An om a l .i es of s u l f u r d i ox i de and other gases have been defined, by direct measurement, around various sulfide bodies. These readings were made (1) in soil gas and (2) in the atmos• phere, from both ground vehicles .an d , to a limited extent; from helicopters. Test areas included porphyry copper and molybdenum deposits, sulfide bearing vein 5ystems, pyrite zones associated with sandstone uranium accumulations, and pyrite- bearing mJne dumps. Some of the deposits are covered by as much as several hundred feet of overburden or barren rock, while others outcrop,0or have been exposed by mining operations.

Depending on local conditions, background values of sulfur dioxide in soil gas and the atmosphere range from 1 to 15 parts per billion. Using present techniques, anomalous readings are recognized at approximately two times background. Apparent II de p t' h p e n e t r a t i on II on kn own d e po s i t s h a s r a n g e d to s e v e r a 1 hundred feet. Readings have been made over known deposits from a helicopter and ground vehicle moving at up to 40 mph. The rate at which the survey may be carried out depends largely on the size and extent of the anomaly.

The existence and magnitude o f i s u l f u r dioxide anomalies around sulfide-bearing deposits is a function of geology, target size, soil moisture, and climatic conditions such as temperature and temperature changes, barometric pressure, wind v e 1 o c i t y , a n d p 'r e c i p i t at i on . I n du s t r i a 1 S O po 1 1 u t i on can effectively mask the presence of the anomal i e s sought.

Tidak tersedia versi lain

Tidak Ada Data