Th e deepest of the canyons that cut through the mountains of - TopicsExpress

Th e deepest of the canyons that cut through the mountains of the Great Northern Continent fi nally provided the solution to the riddle. Th e expedition team, picking their way through the boulders at the foot of that mighty ravine, knew, even as they fi rst glimpsed the rock layer, that this might be what they were looking for. Th e stratum, tilted at a crazy angle by the earth movements that had thrown up the entire mountain range, was . . . diff erent. Metres thick, with irregular protrusions, an irregular patchwork of grey and black and red, it contrasted vividly with the familiar layers of shale and sandstone on either side. It was like nothing they had seen before. Th ey had, of course, been seeking such proof. But this surpassed their expectations, and promised to resolve the tantalizing scraps of evidence that had perplexed and divided scientists for so long, ever since exploration of the planet’s past had begun. Getting to the stratum was not easy. As luck would have it, it did not, here, extend down to river level, being cut off at the base by a huge natural dislocation in the rock strata, another inheritance from these mountains’ violent past. Th e team had to climb halfway up that vertiginous ravine. But they had good balance, these explorers, their tails and sharp claws helping them scramble up the near-vertical rocky surfaces. Th e hard material of the stratum formed a natural overhang, and, once they had climbed over that, they could explore in some comfort. Th ere was an animated susurration as they communicated their discoveries. Here, an exposed rock surface with a regular, rectangular pattern, unlike any produced by normal geological processes; there, layers of angular pebbles with hard P R O LOGUE xiv organic coatings. Th e remains of a long tubular structure, now oxidized, that had once been metallic. Parallel-sided shards of a white glassy substance. Another oxidized metal fragment, this time hinting at a complex internal structure: not a biological skeleton, but obviously manufactured. Th ere could now be no doubt. Th ere had lived here, many millions of years ago, an ancient civilization, and one that could colonize on a grand scale: the stratum extended as far as their vision carried in the cliff s above. Th e explorers took samples from above and below that remarkable stratum, but the more experienced of them were convinced, already, of its deeper signifi cance. It was at the same geological level as the traces of the ancient, catastrophic, environmental change that had, over years of their researches, emerged as an ever-clearer part of this planet’s geological record. So, the catastrophist school of thought was—well, perhaps not altogether vindicated, but at least they now had a basis in hard fact. Th ere was now good reason to think that the ancient, planet-wide catastrophe had not been, as many had argued, a purely environmental crisis. Rather it had been associated with (or caused by?—the arguments would rumble on for many years yet, even as yet more astonishing evidence was to emerge) a major, intelligent yet transient civilization, many millions of years ago. Of course, there had been signals in the rock strata that had hinted at such a thing. Th ere were the major changes in animal and plant life, comparable to those yet more ancient biological convulsions that could be discerned even earlier in the planet’s history. Strange chemical and isotopic signals were present in the rock strata. Isolated artefacts and fragmentary dwelling-structures had been uncovered. An ancient civilization? Not necessarily. For these appeared so suddenly in the geological record that they, it was argued, were more likely to represent earlier extraplanetary visitors, who left because of, or had been killed off by, the environmental vicissitudes of the time. P R O LOGUE xv But now the doubters could be answered. Th is was a critical moment in the understanding of the planet’s history, and the explorers knew it. Th e fi rst undoubted evidence of a sophisticated civilization with the capacity to re-engineer part of the planet’s surface. Th e silence that had accompanied this dawning realization was broken by a shrill whistle from one of the party. On one of the rock surfaces, a skull was showing.