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CAMBRIAN EXPLOSION. “The familiar Cambrian explosion, which started around 540 million years ago, was a game-changer for life on Earth. Bacteria (and archaea) had ruled the planet for over 3 billion years before multi-cellular animals came on the scene. When they did, they diversified rapidly (at least in terms of the span of geologic time). Though we’re right to be impressed by the sudden explosion of life, it’s not the only remarkable thing in that portion of Earth’s history.” https://lnkd.in/dtYSB5v View in LinkedIn

TECHNOLOGY. "The first notable attempt was made in 1954, by the philosopher Martin Heidegger in his ground breaking essay, The Question Concerning Technology. In it, he describes technology not as something we build, but as something we uncover and enframe. In other words, we are not wholly responsible for man-made wonders, nor are we entirely in control." https://lnkd.in/dZh-rjw View in LinkedIn

GLACIAL EROSION THEORY. “Erosion alone can't explain all the details of this episode, and you need something that affects the entire globe. Is there anything else that can wipe a few kilometers of rock off the Earth's face? The authors propose that three periods of epic cold snaps in the 180 million years leading up to the start of the Cambrian—sometimes referred to as “Snowball Earth” periods—could be the key.” https://lnkd.in/d3DMx6k View in LinkedIn

TECHNOLOGY. "It is vastly easier to theorize about technology than it is to measure it. It is our principal contention that patent technology codes can be used to track and characterize technological change." https://lnkd.in/dp-phxx View in LinkedIn

ZIRCONIUM DATA. “The zircons in the database span nearly the entire history of the Earth, and by far the most noticeable wiggle lines up neatly with the Great Unconformity. When they ran the numbers to see how much erosion would be required to explain a wiggle of that size, they found that it would be something in the neighborhood of 3 kilometers (or 2 miles) of rock shaved off all the world’s continents and dumped on the ocean floor.” https://lnkd.in/dtYSB5v View in LinkedIn

GLOBAL GAP. “This gap can be found all around the world, and has picked up the name the Great Unconformity. Cambrian sedimentary rocks rarely rest on anything other than much older metamorphic or igneous rock, implying that whatever rock formed in the intervening time was scrubbed away by something. This erasure of a chunk of geologic history has long been an enticing mystery for geologists.” https://lnkd.in/dtYSB5v View in LinkedIn

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