滇西武定大矣波辉绿岩体岩石学及产出特征研究  

A Research on Petrology and Output Characteristics of Dayibo Diabase in Wuding of Western Yunnan

作　　者：杨德敏[1,2] 刘陈明[1] 张世涛[2] 马绍春[1] 

机构地区：[1]云南国土资源职业学院,云南昆明650093 [2]昆明理工大学国土资源工程学院,云南昆明650093

出　　处：《中国锰业》2016年第6期67-70,73,共5页China Manganese Industry

摘　　要：武定县大矣波辉绿岩体是该区钛铁砂矿重要含矿母岩,一直以来认为是侵位于泥盆系中统缩头山组（D2s）地层,其时代为华力西期。但是笔者在该区野外工作中首次发现很多地质现象揭示该岩体的侵位地层、侵入时代可能要重新界定,提出该岩体的侵位地层为三叠系晚期舍资组地层（T3s）,侵入时代可能为燕山期,依据如下：1.在紧邻岩体接触带附近的三叠系晚期舍资组地层（T3s）底部含豆状赤铁矿砂岩具有明显磁性异常,野外现场测试能明显大幅度引起罗盘小磁针偏转;2.露头上覆盖在岩体之上的三叠系晚期舍资组地层岩石发育多处明显穿层节理,有平行排列特征;3.岩体接触的北东、南西两侧三叠系晚期舍资组地层（T3s）产状明显相对（北东倾向55°∠20,南西倾向230°∠26）;4.在该区远离岩体的三叠系晚期舍资组地层（T3s）,在同样底部有含有赤铁矿层（鲕状赤铁矿）取手标本样,野外实测不具有磁性。室内对同期沉积的含豆状（鲕状）赤铁矿砂岩岩石标本进行高精度磁测,紧邻岩体岩石标本磁化率为其他的10-200倍;上述依据揭示出该岩体同围岩为侵入接触关系。Dayibo Diabase in Wuding is an important Ore-bearing rock of the llmenite placer. It has always been considered to be emplaced in Suotoushan formation of Devonianstrata. It is time for the Variscan. But the author has found that a lot of geological phenomena reveal the emplacement of the rock formation and the times of the invasion may have to be redefined. It proposes that rock invade stratum is Shezi formation of Triassic and the age of invasion may be phase of Yanshan, which is based on the following： 1 ） There is Bean - shaped red iron ore rock with significant magnetic anomalies at the hematite of Shezi formation stratum of Triassic bottom at the rock contact zone in immediate vicinity. It will obviously cause small compass needle deflection in the field test; 2 ） There are layer joints on the formation stratum of Triassic rock that overlies on the rock outcrop. They are parallel features; 3 ） The attitude of stratum is the opposite in the formation of Triassic （ Netendency 55 （ ° ） ∠20 , SWtendency 230 （ ° ） ∠26） at the rock contact zone in the immediate vicinity; 4） The hematite of the formation stratum of Triassic bottom in places far from the rock will be nonmagnetic in the field test. For the same period in the deposited containing lenticular （oolitic） hematite rock samples, we get on precision magnetic survey indoors. The magnetic susceptibility of rock contact zone is 10 -200 times to others. The basis of the above reveals of the diabase is intruded into the surrounding rock.

关 键 词：辉绿岩体 武定 地质特征 赤铁矿 磁异常 舍资组 

分 类 号：P618.13[天文地球—矿床学]