-------- Original Message --------
Subject:        Re: MAPS-L: USGS folios - Geologic Atlas of the US
Date:   Sat, 29 Jul 2006 07:25:20 -0500
From:   Mike Flannigan <[log in to unmask]>
To:     Maps, Air Photo & Geospatial Systems Forum
<[log in to unmask]>, [log in to unmask]
References:     <[log in to unmask]>



This Geologic Atlas of the US effort appears to be done
for reasons other than conveying the information in the
book.  They have chosen to offer a 100 MB tiff file for
the scan of one page of text.  I guess some pages will
have graphics on them, but many don't.  I'm sure they
are aware that a simple OCR of these text pages
would reduce the size by a factor of more than
1 : 1,000.

They state:
"Each of the folios includes both topographic and
geologic maps for each quad represented in that
folio, as well as geologic reports with information on
the geology and economic geology on that area. Only
227 folios were produced, so the area covered is
very limited."

Given the size of the files it would be nice to have
an index of what is available - which pages offer
the map data and which are simply text.


This site:
http://www.libraries.psu.edu/emsl/guides/pageomaps.html
offers 4.4 MB SID files of the maps from the PA section.
I must admit the TIFF files would be much better quality for
the graphical maps than these SID files are.



Mike Flannigan


On Fri, 28 Jul 2006, [log in to unmask] wrote:
>forwarded from geonet
>
>-------- Original Message --------
>Subject:        [Geonet] USGS folios - Geologic Atlas of the US
>Date:   Fri, 28 Jul 2006 14:25:11 -0400
>From:   Mary Scott <[log in to unmask]>
>To:     maps-l
>
>
>
>Did others know that the full set of 227 folios has been digitized by
>the Map Library at Texas A&M?  I just found them as I was trying to
>decided what to do with my crumbling sets.
>
>http://txspace.tamu.edu/handle/1969.1/2490
>
>Mary
>