Flume simulation of wave-induced release of internal dissolved nitrogen in Taihu Lake, China

A wave flume simulator was used to study internal nitrogen release from the surface sediment collected from Taihu Lake,China.Particulate nitrogen concentrations were positively correlated with the concentrations of suspended solids,primarily from surface erosion related to the shear stress and duration of wave action.In response to 4 cm-and 10 cm-high wave production representing waves generated in Taihu Lake by gentle and gusty winds,respectively,the mean dynamic release rate of ammonium(NH+4) from the sediment to the overlying water was 1×10-3 mg/(m2.s) and the NH4+ concentration in the overlying water increased by 0.016 mg/L,indicating that waves resulting from strong wind can induce the rapid release of dissolved nitrogen from Taihu Lake sediments.The decrease in interstitial NH+4 concentrations at all sediment depths was associated with an increase in NH4+ concentrations in the overlying water by 0.01 mg/L,showing that sediment below the eroded layer was the main source of internal nitrogen release.Changes in the interstitial dissolved oxygen and NH+4 concentrations showed that wave-induced pore water movement can greatly increase the diffusion rate,and that these effects can influence the sediment to a depth of at least 15 cm.Diffusion induced by pore water movement may be very important for the formation of an active sediment layer in Taihu Lake.     

某钨锡石英脉矿床的成矿规律及其找矿方向

本文拟将我队几年来工作的实际资料,对矿床的地质特征与成矿规律作一介绍,希同志们批评指正。一、矿田地质简述:矿田内所出露的地层主要为下、中泥盆纪,上泥盆纪仅在向斜盆地内局部保存,下泥盆纪莲花山组砾岩、砂岩夹页岩厚约357米;四排组页岩厚384米。中泥盆纪郁江组砂岩及页岩,夹薄层泥质灰岩及1—2层铁质粉砂岩,厚409米;东岗岭组灰岩,泥质灰     

有机质在滇中郝家河砂岩铜矿成矿过程中的作用

郝家河砂岩型铜矿产于滇中中生代陆相红色碎屑岩建造中是滇中砂岩铜矿的一个中型铜矿床.本文以矿区宏观地质特征和微观分析数据为基础,论述了有机质参与成矿过程的事实及其在成矿过程中的作用.     

我国玻璃硅质原料的矿物及化学特征

1.我国玻璃硅质原料概况:我国玻璃硅质原料矿床按其成因可划分为如下类型:(1)正石英岩(沉积变质型):主要产于元古界的辽河群及青山组、钓鱼台;矿层呈层状夹于石英绢云母片岩、云母石英片岩中。厚层状,分布稳定,矿石都经不同程度的变质(压溶)作用,硅质高,铝质、铁质低,多属优质矿石,主要分布在长江以北地区,多为大型或特大型矿床。(2)石英砂岩(沉积型):主要生成于泥盆纪,少部份为震旦纪或寒武纪,即     

云南大姚凹地苴铜矿床数学模型的建立

大姚铜矿是我国重要铜矿山，对该矿床的最大矿体之一Ⅱ-1号矿体进行了研究，在地质规律研究的基础上，收集了与该矿体相关的铜、银品位数据，建立原始资料数据库，并对所收集的数据进行了可靠性讨论；对9061件铜样品和4160件银样品进行了统计分析，结果表明，铜、银品位服从对数正态分布；铜、银共生相关关系，为弱相关关系，需要分别建立其数学模型。计算了铜、银走向、倾向、厚度方向及平均实验变异函数，并进行了理论拟合和验证，结合矿体的地质特征对获得的参数进行了讨论。     

个旧-大厂地区地质构造演化及锡多金属成矿

个旧-大厂锡多金属矿床不是简单的燕山晚期地台环境的“花岗岩岩浆期后气液矿床”，矿区地处三大板块的交接部位附近的个旧-大厂锡矿，前泥盆纪区域构造岩浆活动及锡多金属成矿作用强烈，泥盆纪-三叠纪裂谷作用和锡多金属成矿特点突出。泥盆纪受北西向同沉积断裂控制，在南丹-河池一带裂谷作用明显，发生了海底喷流成矿，加上印支-燕山期构造岩浆改造，形成了大厂锡矿。三叠纪受北东向个旧-兴义-晴隆同沉积断裂控制，在个旧、兴义一带发生的裂谷作用，伴随基性火山成矿、喷流热水沉积成矿和燕山晚期花岗岩改造(叠加)成矿，从而形成了个旧锡矿。     

牟定郝家河铜矿含矿浅色层及矿床成因

牟定郝家河铜矿含矿浅色层明显受构造控制，常见与紫色层穿层接触关系，二者在物质成分和粒度成分上大致相似，说明含矿浅色层和矿床为沉积─改造成因。