音频大地电磁测深法在辽宁瓦房店金伯利岩矿区的应用

辽宁瓦房店地区是我国著名的金刚石矿产地之一,前人在该区做过大量的研究工作,但找矿方法一直没有突破.本文采用音频大地电磁测深法(AMT)对已知的金伯利岩矿区进行试验,探讨AMT技术在金伯利岩矿区深部探测的应用效果.针对30号金伯利岩岩管区布设了5条剖面,结果显示岩管呈低阻反映,异常明显.结合地质资料,初步推断该区断裂、成矿带和低阻异常展布特征,为在该区进一步开展矿产勘查提供基础资料,对今后瓦房店地区寻找隐伏的金伯利岩体具有重要意义,也为其他类似地区寻找隐伏金伯利岩提供新思路.     

Sea-Level Change Over the China Sea and Its Vicinity Derived from 25-Year T/P Series Altimeter Data

The characteristics of sea-level change in the China Sea and its vicinity are studied by combining TOPEX/Poseidon (T/P), Jason-1, Jason-2, and Jason-3 altimeter data. First, the sea-surface height is computed by using monthly data via collinear adjustment, regional selection, and crossover adjustment. The sea-level anomaly (SLA) from October 1992 to July 2017 is calculated based on the difference that is obtained by the value derived from the inverse distance weighting method to interpolate the CNES_CLS15 model value at a normal point. By analyzing the satellite data at the same time in orbit, three mean bias groups over the China Sea and its vicinity are obtained: the difference between T/P and Jason-1 is ??11.76 cm, the difference between Jason-1 and Jason-2 is 9.6 cm, and the difference between Jason-2 and Jason-3 is 2.42 cm. To establish an SLA series for 25 years in the study area, the SLAs are corrected. Mean rate of sea-level rise of the Bohai Sea, Yellow Sea, East China Sea, and South China Sea of 4.87 mm/a, 2.68 mm/a, 2.88 mm/a, and 4.67 mm/a, respectively, is found by analyzing the series of SLAs.     

云南程海现代沉积物环境记录研究

本文通过对程海沉积物Ｃ、Ｈ、Ｎ等元素含量及其比值的综合分析,辨识了程海沉积物有机质Ｈ／Ｃ及Ｃ／Ｎ值的环境指示意义,发现它们增可作为程海水位波动及区域气候干湿变迁的替代性指标。研究结果表明：程海的水位和区域气候干湿主为化明显以历了两个不同的阶段,但整体上程海水位一直呈下降趋势,反映区域气候整体上向干旱化方向发展。     

潮间带低速层中高速埋伏岩体计算模式的建立

在某些沿海潮间带区域的低速层中常存在一定数量的巨大高速滚石埋伏岩体。这些埋伏岩体会给工程地质勘察带来很大的困难 ,甚至无法进行工程地质勘察。根据浅层折射波方法原理利用浅层折射波相遇时距曲线与折射波射线路径关系建立了求取浅层高速埋伏岩体的埋深及其厚度的计算模式 ,利用这些公式可以较准确地确定高速埋伏岩体的位置、埋深及其厚度 ,对工程地质勘察是十分有利的。     

青藏高原西北缘盆山过渡带陡坡地貌的形成时代与成因

平均海拔大于4500 m的青藏高原,是通过高原边缘的陡坡地貌与海拔低于1500 m的周缘盆地或平原相连接的,这些围绕高原的陡坡地貌是何时、如何形成的呢？本文通过对西昆仑山中段北缘主逆冲断层上盘陡坡地貌区9件磷灰石样品的裂变径迹年龄与长度分析表明：在海拔3900～4635 m的陡坡地貌中的裂变径迹样品年龄为6.2±1.4 Ma～0.9±0.3 Ma,呈现“上新下老”的反序分布特征; 而通过热历史模拟显示约5 Ma,约3～2 Ma,约2～1 Ma 和约1 Ma该地区出现多阶段的隆升与剥露。结合前人研究成果和野外地质的观察认为,现今青藏高原西北缘陡坡地貌的形成是中新世晚期以来高原边界叠瓦状断裂系经历了约8 Ma、约5 Ma、约3～2 Ma、约2～1 Ma和约1 Ma多阶段后展式逆冲运动的结果,这为青藏高原周缘陡坡地貌的形成和青藏高原的隆升时代与型式提供了关键的热年代学约束。     

江西相山铀矿田邹—石断裂新解

邹—石断裂分布在江西相山铀矿田西部,前人认为是一条重要的成矿构造.本次研究发现矿体并不产于邹—石断裂本身,断裂没有控制矿体几何形态,不是矿质直接充填或交代的地质构造单元,不具成矿构造的特点.由于邹石断裂在地形上呈现线性沟谷,遥感影像图上呈现清晰的线性影像,切错了花岗斑岩.构造岩主要是围岩的破碎角砾、构造透镜体和断层泥,以脆性变形为主,温热水与之关系密切,故认为,邹—石断裂具有新构造活动的踪迹,可能形成于新近纪—第四纪,属矿后构造.     

百度地图位置解析技术在地震应急基础数据库的应用

分析百度地图位置解析技术功能及特点,提出使用地址解析及坐标转换功能,对地震应急基础属性数据进行解析,实现基础属性数据空间化,设计地理坐标纠偏算法,提高地震应急基础数据的可用性,为地震应急工作提供数据保障。该算法操作简单,运行快捷,解决了地震应急基础数据库中属性数据及时更新的关键技术问题。     

The Influence of Element Diffusion at the Sediment—Water Interface on the Basic Chemical Composition of Overlying Water Mass in Lake Lugu,China

Little work has been done on the influence of seiments on the basic chemical composition of overlying water mass.This paper deals with the vertical profile of the basic constituents such as Ca^ ,K^ ,Na^ ,and HCO3^-,as well as of pH in the overlying water mass and sediment porewater of Lake Lugu-a semi-closed,deep lake in Yunnan Province.The reand sediment porewater of Lake Lugu- a semi-closed,deep lake in Yunnan Province.The results revealed that those basic constituents may diffuse and transport from bottom sediments to overlying water mass through porewater.In the paper are also quantitatively evaluated the diffusive fluxes and the extent of their influence on overlying water mass,indicating that the lake sediment-water interface diffusion plays an important role in controlling the basic chemical composition of water in the whole lake.     

商丹断裂带东段基性岩、超基性岩中的铁铬镍资源潜力预测

对商丹断裂带东段基性-超基性岩带（体）及其中的铁、铬等矿化特征作了概述,在岩带中圈出了A、B、C、D四个基性-超基性岩体集中区,对该带中铁铬镍等矿产资源潜力作了地质预测,认为该基性-超基性岩带是岩浆型铁、铬、镍等矿产的良好找矿远景区,提出了下步找矿工作思路、方法手段的建议.     

Tiller recruitment and mortality in the dryland bunchgrass Eragrostis curvula as affected by defoliation intensity

A greenhouse experiment was conducted to investigate the effects of moderate (14 cm) vs. severe (7 cm) defoliation on tiller recruitment and mortality within the interior and on the perimeter of weeping lovegrass (Eragrostis curvula) tussocks. Tiller number per marked shoot within the interior was significantly greater in plants defoliated at 14-cm stubble height than at 7-cm stubble height (2·37 vs. 0·43, p<0·05) 28 weeks after defoliation; likewise, tiller number per marked shoot was also greater on the perimeter of tussocks in the higher stubble than the lower stubble defoliation treatment (5·10 vs. 2·03, p<0·05). Tiller natality increased significantly 4 weeks after defoliation except for tillers cut to 7-cm stubble height within the interior of tussocks where tiller natality reached a peak at 4·5 weeks after defoliation. During the later stages of canopy development, tiller numbers per marked shoot gradually declined as tiller mortality increased. Tillers began senescing 13 weeks after defoliation, and the senescence rate was 52% greater in the 7-cm stubble height treatment than in the 14-cm stubble height treatment (2·33 vs. 1·53, p<0·0001). Within the interior of tussocks, number of the marked tillers more than doubled under the 14-cm stubble height treatment, whereas the plants lost 57% of the monitored tillers under the 7-cm stubble height treatment. We concluded that the central dieback process in weeping lovegrass is accelerated by severe defoliation.