The phrase "are amassed on a" is correct and usable in written English.
It can be used when describing a collection or accumulation of items or information that is gathered in a specific location or context.
Example: "The resources are amassed on a central database for easy access by all team members."
Alternatives: "are gathered on a" or "are collected on a".
Sent to the local public library for research, I pawed through whatever weirdly idiosyncratic, random collection of "reference" books had been amassed on a particular topic.
While the Taliban number tens of thousands of fighters, and are amassed on the cusp of numerous provincial capitals, the bulk of Isis' estimated 600-800 fighters are tucked away in remote mountains.
"The people in the U.S. Army who are responsible for issuing these solicitations are, almost to a man, completely unaware of the many volumes of data that were amassed on these systems during the cold war," he said.
Moreover, they have been tested these past days, as they have been tested since Australia in January, by what is without doubt the deepest pool of talent ever to be amassed on the men's side.
Netflix has real advantages — the sophistication of its streaming technology, the trove of data it's amassed on viewing habits — but competition will make it hard to boost profits.
The region has been coated in the stuff since the 18th century, when spectacular fortunes were amassed on French- and British-owned sugar plantations worked by African slaves all along the River Road between New Orleans and Baton Rouge.
It now has 3.5 million active users on 8.5 million total downloads, and some 20 million tasks have been amassed on the service in the last two months.
As far as Forbes can figure, the entire amount was amassed on the backs of naive investors who bought penny stocks, first through Brennan's now defunct First Jersey Securities, later through numerous other fronts.
It is rather painful to some of us to think that part of this surplus was amassed on the hardship endured by children.
