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Author Topic:   The great extinctions in geologic history
Minnemooseus
Member
Posts: 3941
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 10.0


Message 1 of 10 (1452)
01-01-2002 7:52 PM


Seems to me that this topic deserves it's own line of discussion, so I'm bringing this over from message 67 of the "Is the Global Flood Feasible? Discussion Q&A" string.
See "The Five Worst Extinctions in Earth's History" at:
http://www.space.com/scienceastronomy/planetearth/extinction_sidebar_000907.html
Moose
------------------
Old Earth evolution - Yes
Godly creation - Maybe

Replies to this message:
 Message 2 by mark24, posted 01-02-2002 6:14 AM Minnemooseus has not replied
 Message 7 by Faith, posted 11-26-2005 4:08 AM Minnemooseus has not replied

  
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 2 of 10 (1453)
01-02-2002 6:14 AM
Reply to: Message 1 by Minnemooseus
01-01-2002 7:52 PM


Moose, from your source ;
Permian-Triassic extinction, about 251 million years ago. Many scientists suspect a comet or asteroid impact, although direct evidence has not been found. Others believe the cause was flood volcanism from the Siberian Traps and related loss of oxygen in the seas. Still others believe the impact triggered the volcanism and also may have done so during the Cretaceous-Tertiary extinction. The Permian-Triassic catastrophe was Earths worst mass extinction, killing 95 percent of all species, 53 percent of marine families, 84 percent of marine genera and an estimated 70 percent of land species such as plants, insects and vertebrate animals.
My point is that direct evidence has been found, recently, within the last 5-6 years.
Secondly, before anyone gets excited, flood volcanism refers to lava, not water.
I realise I was a bit absolute in saying that the P-T extinction was attributed to bolide impact. What I SHOULD have said was, there is now evidence of global effects caused by bolide impact, which in conjunction with other factors may have lead to the extinction.
I repeat the link here,
http://www.gsajournals.org/gsaonline/...
{Shortened display form of URL, to restore page width to normal. At this time, the link seems to no longer point to the material it once did. - Adminnemooseus}
From the above link ;
Possible sources of isotopically light Sr for marine sediments include volcanic gas, Sr dissolved from the seafloor hydrothermal system, and ejecta from the mantle. Volcanic gas can be ignored quantitatively. An increase in dissolved Sr from the seafloor hydrothermal system leads to a decrease in the 87Sr/86Sr of seawater (87Sr/86SrHOAC-leachate). An increase in ejecta from the mantle causes a decrease in 87Sr/86Sr of clastics (87Sr/86SrHCl-residue initial) and no decrease in 87Sr/86Sr of seawater, because most of the Sr in ejecta do not dissolve in water. Therefore, a negative shift of 87Sr/ 86SrHCl-residue initial and the absence of a negative shift of 87Sr/86SrHOAC-leachate indicate that the source of light Sr was ejecta from the mantle. Rapid supply of mantle material agrees with the other evidence of an extraterrestrial impact and the decrease in sulfate sulfur isotope ratios, which leads to our conclusion that a rapid release of an enormous volume of sulfur from the mantle to the ocean-atmosphere system occurred as a result of the impact.
Indicating materials from the mantle WERE involved, if only as a result of the impact.
------------------
Occam's razor is not for shaving with.
This message has been edited by Adminnemooseus, 11-26-2005 12:56 PM

This message is a reply to:
 Message 1 by Minnemooseus, posted 01-01-2002 7:52 PM Minnemooseus has not replied

Replies to this message:
 Message 9 by Adminnemooseus, posted 11-26-2005 11:39 AM mark24 has replied

  
TrueCreation
Inactive Member


Message 3 of 10 (1538)
01-03-2002 10:19 PM


What evidence is there that these impacts did indeed have to happen only during the Permian-Triasic, and other geologic periods, and not other periods in geologic time? Besides that we see declines in animal populations after certain periods in the geologic column as most people would indicate as 'extinctions'.
-------------
[This message has been edited by TrueCreation, 01-03-2002]

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Minnemooseus
Member
Posts: 3941
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 10.0


Message 4 of 10 (1539)
01-04-2002 12:11 AM
Reply to: Message 3 by TrueCreation
01-03-2002 10:19 PM


quote:
Originally posted by TrueCreation:
What evidence is there that these impacts did indeed have to happen only during the Permian-Triasic, and other geologic periods, and not other periods in geologic time? Besides that we see declines in animal populations after certain periods in the geologic column as most people would indicate as 'extinctions'.
I don't really see the point behind this question. That impacts have been implicated in the great extinctions that define the ends of the Paleozoic and Mesozoic periods, makes no comment about the happenings of other impacts at other times.
Certainly other impacts have happened. Seemingly, any others that happened in the Phanerazoic were not of as great a magnitude as the two noted above.
Side note: Strong evidence indicates that an extra-terrestrial object impact was behind the formation of the great nickel deposit at Sudbury, Ontario, Canada. This happened in the pre-Cambrian, before significant life was on Earth.
Moose
------------------
Old Earth evolution - Yes
Godly creation - Maybe
{Edited to unbold the text. - Moose}
This message has been edited by minnemooseus, 11-26-2005 12:53 PM

This message is a reply to:
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ReverendDG
Member (Idle past 4110 days)
Posts: 1119
From: Topeka,kansas
Joined: 06-06-2005


Message 5 of 10 (263160)
11-25-2005 11:28 PM


just because
Bump for great justice!

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arachnophilia
Member (Idle past 1343 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 6 of 10 (263167)
11-26-2005 12:34 AM
Reply to: Message 5 by ReverendDG
11-25-2005 11:28 PM


Re: just because
only beat the newb by a month and a half.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 7 of 10 (263184)
11-26-2005 4:08 AM
Reply to: Message 1 by Minnemooseus
01-01-2002 7:52 PM


What's notable about that story is its typical evolutionist commitment to leaving out the evidence and giving only the totally speculative imaginative interpretation. Such and such happened you see. Not a bit of data. Nothing about the fact that this complete imaginative scenario about supposed great extinctions was concocted on the basis of bits of minerals found in the geologic column here and there and an absence of fossils that evo theory would expect to have been there. The best that can be said for it is that it does mention that there are other interpretations. But not a bit of data is provided for the sake of the hapless reader who is required to take the interpretation completely on faith.

This message is a reply to:
 Message 1 by Minnemooseus, posted 01-01-2002 7:52 PM Minnemooseus has not replied

Replies to this message:
 Message 8 by Nighttrain, posted 11-26-2005 5:25 AM Faith has not replied

  
Nighttrain
Member (Idle past 3993 days)
Posts: 1512
From: brisbane,australia
Joined: 06-08-2004


Message 8 of 10 (263195)
11-26-2005 5:25 AM
Reply to: Message 7 by Faith
11-26-2005 4:08 AM


Faith, go away and wallow in your delusions and let us wallow in ours.

This message is a reply to:
 Message 7 by Faith, posted 11-26-2005 4:08 AM Faith has not replied

  
Adminnemooseus
Administrator
Posts: 3974
Joined: 09-26-2002


Message 9 of 10 (263274)
11-26-2005 11:39 AM
Reply to: Message 2 by mark24
01-02-2002 6:14 AM


Bad link in Mark's message
I don't follow why this topic was bumped, but I do see that Mark24's link seems to have nothing to do with the content of the quoted. Perhaps it was once correct, but no longer is? Have a fix, Mark?
Adminnemooseus

This message is a reply to:
 Message 2 by mark24, posted 01-02-2002 6:14 AM mark24 has replied

Replies to this message:
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mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 10 of 10 (263311)
11-26-2005 12:38 PM
Reply to: Message 9 by Adminnemooseus
11-26-2005 11:39 AM


Re: Bad link in Mark's message
Moose,
No fix, topic's too old!
Mark
{I fully understand. - Adminnemooseus}
This message has been edited by Adminnemooseus, 11-26-2005 12:49 PM

This message is a reply to:
 Message 9 by Adminnemooseus, posted 11-26-2005 11:39 AM Adminnemooseus has not replied

  
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