Plate Tectonics: Origins and Implications

[BillTre]

Here is a NY Times article that seems to be based on this special issue of the Philosophical Transactions of the Royal Society A: Mathematical, Physical, and Engineering Science (which is open access for downloading pdf's!).
Discussed are things like:

• when did plate tectonics start
• what conditions lead to plate tectonics
• how important is plate tectonics to the evolution of life (in various possible ways)

The times article mostly raises questions.
The journal issue has several articles on specific issues.
I have only glanced at the journal articles yet.

 

[trurle]

Here is a NY Times article that seems to be based on this special issue of the Philosophical Transactions of the Royal Society A: Mathematical, Physical, and Engineering Science (which is open access for downloading pdf's!).
Discussed are things like:

• when did plate tectonics start
• what conditions lead to plate tectonics
• how important is plate tectonics to the evolution of life (in various possible ways)

The times article mostly raises questions.
The journal issue has several articles on specific issues.
I have only glanced at the journal articles yet.

I think the NY times article you linked is an example of "false balance" fallacy. Article is too stuffed with "fringe science" theories.

From the planetary geology works i read seems consensus is what plate tectonics was active from formation on large planets like Earth, Mars and Venus. Moon plate tectonics is questionable though.
Initially plate tectonics produce not the continents and oceans but multi-fold mountain patches (micro-continents) which are mostly destroyed on Earth by now, but are still recognizable on Venus (largest being Ishtar Terra and Aphrodite Terra).
Later, when the heat production drops, plate tectonics may cease, faster on small Mars or waterless Venus. Then came the "giant volcano" phase, as heat is venting through increasingly thick lithosphere in few weak spots (frequently triggered by asteroid impacts) instead of lines. Mars bear evidence of being in "giant volcano" stage now.

 

[Ophiolite]

I think the NY times article you linked is an example of "false balance" fallacy. Article is too stuffed with "fringe science" theories.

From the planetary geology works i read seems consensus is what plate tectonics was active from formation on large planets like Earth, Mars and Venus. Moon plate tectonics is questionable though.
Initially plate tectonics produce not the continents and oceans but multi-fold mountain patches (micro-continents) which are mostly destroyed on Earth by now, but are still recognizable on Venus (largest being Ishtar Terra and Aphrodite Terra).
Later, when the heat production drops, plate tectonics may cease, faster on small Mars or waterless Venus. Then came the "giant volcano" phase, as heat is venting through increasingly thick lithosphere in few weak spots (frequently triggered by asteroid impacts) instead of lines. Mars bear evidence of being in "giant volcano" stage now.

I'm not really sure how you formed the impression of early plate tectonics on, as it does not match the consensus view or the evidence. Your comments on micro-continents is accurate, but they do not owe their genesis to plate tectonics. The presence of plate tectonics on Venus and Mars at any time is controversial.

I ignored the NY Times article and went straight to the papers. It is clear from them that the onset of plate tectonics remains an area of active investigation with plenty of controversy, but I do not see in them anything that supports your assertion that "plate tectonics was active from formation on large planets like Earth, Mars and Venus." Perhaps you can provide citations for papers that set out such an argument.

Those interested in the topic, but unwilling to wade through the dozen papers provided by the OP may find this comparatively recent paper a sound read. Jean Bedard, Stagnant lids and mantle overturns, 2017. While the author promotes a particular hypothesis he reviews (with many relevant references) a broad range of views on plate tectonics and other possible tectonic and magmatic mechanisms.

 

[trurle]

I'm not really sure how you formed the impression of early plate tectonics on, as it does not match the consensus view or the evidence. Your comments on micro-continents is accurate, but they do not owe their genesis to plate tectonics. The presence of plate tectonics on Venus and Mars at any time is controversial.

You likely use very narrow definition of "plate tectonics". I see the "plate tectonics" definition from paper you cited (and paper on Venus geology from previous link too https://royalsocietypublishing.org/doi/10.1098/rsta.2017.0412 ) include both subduction and continental drift , although i.m.h.o. definition of "plate tectonics" as simply as "horizontal movement of independent crustal blocks" is more common. I am aware subduction was not proven for Venus and Mars. Subduction may be a feature of highly recycled crusts on Earth only.

 

[Ophiolite]

You likely use very narrow definition of "plate tectonics". I see the "plate tectonics" definition from paper you cited (and paper on Venus geology from previous link too https://royalsocietypublishing.org/doi/10.1098/rsta.2017.0412 ) include both subduction and continental drift , although i.m.h.o. definition of "plate tectonics" as simply as "horizontal movement of independent crustal blocks" is more common. I am aware subduction was not proven for Venus and Mars. Subduction may be a feature of highly recycled crusts on Earth only.

Subduction and continental drift are part of plate tectonics, but they may occur independently of plate tectonics - the point expressed with great clarity in the OP papers and the addition I offered. For emphasis: subduction and plate tectonics are not synonyms.

Plate tectonics theory postulates that the entire crust of the Earth is divided into a suite of plates that behave as rigid elements that rotate independently around Euler poles. Interaction between these plates may be at subduction zones, mid ocean ridges, triple junctions, or transform faults. Any continental drift or subduction missing any of these elements is not plate tectonics.

I agree we are using different definitions, but yours appears to be a colloquial one and not one that enjoys currency among most (or any?) geologists. The excellent papers provided in the OP links explore when plate tectonics arose, what preceded it, the nature of the transition, and the consequence for crustal, especially continental development , as well as its impact upon mantle behaviour. Let's focus on that.

 

[Astronuc]

A Tour of Earth's Ancient Supercontinents​

9:15 - 12:15 NASA Magellan Mission and Mapping of Surface of Venus (some discussion of plate tectonics or the lack thereof)

Some interesting comments and ideas. The narration mentions zircons (including U/Pb ratios), fossilized plants, fossilized sea and terrestrial creatures, types of rocks (basalt vs granitic; metamorphic vs sedimentary) and their compositions, . . .

Nomenclature/key words: Orogenic belts/formations, cratons, magnetic reversals, Abraham Orterlius (1527-1598), continental drift, paleogeography, glossopteris,

A possible time line of plate tectonics:
Archeon Eon (4 to 2.5 billon years ago), Ur (hypothetical first super continent, 3.1 billion years ago, based on cratons dating to about 3 billion years; more conservative model has kratons formed in a succession of supercontinents that formed and reformed during a period from the mid Archean and early Proterozoic eons; Vaalbara (3.4 to 2.7 billion years ago), some link between Kappvaal and Pilbara cratons), Superior (2.7 - 2.3 billion years ago, based on the Canadian Superior craton), Scalvian (2.6 to 2 billion years ago, based on Canadian Sclavian craton),

Proterozoic Eon (2.5 billion to 541 million years ago), Columbia supercontinent (1.8 to 1.5 billion years ago), boring billion period (1.8 billion to 800 million years ago), Rodinia (1.1 billion to 600 million years ago), Pannotia (650 to 500 million years ago), Gondwana (500 million to 180 million years ago), Silurian Period (443-419 million years ago), Pangea (335 to 175 million years ago, the last supercontinent)

Volcanic evolution of the Pacific Northwest: 55 million year history​

At 3:54 in the Volcanic evolution video, there is mention of a pivot point in NE Oregon about which a piece of the N. American plate rotates clockwise. Pivoting of the continents (or plates) is mentioned in the first video, and I find the pivoting interesting. We currently is live in a time of continental dispersion, but it is predicted (46:35 in the first video) that Africa and Arabia will continue to move northward into Europe, closing the Mediterranean Sea and forming new mountains, Australia and Antarctica will combine (with NZ perhaps) and move to the N, and N. America and S. America will pivot into one another and move to the Afro-Eurasian amalgamation - in the future (200 million years or so).

 

[Astronuc]

I came across a video made about 1970. The video discusses the understanding of the time, and the scientific evidence used to support the idea of plate tectonics.



One criticism of the video is, "the glaring omission of Marie Tharp and Bruce Heezen's seafloor mapping work and the contributions of USGS geologist George Plafker is evident. Perhaps someday a new documentary video will be produced that gives them the credit they are due."

https://blogs.loc.gov/loc/2021/08/marie-tharp-mapping-the-ocean-floor/
https://ocean.si.edu/ecosystems/deep-sea/making-mark-ocean-floor
https://www.sciencenews.org/article/marie-tharp-maps-plate-tectonics-seafloor-cartography
https://web.whoi.edu/womens-comm/marie-tharp-pioneering-mapmaker-of-the-ocean-floor/
https://marietharp.ldeo.columbia.edu/about-marie-tharp

Marie Tharp’s Adventures in Mapping the Seafloor, In Her Own Words
https://news.climate.columbia.edu/2020/07/24/marie-tharp-connecting-dots/

Tharp was one of the first women to work at the Lamont Geological Observatory (now the Lamont-Doherty Earth Observatory at Columbia University). That was in 1948, a time when women weren’t always welcome in the world of science. Despite these extra obstacles, she went on to change the course of history for geology and ocean exploration.

Marie's father, William Edgar Tharp, was a soil surveyor for the U.S. Department of Agriculture, Bureau of Chemistry and Soils. Papa was a field man and his assignments were to make a soil map of a county, produce a written report describing the soil types and recommended uses and to collect soil samples for analysis in the chemistry division. These were printed by the government and distributed to farmers, insurance companies and the university extension divisions. We were constantly on the move, with Papa working in the Southern states during the winter and the Northern states in the summer. By the time I finished high school I had attended nearly two dozen schools and I had seen a lot of different landscapes. I guess I had map-making in my blood, though I hadn’t planned to follow in my father’s footsteps.

Bruce Heezen


George Plafker
https://pubs.usgs.gov/publication/70196820
https://www.geosociety.org/awards/17speeches/penrose.htm
https://www.seismosoc.org/award-recipient/george-plafker/

 

[davenn]

One criticism of the video is, "the glaring omission of Marie Tharp and Bruce Heezen's seafloor mapping work and the contributions of USGS geologist George Plafker is evident.

Gosh, I have never heard of any of those 3 people