要加强学科认同和学科共同体建设,以避免多样化发展可能引起的误解,改变仍然存在的高校学科院系“名实不符”现象,降低高校专业院系停办风险。     

Remarks about magnitudes and maximum intensities of the earthquakes in Friuli, 1976

Summary The magnitudesM and maximum intensitiesI ₀ of 66 earthquakes which occurred in the period from 1901 to 1973 in the eastern alpine area are compared with those of 62 earthquakes occurred in Friuli, northern Italy between 6 May and 15 September 1976. The average focal depth of the Friuli events is about 10 km. The existing empirical relation betweenM andI ₀ for this area is improved by many new data.     

Comparison of the Slow Pyrolysis Behavior and Kinetics of Coal,Wood and Algae at High Heating Rates

Natural Resources Research - Coal, like any other nonrenewable energy resource, will, by exploitation, deplete in the near future. In light of this, biomass is fast becoming an alternative material...     

Correlated features of arrival time and angle-of-incidence distributions of EAS muons

Various features and correlations of the arrival time and angle-of- incidence distributions of muons of extensive air showers (EAS) are studied by analyses based on Monte-Carlo simulations of the EAS development by using the air shower simulation code CORSIKA. Trends and dependencies of the temporal dispersion of the EAS muon component on shower size and distance from the shower core are displayed by the distribution of the arrival time and angle of incidence of the first muon, of the mean and median of the single shower distribution. Special attention is called to multi-correlations in observations at different radial distances from the shower core. These ‘radial’ correlations provide additional information for the discrimination of different EAS primaries, while the correlation of muon arrival time and angle-of-incidence is shown to improve the mass separation only insignificantly. This feature does not basically change, when arrival times and angles of incidence are displayed by transformed quantities like ‘muon production heights’.     

Ein Beitrag zur praktischen Absch?tzung der Ausdehnung von Erdbebenherden

Zusammenfassung Eine gleichmäßige Zunahme der Laufzeitdifferenz zwischen Kompressions- und Scher welle mit der Distanz vom Erdbebenherd erweist sich für den Ostalpenraum als gegeben. Es wird ein Durchschnittswert der Zuwachsrate von 0,12 Sekunden pro Kilometer Herddistanz erhalten. Aufgrund dieser einfachen Beziehung ist es möglich, aus den Daten zweier seismischer Stationen die flächenmäßige Anordnung der Epizentren einer Bebenserie zu bestimmen. Dadurch kann einerseits die Verlagerung der Epizentren im Verlaufe des Bebengeschehens und andererseits auch das Gesamtausmaß des seismisch aktiven Raumes (Herdvolumen) ermittelt werden. Dies wird anhand der Bebenserien in Friaul gezeigt.

---

A contribution to a practical estimation of the dimensions of earthquake foci

Summary First, the uniform increase of the travel time difference of compressional and shear waves in dependence on focal distance is examined for the Eastern Alps. The result is a mean rate of 0.12 seconds per kilometre of distance. Because of this simple relation it is possible to estimate the distribution of epicentres in the case of earthquake series by only two seismic stations. Thus, the migration of foci as well as the full size of the active seismic area (earthquake volume) can be evaluated. In the following, this procedure is applied to the earthquake sequences in Friuli, Northern Italy.

---

---

Mit 5 Abbildungen     

A new approach to the electrical conductivity anomalies in the Drauzug-Bakony geological unit

A major electrical conductivity anomaly has been detected in Transdanubia (West Hungary) in the eastern part of the Drauzug-Bakony geological unit (DBU), a collision zone of the Alpine orogeny. Assuming the source of the conductivity anomaly to be a characteristic formation of the whole DBU, long period magnetotelluric (MT) measurements were made in two regions of the western part of the DBU, in the Gail valley and in the Karawanken. The general features of this formation were studied also in order to elucidate the cause of the Transdanubian conductivity anomaly. The conductivity anomaly detected by long period MT in the Western DBU lies much deeper (12–17 km) than in Transdanubia (5–9 km). As the anomaly in both regions is associated with a well-known tectonic zone, its origin was initially explained by ionic conduction, arising from the presence of pore fluids. The very low resistivity values, the great anisotropy, the effect of charges on the H-polarized MT curves, and the anomalous magnetic field variations also indicated an increase of electronic conduction, possibly caused by graphitic rocks or ores nearer to the surface.

In the Gail valley, audiomagnetotelluric measurements made in 1986 have led to the discovery of these standing blocks of graphitic shales lifted up gradually to the surface by tectonic forces from below the dolomites of the Carnic Alps. It is suggested that the same plate collision arranged the Paleozoic graphitic shales to narrow dikes in the Gail valley as well as in Transdanubia along the Balaton line and zones parallel to it.     

Book Review: Earthquake Microzoning By A. Roca and C. Oliveira (Eds.), Birkhäuser Verlag, 2001, 298 pp., softcover,Euro 52, ISBN 3-7643-6652-4

Studia Geophysica et Geodaetica -