The Accretionary Wedge #15: Pondering the geological future of Earth
Unfortunately there were not many submissions to this months Accretionary Wedge geoscience blog carnival. But, what this month’s installment lacks in quantity it makes up for in quality.
First, Michael Welland of the blog Through the Sandglass ponders far into the Earth’s future — 100 million years — and, inspired by Zalasiewicz’s book The Earth After Us, discusses what future geologists/anthropologists might infer from a single layer in the stratigraphic record.
Essentially none of our infrastructure, creations, and artifacts will survive 100 million years of erosion, burial, diagenesis, and tectonics in their original compositional and structural form, and we ourselves, inhabiting the erosional land rather than the depositional marine realms are poor fossil candidates – think of the extent (or lack of it) of the record of our ancestors in the African Rift Valleys.
At the end of his post reviewing and discussing Zalasiewicz’s book, Michael poses a question to the reader:
So, here’s the question, given that our appreciation of plate tectonic processes was a long time coming, difficult, and highly controversial even while their work was going on all around us, in a post plate tectonics world, how would we discern that those processes had ever happened? What would be the evidence revealed to and by geologists of the future that plate motions and plate margin dynamics had sculpted the appearance of our planet? Something to think about as we gaze more closely at other planets?
Head on over to join the discussion.
Next, Hypocentre at the blog Hypo-theses looks at just the next few decades and proclaims that global warming will cause large earthquakes to completely disappear by 2035. Don’t believe it? Well, you better go check out his post.
Silver Fox at the blog Looking For Detachment investigates where, how much, what kind, and under what conditions ore deposits might be explored for in the future:
I recommend drilling for gold in 1 to 5 million years in the Mendocino, CA, area, with 2 to 3 million years being my best estimate of the proper timing. For proper and exact placement of drill rigs, I would wait for the future, when faults and fractures controlling future ore deposits will be identifiable, and when rocks will be available for sampling.
That’s just one of several specific predictions.
MJC Rocks at the blog Geotripper doesn’t pick a certain interval of time in the future, but ponders the basic processes and relationships of processes that both cause and are affected by the evolution of the Earth within the context of Black Mesa in northern Arizona:
I have no doubt that a layer will be discovered that represents a mass extinction event wherein a vast number of organisms disappeared forever, including the mammalian megafauna, and perhaps many oceanic species, especially at the top of the food chain, such as many kinds of sharks and whales. Will we be identified as the cause of the catastrophe? Who knows? Someone or something might figure it out. Or maybe not; it might be another of those mysteries that nag and bother the psyches of those who study the earth and it’s past.
Kevin from the blog The GeoChristian discusses some events and processes that will occur over four orders of temporal magnitude (from 1,000 to 1,000,000 years) and ponders them within the context of his own faith.
Finally, is my own post that speculates and discusses a million years worth of deposition.
UPDATE: Chris from Highly Allochthonous addresses the question many of ponder about our magnetic field — when will the polarity reverse? And how long does it take? Read the post to learn more.
I thank all those who participated in this month’s Accretionary Wedge … for others, if you didn’t quite finish your submission in time, go ahead and submit it late. I’ll update this post.