Vector graphic of the land mass of the supercontinent Pangea.
Credit: Rainer Lesniewski
It's not just the biologists who are incidentally refuting creationism with just about every peer-reviewed research paper; now the geologists are doing the same.
The problem for creationists is that their superstition has no basis in facts because it didn't happen and the record of how it did happen is in the evidence that science is revealing, so inevitably that evidence is going to refute the childish fairytale that creationists were taught by their parents who were taught it by their parents...
Take this piece of geological research into the formation of the East Coast of the USA, for example. It was carried out by scientists from the University of New Mexico, Southern Methodist University seismologist, Professor Maria Beatrice Magnani, and scientists from Northern Arizona University and the University of Southern California. It occurred in that long 'pre-Creation' history before creationists think Earth was magicked up out of nothing.
It is based on the knowledge that the East Coast of America formed when the supercontinent, Pangea, broke up some 230 million years before creationists think Earth existed.
Because it wasn't known about by the parochial and scientifically illiterate Bronze Age authors of their holy books, creationists are completely unaware of the way the present land-masses were formed on the breakup of Pangea, despite the abundant tectonic evidence in the form of mid-ocean ridges with their embedded record of multiple magnetic reversals over millions of years, subduction zones, earthquakes, volcanoes and uplift folds to form hills and mountains at tectonic plate margins.
Geology is a science about which my education has been somewhat lacking (I'm a biologist, physiologist and biochemist by training) but as I understand it, the edges of continents that were the site of the original rifts that opened up to form the oceans, particularly the Atlantic Oceans, will also show evidence of magma that would have welled up in the initial stages of the split.
In the case of the North American Atlantic coast, which is passive in this process because it is simply being pulled away from what is now Northwest Africa, and has not been subject to collisions with other plates, or any significant volcanic activity, these traces of magma are still to be found in the edges of the continental shelf beneath the ocean floor. Associated with the passive margin is a magnetic anomaly, The East Coast Magnetic Anomaly (ECMA), that runs parallel to the American East Coast.
My knowledge of the American East Coast is limited to two week vacation in Boston about 12 years ago, during which I tried bathing in Cape Cod Bay from a beach near South Wellfleet, to discover that I was standing barefoot on king crabs, either dead or alive (their remains littered the beach along Cape Cod), so I didn't spend long in the water - not that they were any threat to me but because they are not very pleasant to walk on.
As the Southern Methodist University news release explains:
A recent study published in the Journal of Geophysical Research: Solid Earth sheds new light on the formation of the East Coast of the United States – a “passive margin,” in geologic terms – during the breakup of the supercontinent Pangea and the opening of the Atlantic Ocean around 230 million years ago.The highly technical paper in the Journal of Geophysical Research: Solid Earth (JGR Solid Earth) also contains a 'Plain Language Summary':
In geology, passive margins are “quiet” areas, locations with minimal faulting or magmatism, where land meets the ocean. Understanding their formation is crucial for many reasons, including that they are stable regions where hydrocarbon resources are extracted, and that their sedimentary archive preserve the climate history of our planet as far back as millions of years.
The study, co-authored by scientists from the University of New Mexico, SMU seismologist Maria Beatrice Magnani, and scientists from Northern Arizona University and USC, explores the structure of rocks and the amount of magma-derived rocks along the East Coast and how they change along the margin, which may be tied to how the continent was pulled apart when Pangea fragmented. This event may have also influenced the structure of the Mid-Atlantic Ridge, a vast underwater mountain system running down the center of the Atlantic Ocean.
The study team analyzed rocks deep below the ocean floor, about 10 to 20 kilometers down, using special instruments called ocean-bottom seismometers. The instruments measure the sound speed of rocks beneath the surface, helping scientists figure out composition and rock type. This research is part of a considerable effort to investigate how continents break apart, one of the most important questions in the Earth Sciences.
Research team members included Colin C. Brand and Lindsay Worthington, from the University of New Mexico, Donna Shillington, from Northern Arizona University, and Thomas Luckie, from the University of Southern California, Los Angeles.Passive margins define the majority of the Earth’s coastlines and are home to much of the world’s population. They are vulnerable to changes driven by long-term climate variations and sea-level rise. Understanding their beginnings and the processes that shape them offers clues on how they can be affected by and respond to geohazards, including earthquakes, submarine landslides, and erosion.
Professor Maria Beatrice Magnani, co-author
Department of Earth Sciences
Southern Methodist University, Dallas, TX, USA.
AbstractIt's probably rubbing salt in creationist's wounds to point out that the seismologist involved in this research, Professor Maria Beatrice Magnani, is a professor in the Southern Methodist University, where teaching science includes the evidence for an old earth and evolution rather than the counter-factual origin myths from the Bible, despite being a Protestant Christian organisation.
Detailed models of crustal structure at volcanic passive margins offer insight into the role of magmatism and the distribution of igneous addition during continental rifting. The Eastern North American Margin (ENAM) is a volcanic passive margin that formed during the breakup of Pangea ∼200 Myr ago. The offshore, margin-parallel East Coast Magnetic Anomaly (ECMA) is thought to mark the locus of syn-rift magmatism. Previous widely spaced margin-perpendicular studies seismically imaged igneous addition as seaward dipping reflectors (SDRs) and high velocity lower crust (HVLC; >7.2 km/s) beneath the ECMA. Along-strike imaging is necessary to more accurately determine the distribution and volume of igneous addition during continental breakup. We use wide-angle, marine active-source seismic data from the 2014–2015 ENAM Community Seismic Experiment to determine crustal structure beneath a ∼370-km-long section of the ECMA. P-wave velocity models based on data from short-period ocean bottom seismometers reveal a ∼21-km-thick crust with laterally variable lower crust velocities ranging from 6.9 to 7.5 km/s. Sections with HVLC (>7.2 km/s) alternate with two ∼30-km-wide areas where the average velocities are less than 7.0 km/s. This variable structure indicates that HVLC is discontinuous along the margin, reflecting variable amounts of intrusion along-strike. Our results suggest that magmatism during rifting was segmented. The HVLC discontinuities roughly align with locations of Mid-Atlantic Ridge fracture zones, which may suggest that rift segmentation influenced later segmentation of the Mid-Atlantic Ridge.
Key Points
- High velocity lower crust beneath the East Coast Magnetic Anomaly is variable along-strike and discontinuous in some places
- The lower crust variability reflects variable intrusion into lower continental crust and represents magmatic segmentation during rifting
- The high velocity lower crust discontinuities are coincident to Mid-Atlantic Ridge fracture zones, suggesting a rift-to-ridge connection
Plain Language Summary
The East Coast of the United States is a passive margin that formed during continental breakup of Pangea, the most recent supercontinent. Although passive margins are generally not locales of active faulting and magmatism, by investigating their current structure, we gain insight into processes during past rifting. We know that extensive volcanism and magmatic addition to the Earth's crust occurred during the breakup of Pangea, but we do not fully understand how the distribution changes from north to south along the margin. To study these rocks, which are buried 10–20 km beneath the seafloor, we use ocean bottom seismometers to determine the sound speed of rocks beneath the surface, which can tell us about composition and rock type. We found that the thickness and extent of magma-derived rocks are variable along the margin, with gaps up to 30 km wide. This variability is likely related to processes happening in the continental rift which may have influenced the structure of the Mid-Atlantic Ridge that formed after rifting ended.
Brandl, C. C., Worthington, L. L., Magnani, M. B., Shillington, D. J., & Luckie, T. W. (2023).
Discontinuous igneous addition along the Eastern North American Margin beneath the East Coast Magnetic Anomaly.
Journal of Geophysical Research: Solid Earth, 128, e2023JB026459. https://doi.org/10.1029/2023JB026459
© 2023 John Wiley & Sons, Inc. .
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
By trying to associate evolution and acceptance of an old Earth with Atheism, creationist frauds are deliberately trying to mislead their dupes into believing that you can't be a Christian and accept scientific evidence when, in fact, the vast majority of Christians accept the evidence for evolution on an old Earth; it's the fundamentalist extremist to be found in the creationist cult who are the tiny minority of oddballs, even within their own religions.
But if the money-grubbing frauds who lead their cult want them to believe that accepting the scientific evidence is also rejecting what religions teach, then who am I to argue? They obviously understand better than most how science undermines and destroys religious dogma, and so threatens their income and power, so they need the fools to stay ignorant and misinformed.
No comments :
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.