More informationOVERVIEW OF FALCON(TM) AIRBORNE GRAVITY SURVEY...

More information

OVERVIEW OF FALCON(TM) AIRBORNE GRAVITY SURVEY TECHNOLOGY

The FALCON(TM) airborne gravity gradiometer is a revolutionary new
exploration tool which rapidly and economically scans vast areas of
the earth for certain types of orebodies.

Using the same ancient principle that caused Isaac Newton to wonder
why the apple fell from the tree, the Falcon technology can measure
minute density differences between rocks in the earths upper crust.
Dfferent rock types have an identifiable and measurable effect on
the force of gravity.

It has been possible to measure gravity for about 300 years and
increasingly sensitive measurement systems have become common tools
for the modern geophysicist. But, unlike the magnetic and radiometric
signature which the earth produces and which is commonly surveyed
from the air, accurate gravity measurements have only been possible
with cumbersome ground-based instruments.

FALCON(TM) is an offspring of gravity gradiometers developed for the
US Navy by Bell Aerospace Textron (now Lockheed Martin) at a cost of
around US$400 million. The systems are mounted in submarines and
measure the gravity response of the external environment, enabling
the vessel to obtain a picture of the adjacent sea-floor topography.
This allows silent navigation, avoiding the use of traditional echo
sounding techniques which produce a telltale ping.

In recent years this gravity technology has become more accessible
and its existence was recognised by BHP Billitons Project FALCON(TM)
technology team in 1991 during a worldwide search for a gravity
measurement system that could satisfy the geophysicists dream of an
airborne instrument sensitive enough to detect underground orebodies.

The Project FALCON(TM) technology team initiated a feasibility study
in 1993 to identify and solve a wide variety of issues necessary to
allow the instrument to operate effectively in the hostile
environment of a light aircraft. The instrument had to be capable of
measuring gravitational signals that are one ten millionth of the
intensity of the aircrafts motion. To understand this, it would be
like hearing a conversation next to a 747 plane at take-off!

The team began constructing two operational systems in 1995. BHP
Billiton Research staff managed the negotiations, development and
construction of the airborne gravity gradiometer and the development
of data processing and interpretation software. Lockheed Martin built
the instrumentation at its laboratories in Buffalo, New York.

Exclusive rights to the technology for minerals and petroleum
exploration were negotiated for a five year period. This has recently
been extended to 10 yars.

The first system became operational in October 1999 and the second in
April 2000. Once the systems were operational they were tested
against known mineral targets around the world. These tests confirmed
that FALCON(TM) could accurately and rapidly measure gravity from the
air and identify the location of mineral deposits. By discovering
several previously unknown kimberlite pipes in BHP Billitons diamond
leases in far north Canada, FALCON.... has shown that it can perform
tasks well beyond its original design.

The first two units, dubbed Newton and Einstein, are deployed in
Cessna Grand Caravan aircraft owned and operated by Sander
Geophysics, under an exclusive contract with BHP Billiton.

BHP Billiton is currently building two additional units. The first,
called Galileo, will also be mounted in Cessna Grand Caravan
aircraft to be operated by Fugro Survey Pty Ltd under an exclusive
contract to BHP Billiton and will be deployed in Australia. The
second will incorporate the latest digital technology that will allow
the physical size and weight to be reduced. It will be called
Feynman, completing a quadrella honouring physicists who have
changed the worlds scientific direction.

Geophysical tools have assumed a major role in mineral exploration in
the past 50 years, with airborne magnetic and electromagnetic surveys
considered a vital part of modern exploration. Gravity surveys, until
now, have been restricted to ground-based operations with lrge-scale
surveys taking considerable time and therefore forming a relatively
expensive tool.

Gravity surveys have traditionally been key tools in mineral
exploration. However, ground-based surveys are slow and expensive.
FALCON(TM) surveys are substantially faster and less expensive under
most terrain conditions. High-resolution gravity surveys, until now
restricted by cost and speed to small areas, with FALCON(TM) have
become a regional exploration tool.

For further information contact:

In Melbourne: In Perth:
Phil Harman or Nic Limb Dave Isles
Gravity Capital Limited
Tel: (03) 9909 7655 Tel: (08) 9321 2062

Falcon Website: http://bhpbillito.com//bb/falcon/falcon.asp