beausoleil

Are these the same as the ooids my students like to perplex me with?

roxrkool

Okay, I see what you were saying. Sorry.

You are trying to figure out what the source of the extremely fine-grained sediments is for the varves in the Green River Formation. Or rather how those seds came to be prior to deposition, correct?

What is the Creationist's source for these sediments and how do they account for the layering? What is their process for producing 4,000,000+ layers of very fine-grained sediment over 4,000 or so years?

And where does the aggregate/conglomerate fit in?

As for the flood model, I see what you mean by "decent."



Jimmy, are you a mudlogger? Driller? Evironmental Scientist?

SULPHUR

These are common in northern european areas and show the difference in melt water deposition between seasons which can be measured back 40 000 years.

ps418

Nah. Ooids are spherical accretionary structures formed by the repeated precipitation of calcium carbonate layers on some "nucleus," which is often a biogenic particle, such as the tiny shell of a forminifera. They form in shallow marine environments with high carbonate precipitation rates, such as the some areas of the Bahamas. There are some massive layers of ooids in the geologic record, known as oolites.

Patrick

SULPHUR

A similar thing to pisolites

ps418

Interestingly, there are conglomerates in the geologic record consisting of rounded metamophic rocks such as quartzite, which are extremely resistant to both chemical and physical weathering. This implies weathering of quartz crystals from igneous source rocks (typically granite), formation of new sedimentary rock, burial and metamorphosis of the sedimentary rock, following by exhumation of the metamorphised sediments, further weathering, and a second burial. Also, rounding of rocks is not simply due to physical weathering, abrasion, etc. It is also due to chemical weathering.

Another interesting thing about the sedimentary rock in the geologic record is its sheer volume. The volume of sedimntary rock in phanerozoic deposits is something like 1/2 the volume of all the water in the oceans. Its highly doubtful, to say the least, that the flood could perform the erosion miracles required of it. Strahler writes: "Fully lithified, hard, dense rock --such as ... [various] kinds of igneous and metamorphic rock ... could withstand forty days and nights of torrential rainfall with scarcely a measurable quantity of erosional removal .... Even on the assumption that a thick (100-meter) layer of decayed rock (saprolite) was available... it would be woefully inadequate to supply the quantity needed to form all existing Proterozoic and younger sedimentary and metasedimentary rocks" (Creation Science, p 201).

Patrick

SULPHUR

In the first part you described owen conglomerate perfectly

Valentine Pontifex

I am having a very hard time believing that figure. That would require three to four miles average thickness of phanerozoic sedimentary rock on the non-ocean area of the Earth.

SULPHUR

lets look at the age of the earth . 4.5billion years is a reasonable number,and then consider the first signs of life on earth. I think it is about 3.8 billion years. that gives a fair amount of time for geological stabilisation. Lots of rocks

ps418

No, it wouldn't require that at all, because the volume of Phanerozoic sediments here includes those deposited in the ocean basins as well as those deposited on land. My source is Robert Moore's article in Creation/ Evolution, Issue XI, Winter 1983, p. 10, and Moore's source is Blatt et al, 1980, Origin of Sedimentary Rocks, Second Edition, p. 34. Moore has the volume of the world's oceans at 1,350 x 10^6 km3, and the volume of Phanerozoic sediments as 654 x 10^6 km3.

Patrick