'Black Shiver Moss' is a far from prosaic title for a volume of poetry.

As an indicator of mood, it could be a well-placed fictional construct, designed to introduce a sense of foreboding.

But it is actually a proper noun; a real place, high up on a plateau below the Yorkshire Dales peak of Ingleborough, and concealing the subterranean maw of 'Black Shiver Pot' beneath a porous bedrock of limestone.

And it can be bleak, particularly in winter.

Not that Graham Mort's latest collection is unremittingly bleak. There is a fecundity to the poems which almost overwhelms the senses; enough physical, floral and animal drama to call the tableau intransigent, were the rhythms of Mort's style not so seductively comforting.

The ebbing and flowing of lines induce a sense of enjambment even where full stops punctuate the thought train. A blackbird's 'cadenza' in the opening poem, 'Waking in Picardy' is a precise figure not only for the free-form rhythm of the bird's dance, but for the poem's insouciant vigour.

And movement: the poem conjures an affirmation of endurance, growth and survival through the ongoing movement of words.

The text proceeds, in places, at a train's pace of observation, pausing for breath only at wheezy junctures of metrical change or reversal.

There is a febrile beauty in some of the images Mort collects on the way: 'damselflies glisten, sex to sex / promiscuously winged'. And all of the exacerbated wilfulness of nature's surplus emergent in that state of semi-awareness which precedes awakening ('Waking in Picardy').

The extended metaphor Mort uses, in this poem, to describe the imagination's 'waiting' for full consciousness, is submarine, and is redolent of the anthropomorphism of Ted Hughes: 'pike sunk into green, camouflaged / in striped, eternal patience; / their sag-belly grins hatch under / clouded water, below the bloomed / skin of wakefulness'.

And again, in 'Froglet', a tiny animal becomes a silent titan of the underworld, watching and waiting: 'a dwarf god growing / into lordship of its world, / peering at thunder clouds'.

There is anthropomorphism, too, in Mort's frequent use of the fire motif.

Accompanying his journey of memory through the UK, France and contemporary South Africa where the poet has lived and worked, fire directs, describes, and sometimes distils economy and simplicity from inventories of loose threads.

In the incandescent 'An Old Flame', fire roars across borders and time in a relentless inscribing of metaphors, which, as the psychoanalyst-philosopher Gaston Bachelard found, are the primordial building blocks of fire's linguistic serviceability.

The power to destroy and create, wrapped in the Promethean gift of flame, encompasses 'a torchlit carnival, a feast of flyblown wedding meat' as easily as embodying the promiscuity of hate in 'tyre necklaces'.

In this brilliantly effective poem Mort explores the kinds of binary opposition which are integral to Tony Harrison's entire oeuvre, and like Harrison, he seeks resolution in fire's paradoxical power to clarify. He finds it in the power of apostolic tongues of fire - progenitors, in Harrison's words, of 'glossolalia and dulciloquy' - now 'rising' to ignite 'a new language' from an irony of 'breech and muzzle'.

There is a powerful suggestion, especially here but also in the fine poem 'Diablo', of Louis MacNeice's seminal 'Brother Fire'. The relishing of the language of fire for its own sake - it's power to move with alacrity, to consume and overtake like a wild and feral animal - is almost overwhelming.

Another extended fire metaphor, 'Diablo', re-doubles Mort's mandate. The poem concludes in a cremation of the imagination where the poet's work, his language, is burnished for posterity, and incandescent words are given reinvigorated meaning.

Mort's characteristic, and astonishingly acute, use of the verb form infuses mood and tone into narratives of existential confusion and anxiety. The austerity of the South African townships and the harsh, unremitting heat of the landscapes in which they endure, are places where sounds 'cauterize' and time 'exfoliates' ('Last Day in Orbs'), and where a politics of questionable success might be described in a metonymy of newly burned, ashy plains, as viewed from an aeroplane.

Elsewhere, that dark before dawn when the mind is at its lowest ebb is 'assassinating' to the spirit, where thought of loved ones is the consolation of 'kindling' ('Saving Daylight').

Some of the poet's own preoccupations - spectral presences just out of reach, the dead calling back to the living - create moments of elegy in a narrative of uncertainty.

'Spectre' occupies a liminal space between past and present where the narrator addresses the synaesthesias of 'your future life' as though to underwrite a desperate need for continuity, whilst 'La Maison Bleue' recalls the past from the perspective of a revenant apostrophising the present in order to restore lost memory.

It seems clear that intimations of personal mortality shape the direction of several of the poems. 'Bypass', with its easy innuendo, is a profoundly disconcerting, and finally moving poem, which follows another 'revenant' on a drive home to announce his continued existence to a wife who knows he is six years dead. 'Bisoprolol Fumarate', also the name of a form of heart medication, precedes 'Bypass', and yields an illustration of fragility and finitude in a frighteningly claustrophobic metaphor: the heartbeat 'that faint ka-boom / of hatches clanging on a sunken hull, / doors closing in a darkening room'.

Graham Mort's closely observed and beautifully wrought incantation works by gradual accretion on the receptive mind. Aided persuasively by a choice of poetic forms which induce a kind of reader narcosis, the poet is sometimes able to render topographical and cultural differentials subordinate to the sound of the words which describe them.

This is not to suggest that the toponyms of the Yorkshire Dales, the Lake District, Spain, South Africa and Italy are without unique identification. Mort's aerial sense of geographical liberation does not dissolve boundaries of detail or immensities of experience; rather does it release meaning where it is most necessary.

The simple, harrowing architectural dislocations of the Italian town of 'Amatrice' after the earthquake yield, in the end, a deeply moving, and unspoken, gesture of love - a respecter of no borders:

'Amatrice, they said,
bearing witness, their blue jackets torn at the
sleeves. Amatrice: its leaves shivering,
their palms unreadable, lying still in ours'.