The phrase "ago formed" is not correct and usable in written English.
It does not convey a clear meaning and is not a standard construction in English.
Example: "The organization was formed long ago."
Alternatives: "previously established" or "created in the past."
A Plinian eruption ca. 2 ka ago formed the widespread deposits of the Masaya Triple Layer.
Here the family had long ago formed an alliance with the Wahhabi religious revivalists, who espoused a puritanical Islam.
Ag2O and AgO formed by potentiostatic oxidation of silver in 0·1N KOH have been chemically analysed for the mean valency of silver ion.
A pioneering touchstone of metal's extreme wing, it long ago formed a closed circuit for itself, a system of structural convolution.
Behind the coastal fringe lies the equatorial forest zone that until a century ago formed a continuous area more than 125 miles (200 metres) wide.
The dunes are interspersed with hardened flat plains – remnants of shallow lakes that existed thousands of years ago, formed by monsoon-like rains and runoff.
India eventually collided with Eurasia approximately 50 million years ago, forming the Himalayas.
The volcano is actually just a remnant on the edge of huge Mount Tehama, which collapsed thousands of years ago, forming the fascinating caldera defining the surrounding mountain formations.
Terrestrial deposition continued in those rifts and in the surrounding areas, with local interruptions, until early in the Cretaceous Period (about 145 million years ago), forming the Gondwanan deposits.
The characteristic part of Australia's plant life that is little shared with other lands, together with those specialized characteristics that apparently originated on the continent long ago, form what has been designated as an Australian (or autochthonous) element.
Bush announced 5 years ago forms a kind of matched set with the conviction, widely held by those who dislike Bush and his policies, that the Administration conspired to use the 9/11 attacks to launch an unrelated military adventure.
