Effect of volatiles erupted from Mesozoic and Cenozoic volcanic activities on paleo-environmental changes in China

Based on the determination of composition of volcanic volatiles and petrologic estimation of the total mass of volatiles erupted, we showed important advances in the study of the impact of Mesozoic and Cenozoic volcanic activities on paleo-environmental changes in China. The volcanic activities include western Liaoning and Zhangjiakou Mesozoic intermediate-acidic explosive eruptions, southern Tibet and Shanwang Cenozoic volcanism, and Mt. Changbai volcanic eruption around one thousand years ago. The paper predominantly discusses the earth’s surface temperature changes, ozone depletion, acidic rain formation and mass mortalities of vertebrate induced by the Mesozoic and Cenozoic volcanism in China. __________ Translated from Bulletin of Mineralogy, Petrology and Geochemistry, 2007, 26(4): 319–322 [译自: 矿物岩石地球化学通报]     

Pelagic records from the Equatorial Ninetyeast Ridge and significant environmental events during the past 3.5 Ma

This paper presents pelagic records of planktic foraminifera, as well as data of stable isotope stratigraphy and carbonate stratigraphy since 3.5 Ma B.P. from site ODP758 in the Ninetyeast Ridge of the Indian Ocean. Based on these data, manifestations and related mechanisms of major tectonic and environmental events such as the rapid uplift of the Himalaya Mountains, “middle Pleistocene climatic transition” and “mid-Brunhes dissolution event” in the region are discussed. According to the analysis and comparison of various indices and changes in terms of foraminifera assemblage, paleotemperature, paleosalinity and themocline from site ODP758, the authors deduce that the paleoclimatic changes might correlate with the mid-Pleistocene transition at 1.4–1.7 Ma B.P. The changes of CaCO₃, mass accumulation rates (MAR) of CaCO₃ and non- CaCO₃ MAR indicate that the loaded terrigenous sediments increased at 1.7 Ma, which is in agreement with the uplift history of the Qinghai-Tibet plateau as shown by the available data. The last two changes coincide with the uplift of the Qinghai-Tibet plateau, hence they are called “Qinghai-Tibet movement” (1.7 Ma), and the “Kunlun-Yellow River movement” (1.2–0.6 Ma). The changes of the CaCO₃ content, coarse fraction (> 150 μm) content and planktonic foraminifera biostratigraphy show that strong dissolution of abyssal CaCO₃ occurred in the study region during 0.5–0.4 Ma. The event was consistent with the “mid-Brunhes dissolution event” in the sedimentary records of the Atlantic Ocean, Pacific Ocean, Indian Ocean and Nansha sea area of the South China Sea. __________ Translated from Geological Bulletin of China, 2007, 26(12): 1627–1632 [译自: 地质通报]     

Sedimentary characteristics of terrigenous debris at site MD05-2905 in the northeastern part of the South China Sea since 36 ka and evolution of the East Asian monsoon

Sediments with high sedimentation rate at site MD05-2905 in the Northeastern slope of the South China Sea provide unique materials for a high-resolution study on the paleoenvironment. Based on precise dating of AMS ¹⁴C, grain size analysis of terrigenous debris at core MD05-2905 was conducted after organic matter, biological carbonate and biogenic opal were removed. The results show that 15.5–63.5 μm coarse grain size ingredients may indicate East Asian winter monsoon changes and that 2–9 μm fine grain size ingredients may be used as a proxy of evolution of the East Asian summer monsoon. The results of grain size analysis, which suggest East Asian monsoon intensity, reveal that a winter monsoon dominated the glacial regime and a summer monsoon dominated the Holocene regime. It was also shown that the summer monsoon increased gradually, experienced several abrupt changes and reached a culmination in the early Holocene (11200–8500 a B.P.) since 36 ka. Controlled by precession periodicity, it may be related with the amount of solar radiation at the highest stage, which needs further study. __________ Translated from Advances in Earth Science, 2007, 22(10): 1012–1018 [译自: 地球科学进展]     

Spatial distribution features and environment effect of heavy metal in intertidal surface sediments of Guanhe estuary, Northern Jiangsu Province

In northern Jiangsu coastal zone area, Guanhe River is the biggest river and has the best navigation conditions among rivers which flow into the Yellow Sea. The grain sizes show gradual increase from the high intertidal zone to lower intertidal zone. The heavy metal values have slight changes along both sides of the river mouth, but show an evident change perpendicular to the tidal flat. In the latter case, they show a good correlation with grain size fluctuation, that is, the heavy metal values gradually decline when the grain size increases from the high intertidal zone to the lower intra-tidal zone. Analyses of the heavy metal elements show that on the Guanhe estuary surface sediment, the content of the elements Hg, As and Cu is above background values; Pb and Zn contents are rather close to the background values; and Cd content is less than the background values. The element Hg comes out to be harmful in a medium level to ecological environment, while the elements of Cr, As, Cu, Pb, Zn and Cd fall in a safe range of MPL. On the whole, Guanhe estuary tidal flat is not very harmful to the ecology in terms of the heavy metals. __________ Translated from Marine Geology & Quaternary Geology, 2007, 27(5): 23–32 [译自: 海洋地质与第四纪地质]     

邵于庄煤炭勘查区新生界松散层水文地质特征

邵于庄煤炭勘查区新生界松散层厚度较厚,下伏为二叠系含煤地层,可采煤层多。区内含、隔水层组成复杂,由四个含水层和三个隔水层组成。通过对含水层水文地质条件分析,提出了第一、二含水层是矿区的主要供水水源,为保证未来建设和开采时的生活用水和工业用水,应做好水源的保护工作;同时指明了第四含水层是浅部煤组开采的主要补给水源,在煤矿设计和开采过程中,应重点予以防治。     

西藏扎布耶盐田盐渍土的改性配比试验

根据盐渍土的物理化学性质,采用掺入不同比例石灰或水泥的方法进行改性处理。经击实、抗剪和抗压强度试验结果表明,盐渍土掺入石灰或水泥改性后,混合料的最大干密度、最优含水率、强度指标等均有增加,特别是内聚力迅速增长。研究表明,盐渍土混合料的性状得到了明显改善,改性后的混合料可用于修建盐田埝堤类相关工程。     

辅助纬度反解公式的Hermite插值法新解

利用计算机代数系统,推导出了地图投影中辅助纬度与大地纬度间的正反解变换公式,发现和纠正了传统正解公式高阶项中的一些错误;借助Hermite插值法得到了符号形式的反解表达式.将各辅助纬度展开式系数表示为简单的偏心率e的幂级数形式,使得系数的表示形式更为统一.     

贵州省大方县五凤井田水文地质特征初探

五风井田位于贵州省大方县城东侧,面积89.22km^2,含煤地层为二叠系上统龙潭组,主要可采煤层为6中、26、33号煤层,煤炭总资源量26 130万t。井田内主要含水层为三叠系茅草铺组岩溶溶洞含水层（T1m）,夜郎组玉龙山灰岩岩溶裂隙含水层T1y2）,二叠系中统长兴组岩溶裂隙含水层（P3c）、茅口组岩溶溶洞-暗河含水层（P2m）。矿床属于以岩溶充水为主,水文地质条件中等的矿床。井田的充水水源为地表水、地下水和小煤矿、采空区的老窑积水,充水通道为断裂破碎带及采矿冒落裂隙带。     

山西天池煤矿构造特征及其形成机制

基于天池煤矿地质勘探资料,结合区域构造背景研究了矿井地质构造特征及形成机制。天池煤矿构造属简单构造,地层总体呈走向北东、倾向北西的单斜构造,矿井内褶皱发育程度较低,断层以正断层为主,其次为低角度逆掩断层。陷落柱分布较为杂乱,成群出现,常见于褶皱轴部。自三叠纪末期开始一直受到区域构造活动的控制作用,印支期受SN向的挤压,形成了一些近EW向的构造;燕山期经历两期NWW--SEE向挤压使井田内地层及煤层主体呈NE走向;喜山早期的NE—SW向挤压,导致NE向断层的性质发生转变;上新世开始表现为区域上的伸展作用。