July 15, 2004

TERTIARY DISCOVERS NEW KIMBERLITE BODY AT FINNISH DIAMOND TARGET

• Two Separate Kimberlites Intersected In Drilling Of Same Prospect
• Samples Now Being Laboratory Evaluated For Microdiamonds
• New Aeromagnetic Anomaly 20km Away To Be Drilled Next Month
• Company Enlarges Search Area To Take In 21 Targets

AIM-listed Tertiary Minerals plc announces today that it has intersected two separate kimberlitic bodies in the first hole of its diamond exploration project in the Karelian Craton of Finland.

The objective of drilling was to test a ground magnetic anomaly that, based on previous exploration reports, was believed to reflect a small kimberlite pipe or dyke. This hole confirmed the presence of massive hypabyssal kimberlite (Group I geological characteristics) from 71.55m to 98.43m down-hole. Unexpectedly, the hole also intersected a second kimberlite (Group II geological characteristics), between 51.35m and 59.85m down-hole.

This second kimberlite differs from the first in that it is micaceous, contains visible kimberlite indicator minerals, is only slightly more magnetic that its host rocks and may be significantly older that the massive kimberlite, says executive chairman, Mr Patrick Cheetham. This second kimberlite was not encountered in earlier drilling, he adds.

A second, larger diameter hole was drilled adjacent to the first for sampling purposes. This returned a further intersection of the Group II kimberlite from 46.41m to 48.75m down-hole where the hole reached the technical limit of the small drill rig used. Samples of both kimberlites have now been sent to independent diamond laboratories for an evaluation of microdiamond/indicator mineral content and chemistry.

The presence of two types, and possibly two distinct generations, of kimberlite is particularly encouraging for the wider distribution of kimberlite in the project area and more generally in this underexplored part of the Karelian Craton, comments Mr Cheetham.

Some 20km away, a ground magnetic survey has defined the surface position of a similar aeromagnetic target which Tertiary plans to drill test in August.

“In view of the early success being generated by our diamond exploration programmes, the company has applied for further claim reservations and now has 21 targets under claim or claim reservation”, says Mr Cheetham. All lie within the Karelian Craton, a block of ancient crustal rocks with all the characteristics necessary to host and preserve diamondiferous kimberlites. It extends into Russia where it hosts the world-class Arkhangelsk diamond deposit.

Further Information: Patrick Cheetham, Tertiary Minerals:
Tel: 01625-626203

Ron Marshman/John Greenhalgh, City of London PR Ltd.
Tel : 020-7628-5518