22 Journal of the Biblical Creation Trust. 2022, Volume 4, pages 22–25 Flood geology explains Grand Canyon folds PAUL GARNER ABSTRACT The Grand Canyon of Arizona, in the southwestern United States, has been eroded through a high, uplifted plateau. At the time of uplift, steep faults in the region’s basement rocks were reactivated, causing the overlying sedimentary strata to drape over the tops of the faults in a series of step-like folds. The conventional geological model suggests that about 450 million years elapsed between the oldest of the sedimentary strata being deposited and the time they were folded, in which case the rocks had ample time to be compacted and hardened into solid rock. By contrast, in the creationist model only a short time, perhaps a few months, may have elapsed between the time of deposition and the time of folding. Recent observations based on careful examination of thin sections taken from the folds and the surrounding rocks indicate that the rocks were soft and uncemented at the time of folding, favouring the creationist model. INTRODUCTION The Grand Canyon is a dramatic erosion feature in northern Arizona, more than 1½ kilometres deep and exposing a thick section of flat-lying sedimentary rock strata belonging to the Cambrian to Permian systems (Beus and Morales 2003). These horizontal sedimentary strata sit on top of an even older eroded basement of crystalline igneous rocks and tilted sedimentary rocks belonging to the Precambrian. Earth movements uplifted the region to form a series of high-standing plateaus, and the Grand Canyon was carved through the uplifted terrain. At the time of uplift, steep faults (or fractures) in the Precambrian basement rocks were reactivated, causing the overlying sedimentary strata to drape over the tops of the faults in a series of step-like folds (Figure 1; Huntoon 2003). One of these spectacular folds can be seen in Carbon Canyon, a side canyon along the Colorado River in Grand Canyon, shown in Figure 2. At this location, the oldest of the flat-lying sedimentary strata – a rock unit known as the Tapeats Sandstone – has been folded at a 90º angle by the earth movements. As a consequence, the sandstone layers on the western side of the canyon are oriented almost vertically. THE TIMING OF THE FOLDING When did these rock folds form? The conventional geological model gives a very different answer to the creationist model. According to the conventional model, the Tapeats Sandstone was deposited about 507–508 million years ago. Subsequently, hundreds of millions of years elapsed, during which other sedimentary strata built up on top of the Tapeats Sandstone, burying it deeply. Eventually, about 60 million years ago, the Colorado Plateau began to be uplifted, fracturing the Precambrian basement rocks and folding the overlying sedimentary strata, including the Tapeats Sandstone (Huntoon 2003, p.240).1 So in this model about 450 million years elapsed between the time the Tapeats Sandstone was deposited and the time it was folded – more than enough for the deeply buried sandstone to be compacted and hardened into solid rock. In this scenario, the sandstone was only able to be folded in a ‘plastic’ fashion because of the elevated temperatures and pressures associated with its deep burial. By contrast, the creationist model suggests that the rocks of the Grand Canyon region were formed only thousands of years ago as a result of events in biblical Earth history. Most probably, the Precambrian basement rocks date from Creation Week and the time before Noah’s Flood, while the overlying sedimentary strata, including the Tapeats Sandstone, were deposited during the worldwide Flood itself (Austin 1994). Around the end of the Flood the Colorado Plateau was elevated by earth movements, causing the folding of the freshly deposited sedimentary strata. In this model, the time that elapsed between the deposition of the Tapeats Sandstone and its subsequent folding was short – perhaps only a few months – and so the sandstone and the other sedimentary strata above it were likely still soft when they were uplifted to form the plateau (Snelling 2009). Editor’s note: An edited version of this article was first published in Dutch in Bijbelvast (6):12–15 in May 2022. Bijbelvast is a publication of Logos Instituut (http://www.logos.nl).