Hodgepodge of local geology

Wow, what a title but that is what hit me when I was trying to decide on what to write on.  My schedule for the summer is always hectic and when I have time to sit down and write a blog, I better have a topic.  So this time I thought it might be good to bring you up to date on several items that might be on interest.

My first topic is probably one of the most popular subjects where readers have responded.  It is on gold in the area and this was one of my first ever blogs I wrote.  I spilled the beans in that blog with locations where gold is best to be found in York and Lancaster counties.  Several weeks ago one recreational prospector named Chris Martz sent me a picture of a gold nugget he found in PetersCreek in LancasterCounty.  PetersCreek in southern portion of the county is regarded by myself as the best gold-producing stream in southeastern Pennsylvania.  Recreational panners from the region descend on that area asking property owners to access the stream.  The nugget was analyzed by a jeweler and weighed in at 22 grams.  Nice find  Chris and it was the first nugget that I have seen come out of this area.  I still recommend to folks wanting to learn the art of panning to join a chapter of the Gold Prospectors Association of America.  By being a member, you have access to a number of claims across the country, proper insurance and around those folks who have knowledge on panning and gold.  Locally, the Delaware Valley Chapter has several claims in southeastern Pennsylvania and meet in the Reading area.  Check their website out for details.

In relation to gold panning, the York County Parks  popular Panning for Gold day in Spring Valley County Parks is coming up on Saturday, July 27th from 9am – 2 pm.  This is always a fun time for everyone and you can actually find gold in the East Branch of the Codorus Creek should luck be on your side.  The program is free and no registration is requited – just show and go.  Some pans will be available or you can purchase a pan there from the East Coast Gold Panners and Treasures Hunters Association.  Expert gold pannres also come into the park since they know that the last Saturday in July is the only day throughout the year that gold may be removed from the stream (due to Park regulations).

A common question I receive from new folks into this hobby is where can they go panning.  Unfortunately, there is no public land in the state where panning is allowed.  Property owners have to be consulted for permission and I know to new folks that is hard to do, especially if you are from outside the area.  I feel bad for these folks that there isn’t any public lands where they can become educated.  This is the big advantage on joining a gold panning organization.

Another update is the groundwater survey of CarrollTownship in northern YorkCounty.  Jones Geological Services and the United States Geological Survey have teamed to conduct this study as a result of the 2008-2010 earthquake swarm that occurred there.  A theory that perhaps groundwater was involved in these tremors was proposed and we are attempting to look for any hints with that.  The survey is still in  progress with several monitors installed in abandoned wells measuring the water levels.  Results will eventually be posted on my website at jonesgeo.com.  We are grateful to a number of property owners, CarrollTownship and the Dillsburg Area Authority in making this project possible.  I had one report of a small tremor felt west of U.S. Rte. 15 in mid March.  Not large enough to be recorded by any seismographs, a report like this from residents is beneficial in our record keeping.

Speaking of earthquakes, I just saw a short article in the July issue of Earth magazine about very small seismic activity associated with Superstorm Sandy.  Apparently as a result of waves crashing on the bottom of the ocean, into the shore and particularly into each other, this was enough to be detected by seismographs as far west as Seattle, Washington.  The strongest seismic activity was recorded on October 29, 2012.  Much of the seismic activity was recorded by the EarthScope instruments, a temporary array of seismographs that is being set up across the country from west to east.  Not to advertise, but if you would like to read up-to-date information about our Earth and interesting articles subscribe to Earth magazine (www.earthmagazine.org).  Now that is some cool stuff reported about Superstorm Sandy.

My last update is concerning our freshly started tour of the YorkCounty libraries in connection with their Summer Reading Program.  What better  theme for this popular summer activity is Digging into Reading and we have designed a fun child-participation program called “Tracking Dinosaurs.”  I have to admit, I am not a vertebrate paleontologist nor expert on the dinosaurs.  Yes, I know about the dinosaurs and related animals that lived in our area during the early part of the Mesozoic, but when it comes to the more popular dinosaurs like T-rex and Triceratops, the children know more than myself.

We have fun allowing the children demonstrate how dinosaurs walked, trace trackways and make up their own theories about what happened.  The faces you see on some of these children is worth the trip to that library, especially when they find out they are receiving a fossil to take home.  The best reaction of or participants occur after they learned that they have just licked a coprolite to identify it (with the persuasion of myself since I pretend to forget what it is).  Now don’t ruin the experience if you plan to attend one of these library programs, we love to the see the youngster’s reactions.

I admit that science is boring.  Jones Geological Services believes in including some humor into the program to keep the audience attentive.  I think that the humor will help them retain some information or something that may be unlocked later in school when they hear a term that is recalled from such a program as ours.  Every child has their own special expression when they come over to you to say Thank You.

Finally, if you are planning to go on a vacation this summer, drop me an email or through the blog to ask me for some geologic information about your destination.  Remember, geology is everywhere, no matter if it is Disney World, Myrtle Beach, Pennsylvania Grand Canyon, Watkins Glen or Boston. 

Believe me, I spend a couple of hours researching the geology of a destination so I can gain just alittle more out of the experience.  On the other hand, maybe I am half crazy!!

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Iron mines of York Township

I have outlined in previous blogs some history and locations of some of the many iron mines that once existed in YorkCounty.  I still find it hard to believe that some local historians who know the stories of some of the largest industries in YorkCounty from the 19th and early 20th centuries have never heard that YorkCounty was one of the leading counties in southeastern Pennsylvania for iron removal from the Earth.

For this blog I have decided to highlight those in YorkTownship.  Although not having many mines (or called banks in the 19th century), these operations were important and also lead to the naming of a small community in the area.  Five iron mines have been identified in YorkTownship.  The best documentation of these banks comes from Persifor Frazer,  Jr. when he completed a report in 1874 on all of the iron mines in York and Adams counties.  During his survey for the Pennsylvania Geological Survey, Persifor visited each site and reported its status.  The report was published in 1876. All information below in italics is information taken from Frazer.   In his book “History of York County”, published in 1886, Gibson also presented some details regarding the OreValley area mines.

The Moser’s (new) Bank is located in a wooded area east of the intersection of Cape Horn Road and Ruppert Road.  Kreutz Creek is found just to the east of the wooded area.  Although this bank is situated just outside of the township boundaries, it is still noteworthy and several banks existed near this operation within the township.

“It was opened in 1865 and leased by Mr. Myers of Marietta, but has not been worked fro some years.  The clay banks and bottoms are much covered by vegetation.  The engine house is still standing, although the machinery has been all taken away.  The exposure is very poor, but the ore is seen in places in the sides of the pit.  The specimen obtained from this bank was a pale buff limonite, containing the other hydrated oxides of iron and much clay.”

Presently, the visible pit measures about 150 feet in length with much underbrush.  Some tailing piles are found on several sides of the pit.  During the winter months, a foundation of the probable engine house can be seen on the eastern side toward Kreutz Creek.

Ensminger’s Openings were reportedly about 1,700 feet southwest of the Moser’s new bank.  Remnants of this bank are found in a wooden area in Bellview Acres, immediately south of FitzPark.  Several tailings piles and shallow depressions still exist.

“The east bank was opened in 1866 by K. H. Storm and Price.  It was reopened last fall, 1873, by Mr. Powell of York.  It has never been properly worked.  Some of the ore has been sold to Myers and Hess.  It is thought to be a “vein” by Mrs. S. Ensminger, by which is to be understood that the ore is tolerably regular and continuous.”

The Moser’s (old) Bank is located just north of the intersection of Springwood Road and Camp Betty Washington Road in what is known as “OreValley.”  Can you guess where this term came from?  This is obviously the largest iron operation located in YorkTownship and today the best preserved.  The Schaefer family owns the property on which the mine stands.  The bank is now water-filled and used by the family as a recreational spot.  The Schaefer house actually is built on a large tailings pile.

Mr. Schaefer stated that the bank filled up with water very suddenly while the workers were relaxing under a cluster of apple trees.  It was reported that the carts and mules were still in the hole when the flooding occurred.  Mr. Schaefer also remembers hearing that the operation goes as far as the OreValleyElementary School.

“The excavation, which is very great in size, has almost entirely fallen shut, and the sides are obscured by the wash from above, while there is considerable water in the bottom.”

“The bottom is strewed with lumps, of which much is compact and lean. The length of the bank is about 250 yards, and the deepest part being at the northeast end. The amounts of lump and wash ore obtained from this bank were about equal.”

This bank was originally opened about 1824 and worked first by the York Furnace Company; second by John A. Wright & Company; third by Schonberger, Musselman & Company; fourth by Musselman and Watts, and fifth by Musselman & Sons.  The total yield from the time Schonberger, Musselman & Company purchased the bank in 1850 was 42,090 tons.”

“The ore was hauled to York at about $1.00 to $1.25 per ton.  The load weighed 3 to 5 tons.  The hauling was done by john Strine, who owned an interest in the bank.  IT was taken out of the bank both by carts and inclined railroad.  It was used by Musselman in his furnace in Matietta.”

Frazer reported finding a sample containing lepidocrocite and stalactite limonite and turgite.  Another specimen collected had rounded crystals and covered with black glassy turgite.

“A partial analysis furnished by the Messrs. Watts was as follows:

Metallic iron                40%

Silica                           32.7%

Sulphur                        Trace

Phosphorus                  1.1%

Water                          8.1%

Sum                             81.94%

Undetermined             18.1%

Moser’s (oldest) opening was located across Springwood   Road from the previous bank.  Today, only a wooded grove shows evidence of a possible location of a bank.  No evidence of any excavations, structures or tailings were observed.  This opening, as described by the name, was the oldest of these openings.  Frazer suggests that this small pit was part of the Musselman & Company operation.

The final bank is not associated with OreValley and in fact nearly along the western fringe of the township.  Located on the north side of LakeWilliams and owned by the York Water Company, a pit measuring 60 feet by 90 feet and several small tailings are still visible, better in the winter months.  The site is about 0.25 mile east of Water Street.  Frazer reported this operation to be on Leader’s Hill.  Several threaded pins with nuts on top were also spotted in the vicinity.  Several specimens of pyrite within the phyllitic rock were also seen.  Frazer reports this bank as “an old opening with no ore showing.”  No definite time frame could be found for this small operation but one would suspect the 1860-1865 period might be a good window.

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Some questions regarding local geology

I thought I would write this blog using some common questions.  I haven’t received many questions from the readers, but I do thank you for your comments.  I hope some of these blogs helped you understand geology better or aided in some aspect of history or geology.  Asking questions in a great way to find out more information and I don’t mind answering them.  If I don’t know the answer, I have contacts that might.

Probably the most asked question or misunderstanding is where were glaciers located in Pennsylvania? Well, the ice line was south of Scranton and actually located well within the anthracite coal belt of northeastern Pennsylvania.  In central Pennsylvania the great wall of ice made it as far south as about Shamokin Dam north of Selingsgrove.  Northwestern Pennsylvania was also covered with glacial ice.  That means that there was never any glacial ice covering a section of our region.  Because of their appearance, many folks think the conglomerate exposed on the top of the Hellam Hills, such as RockyRidgeCountyPark in SpringettsburyTownship and Chimney Rock in HellamTownship are great examples.  This is actually one of the oldest sedimentary rocks in the state anf not involved in any Ice Age formation.  I wouldn’t say that our area was never affected by the Ice Age.  When the ice was melting about 10,000 years ago, much water was sent down the Susquehanna River, doing rapid downcutting into the landscape and laying the foundation for our topography in the River Hills.  Should you want to read about a Ice Age sinkhole in YorkCounty, search back into this series and find one written on Bootlegger’s Sinkhole near Emigsville.

Map showing locations of the glaciated areas in Pennsylvania

Map showing locations of the glaciated areas in Pennsylvania

Another question would be Ski Roundtop.  Many folks in the northern part of the county believe this popular ski resort was a volcano.  I can see where that impression comes from.  From our home, we can see the peak and it looks like a volcano.  Well, was it?   Using present-day evidence of rock exposures there, we do not see any volcanic rocks that point to that evidence.  Yes, there are igneous rocks there known as diabase, but these rocks formed deep within the Earth from magma that never made it to the surface.  Nicknamed “ironstone” this rock is massive and very hard. Diabase is very common in northern YorkCounty located within what we call the Piedmont Gettysburg-Newark Section of Mesozoic Basin.  The same rock is found at Devil’s Den and Little Roundtop on the GettysburgNationalMilitaryPark.  If Ski Roundtop was a volcano, all evidence has been eroded away, which is possible since 4-5 miles of our crust has disappeared since 140 million years ago.

Geologic map of the Ski Roundtop area.  Red represents diabase.

Geologic map of the Ski Roundtop area. Red represents diabase.

What other economic minerals were mined in YorkCounty besides iron?  Another good question and those mostly interested in mining history.  If you are not aware, there were at least 170 different iron operations in YorkCounty between the 1770’s and 1910.  YorkCounty was one of the leading iron ore districts in our state and is often overlooked by historians when they are trying to highlight the important early industries.  Back to the question at hand.  Copper was exactly removed from a shaft in the early 1900’s along Bull Road along the Dover-ConewagoTownship line.  Several friends of mine remembered accessing the shaft in the 1950’s.  Today a depression into a hillside represents the shaft.  No name has been found associated with this small operation.  Another small copper operation was located in ManchesterTownship north of Roundtop.  Known as LeCron’s Prospect, this vertical shaft has fallen in and is located in a heavily overgrown woods.  It was reported in the 1890’s that a tooth of a Triassic-aged reptile was recovered.  Small copper mineralization is occasionally found in the northern YorkCounty area mostly that of malachite.  The famous azurite-malachite hole along Old York Road north of Rossville is such an example.  A small amount of lead in the form of the mineral galena was reported in the 1800’s in Frystown, what is now East Philadelphia Street near Sherman Street.  No mining of the galena has been reported.

The Rossville azurite and malachite hole

The Rossville azurite and malachite hole

There has been a family lore story for many generations regarding gold near Airville.  Supposedly, a father and his two sons were prospecting gold from a nearby stream in the 1820’s.  The one son felt he was not receiving his percentage of profit from the work and murdered his brother and father, spending the rest of his life in prison.  There  has not been a report of gold mining in YorkCounty although about 15% of the streams in the county contain gold.

A pan showing magnetite, a heavy mineral found with gold

A pan showing magnetite, a heavy mineral found with gold

Another question is regarding faults.  Are there any faults in the area?  This question is often introduced after a major earthquake somewhere in the world and the faults are discussed.  Yes, faults are actually common in most regions and especially in an area such as ours that contain old rocks and have been through several episodes of continental wrecking and splitting.  The Martic Line that crosses YorkCounty in the southern section is probably the most famous fault.  However, the YorkValley where U.S. Rte. 30 runs probably contains the most faults.  If you have a chance to visit one of the area limestone quarries, you can’t miss faults on the walls.  Now are any of these faults still active?  Based on what we have observed, the answer is no.  Although the area has had several earthquakes, we are not certain that they are a result of the release of energy along one of these faults.

A fault exposed in the York Building Products Westgate quarry.

A fault exposed in the York Building Products Westgate quarry.

Finally, did we have any volcanoes in York County?  Well yes and you would know this if you are a faithful follower of the blog.  There are volcanic rocks found in the Hellam Hills (exposed at Accomac), the Pigeon Hills (exposed along Beaver Creek Road), along the York County Heritage Rail Trail between Glen rock and New Freedom and along the shore of the Susquehanna River at Holtwood Dam.  All of these rocks are related and are about 600 million years old and formed as a result of an early supercontinent known as Rodinia rifting apart.  If you are familiar with the mid-oceanic ridge, this is how these rocks were formed.

Metabasalt from southern York County

Metabasalt from southern York County

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