Panorama from Point Sublime [Grand Canyon] – Printed by Julius Bien 
If you want to know about Protoliths, Abyssoliths, Xenoliths and Tectonic Knots, of index fossils, totemic assemblages of ophiolitic Serpentine, of erratic stones and aesthonspheric calligraphy, geochronology, abyssal plains and gravity maps, you might do well to journey with John Mcphee over the coarse of a few decades, and four books, while he traveled with a handful of distinguished geologists across the 50th parallel of the US. His epic account of the geology of North America, in Annals of the The Former World, contains 4.5 billion years of geological history crammed into the 900 pages. Mcphee is well-know as a master stylist. His drama of lithology and stratigraphy relies on the clever interplay between the story the Earth and the life stories and anecdotes of those geologists who helped him unpack the annals of deep time. The author melds metaphors between micro-time and deep time instinctively, juggling time scales of the vast and minute to bring into focus what geologists call the ‘bigger picture’. While examining a rock at the Rawlins Uplift he says ‘we were looking at moments of over half the existence of the Earth… In 1/250th of a second a camera could capture 26 hundred million years’. Later ‘The difference between a human lifetime and 400 Million years would seem to be the difference between time incomprehensible and time infinitesimal, but what brings them together is that the smaller unit – bridging in the mind the intervening aeons – can imagine and virtually see the larger one.
Engraving of the unconformity at Jedburgh from Theory of the Earth Volume 1 – James Hutton 
The concept of geological deep time was coined by the Scottish Geologist James Hutton, in his treatise Theory of the Earth, in the late 18th century after geochemical inspection of rock in Scotland and Scandinavia. Up until his discovery the religious-centric world-view held that the age of the planet was a few thousand years old. Stratigraphic signatures and compositions of rock gave rise to Hutton’s revised estimation of hundreds of millions years – still quite a way short of the actual 4.54 billions years we now know it to be.
According to James Hall, who popularised Hutton’s work, ‘the mind seemed to grow giddy by looking so far into the abyss…We found no vestige of a beginning, no prospect of end’. Stephen Jay Gould, in his book Times Arrow, Times Cycle commented that these swathes of time are so immense that we can only understand them as metaphors in relation to the time humans have existed in the planet.
Mcphee’s writing is poetic whist still retaining scientific rigour, his stories seem to disclose an immensely slow but purposeful unfolding of tectonic history. We travel with him exploring road-cuts in order to better understand the orchestration of mountain ranges by reading backwards through time. The author reverse engineers the cryptography of geology by examining index fossils, by separating gneisses from schists, and by exploring more recent techniques such as geochronology, thermochronology and acromagnetic mapping.
Geological Cross Section of Colorado – Josiah Edward Spurr 
‘The writing of Stratigraphy is a cryptic one, but before you have crossed the range you have seen rock of such varied ages and provenance that time itself becomes nervous – Pilocene, Miocene, Eocene, Jurassic here, Triassic there… it seems random, a collector of relics of varied ages’. He reminds us that ‘Nature is messy, don’t expect it to be uniform or consistent’. Lithographic time gaps confuse matters and the cooling of magma can corrupt the chronology, but here and there is some order and the writings of these rocks can decoded to show their past and future intentions. ‘Corrugations of abyssal plains read indefinitely as extending barcodes’ and ‘The structure of the sea floor is a simple set of tree rings…..carrying easily decipherable magnetic structures’. Or according to Anita Harris, his traveling geologist companion in one section, ‘Rocks are books, they have a different vocabulary and alphabet, but you can learn to read them…they tell you about temperature and pressure…the colours, grain, sizes and the ripples give you clues to the energy of the environment of deposition. As you ascend mountains you descend through the layers of the ancient oceans. A road cut to a geologist is the Rosetta Stone to a Egyptologist’.