贵州西部龙场玄武岩型钛矿床地质特征及成因

Geological characteristics and genesisof Longchang basalt type titanium deposit in West Guizhou

贵州西部龙场钛矿床初步估算资源量数千万吨,达到大型钛矿床规模。研究表明:龙场钛矿床为产于峨眉山玄武岩组第三喷发旋回顶部强蚀变玄武岩、杏仁玄武岩中的大型钛矿床。含矿层及其上覆、下伏岩层w(TiO 2)均大于2.8%,具有高钛背景值特征。矿石矿物主要由黏土矿物、铁矿物、钛矿物组成,其中钛矿物主要为锐钛矿及少量金红石。矿石主量元素为Si、Al、Fe、Ti、Ca、Mg、Na、K、Mn、P等,主量元素及其氧化物含量占矿石化学成分的80%以上,其中w(TiO 2)为6.50%~9.34%,平均6.95%;微量元素有V、Cu、Ba、Zn、Co、Ni、Cr、Sr、Li、Rb、Pb、Cd、Nb、La、Ga、Ge、Be、Ce、Sc、Ta、Th、Tl、Y、Mo、Sn、In、Se、Te、Hf等。峨眉山玄武岩为矿床主要成矿母岩,表生风化淋滤作用可能是TiO 2相对富集成矿的主要原因之一。

Longchang titanium deposit is a large-scale deposit in the west of Guizhou Province,in which there is a total amount of mineral resources of more than tens of million tons.The study result shows that the deposit is hosted in the strong alteration basalt and almond basalt at the top of the third eruption cycle of Emeishan basalt formation.The contents of TiO 2 in ore-bearing strata,overlying strata and underlying strata are more than 2.8%,characterized by high background value of titanium.Ore minerals are mainly composed of iron and titanium minerals,in which the titanium minerals are mainly anatase and a small amount of rutile.The main elements of the ore are Si,Al,Fe,Ti,Ca,Mg,Na,K,Mn,P,etc,accounted for more than 80%of the chemical composition of the ore.The content of TiO 2 is 6.50%–9.34%,with an average of 6.95%in the ore.Trace elements include V,Cu,Ba,Zn,Co,Ni,Cr,Sr,Li,Rb,Pb,Cd,Nb,La,Ga,Ge,Be,Ce,Sc,Ta,Th,Tl,Y,Mo,Sn,In,Se,Te,Hf,etc.Emeishan basalt is the main ore-forming parent rock of the titanium deposit.The surface weathering and leaching process might be one of the main reasons for the relative enrichment of TiO 2.