Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
2 online now:
Newest Member: popoi
Post Volume: Total: 915,806 Year: 3,063/9,624 Month: 908/1,588 Week: 91/223 Day: 2/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Earth science curriculum tailored to fit wavering fundamentalists
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(6)
Message 896 of 1053 (762007)
07-07-2015 1:02 PM
Reply to: Message 892 by Faith
07-06-2015 10:10 PM


Re: Geologic column
The column has many local versions but the Geo Time Scale incorporates them all. Which are you all talking about? I'm surprised anybody would say the complete Geo Time Scale can't exist in any one place. I've never said that, and I've seen many cases where the whole range of time periods is represented.
I think of the Geological Time Scale as an immense tape that records geological events. There are many tracks on this tape, one for each location on earth, blindly painting a picture of what was happening at any given time.
At any given time, there are hundreds of processes being recorded on various tracks and nothing at all on others.
On some tracks there are gaps in the record, processes occur for a while and then, seemingly stop, only to begin again.
In fact, it appears that some parts of the record are deleted, but at no time are all of the tracks silent. Somewhere, there is activity.
If we are lucky, we can find a track where there is continuous information recorded on very long stretches of the tape, but that is not the rule. We live on an active planet and there are also pesky processes that erase the record on one track or more.
Often we see trends of ancient life in the record, that we describe such as 'no life', 'early life', 'old life', 'middle life', etc.; that appear to span all of the tracks at once. This is the record of life on earth.
Each of those tracks is a 'geological column', each unique to its location with its sedimentation, igneous activity, mountain building and erosional gaps showing what has happened at that very spot.
This will continue until the tape (time) stops or all processes stop. While we have an idea when it began, and we can observe the present record forming, we cannot see the end. The record lies in the past.

This message is a reply to:
 Message 892 by Faith, posted 07-06-2015 10:10 PM Faith has replied

Replies to this message:
 Message 897 by ThinAirDesigns, posted 07-07-2015 1:42 PM edge has replied
 Message 899 by Faith, posted 07-25-2015 10:09 AM edge has replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 898 of 1053 (762031)
07-07-2015 4:04 PM
Reply to: Message 897 by ThinAirDesigns
07-07-2015 1:42 PM


Re: Geologic column
Feel free. The analogy can be carried out to almost any level on any subject. Emphasize that erosion 'erases' parts of the recording. That's how we know that it happens, regardless of what some YECs seem to think about the non-existence of unconformities.

This message is a reply to:
 Message 897 by ThinAirDesigns, posted 07-07-2015 1:42 PM ThinAirDesigns has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 902 of 1053 (763489)
07-25-2015 1:41 PM
Reply to: Message 899 by Faith
07-25-2015 10:09 AM


Re: Geologic column
That's an impressive description of how a geologist thinks. It's really amazing how the human mind has such organizing power that even a random ink blot, or the random depositions of sediments and dead things by a worldwide Flood, can be perceived as a coherent meaningful story.
As usual, it's a little more complicated than that.
Both the distribution of rocks and the distribution of fossils are hardly 'random'. They are formed by processes which leave behind evidence in the form of patterns that tell us something about the rocks themselves.
This is something that YECs need to understand. Geology is not random. If randomness were the case, then predictive tools such as basin analysis and palynology (paleontology) would not be possible. And yet, there you are drilling into formations that might not exist in the case of random geology.
I'm not sure how to get this across to YECs. Maybe more exposure to the field, or some practical examples.
TAD, I might recommend, The Map that Changed the World for a presentation on how geology started moving from a 'natural philosophy' to an actual science, although someone must have already recommended it to you somewhere in this thread. It's all about patterns and processes.

This message is a reply to:
 Message 899 by Faith, posted 07-25-2015 10:09 AM Faith has replied

Replies to this message:
 Message 903 by Faith, posted 07-25-2015 2:53 PM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(2)
Message 915 of 1053 (768711)
09-13-2015 11:08 AM
Reply to: Message 912 by Tanypteryx
09-12-2015 2:15 PM


Re: Igneous rock over sedimentary layers
Those cases are not used to date the underlying layers are they? They could be used to date overlying layers, right
The issue would be the presence of significant unconformities beneath or above the lava flows. I would be very careful about either unless I was in a fairly continuous sequence of sediments briefly interrupted by a volcanic event.
In the case of a sill, the only relationship would be intrusive younger than sediments on either side.
ETA: One thing to remember, in partial answer to TAD's question, is that usually volcanic ages are used more to bracket the sedimentary rocks rather than date them directly. In other words, rocks or sediments below a dateable volcanic layer would be considered older and above such a layer as younger. Now if the layers were all continuous and interlayered, you could be pretty certain of the absolute date. This is the case with the KBS tuff situation, IIRC.
Edited by edge, : No reason given.
Edited by edge, : No reason given.

This message is a reply to:
 Message 912 by Tanypteryx, posted 09-12-2015 2:15 PM Tanypteryx has replied

Replies to this message:
 Message 916 by Tanypteryx, posted 09-13-2015 11:35 AM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 925 of 1053 (768829)
09-14-2015 11:28 AM
Reply to: Message 924 by Faith
09-14-2015 10:58 AM


Re: Moderator Provided Information, that's wrong
So they fell out of suspension, they dropped out of the water anyway. But limestones may precipitate out as petro said, and that would be the Tapeats and the Muav.
I don't think you intend to mention the Tapeats here. I've seen the Muav described as precipitated, but I'm not sure that's entirely accurate since few limestones are 'pure' and usually have a fine siliciclastic component.
Indeed, 'precipitate' would be a nonstandard usage in the rocks we are discussing, but it is also kind of vague. Often, I try to use the phrase 'chemical sediment' to avoid ambiguity.
I think that, for a layman, the confusion is understandable.
ETA: I have no problem with making the clarification, however.
Edited by edge, : No reason given.

This message is a reply to:
 Message 924 by Faith, posted 09-14-2015 10:58 AM Faith has replied

Replies to this message:
 Message 926 by Faith, posted 09-14-2015 11:35 AM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(3)
Message 931 of 1053 (768857)
09-14-2015 2:00 PM
Reply to: Message 929 by Faith
09-14-2015 1:02 PM


Re: Moderator Provided Information, that's wrong
So how do you explain the layering of the diatomite and tuff? The layers look like all the other layers which were deposited from water.
There are two distinct types of alternating layers (I'm not going to say 'sediments' even though the environment is sedimentary and I could do that. I'd like to keep the distinction between sedimentary and volcanic deposition if possible, even though they overlap).
Based on past experience, I'd say it was playa lake without a lot of clastic (sand, etc.) input, but a constant rain of diatom tests and intermittent volcanic eruptions.
Disclaimer: I am not on site nor familiar with this location. Just going by what's been said here.
Edited by edge, : No reason given.

This message is a reply to:
 Message 929 by Faith, posted 09-14-2015 1:02 PM Faith has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 940 of 1053 (769245)
09-18-2015 10:05 AM
Reply to: Message 934 by Tanypteryx
09-14-2015 3:53 PM


Re: Moderator Provided Information, that's wrong
You call this even layering?
I might generalize them as 'thinly bedded', but then, I'm not sure what Faith means by 'even layering'.
You will notice that she never does answer your question.
I wonder what she thinks of varves.
If so, I have to wonder what you would call uneven layering?
Again, not answered.

This message is a reply to:
 Message 934 by Tanypteryx, posted 09-14-2015 3:53 PM Tanypteryx has replied

Replies to this message:
 Message 943 by Tanypteryx, posted 09-18-2015 2:01 PM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 941 of 1053 (769246)
09-18-2015 10:20 AM
Reply to: Message 939 by ThinAirDesigns
09-18-2015 9:59 AM


Re: Dating lab returns
I apologize in advance for this question because i know I've seen it answered multiple times on this forum but I just can't think of a search term that would return what I need.
Let's suppose the viable dating range of a given RID method is 1 million years to 1 billion years.
Let's suppose I send in a rock #1 that is a half a million years old.
Let's suppose I also send in a rock #2 that is 2 billion years old.
My recollection is that the lab will NOT send you a results saying that the first rock is 1 million years old (even though that may be what their equipment returned) but rather a return saying something like "Less than a million"? Same with the other rock ... "More than a billion".
Would it be something like
Rock 1: =< 1,000,000
Rock 2: => 1,000,000,000
Is there some additional language a lab would put with this to note that the date range is outside the normal range return of their equipment/method.
Thanks so much.
If the lab knows nothing about the rock, they cannot tell if the sample is beyond the useful range or not by radiomtric analysis. All they can tell is that it is near the upper or lower detection limit.
Personally, I've never had this happen, so I can't say, but this is one of the flags for an inappropriate application of technique.
I'm thinking that you'd end up with erratic results due to measurement of very small quantities of parent and daughter isotopes. Then you get into the statistics of very small numbers and the effects of background quantities.
I'm also guessing that the result will be reported with a larger than usual error estimate. Someone here else might have more experience with that.

This message is a reply to:
 Message 939 by ThinAirDesigns, posted 09-18-2015 9:59 AM ThinAirDesigns has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 942 of 1053 (769247)
09-18-2015 10:36 AM
Reply to: Message 938 by Dr Adequate
09-14-2015 5:49 PM


Re: Moderator Provided Information, that's wrong
I said : "The diatomite was caused by the deposition of diatoms and the volcanic tuff was caused by the eruption of a volcano."
What did you expect it to look like? How does it fall short of your expectations?
I doubt that you will get an answer here. Faith is simply trying to ask questions until she finds one that you can't answer (or give up due to boredom).
By the way, for those who dig a little more deeply into sources, one of the sources for this picture misidentifies the material being imaged. It says:
"Diatomite and volcanic tufa layers.jpg"
The actual material is 'tuff' which has nothing to do with 'tufa'. Be careful of geological jargon...
Category - Wikimedia Commonsiatomite?uselang=itWikimedia

This message is a reply to:
 Message 938 by Dr Adequate, posted 09-14-2015 5:49 PM Dr Adequate has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(3)
Message 977 of 1053 (782268)
04-21-2016 5:54 PM
Reply to: Message 974 by PaulK
04-21-2016 5:33 PM


Re: The geological range of the tapeats / redwall
This is true. However it is not completely unjustified.
The Tapeats Sandstone, the Potsdam Sandstone, the Saint Peter's Sandstone, and the Sawatch Quartzsite, among otbers are all time-equivalent units. These are all basal Sandstone units related to the first major Paleozoic marine transgression.
What Snelling fails to tell you is that there are discontinuities due to non-deposition (which would mean contemporary land masses) and/or later erosion. He also fails to tell you why this scenario indicates rapid deposition. That is simply another baseless assertion.
Edited by edge, : No reason given.

This message is a reply to:
 Message 974 by PaulK, posted 04-21-2016 5:33 PM PaulK has replied

Replies to this message:
 Message 978 by ThinAirDesigns, posted 04-21-2016 6:15 PM edge has replied
 Message 987 by PaulK, posted 04-22-2016 12:56 AM edge has not replied
 Message 991 by JonF, posted 04-22-2016 8:12 AM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 981 of 1053 (782279)
04-21-2016 9:13 PM
Reply to: Message 978 by ThinAirDesigns
04-21-2016 6:15 PM


Re: The geological range of the tapeats / redwall
Still, rapid deposition does not mean old ages. One could have rapid deposition of one layer ... hundreds of millions of years ago.
This is deception on the part of Snelling..
Also, note that he is switching from the Tapeats to the Coconino in the same paragraph. This is more deception. The Tapeats is a beach sandstone and the Coconino is an eolian sand deposit. And yes, we can tell the difference.

This message is a reply to:
 Message 978 by ThinAirDesigns, posted 04-21-2016 6:15 PM ThinAirDesigns has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 982 of 1053 (782283)
04-21-2016 9:27 PM
Reply to: Message 980 by ThinAirDesigns
04-21-2016 6:46 PM


More nonsense.
The White Cliffs of Dover were deposited at about the same time as the Cretaceous Seaway in North America. At that time, the oceans were at a higher level covering large amounts of the continents.

This message is a reply to:
 Message 980 by ThinAirDesigns, posted 04-21-2016 6:46 PM ThinAirDesigns has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 983 of 1053 (782284)
04-21-2016 9:39 PM
Reply to: Message 980 by ThinAirDesigns
04-21-2016 6:46 PM


More nonsense.
The White Cliffs of Dover were deposited at about the same time as the Cretaceous Seaway in North America. At that time, the oceans were at a higher level covering large amounts of the continents. This resulted in large areas shallow seas covering the continental shelves with little input from continental sediments. In Europe and into the Middle East the sediments were starved of terrigenous sediments and developed carbonate banks. In North America, formations such as the Niobrara limestone are the equivalent of the White Cliffs of Dover. However, there were land masses to the west in North America.
It all makes sense if you understand the distribution of rocks in a global conrext.

This message is a reply to:
 Message 980 by ThinAirDesigns, posted 04-21-2016 6:46 PM ThinAirDesigns has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 984 of 1053 (782285)
04-21-2016 10:04 PM
Reply to: Message 979 by Faith
04-21-2016 6:35 PM


Re: The geological range of the tapeats / redwall
Well, considering that YECS do not recognize that these time periods exist, it is no wonder that it is a mystery to them. However, there is little doubt that they exist and that they are associated with major geological changes.

This message is a reply to:
 Message 979 by Faith, posted 04-21-2016 6:35 PM Faith has replied

Replies to this message:
 Message 988 by Faith, posted 04-22-2016 3:39 AM edge has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 1018 of 1053 (782408)
04-22-2016 11:22 PM
Reply to: Message 1006 by Faith
04-22-2016 12:04 PM


Re: The geological range of the tapeats / redwall
All of them. Every single boundary that marks off both a sedimentary deposit and a time period.
Actually, the rock types fit within a time period. And those 'rock types' are not pure. For instance the Supai group is a sequence of thin beds of mudstone, sandstone and limestone in no particular order nor purity.
In general, the contacts are not as sharp as you think. Yes, from a great distance, they are distinct, but upon viewing in detail, most contacts are gradational.
Have you actually visited the GC?
My impression is that you have not.
But what I'm hoping is that someone else will come along who simply gets what I'm talking about from what I've already said. I've explained it as well as I'm able. There's no point in trying harder to convince somebody who is determined not to be convinced, even if I had more I could say about it.
The reality is not what you make of it. Consequently, you will never have any support.

This message is a reply to:
 Message 1006 by Faith, posted 04-22-2016 12:04 PM Faith has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024