Thursday, August 19, 2004  Open Thread. Subject: Age of
Dinosaurs  Time for a little back and forth.  1 comment:
Kendall said...  Back in the years from 1785 to 1800 geologists
were looking at layers of rocks in outcroppings. The rocks
contained fossils of animals that similar to modern marine
animals like clams and barnacles. The chemical composition of
the rock was similar to what they knew about the chemical
composition of modern sea-beds. So it made sense that these
rocks in the Scottish Highlands were once the floor of an ocean.
In modern oceans they could observe the slow accumulation of
sediments and they could see the same kind of layering in recent
sediments that they saw in their rocks. This was further
evidence that the rocks had, at one time, been under an ocean.
And that older rock layers were under the younger layers.  Some
observers found a deposit that had lots of crocodile fossils in
it scattered through many layers. Looking at the fossils it was
clear that those in the upper layers were muc