Archaeological Investigations In Ogbodu- Aba (Isi-Uzo Local Government Area, Anambra State) Using Electrical Resistivity Methods

ABSTRACT

E l e c t r i c a l r e s i s t i v i t y p r o f i l i n g was conducted around

Ogbodu-Aba t o l o c a t e suspected s u b s u r f a c e c a v i t i e s of

a r c h a e o l o g i c a l i n t e r e s t . The method employed was t h e Wenner

e l e c t r o d e system and t h e t r i p o t e n t i a l t e c h n i q u e , which involved measuring 3 r e s i s t a n c e s (at a s t a t i o n ) corresponding t o t h r e e d i f f e r e n t e l e c t r o d e arrangements: CPPC, CCPP and CPCP, The

c(+ r e s i s t a n c e s were d e s i g n a t e d as R , R and R* and t h e

c a l c u l a t e d apparent r e s i s t i v i t i e s denoted a s @d , eb and el

r e s p e c t i v e l y ,P l o t s of @N and eS a g a i n s t mi d p o i n t s we r e made For

every t r a v e r s e , while a t h i r d p l o t ; t h e percentage r e s i d u a l

r e s i s t i v i t y ( pd- @ - e* x -11 00 a g a i n s t mi d p o i n t s was a l s o ecx made f o r each t r a v e r s e . The diagrams were s t u d i e d and a f t e r due c o n s i d e r a t i o n s , e i g h t anomalous,zones were d e l i n e a t e d Eased on a v a i l a b l e , r e l e v a n t g e o l o g i c a l and a r c h a e o l o g i c a l i n f o r m a t i o n , t h e anomalies were a t t r i b u t e d t o t h e p o s s i b l presence of hollow c a v i t i e s ( a n c i e n t b u r i a l s i t e s ) i n t h e s u b s u r f a c e . The s i z e s and depths of b u r i a l of t h e i d e n t i f i e c a v i t i e s ranged from 1.5 t o 6m and 0.55 t o 1.5m r e s p e c t i v e l y .