Those who might think that water flow through an overlying rock is rapid
should realize that water flows about half as rapidly through rock as does
oil ( Chris Clayton, Differential Flow Rates of Petroleum and Water in
fine-grained sediments, AAPG, sept. 1993, p. 1613) The authors attribute
this to the lack of unbound water in rocks.
While I can not find a reference, I would be willing to bet that groundwater
flow in a hydrothermal region, cooling a batholith, would still take longer
than a global flood could accomodate, because water does not travel rapidly
through shale. Shales have permeabilities of the order of a few millidarcies.
>GM: "Large batholiths can take 100,000 to 1,000,000 years to cool
>down. Often the batholiths have cooked the rocks around them,
>then erosion, took off the entire top of the batholith and
>sediments above it, and new uncooked sediments were deposited on
>top. Such is the situation at a geologic feature off New Jersey
>known as the Great Stone Dome. The sediments above it are
>uncooked and the sediments immediately in contact with it were
>cooked. A long interval separated the intrusion from the
>overlying sediments."
>
>The first sentence is again model-dependent. If you rely only
>on conduction to cool the hot body - it takes ages! What is the
>link with reality?
>
To state this objection is easy. To produce a realistic model that cools
all batholiths within a year is hard.What other mechanisms are you proposing?
>Sure there are uncovered batholiths with new uncooked sediments
>layed down over them. We have a good example in Yorkshire.
>There is much more to be said: if the erosion went down to the
>granite, then there is plenty of opportunity for water to get at
>it to cool it. The Yorkshire granite seems to have been still
>hot when uncovered - as there is plenty of mineralisation in the
>overlying sediments which seem to be associated with the granite.
>I'm confident that in this case, timescales need not be long.
>But I fully accept that every case must be considered on its
>merits.
>
Not all batholiths were cooled by being eroded to the surface. That also
would create problems fitting all this into a single year. Secondly, I am
aware that large crystals of the various minerals in a cooled batholith are
indicative of slow cooling rates. Lots of batholiths have large minerals.
Rapidly cooled batholiths have small crystals. To fit all the cooling into
a single year would need a miracle.
>GM: "Thermal arguments are great for showing a huge age to the
>earth. The Deccan volcanic field is up to 10,000 feet thick.
>If the flood was 4000 years ago it should still be hot."
>
>There are lots of assumptions in here. The Deccan volcanics are
>made up of separate flows. Each cooled sufficiently to form at
>least a stable surface for the next flow. The mechanisms of
>cooling need to be clarified before cooling times can be
>assigned.
If each flow required a month to cool to this point and each was 100 feet
thick, then the Deccan Traps would require 100 months or 8 years to be
deposited. The Deccan Traps have a volume of 1.7 x 10^6 cubic kilometers of
lava.(W.S. Holbrook and P.B. Kelemen, Nature July 29, 1993, p. 433-436) They
cover 200,000 square miles.
This does not fit a global flood well.
>Note that my comments were related to volcanic systems, which I
>will address first. Magmatic convection occurs within the magma
>chamber - but I am much more interested in the convection that
>occurs outside the chamber. I cited the oceanic ridge systems:
>buried several kilometres down, but with enormous water
>convection cells cooling them. The amount of water moving
>through the oceanic crust is enormous. Conductive heat loss is
>negligible compared with convective loss.
>
Can you give me a source for how much water flows through these systems? I
just looked and couldn't find one. What does enourmous mean?
>I have to limit this post - time is gone. I will briefly throw
>in a few other issues that seem relevant to me. The model of
>batholith formation in vogue has numerous problems. Large magma
>bodies moving upwards through the crust of the earth have the
>problem of "What creates the space into which they move?"
melting and incorporation of the rock into the magma. as well as uplift.
Mt. St. Helen underwent an uplift and even an expansion of the mountain
prior to its eruption.
>The main message of this post is that many geological statements
>about timescales are presupposition dependent. There is a need
>for more genuine testing of these presuppositions than has taken
>place in the past.
>
I agree, but I haven't seen any quantitative estimates of how you would
alter the present presuppositions. Everything has presuppositions so it
seems to me that you should propose new values and show that a batholith can
cool in the timeframe you prefer.
>I said last week that I would reply to Glenn. I'm now in the
>position of being out of the country for a week - so as it will
>take some time to respond to Glenn's reply, please accept my
>apologies now.
Take your time. I look forward to hearing again.
glenn
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm