The Government has staked a major claim with the UN over Atlantic Ocean seabed rights to offshore oil, gas and minerals covering an area equivalent to over half the size of the country.
Ireland's claim will be considered by a seven-strong special commission of the world body in August.
The extension of sovereignty to cover these huge new tracts of the continental shelf could lead to the exploitation of massive sub-sea riches by future generations.
Ireland is only the fourth country in the world to have lodged a claim of this kind after Australia, Brazil and Russia.
A further even larger offshore claim is planned by the Government after boundary disputes have been resolved with Iceland and the Danish-owned Faeroe Islands over parts of the Atlantic in the north, and with France and Spain over parts of the Celtic Sea in the south.
The UN body will not consider any claim from a country if ownership of the seabed involved is counter-claimed by another state.
Foreign Affairs Minister Dermot Ahern said work on the preparation of Ireland's UN submission began over 10 years ago.
"Extensive seismic and bathymetric surveys of the extended shelf claimed by Ireland were conducted on behalf of the Department of Communications, Marine and Natural Resources in 1995 and 1996.
"Detailed consideration and analysis of this data followed and more recently the question of how to handle submissions for the two disputed areas of shelf has been the subject of two separate sets of consultations with the states concerned," he said.
The Cabinet gave the go-ahead to submit a partial submission to the UN Commission on the Law of the Sea in respect of the undisputed area of the extended continental shelf under the Atlantic alongside an area known as the "Porcupine Abyssal Plain".
That submission was lodged with UN Secretary General Kofi Annan on May 25th, the Minister told Labour TDs Seán Ryan and Joe Sherlock.
The claim covers 39,000 square kilometres of seabed which is equivalent to almost half of the country's land area of 69,930 square kilometres.
As the technology for exploiting finds under the seabed in deep waters develops, the new claim will mean that the country could reap an extra bounty in offshore minerals, natural gas, oil, diamonds and gold as well as less valuable gravel, coral and sand deposits.
Ireland and Britain agreed on the borders of disputed areas of seabed in 1988. Since 1968 Ireland has had seabed rights running up to 200 miles out from the shore.
The eventual new claims will allow extension of this out to up to 350 miles in a move that will involve sovereignty over huge extra tracts of the Atlantic.
The issue of who has jurisdiction over Rockall does not affect any seabed claim.
Originally there had been fears that ownership of Rockall and similar rocks would be a crucial factor in offshore seabed claims.
But at international conferences between 1973 and 1982 it was agreed that rocks which cannot sustain human habitation or economic life of their own would have no bearing on claims to the seabed or fishing rights around them.
However, Britain still lays claim to jurisdiction over Rockall.
"This claim is not accepted by Ireland. Each country remains aware of the position of the other," the Minister said.
Ireland is among an estimated 60 states around the world that have substantial areas of continental shelf off their coasts that entitle them to seek extra exploration acreage.