Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 64 (9073 total)
68 online now:
Phat, Tangle (2 members, 66 visitors)
Newest Member: MidwestPaul
Post Volume: Total: 893,319 Year: 4,431/6,534 Month: 645/900 Week: 169/182 Day: 2/47 Hour: 0/2

Announcements: Security Update Released


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Growing the Geologic Column
Percy
Member
Posts: 20767
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.1


Message 1 of 2 (733602)
07-19-2014 9:04 AM


This thread continues the discussion taking place at the end of the Continuation of Flood Discussion thread about how sediments add to the geologic column.

The real geologic column, the actual physical one beneath any point on Earth as opposed to the conceptual and generalized one used for teaching the principles of geology, consists of all rock from the surface down to the molten mantle. This rock is organized into layers of different composition called strata.

Some will argue that because strata is defined as sedimentary layers that some types of rock formations, like igneous intrusions or salt domes, are not strata and are therefore not part of the geologic column. This is a valid point, but the specifics of the rock layers making up the geologic column are not relevant to this thread's topic, so agreement on this point should be unnecessary. In this thread when I say geologic column I shall mean every bit of rock vertically beneath some point on the Earth's surface.

Sufficiently low lying regions are areas of net deposition of sediments. In all low lying regions of the world as sediments are deposited the geologic column grows. Since most low lying regions are submerged we cannot directly observe this process in our daily lives, but there are some exceptions.

The Sahara Desert is one such exception. A recent news item reports that the fictional Star Wars city of Mos Espa, constructed for Star Wars Episode 1 in the Tunisian desert in 1997, is slowly being reclaimed by the desert. Within a century it will be completely covered by sand, which in this case is a windblown sediment. It is a terrestrial location where we can easily discern the year-by-year growth of the geologic column as it covers the buildings.

Lake Mead is another example of growing the geologic column, but in a part of the world very familiar to these discussions: the Grand Canyon region. As soon as it began forming in 1936 it began accumulating sediments. But the Hoover Dam won't last forever. When it's gone so will be Lake Mead, and these sediments will erode away, shrinking the geologic column at that location.

But if the region should subside beneath the waves while Lake Mead still lives then sediments will continue to accumulate, perhaps deeply enough for lithification to occur. turning the sediments to rock.

--Percy

Edited by Percy, : Grammer.


AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 2 of 2 (733605)
07-19-2014 10:18 AM


Thread Copied to Geology and the Great Flood Forum
Thread copied to the Growing the Geologic Column thread in the Geology and the Great Flood forum, this copy of the thread has been closed.

Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.1
Innovative software from Qwixotic © 2022