Page 188 - Introduction to Mineral Exploration

8: EXPLORATION GEOCHEMISTRY 171

(a)
+ + + +

+ +
N +
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+ + 183
+
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Aughrim
+
+ +
+
+
+ + 305
+ + + +
+
+ 0
+ + 183
+
+ 110
+ + 0
+ +
+ +
Ballinglen
+ + 300
+ 305
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+ 183 183
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+
+
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+ 183 0 + +
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+ Tinahely + + +
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+ + Granite Microgranite River

Palaeozoic sediments Microgranite (inferred) 183 Height above sea level (m)
Deep overburden tungsten 0 2km
Soil traverse
anomalies (>20 ppm W)

FIG. 8.14 (a) Regional geochemistry of the Ballinglen tungsten prospects, Co. Wicklow, Ireland. Detailed
dispersion through overburden and soil response are shown in b and c. (From Steiger & Bowden 1982.)

associated with microgranite dykes, which are in delineating the dykes using arsenic and to
also significantly enriched in arsenic and lesser some extent copper and Fig. 8.14b demon-
copper and bismuth. Regional base of over- strates the movement of elements through the
burden sampling (usually 2–5 m depth), which overburden. Tungsten is very immobile and
was undertaken as the area has been glaciated, merely moves down slope under the influence
clearly delineates the mineralized dykes (Fig. of gravity whereas copper and arsenic are more
8.14a). Surface soil sampling was also effective mobile and move further down slope. The