bob@islenet.UUCP (Bob Cunningham) (09/11/85)
> > And a catastrophe *was* occurring at the time these large > > animals became extinct -- the catastrophic end of the ice age. > > > > It may seem odd to talk about the *end* of an ice age as > > being a catastrophe, but remember that large areas formerly > > well watered (in the American West, for example) became desert. > > Much forest land turned to grassland. The ocean level went > > down hundreds of feet. It was an *ecological* catastrophe. > ^^^^ > Of course, I meant that the ocean level went *up* hundreds of > feet. This is due to the melting of huge quantities of glacial > ice that had formerly occupied vast areas of the continents. > > > > ... left-over large > > > dinosaurs and mega-mammals died when the effect of gravity > > > changed after the flood, making the world no longer habitable ... > > > > And then, when an actual catastrophe is cited, which one > > does Ted mention? Not the ice age, which ended a mere > > 10,000 years ago, leaving in its wake massive evidence > > of its occurrence all over the world -- but the biblical > > *flood*! Now, scientists have no more objection to a > > catastrophic flood than they do to a catastrophic ice > > age. The real question is, *where's the evidence*? > > The rise in sea levels drowned many coastal areas around the world. > Likely, many long-settled human communities were disrupted by this. > In the general catastrophe of the end of the ice age there were > many floods. Perhaps ancient stories of floods reveal some such. > > The ocean rise, however, could not have been rapid. It's equally > likely the flood stories reflect some localized floods in the > Tigris-Euphrates Valley, where the Semites of the Bible originated > culturally. As far as the world-enveloping, to the tops of the > Himalayas, flood demanded by Bible literalists goes, I say *No*! At least around here, relatively ancient sea level stands are very well documented in the geologic record. Here is a list of the most obvious ones: type locality approximate altitude feet meters Mahana +1,200 +365 Kaluakapo +625 +190 Manele +560 +170 Olowalu +250 +75 Kaena +95 +29 Laie +70 +21.5 Kahuku +55 +17 Waialae +45 +12 Waimanalo +25 +7.5 Ulupau (Kailua) +12 +3.6 Kapapa +5 +1.5 Manana (Leahi) +2 +0.6 present sea level ............................ Koko -15 -4.5 Waipio between -40 to -350 -12 to -106 Penguin Bank -180 -54 Kahipa-Malama -300 to -350 -90 to -106 Lualualei -1,200 to -1,800 -365 to -550 Waho -3,000 to 3,600 -915 to -1,100 Each of the above can be clearly seen at several locations on a single island -- or more usually -- continuous on several islands. The uncertainty in the currently undersea ancient shorelines represents the difficulty of accurately surveying these at depth. Probably each of the ones listed as a range represent a series of individual shorelines. At least sixteen more well-defined former shorelines have been found, but have not yet been extensively surveyed. Shorelines above the present level are marked by obvious wave-cut terraces, nips, sea clifs, deposits of sediment containing marine fossils, and limestone (old reef coral) terraces. Those below present sea level are marked by topographic benches, cemented sand dunes that could only have been built by the wind above sea level, by stream-cut valleys now colleged with alluvium, and ancient coral reefs (reef coral only grows in water less than 60 meters deep, maximum). A number of correlations with similar features on other Pacific islands have been made ... which I won't go into here. It is difficult to accurately date most of the ancient shorelines. The ones up to +75 meters could coincide with previous interglacial ages (if all or most of the world's ice caps had melted), and the ones down to -120 meters could coincide with major ice ages. The "climatic optimum" about 4,000 years ago probably lasted too short a time to produce any conspicuous shoreline features, although it's possible that the +0.6 meter bench was formed at that time. Reef coral on Midway Island up to a meter above sea level, yielded a C-14 age of 2,400 years ago. C-14 ages of shells from the +1.5 meter and +3.6 meter shorelines are respectivley 24,100 (+/-700) and 31,400 (+/-1,200) years before the present (corresponding to the interval between the Iowan glaciation and the Tazwell substage of the Wisconsin?). The general opinion is that shorelines above +75 meters and below -90 to -120 are almost surely tectonic (the islands rising & falling, not world sea level). Before you ask, the highest ancient shorelines appear to date back to the Pleistocene. Nothing above those levels has been found (up to the top of Mauna Kea ... although that mountain shows the remains of ancient glaciers). -- Bob Cunningham {dual|vortex|ihnp4}!islenet!bob Hawaii Institute of Geophysics