山东临朐-昌乐地区新生代火山岩研究

山东临朐-昌乐地区新生代火山岩是新近纪中新世-上新世火山活动产生的大陆溢流玄武岩,分为牛山期、山旺期和尧山期,主喷发期为牛山期和尧山期,属于碱性玄武岩系列。火山岩化学成分由早至晚向富碱、钛、钙,贫硅、镁、锰的方向演化,岩浆分异程度晚期较早期高。岩石内有大量二辉橄榄岩、方辉橄榄岩等幔源包体和透长石、普通辉石、尖晶石等巨晶。玄武岩K-Ar年龄为4.34～18.87Ma。火山岩岩浆来源于上地幔。     

Investigation of array-derived rotation in TAIPEI 101

We investigate rotational motions derived from measurements by arrays of translational seismometers??hereafter called array-derived rotations (ADRs)??and compare these to measurements made by a commercially available point rotation sensor (eentec? R-1?). We focus on two aspects of the array problem: (1) the requisite conditions for calculating an ADR well and (2) the effect of array configuration on the result. Our data set consists of translational accelerations and rotation rates recorded by an array of Kinemetrics? EpiSensor? accelerometers and two R-1? rotational sensors in the TAIPEI 101 building in Taipei, Taiwan. Our results indicate that (1) array configuration affects the accuracy of ADRs about orthogonal components in horizontal plane, (2) coherence between two point rotation measurements (two R-1?) can determine the maximum frequency of translations viably used for the calculating ADRs, and (3) the performance of the R-1? is adequate, at least above a frequency of 0.12?Hz (periods shorter than 8?s). We also discuss deriving strain from the same array.