37 results found.
... Science Frontiers ONLINE No. 43: Jan-Feb 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Cretaceous Incineration The worldwide deposit of iridium at the end of the Cretaceous implies, to many at least, that the great biological extinctions of this period were the consequence of a meteorite impact. It has now been discovered that clay samples from the Cretaceous-Tertiary boundary also contain 0.36-0 .58% graphitic carbon. It is fluffy stuff and suggests that the planet was once covered by a thick layer of soot. Quantitatively, the soot layer is equivalent to the carbon in 10% of the earth's present biomass. The authors speculate that this soot was created by huge wildfires that consumed much of the earth's vegetation and perhaps fossil fuel as well. Terrestrial life was, of course, devastated -- just as it is in the currently popular "nuclear winter" scenarios. The end-of-the-Cretaceous soot is in fact, thicker and more widely spread than nuclear winter theories predict. (Wolbach, Wendy S., et al; "Cretaceous Extinctions: Evidence for Wildfires and Search for Meteoric Material," Science, 230:167, 1985.) Comment. Questions arise, though: How could a single meteorite impact ignite worldwide wildfires? Why haven't other meteorite impacts, recorded abundantly by large craters and astroblemes, also set fire to the planet and left iridium layers? From Science Frontiers #43, JAN-FEB 1986 . 1986-2000 William ...
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... Science Frontiers ONLINE No. 23: Sep-Oct 1982 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The cretaceous-tertiary extinction bolide The recently discovered worldwide iridium-rich layer is taken by many scientists as evidence of the collision of an asteroid or comet with the earth about 65 million years ago. This cataclysmic event is also blamed (by some, at least) for the apparent sudden biological extinctions recorded on these pages of the fossil record. In this setting, the authors of this paper calculate the effects on the earth of a 10-kilometer-diameter object impacting at about 20/km/sec. Do the theoretical results jibe with the geological and paleontological data? Very definitely. Crater ejecta rich in extraterrestrial material would be blasted to an altitude of 10 km, where winds would insure global distribution. In terms of biological stress, the 10-km projectile would transfer 40-50% of its kinetic energy to the atmosphere, creating a heat pulse that could raise global temperatures 30 C (50 F) for several days. Many large animals might well succumb to such a temperature transient. In addition, the protective ozone layer might be blown away by shock waves and not reform for a decade. (O 'Keefe, John D., and Ahrens, Thomas J.; "Impact Mechanics of the Cretaceous-Tertiary Extinction Bolide," Nature, 298,123, 1982.) Reference. We catalog biological extinctions at ESB1 in Anomalies in Geology. To order this book, visit: here ...
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... Science Frontiers ONLINE No. 60: Nov-Dec 1988 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Global fire at the k-t boundary The worldwide deposit of iridium at the K-T (Cretaceous-Tertiary) boundary has been considered very strong evidence that a large astronomical object (asteroid or comet) devastated our planet some 65 million years ago. Some scientists, however, propose that the iridium layer was instead deposited through widespread volcanic activity. The proponents of an astronomical mechanism should be heartened by a recent paper in Nature, by W.S . Wolbach et al. Here is their Abstract: "Cretaceous-Tertiary (K -T ) boundary clays from five sites in Europe and New Zealand are 102 -104 -fold enriched in elemental C (mainly soot), which is isotopically uniform and apparently comes from a single global fire. The soot layer coincides with the Ir layer, suggesting that the fire was triggered by meteorite impact and began before the ejecta had settled." The composition of the hydrocarbons in the sediments points to the earth's biomass (mainly surface vegetation) as the source of the soot. The total quantity of K-T soot is equivalent to that which would be produced by burning 10% of all present terrestrial plant material. (Wolbach, Wendy S., et al; "Global Fire at the Cretaceous-Tertiary Boundary," Nature, 334:665, 1988.) Comment. Unmentioned in the above article is the possibility that extensive wildfires might have been ...
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... Science Frontiers ONLINE No. 12: Fall 1980 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Rehabilitation Of Cuvier Cuvier (1769-1832) was a catastrophist. To him, the record of death in the layers of fossiliferous rocks was obviously the consequence of terrestrial convulsions. But Cuvier's ideas were swept aside by the uniformitarians who saw the earth and its cargo of life unfolding with almost agonizing slowness. But Cuvier is making a comeback, as illustrated by the following back-to-back articles in Nature. We quote from the abstracts. "Closely spaced samples from an uninterupted calcareous pelagic sequence across the Cretaceous-Tertiary boundary reveal that the extinction of planktonic Foraminifera and nannofossils was abrupt without any previous warning in the sedimentary record, and that the moment of extinction was coupled with anomalous trace element enrichments, especially of iridium and osmium. The rarity of these two elements in the crust of the Earth indicates that an extraterrestrial source, such as the impact of a large meteorite may have provided the required amounts of iridium and osmium." (Smit, J., and Hertogen, J.; "An Extraterrestrial Event at the Cretaceous-Tertiary Boundary," Nature, 285:198, 1980.) "Evidence is presented indicating that the extinction, at the end of the Cretaceous, of large terrestrial animals was caused by atmospheric heating during a cometary impact and that the extinction of calcareous marine plankton was a consequence of poisoning by cyanide released by the fallen comet and of a catastrophic rise in calcitecompensation depth in ...
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... Science Frontiers ONLINE No. 26: Mar-Apr 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Punching A Hole In The Asteroid Hypothesis Scientists have long searched for a cause for the profound geological and biological changes that apparently occurred between the Cretaceous and Tertiary periods. When an iridium-rich layer was found in several areas at this important boundary, many claimed it as proof of an asteroid impact or some other catastrophism that would nicely explain the massive worldwide changes that occurred. With this preamble in mind, consider the following abstract from an article in Science: "Analyses of the clay mineralogy of samples from the Cretaceous-Tertiary boundary layer at four localities show that the boundary clay is neither mineralogically exotic nor distinct from locally derived clays above and below the boundary. The significant ejecta component in the clay that is predicted by the asteroid impact scenario was not detected." (Rampino, Michael R., and Reynolds, Robert C.; "Clay Mineralogy of the Cretaceous-Tertiary Boundary Clay," Science, 219:1983.) From Science Frontiers #26, MAR-APR 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 37: Jan-Feb 1985 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects More Doubts About Asteroids In an apparent reaction to the stampede to climb aboard the extinction-by-asteroid bandwagon, dissenting papers have begun to appear in the scientific literature. For example, Van Valen's list of objections to the hypothesis of asteroid impact at the Cretaceous-Tertiary boundary was reproduced in the last issue of Science Frontiers. Now, in a recent issue of New Scientist, T. Hallam raises still more objections: Tropical plants, mammals, crocodiles, birds, and benthic invertebrates were little affected by whatever happened at the Cretaceous-Tertiary interface. Furthermore, many groups that were extinguished were already well into a decline. Some geologists insist that some of the supposedly synchronous extinctions were probably separated by several hundred thousand years; viz., plankton and dinosaurs. The vaunted iridium anomaly in deep-sea cores is spread through a considerable thickness of sediment. Even after allowing for the mixing of sediments, the iridium-rich layer is thousands of years thick. According to the asteroid scenario, the clay layer separating the Cretaceous from the Tertiary should represent the fallout from impact-raised dust, which would include asteroidal material and a mixed sample of earth rocks. However, in Denmark, the boundary is marked by the so-called Fish Clay, which is almost pure smectite -- a single mineral and not a mixture of terrestrial rock flour. If it wasn't an asteroid impact, why the ...
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... Science Frontiers ONLINE No. 26: Mar-Apr 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Prescient Evolution Lately, a fossil moth egg was found in 75-million-year-old sediments in Massachusetts. The egg is positively assigned to the moth family Noctuidae and extends the fossil record of this family back into the Cretaceous. So what? Well, it turns out that Noctuidae family moths have special organs for detecting the ultrasonic cries of insect-hunting bats. The fossil record of the bats, however, only goes back to the early Eocene, perhaps 20 million years after the Noctuidae moths. Since no other insect predators like bats existed, it would seem that the moths developed these special organs in anticipation of the bats! (Gall, Lawrence F., and Tiffney, Bruce H.; "A Fossil Noctuid Moth Egg from the Late Cretaceous of Eastern North America," Science, 219:507, 1983.) Comment. Do humans have talents that seem unimportant now but which may be useful some day? Calculating prodigies, eidetic imagers, etc. From Science Frontiers #26, MAR-APR 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 15: Spring 1981 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Iceland And The Iridium Layer The high concentration of iridium between the Cretaceous and Tertiary eras (about 65 million years ago) is widely interpreted as indicating a worldwide catastrophe caused by the impact of a comet or meteor. The increase of iridium concentration over normal levels is much higher in northern latitudes, suggesting that the impact point is in this region. But no impact scar of the proper size and age exists. However, if one looks for scabs rather than scars, one finds that Iceland is formed entirely of volcanic rocks younger than the Cretaceous. To Fred Whipple of the Smithsonian Astrophysical Observatory, these facts dovetail nicely. Iceland was form ed by magma welling up from a 100-km hole in the sea floor blasted out by a 10-km meteor. (Anonymous; "The Blow That Gave Birth to Iceland?" New Scientist, 89:740, 1981.) From Science Frontiers #15, Spring 1981 . 1981-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 36: Nov-Dec 1984 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Case Against Impact Extinctions The neocatastrophists seem to be getting overly smug with their iridium-rich deposits at the Cretaceous-Tertiary boundary. Is there really incontrovertible evidence that a large asteroid or comet hit the earth at this point in history, causing widespread biological extinctions? To add some perspective, Leigh M. Van Valen has tossed 15 arguments against impact extinctions on the scales. Ten of these are reproduced below, as taken from Nature. More de-tails may be found in Paleobiology, 10: 121, 1984. Freshwater life was unaffected; In Montana and its vicinity, the last occurrence of dinosaurs was detectably below the crucial boundary; Transitional floras also exist below the boundary; Apparently extraterrestrial material exists below the boundary; The expected effects of eliminating atmospheric ozone are missing; The Cretaceous-Tertiary boundary is coincident with a very large marine regression, suggesting a nonextraterrestrial cause; Marsupials but not placentals were nearly eliminated, while most aboreal multituberculates (a type of vertebrate) and birds survived; The predicted cooling effects on the earth are absent; The predicted effects of acid rain cannot be found; and Assuming a marine impact, no turbidites can be found; assuming a land impact, no large terrestrial crater has been discovered. (Van Valen, Leigh M.; "The Case against Impact Extinctions," Nature, 311:17, 1984.) From Science Frontiers #36, NOV-DEC 1984 . ...
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... Science Frontiers ONLINE No. 63: May-Jun 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects More confusion at the k-t boundary Just a few years ago, many scientists, especially physicists and astronomers, considered the Book of Science to be closed in the matter of what happened at the Cretaceous-Tertiary (K -T ) boundary, 65 million years ago, and why the dinosaurs met their end. It was declared, rather imperiously, that a large asteroid had impacted the earth, causing much physical and biological devastation. Many scientific papers are still being written on this singular period in the earth's history, and the situation is no longer so clear-cut. We select for brief review four papers, each with a different perspective. Occurrence of stishovite. Stishovite, a dense phase of silica, is widely accepted as an indicator of terrestrial impact events. It is not found at volcanic sites. Now, J.F . McHone et al report its existence at the K-T boundary, at Raton, New Mexico. (McHone, John F., et al; "Stishovite at the CretaceousTertiary Boundary, Raton, New Mexico," Science, 243:1182, 1989.) A plus for the pro-impact side. The impact of an asteroid can initiate basaltic flooding and trap formation. Evidence of a global fire. Soot appears at the K-T boundary at many sites, but where did it come from? Chemical analyses of these soots show an enhanced concentration ...
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... Science Frontiers ONLINE No. 132: NOV-DEC 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Sandslides: Desert Catastrophes Some of the most important fossil discoveries being made today come from the desolate Gobi Desert -- a most unlikely place for the sudden mass burial of agile animals. Furthermore, the fossils now coming to light in the Gobi sandstones are not only abundant but also preserved with great fidelity. For example, at Ukhaa Tolgod, paleontologists are excavating the planet's largest assemblage of fossil vertebrates from the end of the Cretaceous Period (71-75 million years ago). In 1993, about 1,000 fossils representing 20 species of mammals and reptiles were collected. Amazingly, these bones were not disarticulated, scattered about, or severely worn. It was obvious that the Ukhaa Tolgod animals had been very suddenly engulfed by a "tidal wave" of sand. It was a catastrophic event of some sort. But what kind of catastrophes occur on desolate, riverless deserts? Wind is always blowing sand about and dunes creep along in deserts, but healthy animals easily avoid burial. Of course, there are rare, sudden downpours even on the Gobi. But one would expect this rain to be quickly absorbed by the sand. Intrigued by the evidence of unexpected catastrophism in the Gobi, scientists from the American Museum of Natural History first took a look at Nebraska's strange Sand Hills. These Sand Hills stretch for thousands of square miles, reach heights of 400 feet, and are believed to be of aeolian ...
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... Science Frontiers ONLINE No. 73: Jan-Feb 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Asteroid impact or volcanos?The debate over the real cause of the terrestrial catastrophism that occurred at the Cretaceous-Tertiary boundary, some 65 million years ago, grinds on. Some physical scientists claim rather imperiously that the dinosaurs and many other species were done in by the impact of a huge asteroid/meteorite. The worldwide iridium spike is conclusive, they say. Many paleontologists and geologists, however, remain unconvinced and prefer widespread volcanism. We have already covered the various arguments in past issues of Science Frontiers; here, we want to advise our readers that a pair of excellent articles by principals in this debate have appeared in Scientific American. Generally speaking, it seems that the proponents of the impact theory are now listening to the other side. For example, multiple impacts are now proposed to account for evidence of the type introduced below. (Alvarez, Walter, and Asaro, Frank; "An Extraterrestrial Impact," Scientific American, 263:78, October 1990. Also: Courtillot, Vincent E.; "A Volcanic Eruption," Scientific American, 263:85, October 1990.) A spike dulled. The case for a single asteroid/meteorite impact has been weakened by a recent reexamination of the classic exposure of the CretaceousTertiary boundary at Gubbio, Italy. Here, the discovery of an iridium "spike" at the boundary was thought to betoken a sudden, catastrophic, extraterrestrial event. On further ...
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... Science Frontiers ONLINE No. 30: Nov-Dec 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Arctic Womb "Magnetostratigraphic correlation of Eureka Sound Formation in the Canadian High Arctic reveals profound difference between the time of appearance of fossil land plants and vertebrates in the Arctic and in mid-northern latitudes. Latest Cretaceous plant fossils in the Arctic predate mid-latitude occurrences by as much as 18 million years, while typical Eocene vertebrate fossils appear some 2 to 4 million years early." (Hickey, Leo J., et al; "Arctic Terrestrial Biota: Paleomagnetic Evidence of Age Disparity with Mid-Northern Latitudes During the Late Cretaceous and Early Tertiary," Science, 221:1153, 1983.) Comment. The anomaly here is in the vision of the high Arctic lands basking in the warm sun busily evolving new life forms well in advance of their appearance in lands closer to the Equator. What happened to the earth's axial tilt. These fecund polar territories should have been engulfed in darkness almost half of the year -- hardly an environment for precocious plant evolution. Further, trees found buried in the Arc-tic muck could never have grown where found due to the long polar darkness. From Science Frontiers #30, NOV-DEC 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 32: Mar-Apr 1984 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Osmium Isotopes Support Meteoric Impact Comparison of terrestrial and meteoric osmium-isotope abundances tends to confirm the hypothesis of a meteorite strike at the Cretaceous-Tertiary boundary. (Luck, J.M ., and Turekian, K.K .; "Osmium-187/Osmium-186 in Manganese Nodules and the Cretaceous-Tertiary Boundary," Science 222:613, 1983.) From Science Frontiers #32, MAR-APR 1984 . 1984-2000 William R. Corliss ...
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... distances exceeding 800 kilometers and are believed to be the consequence of climatic changes associated with the earth's precession and orbital eccentriciy. These rhythms have been captured in bundles of shale-limestone couplets. A bundle of five coup lets, for example, is thought to express 21,000- and 100,000-year Milankovitchtype climatic cycles, as impressed by variations in the earth's orbital precession and eccentricity. Analysis of the Fort Hays Limestone Member, however, reveals that while bundles of five couplets do occur, the number may vary from 1 to 12. Clearly, things are not clear-cut. (Laferriere, Alan P., et al; "Effects of Climate, Tectonics, and Sea-Level Changes on Rhythmic Bedding Patterns in the Niobrara Formation (Upper Cretaceous), U.S . Western Interior," Geology, 15:233, 1987.) Comment. As the rather comprehensive title of this article states, purely terrestrial forces may alter the rhythm. It may be, though, that cyclothem changes reflect actual changes in the earth's orbit resulting from astronomical catastrophism. The Cretaceous saw many geological and biological changes. Cyclothems may tell us more about them. All ten members are never present at one location. The most common sequences are 1, and/or 2, 4, 5, 8, 9 and 10. From Science Frontiers #55, JAN-FEB 1988 . 1988-2000 William R. Corliss ...
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... cling to the southwest corners of the headlands along the NSW coast south of Newcastle. In their scenario, the tsunamis came from the northeast, smashed into the Solomons, southeastern Australia, and northeastern New Zealand. The Great Barrier Reef protected northeastern Australia from the full force of the wave. Young and Bryant favor a Hawaiian landslip as the initiator of the tsunamis, but acknowledge that an asteroid impact could also have done the job. If the wave began near Hawaii, it would initially been about 375 meters (about mile) in height. (Davidson, Garry; "A Tsunamis Tale from Sydney," New Scientist, p. 17, October 17, 1992.) 65,000,000 BP. Northeastern Mexico. The date mentioned is, of course, that of the Cretaceous-Tertiary boundary. This is the time when, many scientists believe, a very large asteroid slammed into northern Yucatan, forming the now-buried Chicxulub crater and wiping out the dinosaurs. Since the impact site was covered with ocean at the time, a powerful tsunamis should have surged out from this area. Indeed, debris attributable to a tsunami has been found on the U.S . Gulf Coast and on some Caribbean islands. J. Smit et al now report finding a layer of debris up to 3 meters thick in northeastern Mexico. This layer was apparently deposited in water about 400 meters deep as the giant wave wreaked havoc along Mexico's shore and its backwash piled up debris offshore. This interpretation is supported by the presence of tektites, microtektites, glass spherules, ...
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... Rock where, atop a 76-meter (250-foot) hill are perched giant blocks of sandstone. These blocks range up to 7.6 meters (25 feet) in size and weigh many tons. No native rocks in the area match them. The Ice Age glaciers never reached Arkansas, so they can't be glacial erratics. Where did they come from? One clue is the presence of glauconite in the sandstone. Glauconite is common in marine rocks, so suspicion points toward the Gulf of Mexico. Geologist G. Patterson, University of Memphis, thinks that the huge chunks of sandstone came from coastal Louisiana and were carried some 650 kilometers (400 miles) inland by the giant tsunami raised by the asteroid or comet that smashed into the Yucatan to close out the Cretaceous. That, of course, was when the dinosaurs were forced into oblivion. But could the tsunami really have transported such huge rocks 650 kilometers? (Falk, Dan; "Washed Up," New Scientist, p. 26, November 7, 1998.) Comments. Tsunami debris from the end-Cretaceous impact has been found along the Gulf Coast and on some Caribbean islands. In northeastern Mexico, geologists have found a debris layer 3-meters thick that is also of the right age. This layer contains tektites, glass spheres, plant material, and an iridium anomaly. (SF#85) However, these debris deposits can hardly compare to the far-inland Arkansas sandstone chunks. From Science Frontiers #121, JAN-FEB 1999 . 1999-2000 William ...
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... Science Frontiers ONLINE No. 75: May-Jun 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Looking For The Smoking Gun We already know the victims (the dinosaurs and other fauna and flora), and there is considerable evidence that the bullet was a cosmic projectile of some sort. The absence of a smoking gun (a sufficiently large terrestrial crater with an age of 65 million years) has allowed volcanists to deny the cosmic catastrophists a complete victory. However, the recent identification of tektite-like glasses at the Cretaceous-Tertiary boundary (KTB) on Haiti is leading geological detectives closer and closer to the missing crater. Elsewhere in the world, the KTB is characterized by an iridium anomaly and a thin layer of "impact clay" consisting of tiny bits of shocked minerals. At Beloc, on Haiti, though, geologists find a 55-centimeter-thick layer of glassy debris. Approximately 25% of this stra tum consists of 1-6 -millimeter particles of tektite-like glass. Most of the glass particles are spherical, but a few have the splash-forms and dumbbell shapes of bona fide tektites. The thickness of the Haitian deposit and the large sizes of the particles suggest that the smoking gun must be nearby. Ironically, the Haiti stratum was originally classified as of volcanic origin; and we must add that we are presenting here only the conclusions of the asteroid school. But where oh where is this crater? The Manson crater in Iowa (now buried) is of the right age ...
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... Science Frontiers ONLINE No. 28: Jul-Aug 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Alaskan Jigsaw Puzzle Alaska seems to be plastered together from bits and pieces that originated far from the present position of this state. The units that now make up southern Alaska, for example, started north of the equator 250 million years ago, crossed into the southern hemisphere, and started back north about 160 million years ago. However, the itinerary of northern Alaska cannot even be guessed at. Present thinking is that this portion of the state was close to the geographic north pole during the late Cretaceous. But this is the period when the huge coal deposits were formed on the Arctic slope. Much of this coal comes from evergreens, which could not have survived in high latitudes due to the lack of sunlight. So, the pieces of the puzzle are at hand, but their travels are a mystery. (Anonymous; "Fragmented Alaska," Open Earth, no. 17, 1982.) Reference. For more on exotic terranes, see ESR9 in our Catalog: Inner Earth. Ordering information here . From Science Frontiers #28, JUL-AUG 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 67: Jan-Feb 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Microorganisms complicate the k-t boundary Ancient bacteria, it appears, have tampered with the K-T (Cretaceous-Tertiary) boundary of some 65 million years ago. A key marker of this boundary is a thin "spike" of iridium that is found worldwide, and which was supposedly deposited by the asteroid impact that helped finish off the dinosaurs. For many scientists, the asteroid-impact scenario has become a "non-negotiable" brick in the Temple of Science. The problem they have faced is that the iridium layer is variable in thickness and concentration from site to site. Sometimes iridium can be detected well above and below the K-T boundary. This variability has tended to undermine the asteroid-impact theory. Recent experiments at Wheaton College by B.D . Dyer et al have demonstrated that bacteria in ground water can both concentrate and disperse iridium deposits. In other words, bacteria could smear out an iridium spike, perhaps partially erase it, or even move it to a deeper or shallower layer of sediment. (Monastersky, R.; "Microbes Complicate the K-T Mystery," Science News, 136: 341, 1989.) Comment. An obvious question now is how bacteria might have affected other chemicals, such as oxygen and carbon isotopes, widely used in stratigraphy. From Science Frontiers #67, JAN-FEB 1990 . 1990-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 8: Fall 1979 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Iridium And Mass Extinctions Alvarez and his colleagues at the University of California, while chemically analyzing a series of sedimentary strata from Italy, discovered that one layer had 25 times the concentration of iridium residing in adjacent strata. The iridium-rich layer forms the boundary between the Cretaceous and Tertiary periods, 65 million years ago. During that death-filled interval, 50% of the earth's genera were wiped out. Such are the two correlated facts: iridium increase and mass extinction. But do they have the same cause? Alvarez et al point out that iridium is rare on earth but much more common out in space. The anomalous concentration of iridium could have been injected by a massive solar flare, a big meteor impact, or come other extraterrestrial catastrophe. Thus is catastrophism being resurrected. (Anonymous; "An Iridium Clue to the Dinosaur's Demise," New Scientist, 82: 798, 1979.) From Science Frontiers #8 , Fall 1979 . 1979-2000 William R. Corliss ...
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... solar system. In short, a large, interlocking edifice of geological and astronomical speculation has been erected upon a foundation of terrestrial crater ages. But how well do we really know the ages of these craters? How complete is the cratering record? The answer to the first question is: "Not well at all." Further, we can be certain that many craters still lie undiscovered beneath sediments. In addition, most meteors/comets splashed into the oceans, leaving no record at all. An updating of the most recent crater data available, such as they are, greatly weakens the case for the popular 28-31 million-year period and strengthens support for a 19-22 million-year period. But neither cycle is in synchronism with the famous K-T (Cretaceous-Tertiary) Boundary, with its perplexing iridium layer and massive biological extinctions. In fact, say V.L . Sharpton et al, the entire known cratering record could well be the consequence of chance encounters between the earth and stray meteors and comets. Thus would pass the periodicities of this world! (Sharpton, V.L . et al; "Periodicity in the Earth's Cratering Record?" Eos, 68: 344, 1987.) Reference. More details on crater periodicity may be found in ETC4 in our catalog: Carolina Bays, Mima Mounds. For information on this book, see: here . From Science Frontiers #52, JUL-AUG 1987 . 1987-2000 William R. Corliss ...
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... s history is not set by Darwin's slow biotic mechanisms, then I think Darwin is in trouble. Is catastrophic mass extinction a major agent of patterning?' If so, 'impacts are a quirky aspect' of the process." Who is speaking within the single quotes above? S.J . Gould, a proponent of the punctuated equilibrium view of the evolutionary scenario. He added: "' The history of life is enormously more quirky than we imagined.'" In fact, the geological record shows so many quirk-inducing impacts that there is little room left for slow, plodding, uniformitarian evolution of the earth itself, life-in-general, and humanity. Mammals, for example, may not have survived the postulated (but now assumed factual) Cretaceous-Tertiary impact event simply because they were small in size - not smarter. (Kerr, Richard A.; "Huge Impact is Favored K-T Boundary Killer," Science, 242:865, 1988.) Comment. It now seems that Cassius was wrong about the stars when he was lining up Brutus to help assassinate Julius Caesar. And the "celestial" situ ation gets even worse below. From Science Frontiers #61, JAN-FEB 1989 . 1989-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 16: Summer 1981 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Paradox Of The Drowned Carbonate Platforms The biological processes that build carbonate reefs and platforms are so efficient that platform growth potential is easily several times the rate of average geological subsidence or sea-level rise. Therein lies the paradox: the geological record is full of drowned carbonate platforms, inferring that the sea has frequently engulfed them in episodes that must be termed catastrophic. Since the usual long-term geologic processes are clearly inadequate, Schlager proposes several more violent schemes; including massive submarine volcanism (Middle Cretaceous) and extraterrestrial deterioration of the oceanic biological environment (Lake Devonian). (Schlager, Wolfgang; "The Paradox of Drowned Reefs and Carbonate Platforms," Geological Society of America, Bulletin, 92:197, 1981.) Reference. See Category ETE2 in our Catalog: Carolina Bays, Mima Mounds, for more on drowned sections of crust. More on this book can be found here . From Science Frontiers #16, Summer 1981 . 1981-2000 William R. Corliss ...
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... News, 130:103, 1986.) Chatterjee has named the new fossil Protoavis. "Protoavis seems certain to reopen the long-running controversy on the evolution of birds. In particular whether the common ancestor of birds and dinosaurs was itself a dinosaur. Protoavis, from the late Triassic, appears at the time of the earliest dinosaurs, and if the identification is upheld it seems likely that it will be used to argue against the view of John Ostrom of Yale University that birds are descended from the dinosaurs. It also tends to confirm what many paleontologists have long suspected, that Archaeopteryx is not on the direct line to modern birds. It is in some ways more reptilian than Protoavis, and the period between the late Jurassic Archaeopteryx and the world-wide radiation of birds in the Cretaceous has to some seemed suspiciously brief." (Anonymous; "Fossil Bird Shakes Evolutionary Hypotheses," Nature, 322:677, 1986.) Comment. But what about all those textbooks that assure us positively that birds descended from dinosaurs and that Archaeopteryx is a classic missing link? Fossil bones and artist's reconstruction of Protoavis. From Science Frontiers #48, NOV-DEC 1986 . 1986-2000 William R. Corliss ...
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... pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects An Antarctic Bone Bed W. Zinsmeister was accustomed to scoff at the idea that the Age of Dinosaurs ended violently with the impact of a giant asteroid some 65 million years ago. He always asked: "Where's the layer of burnt and twisted dinosaur bones?" His certainty was shaken, however, when he began mapping fossil deposits on Seymour Island, Antarctica. He didn't find the dinosaur bones but rather a giant bed of fish bones at least 50 square kilometers in area. Some sort of catastrophe must have annihilated untold millions of fish. And guess what? This great bone bed was deposited directly on top of that layer of extraterrestrial iridium that marks the 65-million-year-old Cretaceous Tertiary boundary at many sites around the world. (Hecht, Jeff; "The Island Where the Fish Had Their Chips," New Scientist, p. 16, November 11, 1995) Cross reference. Bone beds of fish and other creatures are filed under ESB13X2 in Anomalies in Geology. To order this catalog, see here . From Science Frontiers #104, MAR-APR 1996 . 1996-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 21: May-Jun 1982 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Bull's eye pattern of magnetic anomalies In SF#20, concentric rings of gravity anomalies centered in Canada are described. A similar patter of magnetic rings has shown up in the Yucatan peninsula. The inner ring is 60 kilometers across; the second, 180 kilometers. The rocks causing the magnetic anomalies are about 1100 feet down. Since these rocks are probably Late Cretaceous in age, this potential impact feature may be the eagerly sought scar of the asteroid impact that some think wiped out the dinosaurs and left an iridium-rich layer all over the world. (Anonymous; "Possible Yucatan Impact Basin," Sky and Telescope, 63:249, 1982.) From Science Frontiers #21, MAY-JUN 1982 . 1982-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 65: Sep-Oct 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Chemical surprises at the k-t boundary The presence of high iridium concentrations at the Cretaceous-Tertiary (K -T ) boundary, some 65 million years ago, has led to the widely accepted notion that an extraterrestrial projectile slammed into the earth at that time, wreaking geological and biological havoc. But the K-T boundary is anything but simple chemically and paleontologically. To illustrate, J.L . Bada and M. Zhao have found unusual amino acids in sediments laid down before and after this geological time marker. "They find that Danish sediments spanning the narrow boundary layer contain two amino acids, alpha-aminoisobutyric acid and isovaline, that are relatively uncommon in biological materials but abundant in the organicrich meteorites. They suggest that the body which collided with Earth 65 million years ago and left the telltale iridium residue may have been organic-rich, perhaps like a C-type asteroid or a comet. Such a possibility has interesting implications for the extinction and related atmospheric effects, and supports the idea that impact events could have supplied the Earth during a much earlier period with the raw materials for organic chemical evolution." Actually, the above quotation is pretty much in line with present mainstream thinking. Perhaps so, but Bada and Zhao identified two troubling anomalies. First, the amounts of amino acids found were surprisingly high. How could these complex molecules survive the searing temperatures engendered by high-velocity impact? Second ...
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... Science Frontiers ONLINE No. 23: Sep-Oct 1982 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology Ancient Mud Structures in Colorado Astronomy At Poverty Point Astronomy The Cosmic Whirl Where Are the Primordial Stars? Biology Chessie Captured on Videotape Short-circuiting Heredity Remarkable Engineering Design in Nature Geology Facing Up to the Gaps The Cretaceous-tertiary Extinction Bolide Geophysics Zoom Lens in the Atmosphere Psychology High Technology Experiments in Parapsychology ...
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... Science Frontiers ONLINE No. 56: Mar-Apr 1988 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Wandering Molluscs "How could a mollusc which lived all its adult life cemented fast to the seabed in shallow water occur thousands of kilometers apart in the Arabian Gulf and the Caribbean? Almost identical forms of the extinct bivalve Torreites sanchezi have been found in rocks from the Caribbean and the Gulf. Peter Skelton of the Open University and Paul Wright of the University of Bristol suggest that the larval stage of the bivalve must have 'island hopped.'" The two researchers rule out convergent evolution and note that the two seas were never any closer together. They suppose that in Cretaceous times there was an equatorial current that swept the larval forms long distances. (Anonymous; "Wandering Molluscs," New Scientist, p. 33, October 15, 1987.) Comment. The same situation prevails for other species, such as some of the amphipods and the unique life forms dependent on seafloor vents. From Science Frontiers #56, MAR-APR 1988 . 1988-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 43: Jan-Feb 1986 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology The Mysterious Tumuli of New Caledonia How Old is the Los Lunas Inscription? A Japanese Presence in Ancient Mexico? Astronomy Waiting for Saturn's Rings to Collapse Anomalous Distribution of Large, Fresh Lunar Craters The Planets As Fragments of An Ancient Companion of the Sun A Recent Transformation of Sirius? Biology & Geology The Return of the Tasmanian Tiger Life Seeks Out Energy Sources Wherever They May Be The Biological Diversity Crisis Treasures in A Toxonomic Wastebasket Piscatorial Data Processing Exploring the Suberranean World of Life The Cretaceous Incineration Everglades Astrobleme? Geophysics Underground Weather 1500-pound Ice Chunk Falls From Sky Psychology The Voice of God Chemistry & Physics "And So on Infinitum" The Thorny Way of Truth: Part II ...
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... Science Frontiers ONLINE No. 47: Sep-Oct 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Two Points Of Great Impact Geologists have been searching in vain for a large crater that might account for the biological extinctions at the Cretaceous-Tertiary boundary some 65 million years ago. C.J .H . Hartnady believes he had found the culprit. It is somewhat larger than expected (300 kilometers in diameter instead of 100200), but it is of the right age. Supporting this notion is the observation that the Seychelles Bank and Madagascar suddenly shifted their locations at about this time. (Murray, M.; "Point of Impact: The Indian Ocean," Science News, 129:356, 1986.) The existence of another terrestrial cat aclysm at an earlier date is suggested by a layer of shattered crustal rock fragments stretching over at least 260 kilometers in South Australia. Folded within Precambrian marine shales, these fragments reach 30 centimeters in diameter and show evidence of vertical fall. Evidence points to an origin near Lake Acraman, about 300 kilometers west. (Gostin, Victor A., et al; "Impact Ejecta Horizon within Late Precambrian Shales, Adelaide Geosyncline, South Australia," Science, 233:198, 1986.) Reference. The subject of very large terrestrial craters is discussed in ETC2 in our catalog: Carolina Bays, Mima Mounds. Description here . The Amirante Basin (black circle) lies about 500 kilometers north-east of Madagascar. From Science Frontiers #47, SEP-OCT ...
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... features of the earth's evolution. For example: Impacts have determined the positions of the continents. They have controlled the geomagnetic field. They have created volcanoes and massive basalt flows. They have caused mass extinctions. Of course, for two centuries, other catastrophists have proposed similar dire consequences of giant impacts. But Shaw does introduce three ideas that are worth recording here. Large impact craters occur in swaths. Although this has been suggested before, Shaw has mapped out several swaths where large craters of about the same age are located. His "K -T swath" includes the Chicxulub crater (Yucatan), the Manson crater (Iowa), the Avak crater (Alaska), and three more in Russia -- all of which were gouged out about the time of the Cretaceous-Tertiary (K -T ) boundary. Shaw has plotted several other swaths of different ages. The application of chaos theory to solar system debris. Shaw hypothesizes that nonlinear gravitational effects channel asteroids and comets into the inner solar system in intermittent bursts. The bursts are then captured by the earth and other inner planets, with some of these objects grouped in like orbits. Gravitational feedback occurs from earth to orbiting debris. Shaw believes that the uneven distribution of mass inside the earth -- due probably to the impact that created the moon -- influences where asteroids and comets impact. In turn, these large objects keep smashing into the same regions and their cumulative effect contols the flow of material inside the earth. Then, this change in mass distribution feeds back to change orbits and ...
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... that resemble lunar maria include, among others, the Deccan Plateau of India, the Columbia Plateau of western North America, the Parana Plateau of South America, and the Tungusska Basin of Siberia. All consist mostly of basalt lava flows; those on continents include minor quantities of rhyolite, and variable amounts of sediment. All seem to have appeared suddenly, within plates. No consistent context of plate interactions explains them. We suggest that large lava plateaus are indeed terrestrial maria." Alt et al go on to show that these lava plateaus seem to have initiated continental rifts and hotspot tracks where none existed before. A reasonable inference is that these plateaus are the consequence of the impacts of large meteorites. This is particularly the case with the Deccan Plateau, which is agedated as synchronous with the Cretaceous-Tertiary Boundary event, with its legacy of worldwide iridium deposits and the wholesale extinction of life. The paper concludes with: "It therefore appears that random encounters with vagrant asteroidal objects play an important role in setting the course of plate tectonic events. The earth does not control its own agenda." (Alt, D., et al; "Terrestrial Maria: The Origins of Large Basalt Plateaus, Hotspot Tracks and Spreading Ridges," Journal of Geology, 96:647, 1988.) From Science Frontiers #61, JAN-FEB 1989 . 1989-2000 William R. Corliss ...
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... to be derived from advanced organisms, but there were plenty of chemicals typical of primitive bacteria. The mere existence of commercially exploitable deposits of Precambrian oil implies that, far from being devoid of life, the ancient earth was host to immense accumulations of bacteria and other simple organisms. (Anonymous; "Ancient Oil in Australia: A New Bonanza?" New Scientist, p. 26, September 11, 1936.) Comment. As discussed above this Australian oil might have been produced abiogenically. The surface and near-surface Athabasca oil sands in western Canada constitute a well-known deposit of almost unbelievable size. Geologists have long speculated about where such an immense quantity of biological matter could have originated. (Few dare to suggest nonbiological origins!) Now, we learn that below the Cretaceous Athabasca oil sands lies a 70,000 square kilometer "carbonate triangle" estimated to contain about 2 x 1011 cubic meters (about 6 cubic kilometers) of bitumen. This bitumen is closely related chemically to the oil sands above it. A common origin seems likely. (Hoffmann, C.F ., and Strausz, O.P .; "Bitumen Accumulation in Grosmont Platform Complex, Upper Devonian, Alberta, Canada," American Association of Petroleum Geologists, Bulletin, 70:1113, 1986.) Comment. Many geologists believe that these incredible accumulations of organic matter migrated from some distant source to their present location. But just where was this prodigious wellspring of biological activity? Reference. Controversies regarding the origin of oil are covered in ESC13 in our catalog: Anomalies in ...
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... ten times the rate of continental drift. The earth from afar must have seemed to be a disturbed top---on a geological time scale, of course! What could have perturbed the earth? One suggestion blames a sudden shifting of the planet's mass distribution, some sort of subterranean indigestion, like a subducted ocean plate suddenly plunging through into the lower mantle. (Kerr, Richard A.; "Did the Dinosaurs Live on a Topsy-Turvy Earth?" Science, 287:406, 2000.) The biological consequences of such a sudden tilting could have been severe. The event -- known as rapid true polar wander -- may have been accompanied by worldwide volcanic upheavals and reorganization of tectonic plates that would have played havoc with anything living in the Late Cretaceous period, 65 million to 99 million years ago. Although the notion that an asteroid was the immediate cause of dinosaur extinction about 65 million years ago has won wide acceptance, many paleontologists have argued that volcanic activity may have played a role in changing the climate and sending populations of the giant creatures into decline. (Bowman, Lee; "Scientist's Say Earth's Magnetic Field Shifted Rapidly in Time of Dinosaurs," Dallas Morning News, January 21, 2000. Cr. Phelps) Comment. Coincidentally (honest!), we are offering with this mailing a reprint of C.H . Hapgood's The Path of the Pole. From Science Frontiers #128, MAR-APR 2000 . 1997 William R. Corliss Other Sites of Interest SIS . Catastrophism, ...
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... Science Frontiers ONLINE No. 18: Nov-Dec 1981 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Iridium-rich layers and catastrophism Kyte et al have discovered a 2.3 -millionyear-old sedimentary layer under the Antarctic Ocean that contains iridium and gold concentrations comparable to those in the Cretaceous-Tertiary boundary. The noble metals are mostly contained in millimeter-sized grains that resemble ablation debris from a large extraterrestrial object. Unlike the Cre taceous-Tertiary episode, however, the newly found layer is not accompanied by evidence of mass biological extinctions. (Kyte, Frank T., et al; "High Noble Metal Concentrations in a Late Pliocene Sediment," Nature, 292:417, 1981.) Comment. Perhaps those paleontologists who deny the existence of sudden biological extinctions at the CretaceousTertiary boundary are correct and something else besides catastrophism impacted terrestrial life at that juncture. Reference. The implications of iridium "spikes" are found in Category ESB1 in our Catalog: Anomalies in Geology. To order, go to: here . From Science Frontiers #18, NOV-DEC 1981 . 1981-2000 William R. Corliss ...
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