Introduction To Geology

As a Geology tyro I am reading this with interest. I have been a regular visitor for three years and have learnt a lot, especially enjoying RAZD's thread on Age Correlations. So go for it Dr.A!

Hi Dr Adequate,
I am appreciating your efforts in this course of instruction.
I note that the report of the core at site 866 does not mention a lot of coral but certainly a lot of shallow water organisms. Does this still qualify as a coral reef? Is it because coral forms the substrate for the other critters to grow on?

Daniel Wonderly in "Coral reefs and related carbonate structures as indicators of great age" describes Enewetak as a coral-algal reef so I guess that qualifies. In its 4610 feet of reef structure it has erosion surfaces at 300, 1000,and 2280 feet showing periods when sea level fell faster than subsidence was occurring. To fit all this coral growth, with erosion periods, into the time since the Flood as YEC try requires some imagination!

Hi Dr A.
I am late in catching up with your thread, which I enjoy reading, and appreciate your efforts. The slightly faster rotating core is interesting. Could it be it has not slowed as much as the outer layers because the more fluid mantle does not transmit the slowing of the outer layers quickly. The core is spinning as fast as the outer layers were a few tens of thousands of years ago, so one could guess in an equal time into the future it would be down to today's rate, while the outer layers would have slowed further.

I'm not sure where this question for the geologists should go so I am putting it here.
I have recently purchased "The Illustrated Encyclopedia of Minerals Rocks and fossils of the World" written by John Farndon and Steve Parker. In discussing how igneous rocks form they mention the BRS and list the crystallization of minerals from high to low temperature as olivine, pyroxine, amphibole, biotite mica, quartz, muscovite mica, K-feldspar and plagioclase feldspar. From my reading of the BRS I think I have a reasonable understanding of it, and it seems that they have gone backwards up the right hand part of the Y after quartz to high temperature. Am I right?Also I note that the melting point of quartz is 1713 deg C but it comes out of a magma at about 800. Is this difference because of the difference between pure quartz and a complex mixture?

Hi Dr A.
I am currently going through your excellent book.
In the article on Reefs, it says rudist bivalves went extinct at the Cretaceous -Triassic boundary. Should it not be C-Tertiary?