Page 72 - Geochemical Remote Sensing of The Sub-Surface

Geoelectrochemistry and stream dispersion 49

C/~m~
1 . . . . . . . . . . . . . . . . . . . ,a ..... = .....
i o
0.5 9 Ca

iv I I :1 I I I I
0 10 20 30 40 50 60
x,hour
c/~
.
[ ............ I ..... .-~ =' ......

0.5 A I : ~ ~ I I I iCo

0 10 20 30 40 50 60
x,hour

Fig. 2-27. Curves of accumulation of the macrocomponent (Ca) and microcomponent (Co) in a
MDE element collector from samples of surface sediments of different composition: 1- water-
saturated peaty sediments; 2- clay rocks; 3- loamy sands (from Testury, 1996).

survey does not detect these ore bodies (Fig. 2-31A) whilst the MDE survey yields good-
contrast copper anomalies over the ore bodies (Fig. 2-31B).
The Korbalikhinskoe deposits (Rudny Altay) are blind cupriferous pyrrhotite and
polymetallic ore bodies in bedrock patchily covered by soft autochthonous sediments 5-
10 m thick. The ore bodies take the shape of ribbons and lie on the contact of acid tufts,
tuff-sandstones and aleurolites at depths of 75-350 m in the southeast of the area and
500-1000 m in the northwest. The MDE results for copper and lead concentration
distribution allow the detection of the ore bodies at depths of 75-450 m. A cupriferous
ore body corresponds to a copper anomaly (Fig. 2-32, southeast), whilst the polymetallic
ore bodies correspond to anomalies of copper and lead (Fig. 2-32, northwest).

Organometallic (MPF) and thermomagnetic (TMGM) patterns

The MPF and TMGM prospecting methods are based on the use of metallo-organics
(fulvates and humates of metals) and oxides of iron and manganese (metals bound in
oxides and hydroxides of iron and manganese). These forms of metals are the result of
the secondary fixation of the movable forms in rocks and have features such as (1)
increased concentration coefficient and (2) only a weak bond with their initial geological
source (in comparison, for example, with the movable forms collected in CHIM and
MDE). Samples for MPF are taken from the humus-enriched layer at a depth of 5-10
cm, and samples for TMGM are taken from the sand-clay layer at a depth of 15-20 cm,