Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
7 online now:
Newest Member: popoi
Post Volume: Total: 915,816 Year: 3,073/9,624 Month: 918/1,588 Week: 101/223 Day: 12/17 Hour: 1/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Solving the Mystery of the Biblical Flood
wmscott
Member (Idle past 6247 days)
Posts: 580
From: Sussex, WI USA
Joined: 12-19-2001


Message 46 of 460 (2728)
01-24-2002 5:09 PM


Just found some very interesting information on some diatoms found in Antarctica that we had been talking about earlier. It seems some of them did not arrive by ice or wind. "We suggest that if the microfossils in the surface unit arrived by glacial transport mechanisms, they ought to occur within a glacial deposit of younger age than the underlying lodgement tills. If the microfossils arrived by eolian processes, they should occur in surface deposits of disparate origin but of unknown age, both glacial and nonglacial, given the ability for the deposit to trap fine-grained, wind-blown material (McFadden, Wells, and Jercinovich 1987; Wells et al. 1995)." It would seem that my earlier assessment that some of these diatoms could have been deposited by a rise in sea level at the end of the last ice age may be on target. It would also seem that I am not the only one finding marine diatoms on land that were not deposited by glacial activity or by wind action. Here is a link to this site.
http://www.nsf.gov/pubs/1997/nsf97160/ch9.htm#fig1

Replies to this message:
 Message 47 by Percy, posted 01-24-2002 5:56 PM wmscott has not replied

Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 47 of 460 (2729)
01-24-2002 5:56 PM
Reply to: Message 46 by wmscott
01-24-2002 5:09 PM


Are you sure you've interpreted your source correctly? In my reading of the article, the passage you quoted is explaining that the evidence is inconsistent with glacial transport but more compatible with wind driven mechanisms. He goes on to describe an alternative scenario, saying that it "highlights eolian [wind driven] transport."
Are you proposing that a world wide flood would wash across glaciers rather than float them?
--Percy

This message is a reply to:
 Message 46 by wmscott, posted 01-24-2002 5:09 PM wmscott has not replied

edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 48 of 460 (2730)
01-24-2002 5:58 PM
Reply to: Message 43 by wmscott
01-24-2002 3:59 PM


quote:
Originally posted by wmscott:
Edge-You asked "What is your evidence?" on uplift and subsidence being associated with the comings and goings of the ice sheets. We have evidence in that the recorded uplift and subsidence has occurred in stages and has been associated by some geologists with the coming and going of the ice sheets. "The margins of continents have afforded remarkable sites of cymatogenic tilting with repeated uplift upon the landward and depression upon the seaward side of axes trending closely parallel with present coasts. Corresponding with the polycyclic denudational history of the lands is therefore a polycyclic depositional record embodied in the offshore sediments." (The Morphology of the Earth; A study and Synthesis of World Scenery by Lester C. King 1962, p.223) By polycyclic King means that there occurred a number of distinct periods of rapid erosion of recently uplifted land followed by periods of little erosion. He also connected the uplift of the land with subsidence of the sea floors. A number of geologists have connected this pattern with the pattern of the ice ages. An extreme flooding event at the end of the last ice age would have repeated the earlier pattern and due to the suddenness and size of the shift in weight, the effects were more extreme and more sharply felt than the previous events.

Once again, what is your evidence for this last statement? I have no doubt that some isostatic changes occurred with the melting of the ice sheets, and they may have resulted in higher sea levels, but I think you are exaggerating the effect and also confused between alpine glaciation in the coastal ranges with the continental ice sheets of the interior. To my knowledge the only glaciation of the coast ranges of Canada were alpine glaciers. On top of that, you gave us some information that suggested uplift long before the glaciers. Why couldn't tectonics account for all of the uplift?
quote:
edge: "Why wouldn't the continental ice sheets be held back similarly? Moreover, how does the actic ocean ice participate. Seems to me like it can't because it should simply rise with the rising sea level. The amount of cement in your model is disappearing with each post"
Whereas current studies seem to indicate that the Greenland and Antarctica Ice sheets remain intact during a warming climate, evidence such as the fresh water spike indicate that the other continental ice sheets were falling apart and very vulnerable to surging at the end of the ice age.

Of course they were melting. The problem is that there is no diagnostic evidence for surging on the scale that you suggest.
quote:
This difference in response to changing climate conditions is why the ice sheets responded differently. And as I have stated before, it was not necessary for the ice to be in the sea to contribute to the flood waters since whether they were floating over land or ocean, would make no difference.
But I thought that was an integral part of your model. The glaciers surging into the sea and upsetting the climate to such an extent that more glaciers were melted.
quote:
edge: "You have taken a local phenomenon (a jokhulhlaup) and applied it to multiple continental ice sheets. Are you sure that this is valid?"
Yes it is, I didn't come up with it, it is part of what is know about the behavior of the ice sheets. I have merely used it as part of my theory. Most of what I am saying is nothing unusual, I have just picked up the pieces and put them together.

We have already established that this is not the behavior of ice sheets. No complete ice sheets have melted, surged or otherwise been disrupted in history. Jokhulhlaups occur on the fringes of glaciers and ice sheets. Never has an entire ice sheet been affected that I can tell. If you have such information, please share.
quote:
On drop stones in the North Atlantic you replied "Nonsense. The phenomenon is not "ocean-wide."" The source I quoted stated "The layer in the GRIP cores apparently cover most of the North Atlantic"
Correct. The "most" of the North Atlantic. Not all of it. And what about the South Atlantic and the Pacific?
quote:
"selectively collecting facts to support a legend" Some legends turn out to be true, and if it wasn't, then there wouldn't be any evidence for me to collect.
Indeed some are true. Others are false. And no even without legends, there is plenty of data to collect. Just because you base your entire research on a legend does not mean that there is other data.
quote:
"Can you show me a map that tell us where the continental ice sheets were in South America during the ice ages?" See the map on page 64 in the book "Late Glacial and Postglacial Environmental Changes; Quaternary, Carboniferous-Permian, and Proterozoic" edited by I. Peter Martini.
Obviously, I do not have this at my fingertips. Pleas describe the continental ice sheets in South America.
quote:
edge:"So, was that your college geology textbook?"
I have read many geology textbooks, but I have never been to college as a student.

Actually, I kind of guessed that. And yet you are writing geology books. Interesting.
How about some figures, wmscott? Have you figured out how much energy would be consumed by melting a continental ice sheet? Over the time period of your flood? Have you calculated what that would do to the temperature of the atmosphere? Think that might have an effect on other ice sheets?

This message is a reply to:
 Message 43 by wmscott, posted 01-24-2002 3:59 PM wmscott has not replied

ps418
Inactive Member


Message 49 of 460 (2731)
01-24-2002 6:24 PM


WmScott,
Howdy. I'm a geology buff like yourself. I've been reading your discussion on diatoms. Frankly, I think you are quite confused on this issue, and the evidence does not demand, suggest, or even imply a "Noah's Flood" transport mechanism. I will explain why either friday or saturday. After that I'd like to discuss problems with the rest of your theory.
Till then,
Patrick

ps418
Inactive Member


Message 50 of 460 (2732)
01-24-2002 6:28 PM


One more point for the moment, WmScott. As Percipient pointed out, you either misread or misrepresented the article you cited above. The authors are arguing FOR aeolian transport.
Patrick

ps418
Inactive Member


Message 51 of 460 (2739)
01-24-2002 11:04 PM


The following is from:
Davida E. Kellogg and Thomas B. Kellogg, 1997. Diatoms in a South Pole ice core: Serious implications for the age of the Sirius Group, Antarctic Journal of the United States, v. 32.
http://www.nsf.gov/pubs/1997/nsf97160/cover1.htm
Kellog and Kellog note:
"Diatoms are a small but pervasive constituent of snow falling at the South Pole (and at Siple and Taylor Domes), although in a patchy pattern through both space and time (figure 2). Over 40 marine and nonmarine taxa were recorded (table). Abundances are extremely variable, ranging from nil to over 260 specimens in individual samples."
"Figure 2. Diatom abundance fluctuations (specimens per liter) and percentage of nonmarine specimens in the South Pole core. Ages are calendar years based on correlation with the adjacent 1981 core at South Pole (Gow personal communication).
34 percent contain more than 75 percent marine specimens,
4 percent are more than 75 percent nonmarine,
35 percent have intermediate mixtures of marine and nonmarine taxa, and
the remainder are barren or are dominated by species of uncertain provenance
"Diatoms are extremely light and easily transported by winds (e.g., the well-known diatom deposits in the equatorial Atlantic derived from Saharan Africa; Folger 1970), and winds in Antarctica are known to reach very high velocity. The antarctic surface windfield is dominated by katabatic flow, outward and down from high ice domes toward the sea (Parish and Bromwich 1987). Storms tend to track around the continent. Occasional large storms break through the circumflow and penetrate to the South Pole (Bromwich and Robasky 1993). Our diatoms were probably carried by these episodic events, which occur today at most a few times annually. An alternative transport mechanism, stratospheric return (poleward) flow, is unlikely because most of our diatoms are antarctic endemics whereas most stratospheric particles are entrained in tropical areas. Terrestrial sediments containing marine and nonmarine diatoms probably serve as the most important diatom sources. We envision diatom entrainment as episodic, perhaps occurring only a few times in a decade, and responsible for the low background level of less than 20 diatoms per liter of melted ice typical for approximately 70 percent of our samples."
Marine diatoms in soil hardly require a global flood. A strong wind will do just fine. As Kellog and Kellog and others demonstrate, marine diatoms are transported all the way into the antarctic interior by wind today, throughout historical time, and prior to historical time.
You might also want to check out:
Burckle, L.H., and N. Potter, Jr. 1996. Pliocene-Pleistocene diatoms in Paleozoic and Mesozoic sedimentary and igneous rocks from Antarctica: A Sirius problem solved. Geology , 24(3), 235-238.
Kellogg, D.E., and T.B. Kellogg. 1996. Diatoms in South Pole ice: Implications for eolian contamination of Sirius Group deposits. Geology , 24(2), 115-118.
Kellogg, D.E., Kellog, T.B., 1996. Glacial/interglacial variations in the flux of atmospherically transported diatoms in Taylor Dome ice core, Antarctic journal of the United States, 1996, 31(2), p.68-70.
Patrick

Quetzal
Member (Idle past 5872 days)
Posts: 3228
Joined: 01-09-2002


Message 52 of 460 (2746)
01-25-2002 9:31 AM
Reply to: Message 43 by wmscott
01-24-2002 3:59 PM


wmscott:
quote:
Quetzal-On the Pleistocene extinctions were almost (except NA and SA) exclusively BEFORE the actual Pleistocene/Holocene boundary.
wmscott:
As I have said before, I believe some of the dates on when some of the Ice age animals went extinct maybe to earlier, and the fact that some of them died off before hand is to be expected and is not contrary to what I am theorizing.

quote:
On Pleistocene extinction, I like your statement, "in North and South America we see extremely short time frame and extremely severe." it seems that for half of the world we are in agreement, the rest could be dating problems or maybe they did just die off earlier.
I think you're indavertently misconstruing both the data I've presented and the statement you quoted. My fault for not being more clear, perhaps.
1. Australia: extinction event ENDS 20,000 years before the boundary. NO extinctions were noted AT the end of the ice age. In other words, the critters that were present at the LGM remain present PAST the boundary and up to recent times.
2. Eurasia: extinction event(s) END 3,000 years before the retreat of the Wurm glaciers.
3. North America: extinctions take place in less than 1000 years right on the boundary (11,000-10,000 ya). Critters that were present during the ice age and LGM ceased to exist practically overnight. There are fossils before this date, but NO traces AFTER this date.
4. South America: extinctions take place ~8000 ya, IOW 3-4000 years AFTER the retreat of the glaciers.
None of the extinctions take place - worldwide - in a six-month period corresponding to the northern hemisphere winter, as you suggest. Even the "shortest" mass die-off takes place over almost a thousand years! There is literally no way you can compress all the extinctions - especially as "selective" as they appear - into one single short-duration event. Not only are the extinctions separated spacially, they are separated temporally and DIFFERENT REGIONS HAVE DIFFERENT TIMETABLES. Let me know if you still don't understand this distinction.
quote:
On "rates on normal extinctions" on a planet as diverse as the earth is, a number of living species die off and others arise as a steady rate over time. What the 'normal' rate for this is no one really knows, it is argued that human intervention in our time is causing an above normal extinction rate.
This is incorrect. The reason we call the Late Pleistocene die-off an extinction event is because there was a relatively stable period for the first 700,000 years, wherein only a very few genera went extinct, then we have a mass die-off of taxa over the course of the next 40,000 years. The fossil record does not support a "steady rate over time" of extinctions.
I do agree with you that there is evidence rates of extinction have skyrocketed in the last thousand years or so. A good case could be made for a new "extinction event" occuring before our eyes. I wonder if future paleontologists (if any) will be arguing over the causes of the Holocene Extinction?
quote:
The sample cores were taken of the surface soil, the top few inches down.
I guess I would have to know the soil stratiography at the sample sites. You have stated previously that the samples were taken from layers representing the surface as it was 10,000 ya. On what are you basing this determination? Also, surface soils (exposed or disturbed soils) are open to contamination from many sources. It's hard to judge where your diatoms logically came from without some additional info. There's too much chance of sampling error (as Joe T and PS418 have pointed out).
quote:
What marine trace elements are you thinking of?
You really need a specialist soil lab to make a good chemical analysis - which would be able to tell you whether the sample had suffered seawater intrusion at some point. However, soils that have had exposure to seawater usually have elevated pH, are more saline, contain higher than normal concentrations of boron and carbonates (which are water soluble and therefore may not be indicative after 10,000 years), and traces of Mg, Sr, Mn, Fe, Zn, Cu, and Ni. Your best bet would be to get a hydrogeologist to look at the samples.
quote:
Quetzal: "How does the spike, whether from the Mississippi — and there's a fair amount of evidence that the river did flood severely at the end of the ice age — or the Amazon, provide evidence for a global flood?"
wmscott: It shows that the glaciers were releasing very large amounts of water back into the sea at this time and that a sudden huge release was very possible, and the peak of the spike may very well be the record of that release.

Actually, all this shows is that two of the major rivers draining a substantial portion of two continents massively increased flows at the same time. This is actually consistent with the "normal" end of the ice age when both the NA continental ice sheets retreated and the Andean glaciers melted. BTW: The Amazon flow was probably related to increased rainfall due to climate change rather than glacial melt. It has little or no relevance for a "global" flood hypothesis (either for or against).

This message is a reply to:
 Message 43 by wmscott, posted 01-24-2002 3:59 PM wmscott has not replied

wmscott
Member (Idle past 6247 days)
Posts: 580
From: Sussex, WI USA
Joined: 12-19-2001


Message 53 of 460 (2760)
01-25-2002 4:26 PM


It seems a lot of you guys are having problems with this diatom layer found in Antarctica, so let's look at it again. First off the deposit is not found on ice or a glacier, but in a dry valley type environment. What they are talking about in the part I posted was a layer of marine diatoms that did not appear to be deposited by glacial activity or by wind activity.
"These results indicate that for one deposit on which the dynamicists built their viewpoint, the Sirius Group at Mount Fleming, the glacial conveyor mechanism appears erroneous. We suggest that if the microfossils in the surface unit arrived by glacial transport mechanisms, they ought to occur within a glacial deposit of younger age than the underlying lodgement tills."
They then go on to state why wind depositing is a problem.
" If the microfossils arrived by eolian processes, they should occur in surface deposits of disparate origin but of unknown age, both glacial and nonglacial, given the ability for the deposit to trap fine-grained, wind-blown material (McFadden, Wells, and Jercinovich 1987; Wells et al. 1995).'
They then went to describe a theory on how this diatom layer mite have been deposited by wind action.
"Denton, Prentice, and Burckle (1991) proposed scenarios by which airborne diatoms were incorporated into Sirius Group glacial sediments. For these diatoms to become airborne, however, at least two requirements must be met:
Outcrops of Plio-Pleistocene marine sediments were available for subaerial wind-scouring.
The atmospheric circulation system and the ice-sheet configuration were significantly different, so that only the observed Plio-Pleistocene marine diatom flora of the Sirius Group was elevated.
The latter is important because eolian transport at present recycles varying proportions of marine and nonmarine diatoms to east antarctic ice sheet plateau locations (Burckle et al. 1988; Kellogg and Kellogg 1996). In addition, the source area from which these marine diatoms were scoured by wind remained enigmatic, because the preponderance of planktic taxa over benthic taxa in Sirius Group sediments seemingly invalidates uplifted near-shore marine sediments (e.g., Webb and Harwood 1991) and because a stable cryosphere and marine diatom source areas appear to be conditions in contradiction. This contradiction arises because the stabilists melt-down mechanisms cannot account for the necessary ice recession (Denton et al. 1993). Finally, the absence in Sirius Group samples from Mount Fleming of marine diatom species such as Nitzschia curta that dominate today in circumantarctic waters (Burckle 1984) requires that the eolian microfossil conveyor operated before such species became dominant."
Notice in the above paragraph that a source for these presorted diatoms remains 'enigmatic', as in they can't find it. The lack of diatoms of other ages in this layer argues against a wind deposition. It is very interesting that newer diatoms don't appear in this layer as they should if this layer has wind source. I thought the following statement of theirs particularly interesting. "The atmospheric circulation system and the ice-sheet configuration were significantly different, so that only the observed Plio-Pleistocene marine diatom flora of the Sirius Group was elevated." So what they are saying, is that for this diatom layer to have been eolian transported, or carried by the wind; first there had to be a Plio-Pleistocene diatom deposit that became exposed above water and ice, that the wind could whip up. Second this deposit had to be located in such a manner, and the wind flow patterns and ice and land topography was such that only diatoms from this unknown deposit were carried by the wind to where they were found without any diatoms being carried from the sea or other surfaces were the wind could pick them up. Pew! In short, wind depositation seems to be virtually impossible due to the unusual and extreme conditions necessary for the wind to deposit the diatoms in the manner in which they are found. A marine transgression at the time the diatoms are dated to, is a far better interpretation of the available evidence. The weight of the ice sheets has depressed the Antarctica land mass, it is possible that when the ice sheet there was more extensive the land was even more depressed and a fast entry of water/ice into the sea before isostatic adjustment could occur would have temporally raise global sea levels and flooded this area. These post ice age floods occurred to greater or lesser degrees at the end of each ice age or stage. As much as I would like to claim this evidence for the flood, I will be fair and point out that due to the age of the diatoms involved and the location, this flood event could possibly be from a smaller marine transgression of on earlier retreat of the ice age. On the other hand, it could be from the end of the Wisconsin, but until I know more on the dating of the diatoms involved, I will hold off on that claim for now.
Some of you also seem to be having difficulty accepting the idea of large portions or even an entire ice sheet suddenly surging. As I have already posted, the GRIP drop stones found over the area of the North Atlantic are believed to be the result of just such an event. There are also, the last I heard, three teams monitoring one of the largest ice sheets in Antarctica, because it is feared that rising sea levels due to a warming climate could destabilize the ice sheet and cause it to surge which could flood coastal areas all over the world, sort of a mini Noah's flood. The possibility of large sudden movement by ice sheets is today not only believed in, it is feared. Link to site on the possibility of the ice sheets collapsing
Page Not Found | UW College of Arts & Sciences
As for drop stones in other oceans, there are probably are many other areas which have them, perhaps a Internet search will turn up more information, and remember just because we haven't gone and found something doesn't mean it isn't there, you don't know that until you look. And on "entire ice sheets melting"? where did that come from? I am proposing that the ice sheets had been melting slowly over time up until the flood, when they suddenly released a flood of meltwater which resulted in massive surging. As for the long term climate effects of having the remains of large portions of the former ice sheets dumped into the world oceans, the effect would probably be a warming trend for the air while the water may have cooled some what. The removal of glacial ice from land areas would result in a much greater warming effect since land surfaces absorb a much greater amount of sunlight than does ice and snow which reflects most of it back out into space. The ice in the oceans in the form of ice burgs would also have most of their surfaces submerged below water, water absorbs 90% of sunlight compared to ice's 10%. The icebergs would have existed for quite sometime in the oceans, there is no reason to conclude that they would all have to melt during the short time period of the flood. Some of these icebergs were trapped on land as the waters drained into the sea. At one time it was even thought that the Carolina bay lakes were created in this manner, but it seems too improbable given the characteristics of the lakes. Stagnate ice traces found far south of where the edge of the ice sheet edge was, could be evidence of ice that had be moved by floating south as the waters drained.
On the extent of SA glaciers, picture a map of the area about six inches long and mentally drag your thumb down the west side of the map where the mountains are.
On the dates for the extinction of the Pleistocene animals. Remember as I have been repeatedly saying, we do not necessarily have fossil remains of the last animal alive of each species. How long they lived after the last specimen found is impossible to tell. And as I have repeatedly stated, there is a pattern of animals appearing to disappear before the extinction event that killed them off due to these effects. Also there is play in the dates, and many of the finds may have been alive later than currently believed. Since the evidence available indicates that the flood did not cause much erosion, there was little opportunity for flood victims to be buried by sediment which would have preserved their remains. Only would be fossils that happened to settle in areas where sedimentation was occurring, like lake bottoms and sand bars, would have much chance of being preserved. Since the flood did not create a large number of fossils, the ones we find date from before the extinction event and the dates will fail to cluster at the extinction event. This same problem has be noted to happen with other extinction events leading to the creation of theories that the extinct animals where in decline before the event. Due to these factors and the uncertain nature of knowing the exact timing of things in the past, I feel it is reasonable to conclude that a large number of the extinct ice age animals did indeed die in a sudden event at the end of the ice age.
Patrick- does Geology magazine have a web site? I would like to look at the articles you cited. I am aware of wind transport of marine diatoms, if you read the earlier posts you will see this subject has already been well covered as to why the diatoms I have found could not have been deposited by wind action.

Replies to this message:
 Message 55 by edge, posted 01-25-2002 11:18 PM wmscott has not replied

ps418
Inactive Member


Message 54 of 460 (2786)
01-25-2002 8:14 PM


Wmscott,
You seem to be having a problem understanding the evidence I am presenting. For instance, you wrote:
First off the deposit is not found on ice or a glacier, but in a dry valley type environment.
Obviously you did not read the Kellog and Kellog article I recommended. Diatoms are found both in the ice caps, at multiple levels, *and* in the surface of the exposed Sirius tills. Kellog and Kellog again (pay attention):
"Diatoms are a small but pervasive constituent of snow falling at the South Pole (and at Siple and Taylor Domes), although in a patchy pattern through both space and time (figure 2). Over 40 marine and nonmarine taxa were recorded (table). Abundances are extremely variable, ranging from nil to over 260 specimens in individual samples."
And their Geology article later that year states:
Marine and nonmarine diatoms occur throughout a South Pole ice core spanning the past 2000 yr. Similar diatoms occur in East and West Antarctica at Siple and Taylor domes. Because there are no local diatom sources at these locations, diatoms must have been carried by winds from coastal or extra-Antarctic sites. Our data demonstrate widespread historical eolian transport of diatoms to the Antarctic ice sheets, supporting the view that Sirius Group sediments were contaminated by late Neogene diatoms long after they were deposited. If so, there is no reason to postulate a Pliocene deglaciation event in East Antarctica.
And again, here is Kellog and Kellog's illustration, showing the flux of diatoms into ice deposited over the past 2000 years.
Graph from:
David E. Kellogg and Thomas B. Kellogg, 1997. Diatoms in **a South Pole ice core**: Serious implications for the age of the Sirius Group, Antarctic Journal of the United States, v. 32.
http://www.nsf.gov/pubs/1997/nsf97160/cover1.htm
Subsequently Kellog and Kellog documented the atmospheric flux of diatoms to Antarctica over a much longer time scale:
After finding eolian-deposited diatoms in an ice core drilled at South Pole (Kellogg and Kellogg 1996), we were anxious to determine whether wind-blown diatoms are routinely incorporated into ice at other remote antarctic locations. Specifically, we were interested in determining how widespread these diatoms are, how diatom assemblages and abundance patterns differ between the east and west antarctic ice sheets, and how diatom flux varies down long ice cores, especially across glacial/interglacial transitions. We hope to use this information as input into climate models to reconstruct past storm tracks over Antarctica and determine how atmospheric circulation changes across climatic transitions.
As their ice core data from Taylor Dome shows, diatoms have been transported to Antarctica and incorporated into the ice over at least the past 160,000 years.
From:
D.E. Kellogg and T.B. Kellogg, Glacial/interglacial variations in the flux of atmospherically transported diatoms in Taylor Dome ice core, Antarctic Journal of the United States Review 1996, LAND-ICE STUDIES AND GLACIAL GEOLOGY.
Are we clear on this now? Eolian transport of diatoms to the poles is a fact, and has been occurring for at least the past 160,000 years?
Wmscott wrote:
They then go on to state why wind depositing is a problem.
" If the microfossils arrived by eolian processes, they should occur in surface deposits of disparate origin but of unknown age, both glacial and nonglacial, given the ability for the deposit to trap fine-grained, wind-blown material (McFadden, Wells, and Jercinovich 1987; Wells et al. 1995)."
I'm happy to report that this is exactly what the Burkle and Potter paper, published later the same year in the journal Geology, demonstrated. This is precisely why I recommended the paper in the first place. Their abstract reads:
Burckle, L.H., and N. Potter, Jr. 1996. Pliocene-Pleistocene diatoms in Paleozoic and Mesozoic sedimentary and igneous rocks from Antarctica: A Sirius problem solved. Geology , 24(3), 235-238.
"There are two competing scenarios on the behavior of the East Antarctic ice sheet during the late Tertiary. In one scenario, the ice sheet was very dynamic and underwent major drawdown and renewal as late as the Pliocene. In the other, the ice sheet was relatively stable during the late Neogene. The presence of marine diatoms in Sirius Group sedimentary rocks in East Antarctica is at the center of the disagreement. One side regards the diatoms as the major piece of evidence to support the drawdown and renewal hypothesis and infers that they were introduced into the Sirius during renewed glaciation of East Antarctica; others suggest that these diatoms were likely introduced into the Sirius by atmospheric (largely eolian) processes.
"We propose a simple test of the eolian hypothesis. If diatoms were introduced into the Sirius by eolian processes, then they should also be present in older (Paleozoic and Mesozoic) sedimentary and igneous rocks. Samples from two units of the Beacon Supergroup (Devonian to Jurassic) from Beacon Valley, East Antarctica, were analyzed: the Beacon Heights Orthoquartzite (Devonian) and the Feather Conglomerate (Permian-Triassic). Also examined was sediment found in cracks of Paleozoic and Mesozoic (Devonian to Cretaceous) igneous rocks from Marie Byrd Land, West Antarctica. Largely Pliocene-Pleistocene planktonic marine diatoms were found in all sample sets. Because neither Beacon Supergroup sedimentary rocks nor igneous rocks from Marie Byrd Land are Pliocene-Pleistocene in age, such findings strongly suggest that diatoms were introduced into them by eolian processes. This same scenario can be applied to Sirius Group sedimentary rocks."
Now, I want to make sure we both agree that wind transport of marine diatoms is a well-established before moving on to my next point. If you agree, then I want to move on to your arguments against eolian transport for the diatoms you've found in soils.
Til later,
Patrick
PS- Geology is published by the Geological Society of America. Abstracts are available at Geological Society of America , full-text at your local university.
[This message has been edited by ps418, 01-25-2002]
[This message has been edited by ps418, 01-25-2002]
[This message has been edited by ps418, 01-25-2002]

edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 55 of 460 (2789)
01-25-2002 11:18 PM
Reply to: Message 53 by wmscott
01-25-2002 4:26 PM


quote:
Originally posted by wmscott:
Some of you also seem to be having difficulty accepting the idea of large portions or even an entire ice sheet suddenly surging. As I have already posted, the GRIP drop stones found over the area of the North Atlantic are believed to be the result of just such an event.

So this is the only way to get a broad deposit of drop stones? Sorry, but I don't buy that. You have not connected drop stones with jokhulhlaups in anyones minds yet. I would suggest that the drop stones were associated with a major advance of the continental ice sheets under normal expansion.
quote:
There are also, the last I heard, three teams monitoring one of the largest ice sheets in Antarctica, because it is feared that rising sea levels due to a warming climate could destabilize the ice sheet and cause it to surge which could flood coastal areas all over the world, sort of a mini Noah's flood. The possibility of large sudden movement by ice sheets is today not only believed in, it is feared. Link to site on the possibility of the ice sheets collapsing
Page Not Found | UW College of Arts & Sciences

Did you read this article? This process has been going on for 10ky and won't pose much of a hazard for another 7 ky. Hardly a catastrophic event in the sense of a Noachian flood. I think your operative word here is "mini." So, we still have yet to see a process on the scale of which you speak.
quote:
As for drop stones in other oceans, there are probably are many other areas which have them, perhaps a Internet search will turn up more information, and remember just because we haven't gone and found something doesn't mean it isn't there, you don't know that until you look.
You mean that you've done all of this research and not done this yet?
...
quote:
On the extent of SA glaciers, picture a map of the area about six inches long and mentally drag your thumb down the west side of the map where the mountains are.
I believe that I asked for the extent of continental ice sheets. My guess is that there were none. The area was glaciated because it was already high. Exactly as we find modern alpine glaciers. I also believe that even the area you describe was not exactly a continuous alpine-glaciated area. In this case how do you manage all of the uplift of the Andes by isostatic readjustment related to glacial unloading?

This message is a reply to:
 Message 53 by wmscott, posted 01-25-2002 4:26 PM wmscott has not replied

wmscott
Member (Idle past 6247 days)
Posts: 580
From: Sussex, WI USA
Joined: 12-19-2001


Message 56 of 460 (2812)
01-26-2002 8:42 AM


As I have already repeatedly posted, I don't have a problem with wind transported marine diatoms. Also, comparing ice core with till core records of diatoms is like comparing apples with oranges. A flood deposited layer in theory would only be present in the till core and not the ice core. In addition, for the one layer in till core only, this paper's statement of the diatoms being of a secondary nature is hard to believe since as the second paper stated that the diatoms in the one layer and the material they are with, do not show disparate origins as the wind blown ice core materials in the other paper do. As I stated in my earlier post, the dating on these diatoms may be too early and may be related to a smaller earlier flooding event. (the one layer in the till, the rest are wind blown) the dry valleys do contain evidence of a recent flooding in the form of dead seals found over a hundred miles from the sea. these freeze dried animals are believed to have traveled over land away from the sea by mistake and died. However one group is in a neat row all aligned like seals would be in a bad storm while laying on an ice flow. It would seem they died in a storm and were covered by snow, the ice later drifted into the flooded valley during the flood and was left behind. The ice slowly disappeared leaving the dead seals behind. I find it hard to believe these animals traveled to far inland as a group and they all happened to tire out and die in the same place in a neat row. Their behavior seems more typical of a normal group of seals on ice than a very lost and starving group that had traveled over a hundred miles inland. Since the diatoms even in the till layer seem to at best be the documentation of an earlier small event, I regard the dead seals as better evidence. Perhaps in time more flood associated material in these areas will be found. So even if the diatoms in the valleys are dated to an earlier flood and the rest are wind blow, we still have recent indications in the seals of a recently much higher sea level.
The two reasons the marine diatoms found here are not of wind origin are the absence of wind deposed diatoms as shown by their being lacking in samples of the current surface. Apparently due to distance and or wind patterns and mountain ranges, very few wind carried diatoms make it here. If any do, they seem to be too few in number to show up in the sampling method used. The second reason is the pattern of deposit, this layer is not found beneath glacial boulders showing that these rocks were deposited before the diatoms were, then there are other large rocks which appear to possibly be drop stones under which this layer is found. Wind could not deposit diatoms underneath large boulders. The diatoms are not found beneath the surface in the soil in general, which eliminates them being from a reworked source. In short, the pattern of deposit indicates a short period of deposit at the end of the last ice age. The ice had retreated north of this area leaving boulders behind, the flood occurred and rock bearing ice floated south dropping rocks which landed on a surface already covered by a layer of marine diatoms.
edge- I am pressed for time today, so I don't have time to post the information you request. I would suggest doing some reading on the subject, the extent of ice cover in SA and the way the last ice age ended. "Late glacial and Postglacial Environmental changes" is a good book for this. I suggest this because you are mostly questioning mainstream theories on the ice age. I merely believe that many of the huge flooding events happen at the same time and perhaps on a larger scale or range then is currently believed. but you seem to keep questioning basic things like ice sheets surging, doesn't common sense tell you that the bigger a pile of ice is, the more unstable it is? If we are to have a discussion on the details of this, you need to get a better background in the subject.

Replies to this message:
 Message 57 by edge, posted 01-26-2002 11:02 AM wmscott has not replied

edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 57 of 460 (2814)
01-26-2002 11:02 AM
Reply to: Message 56 by wmscott
01-26-2002 8:42 AM


quote:
Originally posted by wmscott:
edge- I am pressed for time today, so I don't have time to post the information you request. I would suggest doing some reading on the subject, the extent of ice cover in SA and the way the last ice age ended. "Late glacial and Postglacial Environmental changes" is a good book for this. I suggest this because you are mostly questioning mainstream theories on the ice age.

Not at all. I am questioning the way you apply them. I have no problems with ice dams, breakouts, jokuhlhaups, glacial lakes, glacial expansions, etc. It's just that you have offered nothing that is diagnostic of a worldwide, Noachian flood.
quote:
I merely believe that many of the huge flooding events happen at the same time and perhaps on a larger scale or range then is currently believed. but you seem to keep questioning basic things like ice sheets surging, doesn't common sense tell you that the bigger a pile of ice is, the more unstable it is?
No, common sense tells me nothing like that, and you have not made a case for it either. You have made a bunch of extrapolations from limited data and explained it with an event that has no broad support in geology and has never been observed. For instance, we know that plate tectonics works. We know where the faults are and their sense of motion. We directly observe motion along these faults. We can calculate the rates of uplift due to convergent tectonics. These more than adequately explain every uplifted shoreline along the western coast of North and South America. And yet you come up with some idea that minimizes this data and explains "everything" even though there were never enough continental ice sheets to account for all of the isostatic adjustment that you suggest.
I admit that you have an interesting idea. However, you have carried it to such an extreme that it cannot be taken seriously. This particularly since you ignore some data, passing it off with a wave of the hand and then bend the rest the data to support the biblical concept of a flood.
quote:
If we are to have a discussion on the details of this, you need to get a better background in the subject.
No comment.

This message is a reply to:
 Message 56 by wmscott, posted 01-26-2002 8:42 AM wmscott has not replied

ps418
Inactive Member


Message 58 of 460 (2830)
01-26-2002 1:34 PM


Wmscott,
Do we both now agree that a) marine diatoms are currently being deposited in Antarctica, that b) the ice core records presented by Kellog and Kellog show that marine diatoms have been transported to Antarctica for the past 160,000 years, and c) that the flux of diatoms to Antarctica has been distinctly "patchy in time and space"?
And regarding the diatoms in the till, all parties agreed by the end of 1996, as far as I can see, that they were indeed deposited by wind. Reasons for the different assemblages are not at all mysterious, do not support any kind of flood event, and are explained by Stroeven, Prentice and Kleman, 1996. On marine microfossil transport and pathways in Antarctica during the late Neogene: Evidence from the Sirius Group at Mount Fleming, Geology 24, pp. 727-730. See also Stroeven and Prentice, GSA Bulletin 109, pp. 825—840. Do you know of a single researcher in this field who disagrees that these diatoms were eolian transported?
Furthermore, if you look, again, at the Taylor Dome diatom record covering the past 160,000 years, you'll see the that the relative proportions of marine and nonmarine diatoms vary considerably over time, and that the assemblages change over time -- this dispatches the complaint in your last post about the different diatom assemblages, which was apparently your only argument against eolian transport for the diatoms in the Sirius tills. How you arrived at the conclusion that these could not be eolian transported is quite mysterious.
Now, let's look at your arguments against eolian deposition for the samples you've looked at. As I will show in this post and my next post, your arguments do not in any way invalidate eolian deposition, nor do they provide any evidence whatsoever for deposition via a "Noah's flood."
Wmscott wrote:
I have no problem with diatoms being carried by the wind. The one here that I have found were not deposited in that manner. If they had been they would be found throughout the soil or at least on the modern surface everywhere.
Again, the diatom record in the Taylor Dome shows that this expectation is wrong. Wind deposition of diatoms is "patchy in time and space." Thus you should not expect to find diatoms in all soil samples, or uniformly distributed within any given soil profile. There's one "argument" down.
where the surface has been disturbed have no diatoms, which if the wind was the source, they would have had them.
Wrong again. This would be a valid prediction only if you assume, contrary to the evidence, that eolian deposition of diatoms is uniform in time and space. The record of diatom flux at Taylor Dome, again, shows that during many intervals, for periods lasting many thousands of years, little or not diatoms were being transported.
See how easy that was? And that's your "best evidence" against eolian deposition?
One more point. What, if anything, is your evidence that tiny silicate diatom tests can persist at shallow depths in soil for at least 4500 years (or 10,000 or 40,000 yrs, depending on the date you eventually pick for your flood)? Do you make any attempt to deal with diatom taphonomy in your book, or did you simply assume that diatoms could persist in a near-surface soil environment for this long?
I found several papers today addressing the preservation potential of diatoms, and they demonstrate that the the breakdown of diatoms in natural environments can occur very quickly, within a few years or less! According to your 'model,' these diatoms had to have remained intact and recognizable for at least 4500 years.
This should come as no surprise, given the tiny size and skeletal porosity of diatoms, and given the occurence of bioturbation, hydrolysis, shrink-swell processes, chelation and other physical and chemical weathering processes that occur in soils.
soil[/I] diatoms preserved in paleosols? I've read numerous papers on paleosols, but have never heard of diatoms being preserved.
Later today I will summarize some of the literature on this subject. From what I've seen so far, though, it looks like very bad news for your diatom flood "evidence."
Patrick
[This message has been edited by ps418, 01-26-2002]

ps418
Inactive Member


Message 59 of 460 (2832)
01-26-2002 1:42 PM


One more point before I continue. When was your flood event, Wmscott? The paleoclimatic record of the last 10,000+ years is extremely detailed, and there should be no confusion on this point.
The biblical flood was ~4500 years ago, give or take a few centuries. Yet the events you mention -- the last deglaciation, Black Sea flood, Heinrich events (marked by ice-rafted debris in Atlantic cores), Pleistocene mammal extinctions, etc. -- occurred long before this, and are themselves seperated in time by many thousands of years. In order to force all these events into a single year you'll need to ignore all the geologic evidence. So, again, when was your flood, and how do you know?
Patrick
[This message has been edited by ps418, 01-26-2002]

ps418
Inactive Member


Message 60 of 460 (2952)
01-27-2002 12:04 PM


Wmscott,
I found several papers addressing the dissolution of diatoms under natural and laboratory conditions. Everything I've seen so far leads me to believe that diatoms being preserved in soils undergoing physical and chemical weathering for 4500 years is not plausible (much less 14,000 years), and that your marine diatoms therefore must have been introduced more recently.
For instance, Bennet et al. (1991) illustrate the rapid dissolution of silicate minerals in a peat bog in Minnesota. The peat here is about 3m thick, and the section is dated by several 14C dates.The age ~1m from the surface is ~1165 yrs, and about 2400 yr at ~2m. The authors present SEM evidence for the progressive dissolution of silicate minerals with depth. Even at a depth of ~200cm and an age less than 2400 yr, silicate minerals show extensive etching, pitting and dissolution features. The authors dont mention diatoms, but because diatoms are much more porous and more likely to disarticulate than silicate minerals like quartz and hornblende, their effective life in the bog histosol would be much shorter than 2400 yr.
Michalopoulos et al. (2000) demonstrate in laboratory experiments that diatoms are converted to aluminosilicate clays in only 20-23 months when incubated at 28C in anoxic muds. They also note that conversion is equally rapid in Amazon Delta. They write:
SEM elemental mapping and TEM studies (electron diffraction, analytical electron microscopy and morphological characteristics) demonstrate that diatom frustules convert to poorly crystalline aluminosilicate phases and microcrystalline clay minerals that primarily contain K, Fe and lesser amounts of Mg. Euhedral pseudohexagonal clay mineral crystallites have formed within the converted siliceous frustules. Two types of euhedral authigenic clays were found, a dominant K-rich phase and a less-ubiquitous K-free type. Under the TEM, relics of diatom frustule microarchitecture can be discerned in otherwise converted frustules.
The rate of diatom conversion is very rapid and can be complete in months to 2 years. This is directly demonstrated with laboratory incubation experiments with cultured diatoms inserted into Amazon anoxic muds. After 20 months of incubation, cultured diatom cells of the genus Coscinodiscous sp. convert to authigenic phases, and on occasion to euhedral K-Fe-rich clay minerals replacing the original siliceous frustule. In addition, converted diatom particles are found in recently deposited (~ months) sediments near the sediment water interface, corroborating the rapid nature of the conversion process
Reyves et al. (2001) present experimental data on dissolution rates for 24 species of lake diatoms. The diatoms were incubated at 25C in distilled water for 4-7 weeks. The solution was sampled at various times to assess diatom preservation at various stages. The longest half-life of any of the taxa (time in which half are dissolved) was 1513 hours for Mastogloia elliptica (see table 1). The next closest was Nitzschia amphibia, at 811 hours. The majority have half-lives less than 500 hours under the experimental conditions.
Maybe the tests of dead diatoms can somehow persist in soils for 4500+ years, but I'd like to see the evidence for that. A simple way to test this would be by examining holocene soil chronosequences. If your hypothesis is correct, soils postdating ~4500BP should not contain the diatoms, and all soils containing the diatoms should predate ~4500BP. If you search the literature thoroughly, you can probably find many well-dated soil chronosequences in your region. You want to look through USGS Open File reports, the Soil Science Society of America Journal, and the journals Catena and Geoderma.
Good luck,
Patrick
Andrejko, M.J and A.D. Cohen. 1984. Scanning electron microscopy of silicophytoliths from the Okefenoke swamp-marsh complex. pp 466-491. In Cohen, Casagrande, Andrejko and Best (Eds). The Okefenokee Swamp: Its natural history, geology and geochemistry. Wetland Surveys. Los Alamos.
Bennett P.C., Siegel D.I., Hill B. and Glaser, P. (1991) The fate of silicate minerals in a peat bog. Geology 19, 328-331.
Bidle, K.D. and F. Azam. 1999. Accelerated dissolution of diatom silica by marine bacterial assemblages. Nature. 397:508-512.
Lawson, D.S. D.C Hurd and H.S. Pankratz. 1978. Silica dissolution rates of decomposing phytoplankton assemblages at various temperatures. American Journal of Science 278:1373-1393.
Mikkelson, N., 1980. Experimental dissolution of Pliocene diatoms. Nova Hedwigia, 33(2): 893-911.
Ryves, D.B., Juggins, S., Fritz, S.C. & Battarbee, R.W. 2001. Experimental diatom dissolution and the quantification of microfossil preservation in sediments. Palaeogeography, Palaeoclimatology, Palaeoecology, vol 172, 93-113.

Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024