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The Great KP Extinction Controversy

Plate tectonics of the North American Continent at the Cretaceous- Paleogene Boundary and Implications For a Terrestrial Cause in the Great KP Extinction Controversy. 1. The Great KP Extinction Controversy. During the Cretaceous (K), dinosaurs had roamed the Earth.

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The Great KP Extinction Controversy

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  1. Plate tectonics of the North American Continent at the Cretaceous-Paleogene Boundary and Implications For a Terrestrial Cause in the Great KP Extinction Controversy 1

  2. The Great KP Extinction Controversy During the Cretaceous (K), dinosaurs had roamed the Earth. But by the beginning of the Paleocene (P), 65 million years ago (Ma), a mass extinction had occurred that wiped out nearly 75% of life on Earth, including the dinosaurs. 2

  3. In 1980, Dr.’s Louis and Walter Alvarez discovered a layer of clay at several sites along the KP boundary containing high levels of iridium, as well as other exotic materials. • Because iridium is rare on Earth’s surface, the Alvarez team proposed that the layer must have been formed by an Extraterrestrial impact. (Alvarez, et al, 1980) • So far, this has been the most widely accepted hypothesis. 3

  4. In 1981, however, Dr. Dewey McLean showed how Deccan Traps volcanism in India could have increased CO2 levels in the atmosphere causing a severe global warming event, thereby causing the extinctions. (McLean, 1981) 4

  5. For decades now, these two hypotheses have battled for top contender, yet, neither has been chosen as the champion. • This presentation will attempt to show that this is because it was neither an asteroid nor the Deccan Traps that caused the extinctions of 65 million years ago. 5

  6. In 1996, Dr. Charles Officer and Jake Page introduced another hypothesis that seems to have gone completely unnoticed in the KP Extinction Debate. • In their book, The Great Dinosaur Extinction Controversy, they showed that, not only were the Deccan Traps occurring in India, but that massive volcanism was occurring all over the world at that time. (Officer and Page, 1996) 6

  7. Particularly, large magmatic events were occurring in North America that were not only coeval with the Extinctions, but also, with the uplifting of the Laramide Orogeny and the disappearance of the Western Interior Seaway. 7

  8. However, as no exact mechanism had been found to account for the exotic mix of materials in the KP boundary layer, this hypothesis was largely dismissed in the KP Extinction Debate. • So, my original question was: If an asteroid had struck the earth at the same time that large magmatic and uplifting events were occurring on opposite sides of the world, could the asteroid have caused some sort of disturbance in the mantle to account for these events? 8

  9. The answer to that question was clearly NO. • The Laramide Orogeny began within North America ~80 Ma and lasted until ~50 Ma. • In India, the KP Boundary layer is found as a separate layer within the Deccan Traps, and at least one study shows that the Traps began erupting some 400,000 years before and continued some 400,000 years after the deposition of the KP boundary layer. (Bhandari, and Shukla, 1996) • So the next question to be answered was…what, exactly, caused the Laramide Orogeny at the KP Boundary? So I began to study the geology of North America directly before, during and after the KP boundary. 9

  10. The Western Interior Seaway • Before the beginning of the Laramide, Texas lay at the bottom of a shallow seaway that stretched across the interior from the Arctic Ocean to the Gulf of Mexico. This cold, salty sea is known as the Western Interior Seaway. • Before the Laramide, bays and estuaries covered most of New Mexico (Chronic, 1987); and Arizona lay along the floodplains of that ancient sea. (Chronic, 1983) 10

  11. Most of the fossils found at the KP boundary in North America were animals that lived within, or along the shores of, the Western Interior Seaway. • North America • in the Age of the Dinosaurs, 75 Ma. • (National Geographic, • January, 1993) 11

  12. Officer and Page (1996) showed that the Western Interior Seaway was mostly gone by 65 Ma. • Critical habitats, and indeed, an entire biosphere, disappeared, before the KP boundary, mainly caused by the uplifting of the western half of North America during the Laramide Orogeny. 12

  13. The Laramide Orogeny • The Laramide Orogeny began within the interior of the continent at ~80 Ma and lasted until ~50 Ma. • However, many major fold and thrust events, as well as, magmatic events, occurred directly at the 65 Ma boundary. • Officer and Page showed that the Laramide magmatic trend had been dated between 69 and 64 Ma (Officer and Page, 1996). 13

  14. TODAY… In Texas…roughly 2/3 of Texas sits on the Cretaceous shelf, while the other 1/3 sits on top of Paleocene and younger sandstone deposited as the Laramide uplifted to the west and sediments filled in the Gulf. (Chronic, 1987) In Arizona…recent evidence shows that the Kaibab plateau, which was uplifted along with the rest of the larger Colorado plateau, had uplifted as early as 65 Ma. (National Geographic, 2007) 14

  15. And in Denver…In 2008, Dr.’s Doug Nichols and Kirk Johnson of the Denver Museum of Natural Science published a book titled Plants at the KT [P] Boundary, which contended that the rapid disappearance of plant life at 65 Ma, followed by a fern spike, was definitive evidence of an asteroid impact… However, Dr. Johnson has also collaborated on another study that this author believes to be definitive evidence that it was NOT an asteroid… 15

  16. In a study done on drill cores from developments throughout the Denver Basin, Johnson and others showed that the Pierre Shale was formed at the bottom of the Western Interior Seaway, dated at 68 Ma. • Above the Pierre Shale lies a layer of volcanic tuff, followed by the KP boundary layer at 65 Ma, containing high levels of iridium. • By 64 Ma, plant life had not only returned, but flourished to become a thriving rainforest. (Raynolds, et al, 2007) • In other words, the Denver Basin went from the bottom of a sea to a thriving rainforest in the 4 million years spanning the KP boundary. • That was not caused by an asteroid, but by the rapid uplifting of the Laramide. 16

  17. Salt Lake and the Great Salt Lake Desert of Utah was once a part of that salty seaway that was trapped by the rapid uplifting of the Rockies. • Utah and Hell’s Creek Montana became the last refuges of the dinosaurs struggling to survive at the KP Boundary. 17

  18. So, then, what, exactly, caused the Laramide Orogeny? • One study shows that "Subduction of an oceanic plateau, about 85-65 Ma (remnants in the Franciscan), produced east-vergent tectonic wedging in the Coast Ranges, possible thrusting along the eastern Sierra Nevada Batholith margin, and development of Rocky Mountain Laramide structures.  The ‘Laramide Orogeny’ is herein redefined to include all Late Cretaceous-early Tertiary (75-45 Ma) fold thrust structures from the Pacific Coast to the Rocky Mountains.“ (Moores, Wakabayashi, and Unruh, 2003) ][=‘ 18

  19. It is within the Franciscan melange that we find our clues to what really happened at the KP boundary.On the west coast of North America, we can still see the scar.(Scripps Institute of Oceanography) 19

  20. The Coast Range Ophiolite (#4, green) represents a Jurassic age oceanic crust that was uplifted onto the continent. The Great Valley Sequence (#1, yellow) that lay on top of the Coast Range Ophiolite represent sediments that were deposited on that ocean floor while it still lay within the ocean. USGS Professional Paper 1515, The San Andreas Fault. Geologic sketch map of California, Based on U.S. Geological Survey (1966), Jennings and others (1970), and Ross (1984). 20

  21. The Franciscan melange, (#5, blue) however, is still somewhat of an enigma, as it lay structurally beneath the Coast Range Ophiolite. It mainly consists of greywacke, greenstone, red radiolarian chert, and, in some areas, blueschists and serpentinite. 21

  22. So, then, what, exactly, is the Franciscan? One study shows that the sandstone (greywacke) found within the Franciscan is volcanic in nature and is made up of greenstone, similar to the greenstone found in the Permanente Terrane. This study also “concluded that these rocks were deposited on the flanks of an oceanic rise or plateau….” (Larue and Sampayo, 1990) 22

  23. Another study shows that the cherts found within the Franciscan are manganiferous, and were formed on the flanks of a mid-ocean ridge. (Crerar, et al., 1982) • Manganese is known to emanate from hydrothermal vents along mid-ocean ridges today. 23

  24. Another study shows that a Jurassic age Hydrothermal Vent Community has been found within the Franciscan, similar to those found around the Galapagos Islands today, complete with tube worms and other sulfur-based life forms. (Little, Danelian, Herrington and Haymon, 2004) 24

  25. The Franciscan, then, would seem to show all of the evidences of being a mid-ocean ridge AND/OR ocean-island plateau, similar to today’s Galapagos Islands. • But WHEN, exactly, did it attempt to subduct beneath North America? 25

  26. One study shows that the Calera limestone formation found within the Franciscan “…was deposited on top of an oceanic rise or plateau during the Late Cretaceous and was subsequently transported NE until it was accreted to the North American continental margin ~63 Ma.” (Tarduno, Irwin, Blake, and Coleman, 1985) 26

  27. One study found in USGS Special Paper 1515 concluded that… “uplift of the Franciscan Assemblage and extension of the upper plate, consisting of Coast Range Ophiolite and Great Valley Sequence, occurred during the Cretaceous (or, at the latest, during the early Tertiary” (Fuis and Mooney, 1990). Other studies show that major Franciscan uplift occurred at the same time as graben formation within the Coast Range Ophiolite at the KP Boundary, ~65 Ma. (Moxon and Grahamm, 1987; Unruh, Dumitru and Sawyer, 2007) 27

  28. Vedder and others showed that thrusting on the Salinian block (#9, light pink) occurred from 65-55 Ma. (Vedder, Howell, and McLean, 1983) • Wakabayashi and Moores, 1988, showed that the Salinian had collided with the Franciscan and was in place by ~60-50 Ma. 28

  29. More recent drill cores from SAFOD show that the sediments on both sides of the Salinian block are arkosic sandstones deposited as the Salinian collided with the Franciscan. Dating shows that these sandstones were deposited between 70 and 64 Ma. (Springer, et al, Lithosphere, 2009)

  30. Los Angeles, Santa Barbara and Ventura all sit on top of thick Cretaceous-Paleocene sediments. (USGS Prof. Paper 1515) 30

  31. As the Salinian block collided with the Franciscan, this would have trapped the MOR/plateau within a backarc basin between the Salinian block on the west and the subduction zone/Coast Range Ophiolite/Sierra Nevada complex on the east. As the MOR/hotspot was thrust beneath the continent, it would move in beneath the downgoing plate, thereby causing the flat-slab subduction that moved the Laramide into the Interior. 31

  32. Pelona-Orocopia Schists • Jacobson and others show that the Pelona-Orocopia-Rand Schists that lie structurally beneath California and Arizona are remnant pieces of that downgoing plate that were pushed up beneath the continent. Protolith and emplacement ages range from 90 Ma in the northwest to 60 Ma in the southeast, and attributes the formation of the schists to subduction of an aseismic ridge. • (Jacobson, et al., 2011) 32

  33. Yellowstone Mantle Plume? This study shows that the Yellowstone mantle plume… was a seamount, in the Pacific, off the coast of California, 65 Ma. But, by 50 Ma, it was beneath the continent. (Oppliger, Murphy, and Brimhall Jr., 1997) 33

  34. It is this event that caused the Coast Range Thrust on the west coast, leading to the uplifting of the western half of the North American continent, the large magmatic provinces within the interior and the disappearance of the Western Interior Seaway at the Cretaceous-Paleocene boundary. This presentation will suggest that this event also caused the deposition of the KP boundary layer, as well as the extinction of the dinosaurs, 65 Ma. 34

  35. All of the materials being used to describe the asteroid, can also be explained by the closing off of this mid-ocean ridge and/or ocean island hotspot on the west coast of North America. Iridium Glass Spherules Shocked Quartz Granite Oceanic Basalt 35

  36. Asteroid? • As of today…the only piece of the “asteroid” ever found is a minute chunk of iron and nickel containing high levels of iridium, chromium, and olivine. (Frank Kyte, 1993) • However, this bit of rock was not found in the Gulf, but in 65 million year old sediments of the North Pacific, due east of the Hawaiian Islands. 36

  37. Iridium • One study shows that rare OsIrRu grains have been found uplifted in the Josephine Ophiolite of Oregon (Port Orford) and northern California. And that these grains are found throughout the Pacific, from the Hawaiian Islands to Asia. • The authors of this study suggested that the Iridium was “…transported from the core-mantle boundary region to the lithosphere as xenoliths in a mantle plume/convection system.” (Bird, Meibom, and Frei, and Nagler, 2002) 37

  38. The Josephine Ophiolite • The Josephine Ophiolite (#8) was uplifted along with the larger Coast Range Ophiolite at the Cretaceous-Paleocene boundary. • Chromium is also found in the uplifted Josephine Ophiolite in Washington. (Brownfield, et al, USGS, 1994) 38

  39. Glass Spherules • It has been shown that the glass spherules found within the KP boundary layer are altered oceanic basalt, which is why it is believed that the asteroid struck in an ocean basin. (Montanari, Hay, Alvarez, Alvarez, Asaro, Michel, and Smit, 1983) • These spherules contained high levels of Re-Os, also attributed to the asteroid. 39

  40. Glass spherules can be created by volcanic processes as magma comes into contact with water. The ocean floors surrounding seamounts are often littered with glass spherules. • Re-Os is also found in the ultramafic rocks of the Josephine ophiolite. (Bird, et al., 2002) 40

  41. “Shocked” quartz • Shocked quartz can also be created by geologic processes and is often found in uplifted ophiolites. • Charles Officer showed how shocked quartz was generated in the eruption of Toba. (Carter, Officer,Chesner and Rose, 1986) • The greywacke of the Franciscan consists of abundant angular quartz and deformation lamellae is present in quartz grains within the Franciscan. (Schemann, Unruh and Moores, 2008) 41

  42. Other Evidence • Air bubbles trapped in amber show that oxygen levels dropped from 35 parts per million at 67 Ma to 27 ppm at 65 Ma. (Dowswell, et al., 2000) • Dr. Gerta Keller showed that foraminefera began disappearing from the record 500,000 years before the KP boundary. (Keller, 2000 ) • High levels of CO2 cause calcium-bodied plankton to dissolve at depths of greater than 4500 ft below sea level. • This could show that CO2 was increasing in the ocean waters at the same time that oxygen levels were decreasing in the atmosphere, before the KP boundary. 42

  43. Miller and others show that at 67 Ma, sea levels dropped dramatically, but that by 65 Ma, sea levels had returned to near normal. (Miller, et al., 2003) 43

  44. But here, we have a chicken and egg problem…As this study was taken in New Jersey on the east coast of North America. • Could the uplifting that was occurring on the west coast cause the appearance of lower sea levels on the east coast? • If sea levels had dropped due to glaciation, as Miller suggests…wouldn’t the Seaway have returned once sea levels returned to normal at 65 Ma? 44

  45. The Real Killer? • Clues to the real killer in the KP Extinction Event, however, may be found in dinosaur eggshells recovered at the KP boundary, as high levels of Selenium have been recorded in them (Koch, ). • Fine particle emissions of the Kilauea eruption of 1983 showed high levels of Iridium, as well as high levels of Selenium, Arsenic, and Fluoride. The authors of this study suggested that the Iridium could have been released as volatile Iridium Hexaflouride (IrF6). (Zoller, 1983) 45

  46. Iridium is not attacked by water, or hydrochloric or nitric acids. It is, however, attacked by molten salts, (NaCl or NaCn). Iridium is also explosive when in contact with oxygen from the atmosphere. • If the Iridium was separated from the Hexafluoride…Hexafluoride combines with Selenium to become a poisonous gas. • Selenium hexafluoride, causes breathing difficulties and respiratory failure leading to death. • A poisonous gas would not show itself in the bones of dinosaurs, but would be recorded in eggshells and…in plants. 46

  47. Dr. Officer showed that high levels of selenium are still found in KP boundary soils throughout North America today. • This map shows where seleniferous plants in North America are still causing trouble for cattle and other wildlife, leading to sickness and death. • The USGS also maintains a Selenium de-contamination task force in the Great Valley of California today. (USGS, Menlo Park, California) Open dots-50-500 ppm selenium Black dots-more than 500 ppm selenium. (Rosenfeld and Beath, 1964, In Officer and Page, 1996.) 47

  48. Before 65 Ma 48

  49. After 65 Ma 49

  50. I will not argue here whether there was actually an asteroid or not. But, IF an asteroid did strike the Gulf at 65 Ma, it did NOT cause: • the uplifting of the entire ocean floor on the west coast, • the uplifting of the western half of the North American continent; • the disappearance of the Western Interior Seaway; • the change in oxygen/CO2 levels; • the drop in sea levels; • the volcanism that was occurring throughout the world at that time; • OR the Extinctions that were already occurring hundreds of thousands of years before it hit. 50

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