�ٲݹ����λ�����������—С���ϲ�dz�ɵ�����Һ�ͽ�- -������ɿ�����ÿ��ݿ�Χ����ҪΪ���������ң������ϸ��� NW �����Լ��д����ơ�����ʯӢ����������巢����Һ��������壬��Ҫ�ɷ�Ϊˮ����Һ�� 15% �� 30%����СΪ 2 �� 12 μm����һ�¶�Ϊ 154. 3�� �� 345. 2 �棬�ζ� w (NaCl)2. 73 ��19. 71 wt%NaCl���ܶ� 0. 63 ��1. 00 g/cm 3 �����ֳ����¡��е��ζȡ��е��ܶȡ��ζȱ仯��Χ���������ͨ�����㣬�ɿ�ѹ��Ϊ 14. 70 ��47. 16 MPa���ɿ����Ϊ 1. 47 ��5. 46 km���ٲݹ���� δ 13 C CO 2 �仯���Ǻܴ󣬽��� �� 6. 7‰ �� �� 4. 6‰֮�䣬��ʾ���Դ�Ŀ���; ������ 34 S ֵΪ��1. 9‰ ��1. 9‰��˵���ɿ��������Դ�ԡ��ɿ���׶�����Ϊ�е��ζȵ��������壬���ɿ�׶����ڴ�����ˮ�Ļ��룬�����¶����ζȿ����½������ݱ�Ϊ���¡����ܶȵ���ˮ��Һ��Χ��ʴ���Ա���ʯ����̼���λ��ȵ���ʴ�����Ϊ�����ٲݹ�������ڵ�����dz�ɵ�����Һ�ͽ�󴲣��γ���̫ƽ������ŷ�ǰ�鸩������չ���챳����

Baicaogou gold ore deposit is located in the famous Wufeng- - Xiaoxinancha metallogenic belt of epi- thermal type gold- polymetallic ore deposits�� The main host rocks of this deposit mainly are granodiorite�� Ore bodies are strictly controled by ductile shear zone of NW�� Ore fluid inclusions in quartz developed gas- liquid two- phase in- clusions��and the main ingredient is water�� The gas- liquid ratio is from 15% to 30% and the size is of 2 ��12 mi- crons�� The homogenization temperature of gas- liquid two- phase fluid inclusions is 154. 3�� ��345. 2�棬with salint- ity 2. 73 ��19. 71 wt%NaCl and density 0. 63 ��1. 00 g/cm 3 ��which shows the characteristics of epithermal��inter- mediate- low salinity��medium- low density and a wide range of salinity�� The metallogenic pressure is 14. 70 ��47. 16 MPa��and the calculated metallogenic depth is 1. 47 ��5. 46 km�� The change for δ 13 C CO 2 is not very obvious��be- tween 6. 7‰ ��4. 6 ‰ in Baicaogou gold ore deposit��which indicates that the fluid may come from deep source�� The 34 S value in Sulfide is ��1. 9‰ ��1. 9 ‰��which suggests metallogenic series of S isotope owning deep source property�� In early metallogenic phase��ore- fluid was low- salinity and medium- temperature in main metallogenicstage�� the fluid mixed with atmospheric precipitation�� which caused rapid decline in temperature and salinity�� final- ly evolved into the low temperature and low density saline solution�� The main wall rock alterations are adularization and carbonatation�� Baicaogou gold deposit belongs to low sulfide epithermal gold deposit��and formed under an ex- tensional environment similar to back- arc basin which could be related to subduction of the Paleo- Pacific plate be- neath the Eurasian continent��