Sir Wilson Harris, who has died aged 96, was a towering figure among the writers of the Caribbean and Central America. Concerned with the human condition, in particular with the marginalised, Harris sought a revolution in form as well as approach. The writing style he developed succeeded in conveying what William Blake called “fourfold vision”: grounded in the real world, transformed by metaphor, cultivating empathy, and having a universal perspective.

It was while working as a surveyor in Guyana in the 1950s, discovering the enigmatic silences of remnant Amerindian cultures and the haunting landscapes of the rainforests, that Harris pioneered his individual and expressive voice, first revealed in poems published in Georgetown in the magazine Kyk-Over-Al and later in a privately printed collection, Eternity to Season (1954).

On a visit to London he met his future second wife, Margaret Whitaker, and he moved to England permanently in 1959, when they married. He had already experimented with the novel form before leaving. However, it only became clear what power sprang from Harris’s newly forged language when his first novel was published in London by Faber and Faber, which went on to publish all his subsequent novels.

Palace of the Peacock (1960) describes a racially diverse crew driven by their obsessive and domineering leader to pursue an elusive “folk” towards the upper reaches of a rainforest river, as far as the ultimate barrier of a waterfall. Harris makes it clear that their journey is towards a death that has already occurred, but which they can still revise. The protagonist, the dictatorial man of action Donne, is also the sensitive and reflective narrator, and indeed the whole crew. What he is in fact pursuing is a resource of human potential – muse, increasing awareness and relationship with the natural world. Harris created “thought-plots”, here and in later fiction, to overcome the restrictions of time and space.

Harris was born in the small community of New Amsterdam, in what was British Guiana and is now Guyana. His mixed ancestry reflected the diverse interaction of cultures and races in Britain’s only colony on the South American mainland. His father, an insurance broker, died when he was two, and his stepfather disappeared, believed drowned, in the rainforests in 1929. This and other childhood memories were to influence the themes of his future fiction. Georgetown, the capital, to which the family had moved in 1923, was a provincial and racially divided place, yet Harris found educational opportunities at Queen’s college. After leaving Queen’s in 1937, he trained as a surveyor, and subsequently led expeditions charting the great rivers of the Guyanese interior and their effects on the flood-prone coastlands.

After publishing his first poetry, Harris found it “impossible to stay in Guyana and write – there were no publishers in the West Indies”. Once he was in Britain, Palace of the Peacock was followed by three further works set in Guyana and its interior, The Far Journey of Oudin (1961), The Whole Armour (1962) and The Secret Ladder (1963), subsequently published together as The Guyana Quartet, establishing their author’s reputation as a leading figure in postcolonial literature.

One thing that set Harris apart was the breadth of his vision. He was interested in physics, anthropology, mythology, alchemy and the pioneers of the unconscious, particularly Carl Jung. He also warned against the trap of victimhood in postcolonial fiction, which could lead the oppressed to become as prejudiced as their former oppressors.

Harris’s work, meanwhile, was striking out in new directions. After three transitional and experimental novels, Heartland (1964), The Eye of the Scarecrow (1965) and The Waiting Room (1967), his writing with a Guyanese setting reached an extraordinary climax in Tumatumari (1968) and Ascent to Omai (1970). A sequence of short stories with Amerindian themes then led to a series of books set in Britain, in which Harris engaged with wider themes of colonialism and postwar immigration, and beyond them with the clash between materialist and spiritual values.

Black Marsden (1972), introducing a set of powerful and shifting characters, was set primarily in Edinburgh, while Da Silva Da Silva’s Cultivated Wilderness (1977), The Tree of the Sun (1978) and The Angel at the Gate (1982) were set in London, where the author had made his home near Holland Park. In the middle of these, Companions of the Day and Night (1975), inspired by a visit to Mexico, signalled great empathy with the neglected achievements of the pre-Columbian arts of Central America.

Harris’s prose style, which had been in danger of becoming mannered by the end of The Guyana Quartet, had by now developed a breathtaking palette, as was confirmed in a triumphant return to the Guyanese landscape in The Carnival Trilogy – Carnival (1985), The Infinite Rehearsal (1987), and The Four Banks of the River of Space (1990) – and Resurrection at Sorrow Hill (1993). At the same time, he engaged with central European works such as The Divine Comedy and Faust.

Faust’s bargain with dark forces within himself forms the implied backdrop of one of Harris’s greatest works, Jonestown (1996). It did not attempt to be a factual account of the Rev Jim Jones’s millennial community in the Guyanese jungle or its appalling end in mass suicide and murder, but an investigation of the roots of evil and power within human personalities and civilisations, and the possibilities of redemption.

Harris was also a prolific essayist, casting unexpected and brilliant light on aspects of his own work or that of other writers and artists, or general cultural and political topics. His last works of fiction, The Dark Jester (2001), The Mask of the Beggar (2003) and The Ghost of Memory (2006), bridge the gap between essay, novel and poem.

He and Margaret were a devoted couple and welcomed many visitors to their homes in London and, later, in Chelmsford, Essex. Margaret died in 2010. In June that year Harris was knighted for his services to literature.

Harris’s first marriage in 1945, to Cecily Carew, ended in divorce. He is survived by his children, E Nigel, Alexis, Denise and Michael, from that marriage, six grandchildren and 13 great grandchildren, and by his sister Daphne.

• Theodore Wilson Harris, writer, born 24 March 1921; died 8 March 2018