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ONE FIFTH OF HISTORY RIPPED OUT. “Believe it or not, the geology at the bottom of the Grand Canyon is extraordinarily common. There, layers of sedimentary rock lie flat atop angled layers of significantly more ancient metamorphic rock. The gap there is enormous—if Earth’s rocks constitute a book of the planet’s history, there are about a billion pages missing. The story only picks up again around 540 million years ago in the Cambrian period, with an evolutionary explosion of complex life just as remarkable as the sudden change in the rock.” https://lnkd.in/dtYSB5v View in LinkedIn

THE FIRST OBSERVATIONS. “Of the many unconformities (gaps) observed in geological strata, the term Great Unconformity is applied to either the unconformity observed by James Hutton in 1787 at Siccar Point in Scotland, or that observed by John Wesley Powell in the Grand Canyon in 1869. Both instances are exceptional examples of where the contacts between sedimentary strata and either sedimentary or crystalline strata of greatly different ages, origins, and structure represent periods of geologic time sufficiently long to raise great mountains and then erode them away.” https://lnkd.in/djabPdZ View in LinkedIn

DARWIN’S PROBLEM. “The apparent absence of a fossil record prior to the appearance of trilobites in the Cambrian famously troubled Darwin. He wrote in On the Origin of Species that if his theory of evolution were true “it is indisputable that before the lowest [Cambrian] stratum was deposited … the world swarmed with living creatures.” Furthermore, he could give “no satisfactory answer” as to why older fossiliferous deposits had not been found.” https://lnkd.in/d8SyHX7 View in LinkedIn

THE GREAT UNCONFORMITY seems to have occurred in north and south America, India and China, at the very least, in the same time period. It resulted in enormous quantities of the sedimentary rocks being dumped into the world’s oceans and sucked into subduction zones to be recycled in the Earth’s core, taking with it fossil records that are usually laid down as an orderly permanent record. No other event in Earth’s history was of such an enormous scale, excepting the period of extreme meteorite bombardment. View in LinkedIn

FRAGMENT FROM NATURE focuses on a part of Earth’s violent history called the Great Unconformity. This wax the pre-Cambrian period when 3-5 VERTICAL KILOMETERS got erased from the surface of the globe. Geologists argue whether it was due to the persistent glaciation of Snowball Earth, or whether then melting ice caused a massive flood, or a combination of both. Either way, it single-handedly could explain the missing fossil history and the otherwise inexplicable Cambrian explosion. It seems that this truly epic story has been buried in obtuse geology writings and that biologists have paid it scant attention. View in LinkedIn

MELTING GLACIERS. “When sea level rose (and the first Cambrian sediments were laid down on the continents) it swabbed the decks. Nothing erodes quite like the power of waves, so as the shoreline gradually moved inland to higher elevations it washed away the soil and sediment that had built up while rocks broke down. This "wave-base razor," as it’s called, cleared out the material that might have otherwise formed sedimentary rocks, and exposed massive areas of "fresh" bedrock. Between the weathering of these fresh surfaces (which weather very rapidly) and the continued breakdown of all the soil and sediment added to the oceans, concentrations of many ions in the seawater rose quickly.” https://lnkd.in/dtYSB5v View in LinkedIn

TECH EVOLUTION. "The rules of Technological evolution thus make a strong argument for accelerating evolution. Compared to the snail-paced evolution of the human species, we have to wonder if we’ll be able to manage the increasing complexity of technology or if the dystopian vision of some futurists will come true: machines will become ‘alive’ with artificial intelligence and not just roam the earth but also rule it." https://lnkd.in/dhVUUSY View in LinkedIn

NOT JUST WEATHERING. “Since the Great Unconformity is global in extent, we know continents were weathering (eroding away rocks and leaving a gap in recorded time) all around the world. This is what happens when sea level is low—weather and seasons and time break down rocks, and rivers carry sediment out to sea. What’s unusual about the Great Unconformity is how intensive and long-lasting it was.” https://lnkd.in/dtYSB5v View in LinkedIn

AI INEVITABILITY. "Despite this long record of failure, AGI must be possible. And that is because of a deep property of the laws of physics, namely the universality of computation. This entails that everything that the laws of physics require a physical object to do can, in principle, be emulated in arbitrarily fine detail by some program on a general-purpose computer, provided it is given enough time and memory." https://lnkd.in/dN7u2Qg View in LinkedIn

SEDIMENTARY ROCK DATABASE. “Shanan Peters from the University of Wisconsin and Robert Gaines of Pomona College tie these ideas together by examining the Great Unconformity a little more closely. Using a massive global database of sedimentary rocks together with geochemical records, they thought about what exactly was going on during this mostly missing chapter in Earth’s story.” https://lnkd.in/dtYSB5v View in LinkedIn