P. Joint Venture Agreement

Tertiary Minerals PLC
06 September 2007


                             Tertiary Minerals plc

6 September 2007

    JOINT VENTURE AGREEMENT SIGNED WITH INMET MINING CORPORATION ON VAHAJOKI
                          COPPER-GOLD PROJECT, FINLAND

   • Inmet Must Spend €I Million Over 39 Months To Earn 75% Interest

   • IOCG Target Identified by earlier Tertiary Regional Programme

   • Immediate Start To Exploration Work At Vahajoki
___________________________________________________________________

Tertiary Minerals plc ('Tertiary' or 'the Company') is pleased to announce that
it has signed an earn-in/joint venture agreement with Inmet Mining Corporation
('Inmet') regarding Tertiary's Vahajoki copper-gold project in the western
Lapland region of Finland.

Inmet is a mid-tier TSX-listed Canadian mining company which owns and operates a
number of base metal and gold mines in Turkey, Canada and Europe including the
Pyhasalmi copper-zinc mine in Finland. In 2006 Pyhasalmi produced 15,000
tonnes of copper, 35,700 tonnes of zinc and over 500,000 tonnes of pyrite.

Under the terms of the agreement an Inmet Mining Corporation subsidiary, 
Pyhasalmi Mine Oy ('Pyhasalmi') will be entitled to earn a 75% interest in 
three mineral claims held by Tertiary Minerals at Vyhajoki by sole funding
exploration costs totalling €1,000,000 before 31 December 2010 (including
€150,000 before 31 December 2008 and €500,000 before 31 December 2009). Once
this total expenditure has been met Tertiary may elect to contribute its 25% of
further expenditure in joint venture with Inmet or convert its interest to a
2.5% Net Smelter Return royalty.

Tertiary's Vahajoki project comprises three claims and is one of a number of
projects generated from a regional Iron-Oxide-Copper-Gold ('IOCG') exploration
programme in northern Finland and Sweden which started in late 2002. Iron
mineralisation was first discovered at Vahajoki in 1938 and drilled by three
different companies between 1943 and 1982. Numerous discrete iron-oxide
(magnetite)-breccia replacement deposits occur in a 1.5km x 3.5km area
associated with a N-S shear zone cutting metasediments and volcanics of the
Perapohja schist belt. Whilst previously considered uneconomic as a stand
alone iron resource, several drill intersections reported by earlier explorers
demonstrate a clear association of copper and gold with the mineralisation,
including :

Hole        Down Hole    Down Hole   Down Hole   Copper       Gold        Iron
No.         From         To          Interval    (%)          (g/t)       %
           (meters)     (meters)    (meters)          

R29           29.7m       86.9m        57.2m     0.43%Cu   0.46 g/tAu   25.8%Fe
R30          103.2m      121.3m        18.1m     0.43%Cu   0.49 g/tAu   29.1%Fe
R31           80.8m      121.5m        40.7m     0.27%Cu   0.33 g/tAu   25.8%Fe

Recent academic work has confirmed the mineralisation is of the IOCG type, which
includes some of the largest copper-gold and uranium deposits in the world,
including Olympic Dam in South Australia.

Inmet is planning an immediate start to evaluation of the copper-gold potential
at Vahajoki with geophysics and drill testing.

Other IOCG projects still held by Tertiary include Ahmavuoma (Cu-Au - N. Sweden)
and Sivakkalehto (Iron - Kolari, Finland) where the company has just announced
plans to start drill testing a prime iron ore target at Sivakkalehto (see
announcement of 5 September 2007).

'This agreement is part of Tertiary's initiative to rejuvenate and expand the
Company's activities in its traditional Nordic base', said chairman, Mr Patrick
Cheetham, today. 'It means we are generating new prospects whilst awaiting a
satisfactory outcome in Saudi Arabia to our application for renewal of the
exploration licence over the Ghurayyah tantalum-niobium project', he added.

Further info:

Patrick Cheetham, Executive Chairman, Tertiary Minerals plc. 
Tel: [phone]
Ron Marshman/John Greenhalgh, City of London PR Limited. 
Tel: [phone]
Jonathan Wright, Seymour Pierce Limited 
Tel: [phone]

Note:
The information in this release has been compiled and reviewed by Mr. Patrick
Cheetham (MIMMM, MAusIMM) who is a qualified person for the purposes of the AIM
Guidance Note for Mining Oil & Gas Companies issued on March 16, 2006. Mr
Cheetham is a Member of the Institute of Materials, Minerals & Mining and also a
member of the Australasian Institute of Mining & Metallurgy.




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