Ancient sediments are usually dated via a uniformitarian lens but when the known history of a sediment bed is investigated it can lead to some non-uniformitarian interpretations. At https://phys.org/news/2022-04-exposed-sediments-reveal-decades-lake.html … Lake Powell, in Utah, has a known history as it was formed after the completion of the Glen Canyon Dam, as recently as 1963. At its peak, in 1983, the lake held a lot of water as a result of the Colorado River in flood. However, since that date the lake has subsided, attributed to drought. As a result we are left with a stranded section of sediment formed by the lake since 1963. Geologists have been taking a look at the sedimentary formation laid down. It is said to be 60 feet in height. Calf Canyon is only submerged when the lake is at a high level. A steep decline in the depth of the lake since the year 2000 has left a lot of sediment exposed, ripe for a survey.
A steep section of the sediments were laid down quickly, during a flooding event in 1983. This could even be described as catastrophic flooding [localised]. Geologists looking at older levels in the geochronological record, from the uniformitarian angle, may have been inclined to date 60 feet of sand and clay over thousands of years, rather than the 60 years of Lake Powell. This research is especially interesting from the perspective of the K/T boundary event [K/Pg in newspeak]. Thick layers of sediment exist either side of the boundary, a layer of irridium enrichment. Might the impact have created sediments quickly?
Apart from gravel at the bottom and top of the formation most of the lake sediment consists of alternating sand and clay. The 1983 flood event, we learn, is marked by a brightly coloured soft sandy layer, a metre and a half tall. Between 4 and 5 feet. Another revealing piece of evidence was that during some years of low lake levels plant roots from shrubs such as tamarisk, were left behind. Sometimes these were visible through several sand and clay levels, showing the persistence of the plants to continue to exist even when growing in a watery environment. Such features have been seen in sediment layers, and coal seams, dated by uniformitarian means in thousands of years. At Lake Powell it was just one year to the next, or one rush of water followed by a lull, and another rush of water.