The phrase 'massive conversion' is correct and usable in written English.
You can use it to refer to a large-scale conversion from one use or purpose to another. For example, "The company is undergoing a massive conversion to become more energy-efficient."
In California, this is certainly the case, with the massive conversion of many agricultural lands to production of almond.
China dominates the global growth in aquaculture food production, primarily through massive conversion of paddy fields to crab ponds.
His father, a plumbing and heating contractor who had a drinking problem, had a "massive" conversion experience, one that Father Duggins honors.
What will survive is the rapid and massive conversion of local authority-maintained schools into self-governing academies, promoted by Gove.
The sport faced potent competition, not only from other professional sports (especially gridiron football) but even more from a massive conversion of Americans from public to private, at-home diversions.
But Lark Hayes, a lawyer for the Southern Environmental Law Center, based in Chapel Hill, N.C., said that while urbanization was clearly a factor in the destruction of forests, there were other major threats as well, particularly by what she called the "massive conversion" of forestland to pine tree plantations.
They swept into the highlands, drove the Ethiopian emperor into exile, forced massive conversions, and by 1533 controlled most of central Ethiopia.
The government has undertaken massive conversions of state-held shares to tradable shares in various state-owned enterprises this year.
The 15 years of guerrilla warfare led to massive conversions to Christianity.
Not only is there "no evidence of massive coercive conversion" to Islam, but also so much of what we know as popular Hinduism — the currently popular devotional cults of Rama and Krishna, the network of pilgrimages, ashrams and sects — acquired its distinctive form during Mughal rule.
And this is the absolutely last chance for a massive Roth conversion.
