A Useful Map

Was doing some research for a project at work a few years back and came across this pretty good 'Geologic Map of Fayette County, Pennsylvania' (1938). The original map was typically annotated and color-coded for identifying geologic formations. I made two copies - one color and one black & white. I also digitized the black & white copy as PDF, TIFF and JPG files.

Lots of good things about this map. The best is that they used the Loyalhanna Limestone as a marker bed, with 100ft structure contours profiling the base of the Loyalhanna Limestone formation. What's so good about that?

1- Very useful for cavers. All the major caverns in SWPA are formed in the Loyalhanna Limestone formation. Anyone out searching for any undiscovered cave openings in limestone rock outcrops or near surface sinks or sumps pretty much have a roadmap for locating good areas to investigate.

2- Practically all of the climbable rock in SWPA consists of sandstone cliffs and large blocks of the Mauch Chunk and Pottsville geologic formations, with the Mauch Chunk bearing right atop the Loyalhanna Limestone - all identified on the map. A useful tool for locating potential unexplored climbing.

3- The best ice climbing in SWPA occurs at abandoned Loyalhanna Limestone quarries. There was also a companion map to this one annotated with all (which is many) of the quarry locations in the county, probably 95% abandoned at this day and age (1938 map, remember). I will post this map as well as soon as I annotate it for easier reference.

Here's the map:

I colorized the cropline of the Loyalhanna Limestone in red (the above is a JPG image). The Mauch Chunk formation is identified by tight-knit diagonal lines (see the map sidebar for symbols and descriptions). I added a few known landmarks that occur in the Loyalhanna (wouldn't it be cool if a cave system linked cross-county,  from Laurel Caverns to across the Yough from Opperman Cave) for orientation - the map is highly accurate.

Yea, the above image is pretty useless. That's why anyone wishing a copy can simply email a request to me and I will forward to you a PDF, TIFF and JPG image, free of charge. All images enlarge to pretty good (perfect) resolution - good for cropping enlarged sections of choice for printing. The original map size is 38"x 50". I can have copies of those available as well, but I will have to charge $15/copy (includes mailing). To all the cheap SOB's whose lower jaw just dropped, take note that 'Kinkos' gave me a price of $55/each to scan and copy the original (which I had earlier simply colorized with a blue pencil) - that's why I decided to digitize a copy and colorize it by computer.

The annotated landmarks won't be included on the copies (unless requested). Speaking of which - for those who don't know (not a Yough River paddler), the Ledges are just that - a small jutting limestone "bluff" formed where the Loyalhanna formation dips below (and under) the Youghiogheny River. I could dig up some photos somewhere with much searching. Easier for me, if you have a copy of Tim Palmer's book, 'Youghiogheny', there's a photo in there.

Interesting final note regarding the Ledges. Along the eastern bank of the river, opposite the Ledges, there's some interesting, wide vertical "fissures" in the Limestone. However, they drop below the river level. Additionally, one very hot summer afternoon, was paddling past the Ledges and there was a foggy mist wafting across the river (from the Ledges direction) that had a subterranean, cavern-like odor as paddling through it. Another time, encountered a large wood rat (a noted cave dweller) scampering along a rock shelf of the Ledges. Always meant to, but never spent any time investigating. Is easily accessible from the 'Yough River Trail - after about a six mile bike ride from the 'Wheeler Bottom' trail parking (about a mile south of 'Camp Carmel'), it would then be a short jaunt through the woods.