contact alteration

基本解释

Of the various types of deposit, the porphyry type occurs within first stage granite-porphyry and at its contact zone where alteration and mineralization zoning is apparent;
斑岩锡矿主要产于花岗斑岩岩筒内部及其接触带，蚀变与矿化具分带现象；
In any case, for the signal to pass through with minimal alteration, the contacts within the connector must maintain good contact force and resist corrosion over the life of the contact.
在任何情况下，对于需要传递而只允许最小限度变异的信号而言，连接器内的触点必须接触良好并能在接触期间抵抗腐蚀。
The subaerial and subaqueous volcanic rocks have significant differences in lithology, texture and structure, alteration, occurence, contact with underlying strata, pore and fissure development.
在充分考虑火山岩储层特征和地层非均质性的基础上，运用常规测井信息、气测录井及测井新技术对火山岩储层进行综合评价。