Liªn ®oµn §Þa chÊt T©y B¾c:

§Þa chØ: thÞ x· Phó Thä, tØnh Phó Thä
Tel: 210.820054; Fax: 210.821029

§¸ phiÕn silic ( tuæi O-S ) bÞ phong ho¸
Weathered siliceous schist (aged O-S)