Re: [asa] Accuracy vs. Methodology in Science Education

From: <mrb22667@kansas.net>
Date: Fri Jun 01 2007 - 14:15:56 EDT

Thank you for giving (what seems to me) a thorough reply complete with
jargon. (That way I can add words like 'speleothem' to my vocabulary.
Assuming constant optimal conditions would be sort of like selective
uniformitarianism -- used by people who have otherwise objected to that notion
as it has sometimes been used. Your examples make a lot of sense.

Again -- thanks for investing your expertise into your reply. I'm putting
this one away for future reference.

--Merv

Quoting Steven M Smith <smsmith@usgs.gov>:

> Christine Smith quoted the following:
> >>
> >> "Brian Benson, an eighth-grade student who won first
> >> place in the Life Science/Biology category for his
> >> project "Creation Wins!!!," says he disproved part of
> >> the theory of evolution. Using a rolled-up paper towel
> >> suspended between two glasses of water with Epsom
> >> Salts, the paper towel formed stalactites. He states
> >> that the theory that they take millions of years to
> >> develop is incorrect.
> >>
> >> "Scientists say it takes millions of years to form
> >> stalactites," Benson said. "However, in only a couple
> >> of hours, I have formed stalactites just by using
> >> paper towel and Epsom Salts.""
>
> Merv replied:
> >
> > This also is not an answer to Brian's question /
> > (statement really) over the antiquity of stalactites,
> > but more commentary on it. Geologists on this list
> > are the ones who could enlighten us. E.g. is it really
> > claimed that these things all took millions of years
> > to develop?
>
> Merv,
>
> Your post deserves a reply. I kept hoping one of the other geologists on
> the list would respond since I am busy dealing with 2 graduations and
> getting ready to do fieldwork this summer in Alaska. Alas! I couldn't
> resist your appeal.
>
> You have picked up on one of the primary misstatements in this 8th
> grader's project. Geologists do not claim that all stalactites "take
> millions of years to develop." As a teaching exercise, Brian should be
> asked to document this statement using primary sources from speleothem
> (cave formation) researchers. In secondary sources, Young-Earth
> Creationists (YEC) claim that scientists claim that stalactites take
> millions of years and then point to stalactites forming on bridges, tunnel
> ceilings, and mines as if they think that we have never noticed. In
> reality, the rate of stalactite growth depends on several factors -- (1)
> the rate at which water seeps through the overlying rock; (2) seasonal
> variation in groundwater flow; (3) the solubility of the specific
> stalactite-forming mineral; (4) the concentration or saturation of the
> dissolved mineral in the dripping water; and (5) even the atmosphere and
> humidity of the cave or void where the stalactite is formed. Every cave
> will be different. Some might only take a few years and some could
> conceivable take a million years to form a particular stalactite.
> (Sidebar: Although I think that stalactite formation is an excellent
> topic for a science fair, it shouldn't belong in the Life Science/Biology
> category.)
>
> Within temperate zones, the seasonal differences in water flow and mineral
> saturation often create distinguishable bands in speleothems. A cross
> section through one of these stalactites would look like tree rings.
> Assuming that each band or couplet represents annual deposition, one could
> simply count the rings to determine a *minimum* age for the stalactite.
> Note that the age of the stalactite is not necessarily equal to the age of
> the cave and is certainly not equal to the age of the enclosing rock and
> especially not equal to the Age of the Earth.
>
> > Close to where I live, flood waters in the summer
> > of '93 eroded some significant gullies (some around
> > 30 feet deep) through hard rock & soil. The resulting
> > "cliffs" were not trivial things to behold. This was
> > taken by some local YECs as a triumphant answer to
> > the claim of the Colorado river needing millions of
> > years to carve out the Grand Canyon. If these large
> > rock formations could be shaped in a matter of weeks
> > by a local flood, then the Grand Canyon feat should
> > be (relatively) quick child's play for global flood
> > waters. So does that represent a slam-dunk for flood
> > geologists on age issues?
>
> There are a whole bunch of YEC arguments that can be described as one
> fallacy. We could call this The Fallacy of Assuming Constant Optimal
> Rates & Conditions. In the science fair experiment described above, Brian
> created the optimal conditions for stalactite growth (an extremely soluble
> mineral, in a saturated or even supersaturated liquid, transported at a
> high rate through a very permeable paper towel, in a reasonably dry
> atmosphere). Assuming Constant Optimal Rates & Conditions, Brian then
> concludes that stalactites always form quickly; perhaps even within hours.
> This fallacy is almost always accompanied by a second and somewhat
> related one. We could call this The Fallacy of Assuming a Minimum Age
> Equals the Maximum Age. In reality, Brian's experiment only demonstrates
> that, at a minimum, the stalactite, cave, or Earth is a few hours old. It
> tells us nothing about the maximum possible age.
>
> An analogy illustrating the two fallacies: The current land speed record
> for a wheeled vehicle is a little over 763 miles-per-hour. Therefore it
> should not take me more than an hour and 20 minutes to drive the 1,000
> miles from Denver to Chicago. However, it actually took me almost 2 days
> in my underpowered 4-cylinder Nissan pickup truck pulling a 20-foot
> trailer. The morals of the story: In the real world, you seldom achieve
> or maintain the constant optimal rates and conditions. Constant optimal
> rates and conditions will only give us the MINIMUM possible time and not
> the maximum. If I had broken down or had an accident in Beaver Crossing,
> Nebraska, it might have taken me weeks or even years before I got to
> Chicago.
>
> Your example of erosion rates during the flood of '93 falls under the same
> category. Geologists recognize that more erosion takes place during one
> '100-year' flood than during 99 years of normal flow. I cringe every time
> I hear someone say like "The Grand Canyon eroded one sand grain at a
> time." Baloney! Most rates are variable and episodic. You can't
> assume constant optimal rates and conditions over any sustained period of
> time.
>
> So how about Noah's Flood? Surely a massive one-year-long cataclysmic
> deluge would provide those optimal rates and conditions, wouldn't it?
> Well, perhaps ... for some things but not for everything. Note that Flood
> enthusiasts call for the deluge to erode solid rock, sort out the debris,
> deposit the sediments in well sorted layers, create solid rock out of the
> layers, and finally erode it again. They also need optimal conditions for
> depositing carbonates and then dissolving carbonates to create caves,
> followed by precipitating carbonates to create speleothems. Each process
> has its own set of optimal conditions and often these conditions are
> mutually exclusive; they are the opposite of what is needed for a
> different process.
>
> The absurdity becomes apparent when you realize the enormity of all of the
> optimal conditions and rates that you would need during the Flood and
> ensuing 4,500 years just to create all the different geologic features
> that we currently see. The following is only a partial list of some
> geological processes and products. Each one takes some period of time to
> happen. Some are fast, some are slow, and some rates we don't know but
> most are probably variable. Only a few of these have ever been used to
> estimate ages of any sort (usually minimum ages for a specific feature).
> The short time frame for the YEC/Flood geology paradigm would require
> optimal conditions and rates for almost all of these (both simultaneously
> and consecutively) in order to produce what we see today in the geologic
> record.
>
> ----Processes and Products that require time----
> * Erosion of solid rock to make sediment;
>
> * Sorting of sediment clasts by size and mineralogy (e.g. nearly pure
> well-sorted, frosted, rounded quartz sands; winnowing of clays ...);
>
> * Chemical weathering (formation of clay minerals from feldspars, micas,
> and other minerals);
>
> * Rock disintegration and soil formation (paleosols, saprolites,
> pisolites, laterites, bauxites ...);
>
> * Formation of distinct clastic sedimentary rock types (shales,
> mudstones, sandstones, siltstones, conglomerates, some limestones ...);
>
> * Formation of different chemical sedimentary rock types (evaporites,
> gypsum, anhydrite, halite (rock salt), phosphorites, carbonates, sinter,
> tufa, travertine ...);
>
> * Diagenesis -- the conversion of sediment into sedimentary rocks
> (dewatering, compaction, cementation, recrystalization, dolomitization,
> formation of chert nodules ...);
>
> * Formation of sedimentary structures indicating different environments
> of deposition (ripple marks, mud cracks, salt casts, crossbedded
> sandstones, paleochannels, facies changes, black shales, red beds, oolites
> ...);
>
> * Formation of structures indicating erosional environments
> (disconformities, angular unconformities, basal conglomerates ...);
>
> * Formation of regularly alternating sedimentary layers (varves,
> turbidites, rhythmites, cyclothems ...);
>
> * Formation of different organically derived deposits (oil, coal, reefs
> and bioherms, crinoidal limestones, algal limestones, fecal pelletal
> limestones, coquina, chalk, diatomaceous earth, coprolite layers ...);
>
> * Formation and preservation of different trace fossils (tracks, trails,
> burrowing, bioturbation ...);
>
> * Formation of different ore deposits (hydrothermal precious metal
> deposits, volcanic massive sulfides, sedimentary exhalitives, skarns,
> porphyry copper or molybdenum deposits, Mississippi-Valley-Type lead-zinc
> deposits, roll-front uranium deposits, banded iron formations, Carlin-type
> disseminated gold deposits, multiple brecciation and void crystallization
> episodes, accompanying alteration of host rock -- silicification,
> argillization, propylitization, sericitization ...);
>
> * Formation of igneous rocks and associated features (cooling of
> batholiths, plutons, contact metamorphism, roof pendants, cross-cutting
> dikes, coarse-grained igneous minerals, porphyries, pegmatites ...);
>
> * Fossilization (burial rates, petrifaction rates, Lagerstatten, fossil
> succession -- including distinct zones for ammonites, pollens,
> foraminifera, radiolaria ...);
>
> * Formation of volcanic features (ash falls, welded tuffs, flood basalts,
> pillow basalts, columnar jointing, shield volcanoes, stratovolcanoes,
> cinder cones, diatremes, diamond-bearing kimberlite pipes, Hawaiian
> Island-Emperor Seamount chain, Yellowstone-Snake River Plain volcanic
> track ...);
>
> * Formation of glacial features (multiple ice ages, continental
> glaciations, glacial tills, tillites, moraines, cirques, U-shaped valleys,
> glaciers & ice sheets with multiple annual layers ...);
>
> * Formation of geomorphic features (incised meanders, retreating
> waterfalls, arches, natural bridges, buttes, mesas, valleys, canyons ...);
>
> * Formation of karst features (solution caves, sinkholes, karst towers,
> cave sediment, stalactites and other speleothems ...);
>
> * Plate Tectonics (mountain building episodes, continental rifts, thrust
> faulting, recumbent folding, subduction zones, trenches, mid-ocean ridges
> ...);
>
> * Miscellaneous features -- lumped because I am running out of steam,
> time, and inspiration (meteor craters, stretched-pebble conglomerates,
> fossil-bearing conglomerates, deep ocean sediments, ocean chemistry, salt
> domes, metamorphism, Precambrian history, reversed paleomagnetic sequences
> ...);
>
> ----------
>
> I apologize for all the jargon. It was necessary shorthand to keep from
> making a book out of this post. Any good Geology 101 textbook will
> describe most of these. I recognize that YECs will pick certain items out
> this list and say that they can explain them (however, see The Fallacy of
> Assuming Constant Optimal Rates & Conditions above). I also recognize
> that the significance of many of these processes and products will not be
> immediately apparent to everyone (Why should we care about
> stretched-pebble conglomerates? etc.).
>
> In summary and conclusion ...
>
> (1) Pointing out optimal conditions or accelerated rates is usually
> irrelevant; at best they only give a minimum age for the specific feature
> and have little to do with the total 'Age of the Earth'. For me, the
> cumulative evidence all points to an Earth age that has to be much greater
> than 6,000-10,000 years.
>
> (2) Just about any geologic exposure has evidence for multiple processes
> and products that require time. The challenge for the YEC/Flood Geology
> paradigm is to logically demonstrate how you can simultaneously and
> consecutively accelerate a large number of these processes to compress
> time and produce an actual geologic section. A layer-by-layer explanation
> of the stratigraphic and geomorphic exposure at the Grand Canyon would be
> a good place to start since this seems to be a favorite YEC locality.
>
> Steve
> [Disclaimer: The statements in this post are my own. Do not credit or
> blame my employer.]
> _____________
> Steven M. Smith, Geologist, U.S. Geological Survey
> Box 25046, M.S. 973, DFC, Denver, CO 80225
> Office: (303)236-1192, Fax: (303)236-3200
> Email: smsmith@usgs.gov
> -USGS Nat'l Geochem. Database NURE HSSR Web Site-
> http://pubs.usgs.gov/of/1997/ofr-97-0492/
>
>

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Received on Fri Jun 1 14:16:28 2007

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