R. Chandrajith et al., Application of multi-element relationships in stream sediments to mineral exploration: a case study of Walawe Ganga Basin, Sri Lanka, APPL GEOCH, 16(3), 2001, pp. 339-350
This study on the application of multi-element relationships in stream sedi
ments to mineral exploration in the Walawe Ganga Basin presents one of the
first of its kind in Sri Lanka. In order to determine the nature of these s
ediments, multi-element analysis of selected grain size (<63 <mu>m, 63-125
mum, 125-177 mum and 177-250 mum) fractions was undertaken. The chemical co
mposition of these fractions were compared with those of the upper continen
tal crust.
Some elements, notably Zr, Hf, Th, U, Ce and La, show very high enrichment
factors (e.g. 54 for Zr) as compared to the upper crustal abundance. These
are presumably associated with heavy minerals such as zircon, rutile and mo
nazite found in abundance in the stream sediments of the Walawe Ganga Basin
.
Principal Component Analysis (PCA) of the geochemical data show that multi-
element relationships could be effectively used to delineate target areas f
or mineral exploration. With the use of PCA, this study reveals that areas
with associations of calc-silicate/marble and charnockitic rocks are probab
le source regions for mineral occurrences, particularly in the axial region
s of anticlines. (C) 2000 Elsevier Science Ltd. All rights reserved.