Attached
Sri L anka is a tropical country, w hich is im portant to study the w eathering erosion, transportation
and deposition processescaused by riversand surface running w ater. A ccording to th e geological
tim e scale, these processes w ere evident during th e Q uaternary period. T herefore lots o f
sedim entary deposits are found w ithin th e costal low land and upland regions, and gem bearing
m inerals are found w ithin the highland com plex. These m inerals have been deposited island-w ide
by the process o f river erosion and transportation. Especially the K alu G anga river basin is
prom inent for the sedim entation o f gem bearing m inerals.A ccording to the paleontological
evidence in Sri Lanka, there is a stratigraphy o f gem -bearing sedim ents in the K alu G anga river
basin in term s o f th e depth o f sedim ents and num ber o f gem -bearing layers. O ur research focuses
onthe study o f this particular stratification pattern in K alu G anga river basin. F or th is purpose, an
investigation w as carried ou t in ten gem m ines representing the m iddle catchm ent o f the river
basin. M ethodology includes G IS m apping, G PS location, sieve analysis, organic content analysis
and pipette analysis. T here is spatial variation in th e num ber and the depth o f gem bearing and
non-gem bearing sedim ent layers in the K alu G anga river basin. It is very im portant to find out
th at tw o gem bearing sedim ent layers belonging to the different geological periods can be found
in the m iddle catchm ent area.Since the lake sedim ents w ere found below the low est gem bearing
sedim ent layer in the catchm ent, it is assum ed that there w as paleontalogical m orphology o f a lake
in the m iddle o f Q uaternary period
