The Book of Unconformities has one more twist. When Raffles consults an eminent Icelandic earth scientist about the troublesome stone, he learns that it was benmoreite and that tales of its magic are nothing but folklore. But, the scientist goes on, the magnetic force would not have been powerful enough to cause the disruption; the system failure was a coincidence. Raffles returns to the beach to repeat the experiment and there the chapter ends.

When the next one begins, Raffles has moved on to Svalbard, an island and former whaling colony off the coast of Norway; now he investigates what he calls blubberstone: plastiglomerates partially composed of ancient whale fat.

This is typical of The Book of Unconformities, which is geographically and intellectually peripatetic. An unconformity, Raffles explains, is a ‘physical gap in the geological record, a material sign of a break in time’. The breaks that take Raffles’s attention are not only geologic. He traces his interest in rocks – his use of them as fixed and ancient points in a difficult and unfixed world – to 1995, shortly after the premature deaths of two of his sisters, months apart. He ends the book with reflections on the fact that he wrote it during his mother’s decline into dementia and on his family’s experience of the Holocaust. Human and geologic records, it turns out, are both cracked by rifts that leave us with no firm footing.

Despite the book’s subtitle – Speculations on lost time – the author does not rush to fill lacunae or attempt to sew these rifts together. Instead, he simply attends to them, exploring absences, presenting them to the reader. Raffles’s style lies somewhere between W.G. Sebald – there are frequent images and photographs, many taken by the author, and the narrative logic elegantly interweaves intimacy and history while blurring the line between digression and subject – and Eliot Weinberger: a gently curated wealth of historical and scientific material arranged in collage, a feat of immense academic labour that never feels laboured.

Each of the book’s sections is named for a stone, an organising principle but not necessarily each section’s primary topic. In the opening chapter, ‘Marble’, Raffles begins by delving into Manhattan’s bedrock and those who pursued it for personal enrichment or with a collector’s zeal. Before long, his historical excavations reach back to the Native Americans encountered by the first colonisers – the Lenape and the Munsee and the Delaware, whose traditions Raffles describes, tracing their habitation back eleven thousand years, collapsing eras within sentences as geology, with its vocabulary of strata and unconformity, collapses epochs.

This book spends significant time with indigenous peoples. In the final chapter, Raffles looks to meteorites, used by Greenland’s Inughuit people as a source of iron for their tools, and taken as prizes by European and American explorers, along with six Inughuit people, who were brought back to America for display and scientific investigation, all treated as cargo, curiosity.

The Book of Unconformities is so absorbing because it is an exercise in cataloguing that reveals the dangers of the urge, poking at the assumptions that tend to underpin scientific enquiry. The founder of American anthropology, Dr Samuel Morton, was a pioneer of cranial race science – guided by the assumption that those with larger skulls were more intelligent – which he used to justify a hierarchy of races with Caucasians at the top. Among its many virtues, The Book of Unconformities appears to rethink the project of anthropology, rejecting its colonialist origins.

Bound up with the desire to read and write and research is the urge to catalogue. We want to better know the world by slotting its parts into our pre-existing intuitions. We sort books into genres, authors into movements, thinking into disciplines, in part because it simplifies decision making. The Book of Unconformities resists cataloguing as a methodology and resists being catalogued. The wonder of geology, Raffles shows, is that our lives are influenced by the forms it describes in ways beyond our comprehension, yet rocks remain magisterially indifferent to our worship, as if inhabiting a separate realm of knowledge, ordered by timescales of which we cannot properly conceive.

In the chapter on sandstone, Raffles visits the Outer Hebrides in order to see the Calanais Stones, a circle built around 5,000 years ago. He has been telling the reader about their history, but as he crests the hill, and the stones come into view, they ‘shunt it all aside with the sheer force of existence’. That is not to say that Raffles uses geology to make trivial our personal tragedies and triumphs. Rather, he uses it to teach us new kinds of attention, where preciousness is determined not by designated standards of measurement but by the kind of awe that can only be found when we acknowledge that there are aspects of our world that exist beyond our knowing.