Dinosaurs on a Tidal Wave

In ….. river valley not far from Houston, Texas, ….. team of ….. American scientists have found ….. geological evidence that ….. vast tidal wave swept ….. whole Caribbean region 65 million years ago, just as ….. Cretaceous period - ….. age of ….. dinosaurs - was ending. Writing in ….. latest issue of ….. US journal Science, ….. geologists claim that ….. tidal wave on this scale could only have been caused by ….. impact of ….. asteroid, probably five to ten kilometres in ….. diameter, plunging through ….. Earth's atmosphere and into ….. sea. That spectacular picture fits well with ….. view of ….. 'catastrophists', ….. geologists who think that ….. sudden disappearance of ….. dinosaurs, along with ….. diverse range of other living things, was caused by ….. series of asteroid impacts.

Each impact would have thrown up ….. world-embracing dust cloud, blotting out ….. Sun and lowering ….. temperatures to ….. point where many plants and animals could not survive. Evidence for that view already comes in ….. clays from ….. end of ….. Cretaceous period. They are enriched in ….. iridium, an element which is very rare in ….. Earth's crust but much more abundant in asteroids.

Of course, ….. clinching evidence for ….. catastrophic view would be ….. discovery of ….. remains of ….. craters where ….. asteroids struck. Unfortunately, no crater of ….. right age has been definitely identified, although if they are all at ….. bottom of ….. sea that is not so surprising. But ….. new work published in Science does provide ….. next best thing - if not the crater itself, evidence of the wave the asteroid created when it struck the sea. The ….. evidence comes in ….. puzzling layer of ….. rippled sandstone found in ….. Brazos River valley, Texas. ….. sandstone is curious because, at first, there seems no good reason why it should be there. It is ….. sudden, thin interruption in ….. thick deposit of ….. mudstone. That, as its name suggests, is ….. compacted mud that quietly accumulated over ….. millions of years that ….. region lay at ….. bottom of ….. shallow, undisturbed sea.

The Times (BrE)