Study of the Saldanha Massif (MAR, 36°34′ N): Constrains from rock magnetic and geophysical data

We present a study of the magnetic properties of a group of basalt samples from the Saldanha Massif (Mid-Atlantic Ridge – MAR – 36° 33 54 N, 33° 26 W), and we set out to interpret these properties in the tectono-magmatic framework of this sector of the MAR. Most samples have low magnetic anisotropy and magnetic minerals of single domain grain size, typical of rapid cooling. The thermomagnetic study mostly shows two different susceptibility peaks. The high temperature peak is related to mineralogical alteration due to heating. The low temperature peak shows a distinction between three different stages of low temperature oxidation: the presence of titanomagnetite, titanomagnetite and titanomaghemite, and exclusively of titanomaghemite. Based on established empirical relationships between Curie temperature and degree of oxidation, the latter is tentatively deduced for all samples. Finally, swath bathymetry and sidescan sonar data combined with dive observations show that the Saldanha Massif is located over an exposed section of upper mantle rocks interpreted to be the result of detachment tectonics. Basalt samples inside the detachment zone often have higher than expected oxidation rates; this effect can be explained by the higher permeability caused by the detachment fault activity.     

Analysis of Dynamic ECG in the 80 Meters Saturation -100 Meters Excursion Heliox Dive

The study deals with the observation of the changes in the electrical activities of 8 healthy divers in the 80 msw saturation-100 msw excursion heliox dive by DCG. Results showed significant changes in the 24 h of average heart rate, the decrease of heart rate at saturation storage depth and decompression periods being 15.5% and 19.7% respectively. Fortuitous supraventricular premature beats appeared in 8 divers and ventricular premature beats in 5 divers during exposure. Transient ischemic ST-T changes in 6 divers occurred repeatedly during diving operations. The discussion puts up the view that the ST-T changes were due to the stress reaction of the body induced by the combined effect of such stress factors as hyperbaric pressure per se, high partial pressure of oxgen, noise and the closed restricted chamber environment.     

Wave Attenuation and Friction Coefficient on the Coral-Reef Flat

Several sets of S4 direction-wave-current-tide meters have been deployed on the coral-reef fiat of Yongshu Reef in the sea area of Nansha Islands. Based on the observational sea wave data, the attenuation characteristics of the waves propagating on the coral reef flat, the bottom friction coefficients and the transfer of wave energy are discussed in the paper. The results show that, in the relative depths of 0. 0613- 0.0867, the wave height attenuation per unit distance of wave propagation is 22.09 %-46.56%, with an average of 31.35 % ; the wave energy, attenuation coefficient, 33.74 %- 53.22%, with an average of 43.61%. The average of the bettom friction coefficients on the coral-reef flat is 0. 1346,which is about 10 times thai on the sand or silt bottom. In the couse of propagation on the reef flat, the waves sustain more loss in high frequency than in low frequency and the spectral energy transfers to the low frequency. These results may be used for reference in island and reef engineering.     

THE NEW PETROLOGY

I suppose that one is not far wrong in saying that Petrology is thescience of rocks.But we have not made ourselves very clear by saying it.To the average student of the subject.who must judge from what he is taught,     

MICROSTRUCTURES OF SOME CHINESE ANTHRACITE

1. Previous works on microscopy of anthracite. The existing method of coal petrography seems to be well adaptableonly to bituminous or lignitic coals; in the case of anthracite,because of itsextreme opacity to light and resistency to most chemical solvent     

NOTES ON A FOSSIL FISH FROM SHANSI

The fossil fish described in this short paper was collected from Taiku,Shansi province.It is a very common species,Carassius auratus Linnaeus ofCyprinidae.The living form is widely distributed in China.I am very much     

"现代地球磁场监测与地磁基本数据积累"项目成果介绍

本文详细介绍了“现代地球磁场监测与地磁基本数据积累”项目的立项背景、目标、所开展的主要工作、取得的成果、研究成果的社会效益和对该领域研究未来工作的展望。     

论羌塘地块结构的不均一性和深部信息

根据藏北羌塘地区最新地质、地球物理资料(以MT为主)综合分析，对比西部和东部综合剖面各单元结构特征，发现羌塘地块结构不均一性特征明显。西部隆起区结构独特，浅中部与深部结构有别，存在一南倾低阻异常带。西中部剖面南羌塘坳陷与西部隆起区深部结构相似，壳内低阻层呈双层。其他地段和东部剖面均呈中隆两坳格局，壳内低阻层仅一层。中部隆起带的深部总是对应一直立极低阻异常带。北羌塘坳陷低阻凹陷规模大，基底埋深大，横向分块明显，北中段热力改造较强，深部存在l～2个极低阻异常区带。总体上表现为南北分区带、东西分块段、垂向分圈层，MT显示壳内低阻层顶界面深度不一，横向变化大，低阻层呈①直切式：从深50～60km处呈柱状直接切断两侧高阻体，升达地面；②蘑菇云状：从深100km处呈宽约50km的蘑菇云状升入到地下10km；③上下叠置三明治式：以双层低阻层或多层高阻体上下叠置呈三明治式结构。南部基底电阻率显著高于北部，基底构造分三块：西南部、中东部和东部。这种结构不均一既有其深部构造作用控制，可能存在热异常柱，又有后期改造作用的叠加。     

Learning styles among geography undergraduates: an international comparison

Growing diversity is focusing attention on the range of different student learning styles. This study assesses whether geographers have a predominant learning style and whether this varies between and within countries. The findings are based on over 900 geography students from 12 universities in Australia, New Zealand, the UK and the US, who completed Kolb's Learning Style Inventory (LSI). The implications for curriculum design and student learning strategies are discussed. It is suggested that departments should aim to produce balanced learners with a full range of learning capacities rather than simply matching teaching to existing learning styles.