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... 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 of polycyclic aromatic hydrocarbons over soots above and below the boundary. This is strong evidence of pyrolytic action at the K-T boundary; i.e ., widespread fires. ( ... , M.I ., and Dahl, J.; "Organic Geochemical Evidence for Global Fires at the Cretaceous/Tertiary Boun dary," Nature, March 2, 1989.) Fire could have been initiated by either volcanism or impacts. The evidence of the traps. Traps, like India's famous Deccan Traps, are extensive flood basalts. In this paper, basalt flooding has been correlated with mass extinctions of marine life during the past 250 million years. The Deccan Traps were formed right at the K-T boundary. Traps could, however, be initiated by asteroid impact, which could stimulate eruptions. (Rampino, Michael; "Dinosaurs, Comets and Volcanoes," New Scientist, p. 54, February 18, 1989.) The dinosaur angle. If ...
Terms matched: 2 - Score: 191 - 15 May 2017 - URL: /sf063/sf063g13.htm
... Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Collision/eruption/extinction/ magnetic reversal An increasingly popular scenario is: (1 ) Every 34 million years the solar system bobs up and down through the thickly populated disk of our galaxy; (2 ) The resulting encounters lead to showers of comets and/or asteroids on earth; (3 ) The mechanic trauma leads to basalt flooding; (4 ) Great biological extinctions occur in consequence; and (5 ) The terrestrial magnetic field reverses in step. Now, if scientists could show that all of these phenomena occur at the same frequency and are roughly in phase, it would constitute one of science's most important syntheses. The stratigraphic record and the estimated ages of meteor craters certainly hint at such synchrony. ... , two more papers have appeared which support the above scenario. First, M.R . Rampino and R.B . Stothers show that during the past 250 million years, eleven episodes of basalt flooding have occurred with an average cycle time of 32 million years. Second, J. Negi maintains that the earth's magnetic record boasts a similar string of disturbances, with an average period of 33 million years. (Anonymous; "Regular Reversals in Earth's Magnetic Field A Fluke?" New Scientist, p. 32, August 25, 1988.) From Science Frontiers #60, NOV-DEC 1988 . 1988-2000 William R. Corliss ...
Terms matched: 2 - Score: 190 - 15 May 2017 - URL: /sf060/sf060p13.htm
... Science Frontiers ONLINE No. 94: Jul-Aug 1994 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Earth's oldest paved road Forty-three miles southwest of Cairo lies a basalt quarry favored by ancient Egyptian artisans. Old Kingdom craftsmen laboriously cut this hard, black, glassy rock into royal sarcophagi and pavements for the mortuary temples at Giza just outside Cairo. To transport the heavy blocks of basalt from the quarry to Giza, the Egyptians built a quay on Lake Moeris, which then had an elevation of 66 feet above sea level and was located 7 ½ miles southeast of the quarry. (The Lake is now much smaller and 148 feet below sea level, indicating a large climate change.) Then, when the Nile flooded ... its waters reached a gap in the hills separating the Lake and the Nile, the Egyptians were able to float the blocks of basalt over to the Nile and down to Cairo. Good thinking! But how did they transport the heavy blocks 7 ½ miles from quarry to quay? The answer: What was apparently the first paved road on the planet. This 4,600-year-old engineering feat averaged 6 ½ feet wide and was paved with thousands of slabs of sandstone and limestone, with some logs of petrified wood thrown in. Since the slabs show no grooves, it is thought that the stone-laden sleds moved on rollers. (Wilford, John Noble; "The World's Oldest Paved Road Is Found near Egyptian Quarry," New York Times, May 8 ...
Terms matched: 2 - Score: 177 - 15 May 2017 - URL: /sf094/sf094a01.htm
... Origin of Ocean Water ESC12 Chemical Anomalies of Lakes and Ground Water ESC13 Petroleum Anomalies ESC14 Coal Anomalies ESC15 Outgassing of Radon-222 ESC16 Methane Anomalies ESD DEPOSITS OF REMARKABLE SIZE ESD1 Bone Caves, Bone Caches,... ESD2 Bone Beds, Fish Beds,... ESD3 Sedimentary Deposits of Exceptional Volume ESD4 Historical Evidence for Large Scale Flooding ESD5 Recent Large Reductions of Polar Ice Cover ESD6 Giant Basalt Flows and Traps ESD7 Giant Accumulations of Oil ESD8 Giant Erratics and Megabreccias ESD9 Deposits of Great Areal Extent ESI INCLUSIONS ESI1 Inclusions in Crystals ESI2 Microdebris ESI3 Erratic Boulders, Stones, and Mineral Patches ESI4 Anomalous Amber Inclusions ESI5 Microfossil-Like Inclusions ESI6 Oil in Fossil Cavities ESI7 Carbon Dust on Fossil Plants ESI8 Great Rarity of Fossil Meteorites and Tektites ESI9 Stretched Pebbles ESM ANOMALOUS SUPERFICIAL GEOLOGICAL MATERIALS ESM1 Unusual ... Sediments of Controverted Origins ESC10 Unusual Growth Structures ESC11 Possible Extraterrestrial Origin of Ocean Water ESC12 Chemical Anomalies of Lakes and Ground Water ESC13 Petroleum Anomalies ESC14 Coal Anomalies ESC15 Outgassing of Radon-222 ESC16 Methane Anomalies ESD DEPOSITS OF REMARKABLE SIZE ESD1 Bone Caves, Bone Caches,... ESD2 Bone Beds, Fish Beds,... ESD3 Sedimentary Deposits of Exceptional Volume ESD4 Historical Evidence for Large Scale Flooding ESD5 Recent Large Reductions of Polar Ice Cover ESD6 Giant Basalt Flows and Traps ESD7 Giant Accumulations of Oil ESD8 Giant Erratics and Megabreccias ESD9 Deposits of Great Areal Extent ESI INCLUSIONS ESI1 Inclusions in Crystals ESI2 Microdebris ESI3 Erratic Boulders, Stones, and Mineral Patches ESI4 Anomalous Amber Inclusions ESI5 Microfossil-Like Inclusions ESI6 Oil in Fossil Cavities ESI7 Carbon Dust on Fossil Plants ESI8 Great Rarity of Fossil Meteorites and ...
Terms matched: 2 - Score: 153 - 15 May 2017 - URL: /cat-geol.htm
... crters so that some scientists have taken up a time-honored human pastime: Looking for cycles or periodicities in the data. (Humans can find cyclicities in almost any collection of data!) To be more specific, some have claimed that large meteor craters come in clusters dated 28-31 million years apart. These catastrophic events have been correlated with biological extinctions, magnetic field reversals, and basalt flooding. The astronomical causes of this supposed periodicity range from the solar-system's crossing of the galactic plane, to the perturbations of an unseen solar companion, to regular perturbations of the Oort cloud of comets that is thought to hover at the fringe of the solar system. In short, a large, interlocking edifice of geological and astronomical speculation has been erected upon a foundation of ... 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 . ...
Terms matched: 2 - Score: 153 - 15 May 2017 - URL: /sf052/sf052g13.htm
... evidence. However, some tektite-like objects are to be found in the immediate vicinities of terrestrial craters, but not in far-flung strewn fields; viz., the Aouelloul Crater in Mauritania, and the Zhamashin Crater in the USSR. Another example has now come to light: the Lonar Lake Crater, a 50,000-year-old impact crater, in the Deccan flood basalts in India. From the paper's abstract: "Homogenous, dense glass bodies (both irregular and splash form) with high silica contents ( 67% SiO2) occur in the vicinity of Lonar Crater, India. Their lack of microlites and mineral remnants and their uniform chemical composition virtually preclude a volcanic origin. They are similar to tektites reported in the literature....Our ... the evidence. However, some tektite-like objects are to be found in the immediate vicinities of terrestrial craters, but not in far-flung strewn fields; viz., the Aouelloul Crater in Mauritania, and the Zhamashin Crater in the USSR. Another example has now come to light: the Lonar Lake Crater, a 50,000-year-old impact crater, in the Deccan flood basalts in India. From the paper's abstract: "Homogenous, dense glass bodies (both irregular and splash form) with high silica contents ( 67% SiO2) occur in the vicinity of Lonar Crater, India. Their lack of microlites and mineral remnants and their uniform chemical composition virtually preclude a volcanic origin. They are similar to tektites reported in the literature.... ...
Terms matched: 2 - Score: 153 - 15 May 2017 - URL: /sf053/sf053g12.htm
... 's pulse?Geological history records a restless planet subject to a succession of chemical and physical upheavals. Have these great paroxysms been random in time? M.R . Rampino and K. Caldeira do not think so: Number of geological events during geologic time "Published data sets of major geologic events of the past 250 Myr (extinction events, sea-level lows, continental flood-basalt eruptions, mountain-building events, abrupt changes in sea-floor spreading, ocean-anoxic and blackshale events and the largest evaporite deposits) have been synthesized (with estimated errors). These events show evidence for a statistically significant periodic component with an underlying periodicity, formally equal to 26.6 Myr, and a recent maximum, close to the present time. The cycle may not ... the earth's pulse?Geological history records a restless planet subject to a succession of chemical and physical upheavals. Have these great paroxysms been random in time? M.R . Rampino and K. Caldeira do not think so: Number of geological events during geologic time "Published data sets of major geologic events of the past 250 Myr (extinction events, sea-level lows, continental flood-basalt eruptions, mountain-building events, abrupt changes in sea-floor spreading, ocean-anoxic and blackshale events and the largest evaporite deposits) have been synthesized (with estimated errors). These events show evidence for a statistically significant periodic component with an underlying periodicity, formally equal to 26.6 Myr, and a recent maximum, close to the present time. The cycle ...
Terms matched: 2 - Score: 153 - 15 May 2017 - URL: /sf087/sf087g11.htm
