March is usually a busy month for my wife and myself.  With Lou Ann as a minister, Lent occurs in March with Wednesday services and other Holy Week activities.  The Geological Society of America Northeastern Section holds their annual gathering also in March.  Not that Lou Ann travels with me, but I was hoping she would have made the trip north to where this blog is being written.  What would you answer if I would ask where is the highest elevation in New England and is the second highest point east of the Mississippi River?  The peak is in the Presidential Range of the White Mountains in New Hampshire and also has a cog railroad that many of you traveled up on a vacation.  The answer is Mount Washington.

No, I am not really on top of the mountain (but I would love to spend a night up there), but the conference is being held at the Mountain Washington Omni Hotel in Bretton Woods.  When they said the resort is at the base of Mount Washington, they weren’t lying.  What a view from the back porch of the hotel!!  Yes, although there wasn’t much snow laying on the ground when we arrived, it is snowing now with several inches expected.  Attending these annual meetings is educational as presenters provide updates on research, talking about the science theories of years past and new technologies.  You get to also see fellow geologists that you only see at these gatherings.

What made me think about writing a blog like this one?  Actually when a fellow geologist friend and myself left the area to head north, I asked him, “If we were to travel in the old days by horse and buggy, I would how long it would have taken to go 545 miles to Bretton Woods?  Yes, alittle exaggerated, but just think about traveling in those days.  One of the papers I heard from a Pennsylvania geologist here was about the first geologic investigation of the Keystone state.  The geologist started in Philadelphia, traveled to Harrisburg, then to Philipsburg and ending in Erie.  Imagine, not only taking a horse and buggy that distance but locating rock exposures, drawing the exposures and staying overnight.  Wow, quite impressive and I don’t think that is for me.

By attending such a meeting as this, you have a chance to compare the field practices of those early explorers to what we use today.  In the early days, they didn’t have topographical maps.  They may have had very crude map showing the mountains, but not much else.  Today we have the use of GPS, 3-D relief maps, highways with a 65 mph speed limit including nice rock exposures and cars.  These pioneering geologists did not have the regional view to correlate rocks, did not really know where the rich coal deposits were nor the important mineral resources or Marcellus gas.

From the 38 themed sessions scheduled at the conference, a lot of information is made available.  Each session lasts up to 3 hours and has presenters every 15 minutes.  Yes, this is what I said!  You have 15 minutes to deliver your information, maybe answer a question.  This meeting occurring in New Hampshire means that many of the papers are centered on New England geology, but you may be able to take some information  back home to use in Pennsylvania.  Finally, the Geological Society is celebrating its 125 years so the conference is running with that theme.  The good news about this annual meeting is that the 2014 meeting will be held in Lancaster, so maybe I will take a horse there to make it feel like old times.

Before I came to New Hampshire, I had several programs to present.  The first program was on the world-famous Peach Bottom Slate for the Harrisburg Area Geological Society.  About 45 geologists attended the program.  You know how they say presenting a program in front of your peers is always the hardest to do.  I find that true also, since everyone has a common interest.  However, you realize shortly into the program that you are in control and let the script roll.  Have fun with the audience as I do.  I judge my audience on how much they laugh at my jokes because science is truly boring unless you spice it up.  The program went well, but during the question period afterwards, I got intimidated.  There was a retired state geologic survey employee in the audience who I knew, but never really talked to him.  He said he had a question and a statement.  I got myself propped thinking that he was going to question something I said.  His question was one about the Susquehanna River which I did not really have a answer for, but told him that.  His statement was that I need a great job presenting the program, so I was relieved.

My other program was a PointPoint program on the Susquehanna River for “Date Night” at Shank’s Mare Outfitters in Long Level.  I have done other programs for this special night over the years and Liz Winand always attracts an interesting group of people for across the region.  This night wasn’t any exception.  There were couples from Lancaster and YorkCounty, some having an interest in geology and others just enjoying the night along the river.  A great group as always with good questions and yes, they laughed at my jokes.

Finally, let me know if there are any topics you would like for me to write about.  I usually write a blog as an educational piece, giving either historic or geologic information for the readers to enjoy.  I have received comments back on numerous blogs with stories of your own or complimentary comments about the blog.  Thank you for those, but do not hesitate to let me know what you would like to see on this page.

The largest mining district in YorkCounty was undoubtedly the Dillsburg magnetite deposit located about one mile east of this quiet borough.  The area holds a wealth of history as well as some of the current events in local geology.  In fact, the Dillsburg area contained another iron field west of town, in what is today known as Dogwood Hollow in SouthMountain.  These mines were the site of valuable limonite ore in the mid 19^th century.  A drive back Dogwood Hollow heading toward CampTuckahoe will show you some of the large dump piles and pits that once flourished.

Location of the magnetite mines east of Dillsburg

The credit for finding the rich magnetite ore east of town goes to local resident and farmer, Abraham Mumper.  During his spring plowing on his farm in 1847, Abraham brought up large black rocks that appeared to be something he never noticed before.  The mineral was identified as rich grade mineral known as magnetite.   Although the chemistry of the ore was higher in sulfur, the percentage of iron wqas higher than the limonite ore on the opposite side of town.   Important to the development of the magnetite ore, it was a known fact that iron masters knew that a mixture of magnetite and limonite for their furnaces produced a better grade of boiler plate iron.  The mixture of ores did not allow the iron to crack.  The quality was desirable for the manufacture of wood stoves and firebacks.

Abraham opened his mine on his farm, which today was located on the west side of Ore Bank Road.  Wow, what a name for a road in a mining district.   “Ore” is the material removed from the Earth and “Bank” was the name given to a mining operation for many of the mines were simply dug into a hillside.  Abraham’s brother, John also got into the action by opening his own mine just north of Abraham’s,  Much of the ore was found very close to the surface just the use of shafting was not required.  The Abraham Mumper mine (which become the Underwood mine and largest producer in the district), sometimes often could produce 30-40 tons of ore a day.

Both the Abraham and John Mumper mines flourished and of course, peaked interest in the remaining lands adjacent to the Mumper farm.  At John’s operation, the ore was followed to depth requiring mine shafts and drifts to be developed.  A two-foot thick magnetite body was encountered 26-feet down, said to be one of the wealthiest ore bodies recovered in this area.  This find also was the base for one of the comedy stories in local mining history.  John Logan, a local attorney owned property on the east side of Ore Bank Road, but not believing that any magnetite was found on his farm, Mr. Jogan sold his land.  Following the discovery of the large John Mumper ore body, John Logan crawled back to the land owner wanting to buy his property back.   Well, John got his wish but paid considerable more for the property.  Mr. Logan and a fellow miner Mr. Longnecker teamed up and developed a shaft which also found the same ore body was that encountered by John Mumper.  This find perhaps took the edge of the foulest story of land purchasing deal.

Abraham Mumper built and lived in this Old York Road residence for many years.

It is said that Ore Bank Road was originally built as an access to wagon the ore into Dillsburg and then transported by rail to furnaces.  This is what separated this ore field to most of the others in southeastern Pennsylvania.  Other mines were built very close to working furnaces so that transportation did not have to be dealt with.  Here at Dillsburg, the ore was not associated with a local furnace and that the ore  was being purchased by various furnace owners.   Later, a railroad was built into the Dillsburg magnetite mining district that would run two to three trains a week.  Today, with observant eyes, you can trace bits and pieces of the railroad bed the whole way over to the northeastern corner of the district near Meadowview and Mumper Lane.

John Mumper built and lived in this Mumper Lane residence.

After Abraham death in 1868, An Alexander Underwoods, a son-in-law of Abraham’s, purchased the mine.  Although Alexander wqas an attorney from Mechanicsburg, he understood the wealth of the ore on the Mumper Farm and modernized the operation.  He hired the Wrightsville Iron Company who developed shafts to further extract the magnetite.   In the meantime John Mumper hired McCormick and Company to take over the mining.  The McCormick’s used their ore in furnaces in the Harrisburg area and in PerryCounty.

Abraham Mumper’s tombstone at the Wolgamuth Church of the Brethren on Old York Road.

Although approximately 9 other mines were opened in this 0.75 square mile area, no production outdid the Underwood and McCormick mines.  A total of 1.5 million tons of ore were removed from 1847 and 1908, when the final operation closed.  The other mines included the Smyser, King (McClure), Bell, Price (Cox), Grove, Altland and Jauss.  Most of the operations included shafts but constant sizeable ore bodies were not found.  As in today’s economy, the area also saw  periods of low demand and production.  The Panic of 1873 was the largest such downfall where the mines were temporary closed.  It was not until 1876 that the economy rebounded.  By the turn of the century much of the ore bodies had been removed. The last two operations were the King and Jauss mines on the east side of the district.

The Price (Cox) mine as it appears in 2013.

In fact, one of the most historic moments of the district occurred near the end of production.  In August, 1906, renown inventor Thomas Edison was invited to travel to the Jauss mine in hopes that he would invest in the operation.  Mr. Edison was involved in iron mining and cement manufacturing in central New Jersey.  Mr. Edison and his son were escorted to the mine by local historian John Morris.  Although Thomas Edison did not invest in the Jauss mine, he did hire John Morris to serve as a mining engineer for a number of his mining ventures.

The Mumper (McCormick) mine is 2013

The area has set dominant since 1908. when the Jauss Mine closed its doors.  However, with World War II coming unto the scene, the Federal Government set geologists out to re-evaluate abandoned mine properties for possible future mining.  Two gentleman,  Neumann and Hotz associated with the U.S. Bureau of Mines were assigned the Dillsburg magnetite area.  Two different phases of core drilling were conducted in 1944 – 1948 and other mineable magnetite bodies were located  with the boundaries of the district.  Their work also proofed that the ore was developed in sandstone and limestone trapped between two bodies of diabase (an igneous rock formed by magma within the Earth).  No development of these ore bodies were ever engaged.

Today, much of the area remains overgrown in either mature forests or secondary =growth caused by recent logging.  Also, in two cases residential housing as encroached very close to abandoned mines.  In fact, one of the mine shafts was exposed in the spring of 2009 in a front yard of a house.  It is not sure if the soil over the shaft subsided because of heavy precipitation  or recent earthquake activity.  The mining district received some public attention in 1976 when the newest edition of “Mineral Collecting in Pennsylvania” book was released listing the Logan-Longnecker mine as a site for varios minerals including nice magnetite and feldspar crystals and a rather rare mineral for the state, datolite.

It is hoped by this writer athat a small portion of the Dillsburg Magnetite District can be preserved by a park or preservation group.  I have been researching this area since 1975 and have come to appreciate its history, minerals and more recently the Dillsburg earthquake swarm that was centered in the southern limits of the district.

With the tragedy involving a sinkhole in Seffner, Florida on February 28^th that killed 37-year old Jeff Bush, this community located 15 miles east of Tampa is now worried about a similar thing happening to them.  There have been two other sinkholes in that region opened up since the February 28^th incident. Many residents hope that a similar occurrence will not happen on their property.  Reading through more newspapers articles about the Seffner area, one resident talked about a sinkhole that claimed half of an apartment building that he and his wife resided in back in 2000.  They were forced to relocate, and they brought a property around the corner.  Another news account discusses that the house where Jeff Bush was killed did have a small sinkhole appear years ago.  That sink was  filled-in and never thought about again.

Florida is known for its sinkholes.  For a great description of sinkhole development and their locations in the “SunshineState”, go to http://www.wtsp.com/assetpool/documents/130301061352_florida_sinkhole_poster.pdf.   Florida is underlain with limestone, a sedimentary rock composed of calcium carbonate.  Because the rock is permeable, groundwater etches its way through the rock, slowly creating caverns.  When groundwater is high and allows the cavern roof to “rest” on the water table, there is no problem.  But when the water table drops and the cavern roof can no longer rely on the water for its support, the roof will fall and also bring down the material above it.  Even when an area goes through a drought season allowing the water table to drop can increase sinkhole development.  With Florida, another factor that forms sinkholes is man-induced.   In central Florida in the LakeWales and Lakeland areas, particularly, mining companies are pumping millions of gallons of groundwater daily to use to process their phosphate sand.  Lowering the water table in such a manner will also induce sinkhole activity.

One of the most famous sinkhole events in recent years occurred in Winter Park, Florida.  Just north of the tourist town of Orlando, Winter   Park was a quiet suburb until 1981.  Toward the end of a lengthy drought period beginning in 1970, this sinkhole grew to 350 feet wide and 107 feet deep.  It swallowed houses, businesses and the community swimming pool.  In the first few days of its existence, the sinkhole attracted more tourists than did Disney World.  News media from around the country swarmed to Winter Park to cover the event.  Even several neighbors sa opportunities to raise money.  They built their own observation decks overlooking the large depression and charged a fee.  For a great description of this sinkhole and what has been learned from studying this classic sinkhole, go to http://www.nodarse.com/docs/sallam_papers/FESJournal_May2009_2.pdf.

Also, rain carries a small percentage of carbonic acid.  As it falls onto a limestone area, the water very slowly acts as a weak hydrochloric acid, enlarging cracks in the limestone.  Over time, the limestone will be undermined enough that gravity takes over and allows the ground to sink.

For those of you who migrate to Florida for a vacation or winter shelter and interested in unique sites, check out DevilsMillhopperGeologicalState Park in Gainesville.  This is a wonderful experience as since 1976, the state made the sinkhole accessible to visitors.  The hole is 120 feet deep and 500 feet wide with plenty of broadwalks and observations along the way.  As you make it down 236 steps to the bottom, you travel through three distinct zones of flora environments and see twenty different springs feeding the pond on the bottom.  There is also a small visitor’s center near the parking area that explains its history and natural history.  For more information of this site, go to http://en.wikipedia.org/wiki/Devil’s_Millhopper_Geological_State_Park.

As a small side note, during our visit to the DevilsMillhopperState   Park in the 1990’s, we were told by another park visitor that a young lady was hanging out in the visitors center area attempting to commit suicide with medications. My wife, Lou Ann, being an ordained minister, felt a need to help this person in need.  She had taken medications as we located an empty pill bottle.  As I called 911, my wife kept the woman walking and talking to her.  Lou Ann learned that things were not going well with her children and felt this was the best avenue to take.  About arrival of the medics, we gave them the pill bottle, gave them a short history of what my wife had learned about the woman and we departed.  We often wonder what became of that park visitor!

I haven’t seen any media discussion about sinkholes closer to home.  After all, the central portion of YorkCounty lies within a limestone belt and what is a possibility of such a “Seffner” event could happen here.  We have had our share of sinkhole stories to tell in York and Lancaster counties over the years.  Luckily nothing like that of Florida and death, but we have had houses condemned and roadways under regular repair due to sinkholes.  In YorkCounty, we have four carbonate units more or less paralleling U.S. Rte. 30.  They include the Kinzer, Ledger, Vintage and Conestoga formations.  However, much of the Ledger and Vintage rock units contain more dolomite and not limestone.

Dolomite is also a sedimentary rock, but the chemistry is what separates it from limestone.  Limestone contains calcium carbonate (the mineral calcite) while dolomite contains calcium magnesium (the mineral dolomite).  Dolomite does not react as readily to acid rain and groundwater as limestone.  Sinkholes are generally fairly rare in a dolomite area.  Also, dolomite produces a clayey soil while limestone produces a sandy soil.  Water will percolate down through a sandy soil faster than a clayey horizon.

In York County, areas of concern for sinkhole development are Thomasville and WestManchesterTownship around the West Manchester Mall.  Across the county line to the west, Oxford Ave between Pa. Rte. 194 and New Oxford has been sites of sinkholes.  In fact, at one time along Oxford   Ave. there was a road sign that read “Sinkholes – Travel at Your Own Risk.”  Although none of these areas have created any injuries or damage to buildings,  it seems that sinkholes have caused more damage in towns.  The most recent incident occurred along West   Philadelphia Street in the spring of 2010.  Two houses had to be demolished after a sinkhole was spotted under the one house.   IN the 1990’s, several home in downtown Columbia, LancasterCounty were condemned due to a sinkhole.  Luckily there haven’t been any injuries associated with these sinks.

U.S. Rte. 30 in the Olive Garden and West Manchester Mall area has been closed several times to allow PennDot to repair a sinkhole.  It is known that you can travel down a sinkhole on the north side of U.S. Rte. 30, travel through a cave and come out of a sinkhole on the south side of the highway.  Some of these sinks have been filled in to eliminate keep people out.  Outside of our area, Palmyra, Lebanon County has had many sinkholes experiences, mostly with roads falling in.  More recently, Harrisburg has had to deal with sinkhole repairs, mostly due to water main leaks that allowed water to “chew” away at the underlying soil.  For information go to the Pennsylvania Geological Survey website and check for “Online publications ——– Open file reports” for maps of York and Lancaster county sinkholes.  The Geological Survey also has a database of sinkholes under the “Environmental Geology” tab.  For information on Pennsylvania sinkholes in general,  go to http://www.dcnr.state.pa.us/cs/groups/public/documents/document/dcnr_014591.pdf.

Some of my favorite sinkhole pictures from our are include:

Sinkhole located on the property of Hershey Medical Center. Opening is about 8 feet across.

A sinkhole in the backyard of a house along Municipal Drive near Pa.. Rte. 94 in Adams County.

This sinkhole occurred under the railroad track in Thomasville. Luckily the train engineer was alert to stop the train before an accident happened.

Known as a solution valley, this elongated depression was formed when 2 or more sinks combined. This one is located near Newville, PA

As we all know the Internet has any information that you can imagine.  The Earth Sciences are included as our technology as taken science to a higher level.  Today, there are many sites to view information that was at one time were found only in publications in a book store or not even available to the public.  In this blog I am going to introduce to you several websites that might be on interest to the local geology.  Several of these sites are “real time” which means you can monitor the website and watch change or become your own junior geologist in studying our portion of the Earth.

First, on a state-wide scale, the Pennsylvania Department of Conservation and Natural Resources has just released an interactive map showing the state parks and interesting geologic features.  This website can be found at http://www.gis.dcnr.state.pa.us/maps/index.html.  The Pennsylvania Geologic and Topographic Survey is adding interesting geologic sites to the map which can be visited by citizens.  Of course, we are lucky to have our fine state parks system, which are also included on this map.

As many of you remember, Hurricane Agnes in 1972 doing severe damage along the Lower Susquehanna river drainage basin.  This also included the Codorus Creek drainage basin.  Since that time, efforts have been made to more closely monitor stream velocity and levels to understand the nature of surface water.  Even the amount of sediment being carried by a stream is recorded to calculate the sedimentation into the Susquehanna River and even the Chesapeake Bay.  This real time data can be viewed at http://waterwatch.usgs.gov/index.php?r=pa&map_type=real&State=pa.  Select any fot on the map to view current records at that particular monitoring station.  It is interesting to watch the water level go up after a heavy rain or during a drought, the water level decreases.  As an experiment, watch the Codorus Creek in Spring Grove and near York to compare levels over a certain time.  Even compare water flow between the Codorus Creek and the Conewago Creek near Manchester.  If you are interested in viewing monitoring stations outside of Pennsylvania, simply go to the top of the page and select another state.  So much information available these days just with a click of a mouse.

Stream flow diagram of the Codorus Creek near York

Let’s take a look at ground water in Pennsylvania.  Over 15 million households in the country rely on water from wells for their drinking water.  One thing I tell students when teaching is that the Earth is no longer producing water.  The water we have is all we have.  That’s why it is important to conserve water resources, either surface or ground water.  Groundwater acts just like surface water.  The water always runs downhill.  The only difference is that groundwater has to flow through bedrock.  Sometimes that is problem as some rocks that are dense like granite or metamorphic rocks do not allow water to flow through it.  Instead, the water has to migrate through the bedrock following cracks or voids in the rock.  Henceforth, good aquifers to drill into as sometime difficult to find to igneous or metamorphic rocks.  A good site to “read” the local groundwater is setup by the United State Geologic Survey.  Go to   http://waterdata.usgs.gov/pa/nwis/current/?type=gw which gives you a list of monitoring wells in Pennsylvania.  There is only one well in YorkCounty on the list near the bottom of the list.  This monitoring well is located in the southbound rest area on Interstate 83 south of the Fishing Creek exit in northern YorkCounty.  Check it out and like surface water, watch the elevations go up and down in relation to the precipitation.  Also if we have an earthquake shake the area, groundwater will also shake and you will see the water elevation jump upwards in respond to the event.

Water level elevations from monitoring well in nortyhern York County.

Speaking of earthquakes, let’s show you a couple of good websites that can be useful to you.  Locally, the only seismograph that is online is the station at MillersvilleUniversity.  Their website is  http://www.millersville.edu/esci/geology/seismograph.php.  Go to the bottom of the page and click on “Global” or Local” to view the real time seismogram.  Read the explanation on the webpage that explains what east-west, north-south and vertical mean.  Professor Emeritus of Geology Dr. Charles Scharnberger still maintains the station and evaluates any major earthquake that might shake our area or around the Earth.  Check out the website if a major earthquake occurs half way around the world.  The seismic waves will still be recorded and viewed from your compute.  This particular station was of value during the Dillsburg earthquake swarm (2008-2011).  Any quake from magnitude 1.8 and larger generated seismic waves that could reach Millersville.and be recorded.

A sesismogram from the Millersville University station from August, 2011 showing an earthquake in Colorado and the Mineral, Virginia quake

The seismograph at Millersville University is a member of the Lamont-Doherty Cooperative Seismographic Network.  This network is monitored by ColumbiaUniversity’s Lamont-Dohert Observatory in Palisades, New York.   A number of seismographs throughout the region and northeast are hooked together to record seismic events.  This is a great site to watch for Mid-Atlantic and Northeastern United States earthquakes.  The address is  http://www.ldeo.columbia.edu/LCSN/index.php.  Click on the first link below the title known as “Finger Quake List” which gives you a catalog of all earthquakes that were recorded by this network. A general location, magnitude and depth will be listed.  When we have to locate the epicenter of an earthquake at least three stations are required.  Using the method of triangulation, within minutes of receiving a signal from the network, the main computer at Lamont-Doherty Observatory locates the epicenter and adds the event to the database.  Again, using the Dillsburg earthquake swarm as an example, after receiving a telephone call right after a tremor occurred, I went to this website and saw the earthquake’s location and magnitude, all based on the information from at least three seismic stations.  Just how accurate is this network?  In the case of Dillsburg, since the Millersville University station was the closest to the epicenter at about 25 miles, we were dealing with a +/- tolerance of about six miles.  This means the epicenter could be anyplace within a six mile radius of Dillsburg.

A map showing a recent epicenter of an earthquake near Williamsport from the Lamont-Doherty network.

Records from 7 seismic stations of the same earthquake near Williamsport.

Many people use my last application for both professional and recreational uses.  Although a program and not a website, Goggle Earth supplies us a great close-up view anywhere in the United States.  With up-to-date aerial photography, you can do measurements across the ground.  It also is a great way to familiarize yourself with an area that you are preparing to travel to.  I have used Goggle Earth to  pre-plan field trips I was planning.  I had a good understanding of the roads before I departed the house.  You can download Goggle Earth for free and look at your favorite vacation spots or relative houses for fun.

Often, folks will ask me the question for which this post is named.  As I was thinking about what to write for this edition, favorite sites came into my mind.  These sites are neat to visit because they have their own identity and represent different episodes of our Earth and history. Not placed in any order, here we go!

Let’s start by traveling south of U.S. Rte. 15 out of Gettysburg.  After bypassing all of the neat history there (and geology), we cross over the Mason-Dixon Line into Maryland.  Travel past Thurmont and if you can hold off the temptation of stopping at Mountaingate Restaurant for a bite to eat, wait, until your return trip home.  Just a short piece down Rte. 15 you will see a sign at the next exit for Catoctin Furnace.  With the many times I traveled this route, I was amazed when I finally got there 2 years just how close it sits to the highway.  In fact, before getting to the exit, you will travel under a footbridge that looks slightly out of place.  The footbridge is there to allow people parking at the Catoctin Mountain Park Visitors Center an opportunity to walk to the furnace site.

The Catoctin Furnace Portal and Stack near Thurmont, MD

Catoctin Furnace has quite a history. A historical marker at the furnace reads, “Catoctin Furnace: An important iron furnace during the Revolutionary owned by Governor Thomas Johnson and his brothers.  Furnished 100 tons of shells used at Yorktown.”  A local hematite iron deposit was discovered in the 1770’s by Thomas Johnson, Jr., who later became governor of Maryland.  One historical account names James and Thomas Johnson as the builders, another account mentions Thomas Baker and Roger Johnson and a later account mentions a Baker Johnson as a later owner. The first furnace sitting here was the Johnson Furnace which was a cold-blast operation working from  about 1776 to 1795 and then was idle until 1803.

An existing wall of the Ironmaster’s house

The furnace was in operation again from 1803 until 1811 with substantial improvements.  Early production consisted of household implements, tools and cast iron stoves.  The works were purchased by John Brien in 1831 and modernized. The Johnson Furnace operated until it was shut down and dismantled in 1890.  The site of the Johnson Furnace was probably in about the middle of the retaining wall behind the existing stack.

Another owner built the Isabella (also referred to as the Catoctin) Furnace in 1856. The Isabella Furnace was supplied with a steam-powered hot-blast mechanism.  The Isabella Furnace was a rather advancement design for a charcoal furnace.  IT might have been designed to use anthracite coal or coke, but neither were available.  The Isabella stack is what remains today.

A display board at Catoctin Furnace showing the historical and existing structures

In the late 1880’s, when the furnace was at its peak, the complex consisted of 80 houses for workers, a saw mill, a grist mill, company store, farms, an ore railroad, and  the stacks.  A magnetite mine on a hill to the southwest supplied the iron ore for the Isabella Furnace.  The furnace closed in 1903, but the magnetite mine continued operating until 1912, supplying ore to a Pennsylvania furnace.

Today, the complex shows the wear and tear of historical structures, but one can get a great idea how a furnace operated, the required materials and facilities needed to produce iron products.  Walk the trail, which is a self-guided trail and see the walls of the ironmaster’s house; the pond and race that supplied the water to turn the waterwheel, slag piles and ruins of other buildings.  A brochure is available for download at http://www/dnr.statre.md.us/publiclands/cunninghamhistory.html,

Ok, let’s shift gears and head into a different region, up north to the world-famous anthracite coal region.  Every time I travel into that region and see the miles of coal dumps and abandoned pits, it amazes me just how much history there is.  Some of the best anthracite coal ever known came out of this region and thousands of articles and books have been penned telling the stories about miners, companies, the good and the bad of the industry and its future.  If you find your way to Hegins, SchulykillCounty and follow Pa. Rte. 25 west toward Shamokin, you will continuously pass old mines and large coal dumps.  After going over the mountain and dropping down toward Shamokin, turn left onto Bear Valley Road.  Follow Bear Valley Road to its dead end (or at least as far as you can travel without getting stuck).  Watch for signs that the road is no longer maintained and travel at your own risk., O My!!!

From where you park the car, walk up the “road a short distance to where you are on flat ground.  There is a large, tall dump pile on your right and the terrain seems to drop off to the left.  There is a well developed trail, mostly worn by 4-wheelers, that leads down the hill.  Follow this trail for about 300 yards and suddenly you will find yourself in a long abandoned coal pit.  In front of you is a mound that looks like a whaleback.  In fact, that is this nick named for the location.  The whaleback is composed of rock that has been pushed up in to an arch shape fold known to geologists as an anticline.  Take your eyes to the left end of the whaleback and notice where it disappears into the high vertical wall.  Look at the rock above the whaleback, the rock there is folded downwards into a structure known as a syncline.  Wait, we aren’t quite done yet.  Look at the far wall of the pit.  It appears as if it is curved and smooth.  That wall is actually one-half of an anticline coming down beside the whale back.

View of the Whaleback looking west from the overlook.

You think that is confusing, it is?  This is one of the best examples of folding of rocks in the United States.  Visualizing the forces that formed these folds and the stress and pressure involved is overwhelming.  These features are clear cut proof of the mountain-building processes that formed the Appalachian Mountains when Africa and North America came together about 340 million years ago.

Look closer at the rock and you may spot some petrified wood and fern fossils in the shale.  The rock formed during the Pennsylvanian Period tells us the story of a time when this area was an “Everglades” environment with abundant vegetation and slowly forming what would become the famous coal region.  The coal was originally bituminous but with the continental collision the coal was metamorphosed into anthracite.  You can see some of the coal veins on the wall containing the syncline.

It is recommended not to walk on the whaleback.  The rock is slippery and gets more dangerous when wet.  Also, there is a lot of loose rock on the surface that could give way when you step on it.  Enjoy this great location but use caution.