大地构造与成矿学
大地構造與成礦學
대지구조여성광학
GETECTONICA ET METALLOGENIA
2009年
4期
613-619
,共7页
热水沉积%锰矿%中二叠世%贵州
熱水沉積%錳礦%中二疊世%貴州
열수침적%맹광%중이첩세%귀주
hydrothermal sediment%manganese deposit%Middle Permian Maokou Formation%Shuicheng%Guizhou
贵州水城二叠系茅口组内发现新锰矿.通过对含锰岩系的地质地球化学研究,其富集Zn,Ni,As,Sb,Sr,Ba,Ga,Ag,V,U元素;锰含量较高层位,Th/U比值小于1,锰含量较低层位,Th/U比值往往高达4~5.Co/Ni比值小于1.含锰岩石的(Fe+Mn)/Ti均大于47,高于20,特别是含锰高的岩石,其(Fe+Mn)/Ti 值在300以上.含锰岩石的Al/( Al+Fe+Mn)均远远低于0.35,一般为小于0.02.稀土配分模式与峨眉山玄武岩相似,∑REE较高,LREE/HREE值偏低等特征.根据锰岩系地球化学和区域构造特征分析,水城二叠系茅口组含锰岩系属于热水喷流沉积的产物.
貴州水城二疊繫茅口組內髮現新錳礦.通過對含錳巖繫的地質地毬化學研究,其富集Zn,Ni,As,Sb,Sr,Ba,Ga,Ag,V,U元素;錳含量較高層位,Th/U比值小于1,錳含量較低層位,Th/U比值往往高達4~5.Co/Ni比值小于1.含錳巖石的(Fe+Mn)/Ti均大于47,高于20,特彆是含錳高的巖石,其(Fe+Mn)/Ti 值在300以上.含錳巖石的Al/( Al+Fe+Mn)均遠遠低于0.35,一般為小于0.02.稀土配分模式與峨眉山玄武巖相似,∑REE較高,LREE/HREE值偏低等特徵.根據錳巖繫地毬化學和區域構造特徵分析,水城二疊繫茅口組含錳巖繫屬于熱水噴流沉積的產物.
귀주수성이첩계모구조내발현신맹광.통과대함맹암계적지질지구화학연구,기부집Zn,Ni,As,Sb,Sr,Ba,Ga,Ag,V,U원소;맹함량교고층위,Th/U비치소우1,맹함량교저층위,Th/U비치왕왕고체4~5.Co/Ni비치소우1.함맹암석적(Fe+Mn)/Ti균대우47,고우20,특별시함맹고적암석,기(Fe+Mn)/Ti 치재300이상.함맹암석적Al/( Al+Fe+Mn)균원원저우0.35,일반위소우0.02.희토배분모식여아미산현무암상사,∑REE교고,LREE/HREE치편저등특정.근거맹암계지구화학화구역구조특정분석,수성이첩계모구조함맹암계속우열수분류침적적산물.
A new manganese deposit in the Middle Permian Maokou Formation in Shuicheng County, Guizhou Province, China was discovered. Study on trace elements of the manganese deposit shows that Cu, Zn, Ni, Co, As, Sb, Sr, Ba, Ga, Ag, V, U is enriched in the manganese deposit. The content of manganese is higher when the ratio of Th/U is lower than 1, and lower when the ratio of Th/U is 4 ~5. At the same time, Co/Ni values are lower than 1 in the manganese deposit.
The plot of Σ Fe/Ti versus Al/( Al + Fe + Mn) shows that all samples located at the hydrothermal sediment area. ( Fe + Mn) /Ti ratio values of the manganese deposit are high , up to 47 ~ 300, especially, ( Fe + Mn ) /Ti ratio values of the manganese deposit are higher, up to 300 in the higher Mn samples. The rock or manganese deposit was considered hydrothermal sedimentation when ( Fe + Mn)/Ti ratio values is higher than 20, and Al/( Al + Fe + Mn) ratio values are low to 0. 35. Al/( Al + Fe + Mn) ratio values of the manganese deposit present about 0.02 in the higher Mn samples. Therefore, ratio values of ( Fe + Mn)/Ti and Al/( Al + Fe + Mn) show that the manganese deposit was formed under a hydrothermal sedimentary environment. Additionally, the higher Σ REE (mean 168 × 10~(-6)) , the lower ratio of LREE/HREE, negative Eu anomalies, and few remarkable positive Ce anomalies (except y-16, y-22) is similar to those of the Emeishan basalt. The geochemical characters of the manganese deposit above-mentioned suggest that manganese mineralization was affected by hydrothermal process of mantle plumes.