Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 64 (9071 total)
66 online now:
Dredge, Tangle (2 members, 64 visitors)
Newest Member: FossilDiscovery
Post Volume: Total: 893,034 Year: 4,146/6,534 Month: 360/900 Week: 66/150 Day: 39/27 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   The Story in the Rocks - Southwestern U.S.
Dr Adequate
Member (Idle past 279 days)
Posts: 16112
Joined: 07-20-2006


Message 8 of 121 (777309)
01-28-2016 10:51 PM
Reply to: Message 7 by Tanypteryx
01-28-2016 6:23 PM


Re: The Kayenta Formation & Dinosaur Tracks
I think they told me these were eggs but I have some doubts.

They're some sort of nodule, I'm fairly sure.


This message is a reply to:
 Message 7 by Tanypteryx, posted 01-28-2016 6:23 PM Tanypteryx has replied

Replies to this message:
 Message 9 by Tanypteryx, posted 01-28-2016 11:13 PM Dr Adequate has taken no action

  
Dr Adequate
Member (Idle past 279 days)
Posts: 16112
Joined: 07-20-2006


Message 15 of 121 (779331)
03-03-2016 12:30 PM
Reply to: Message 14 by edge
03-03-2016 11:33 AM


I read something interesting recently in a very old geology book (by Gideon Mantell, the guy who discovered Iguanadon, so yeah, that old). He said that sandstone could be produced by compaction alone, and adduced the fact that cannonballs shot at sandbags produced sandstone where they impacted. I've not seen this repeated anywhere else, I'd be interested to know if there is any sandstone anywhere that was lithified just by compaction.

This message is a reply to:
 Message 14 by edge, posted 03-03-2016 11:33 AM edge has taken no action

Replies to this message:
 Message 16 by Tanypteryx, posted 03-03-2016 2:54 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 279 days)
Posts: 16112
Joined: 07-20-2006


Message 17 of 121 (779349)
03-03-2016 4:07 PM
Reply to: Message 16 by Tanypteryx
03-03-2016 2:54 PM


I thought the process that forms sandstone is as much a chemical process that forms a binding matrix ...

Yeah, normally it's cemented, with, as edge says, carbonates, or (IIRC) with iron oxides. But Mantell seemed to think it could just be compacted. If anyone knows of an instance of this happening in nature rather than bombing ranges, let me know. Thanks.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 16 by Tanypteryx, posted 03-03-2016 2:54 PM Tanypteryx has taken no action

  
Dr Adequate
Member (Idle past 279 days)
Posts: 16112
Joined: 07-20-2006


(1)
Message 21 of 121 (779357)
03-03-2016 4:24 PM
Reply to: Message 19 by Faith
03-03-2016 4:13 PM


As for bombing ranges in Nevada, I understand that the underground caverns formed by the underground nuclear tests of a few decades ago are lined with thick glass, a later stage of what happens to sand under heat and pressure, yes?

Well normally if sand was subjected to both heat and pressure, it would be as a result of being deep underground, and in these circumstances it would cool slowly and give us the crystalline metamorphic rock quartzite. Glass, you will recall, is what you get when molten rock cools quickly, so that there's no time for crystallization.


This message is a reply to:
 Message 19 by Faith, posted 03-03-2016 4:13 PM Faith has taken no action

Replies to this message:
 Message 22 by edge, posted 03-03-2016 4:32 PM Dr Adequate has taken no action

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.1
Innovative software from Qwixotic © 2022