chapter 10 Petrotemporality at Siccar Point: James Hutton’s Deep Time Narrative Barry Wood People think in five generations – two ahead, two behind – with heavy concentration on the one in the middle. Possibly that is tragic, and pos- sibly there is no choice. The human mind may not have evolved enough to be able to comprehend deep time. It may only be able to measure it. John McPhee (1998, 90) ∵ On a nearly perfect summer afternoon in June 1788, Sir James Hall, James Hutton, John Playfair, and several farmhands launched from Hall’s ocean front estate near Edinburgh on the coast of Scotland and sailed southeast, scanning the rocky cliffs facing the North Sea. After passing Douglas Burn Beach and Reed Point, they reached the spectacular scene of Pease Bay: a two-hundred- yard long beach backed by a rocky promontory called Siccar Point rising seven- ty feet above the sand. The bottom fifty feet consisted of layered, gray-colored schist – the strata indicating formation by horizontal sedimentation except that the layers were standing vertically like a set of encyclopedias on a shelf. This was topped by a chaotic layer of fragmented schist; above this lay a nearly horizontal bed of layered red sandstone (see Figure 10.1). Hutton was ecstatic. In the next few minutes he explained what they were seeing, drawing on his own encyclopedic knowledge of geology and a “theory of the Earth” that he had been working out for years and presented before the Royal Society of Edinburgh three years earlier. What he described was a vast geological history necessary to account for what they were seeing at Siccar Point. This included an immense chronology of separate events resident in various rock strata – the first recognition that the configuration of rocks re- corded ancient events that comprised an overarching historical narrative. Of the three, the mathematician John Playfair may have been the most skepti- cal of Hutton’s ideas; as a former Presbyterian minister, he was imbued with © koninklijke brill nv, leiden, 2019 | doi:10.1163/9789004408241_012 158 Wood figure 10.1 Siccar Point Unconformity, east coast of Scotland, discovered by James Hall, James Hutton, and John Playfair, June 1788. Sedimentary layers of gray schist, standing vertically, topped by nearly horizontal sedimentary layers of red sandstone. the prevailing biblical view of a world created roughly 5,800 years earlier. But Hutton’s narrative astonished him; what Playfair went on to describe was a transforming experience of seeing for the first time the vast depths of time: “We felt ourselves being carried back … An epoch still more remote presented itself … Revolutions still more remote appeared in the distance of this extraor- dinary perspective. The mind seemed to grow giddy by looking so far into the abyss of time; and while we listened with earnestness and admiration to the philosopher who was now unfolding to us the order and series of these won- derful events, we became sensible how much farther reason may sometimes go than imagination can venture to follow” (1805, 72–73). On that singular af- ternoon in 1788, they understood the greater vision of a man who described his life’s work as “reading in the face of rocks the annals of a former world” (McPhee 1998, 77). The description of Siccar Point by James Hutton (1726–1797) signaled the first glimpse of what is now called deep time, a concept made popular by John McPhee in Basin and Range (1982) and now systematically explored by special- ists in other fields, notably the social sciences (Shyrock and Smail 2011). The idea was far beyond what anyone can conceive; as McPhee put it, “Numbers do not seem to work well with regard to deep time. Any number above a couple of thousand years – fifty thousand, fifty million – will with nearly equal ef- fect awe the imagination to the point of paralysis” (McPhee 1998, 29). Hutton .