Coastal sands between Nizampatnam and Lankavanidibba near the estuary of the river Krishna contain as many as 20 heavy minerals of high commercial value. They include titanium, zirconium and rare earths

Syed Akbar
Hyderabad:  The coastal sands between Nizampatnam and
Lankavanidibba near the estuary of the river Krishna contain as many
as 20 heavy minerals of high commercial value. They include titanium,
zirconium and rare earths.

Researchers from Andhra University, Visakhapatnam and Yogi Vemana
University, Kadapa, have found that heavy minerals spread over an area
of 1825 sq km along the estuary of the river Krishna. As many as 60
transects (locations) have been identified along the 24 km stretch
between Nizampatnam and Lankavanidibba in Guntur district.

The research team comprised Dr KSN Reddy, D Deva Varma, EN Dhanamjaya
Rao and B Veeranarayana of Andhra University, and T Lakshmi Prasad of
Yogi Vemana University.

“The beach sands, deposited by the river Krishna, contain Ilmenite and
magnetite (47.67 per cent), pyriboles (20.35 per cent), garnets (3.66
per cent), epidote (3.23 per cent) and sillimanite, zircon,
staurolite, kyanite, apatite, spinel, monazite, biotite, topaz,
leucoxene and chlorite in less than three per cent concentration,” Dr
KSN Reddy said. Ilmenite is a titanium-iron oxide mineral, useful in
the production of titanium oxide.

The researchers divided the area into seven sectors for purpose of the
study and found different concentration of heavy minerals in them. The
sectors nearer to the river mouth contain high concentration of high
specific gravity heavy minerals like ilmenite and magnetite than those
away from the river mouth.

Sector I has the highest concentration of heavy mineral, which ranges
from 12.47 to 31.42 per cent. The dominant heavy minerals are ilmenite
(34.88 per cent). This is followed by sector II with heavy mineral
concentration ranging from 12.73 to 29.75 per cent. It contains
ilmenite, magnetite, pyriboles, besides gemstones like garnet and
zircon.

 “Ilmenite, magnetite, pyroxenes, amphiboles, garnet, epidote and
sillimanite are heavy mineral assemblage in the Nizampatnam-
Lankavanididda area. The wave processes are mainly responsible for
heavy mineral concentration and the redistribution of heavy minerals
along the coast is by alongshore currents and creek dynamics,” said Dr
Reddy added.