This was my second year at MessiahCollege.  I only teach this course every spring as the demand for this course isn’t strong enough to teach both semesters.  After my 2012 initial teaching experience, I learned how Messiah worked, the quality of the students going there and a better idea of what works and doesn’t work.  I went into this year with a better idea of what to teach and how to present it.  Most importantly, unlike 2012, I forced the students to purchase a lab book.  Last year,  I copied lab exercises out of other manuals I had which did not always do well.  With a lab manual the labs were more organized and more rewarding to the students.    I do have the freedom to pick and choose the weekly topics that will be covered.  This works well as I found out from last year what topics went over like a lead balloon, as the saying states.  However, the little catch is that my supervisor has asked me to include several weeks of oceanography and meteorology, neither of each I know much about.  So, there I go, learning just like the students and thanks to PowerPoint lectures to guide me.   I don’t pretend to know much about these two subjects and I admit to the class that I am not an expert.  Yes, I like to watch weather and am a daily observer to the sky trying to predict what is coming, but I don’t understand the concepts.

So why do I like to teach all ages about the Earth and space?  I really can’t answer that, but I just like talking to anyone about the fields.  Yes, I know that the Messiah College students are taking the course for a required lab credit, but I hope they retain just a small piece of information about the school year is over.  I even indicated several times in class that some of these themes can be useful in buying a house of property.  How about if you buy undeveloped property and need to drill a well?  Dig out your textbook and lab manual and refresh on some of the basics of groundwater.  Should I be living in an area with metamorphic or sedimentary rocks?  Which rock is better to build on for a durable foundation?

During the semester, the students have three “out-of-the-classroom” experiences.  In late April we spent a hour under the stars.  A good friend of mine, Dick Copper, brought his telescope on campus for viewing Jupiter, the Orion Nebula and a star cluster.  Dick teaches astronomy labs at GettysburgCollege.  Also in late April, we went on a 3 hour field trip throughout northern YorkCounty to visit several roadcuts to show the students some concepts we had talked about in class.  The best way to teach earth science is to spend time outside putting your fingers dirty.  Our last class together we went to a local private-owned cave and ended the semester panning for gold in Stoney Run.  I wish everyone could have seen the caving portion.

I took the group to LisburnCave.  I visited the quarry some time ago and realized just how little I like tight spots.  Much of the cave only  has 2-foot high ceilings and you have to like seeing clay closeup as you navigate through the 150 feet of hallways.  Out of my 16 students only 9 individuals choose to go into the cave.  No problem I could relate to those not wanting to experience true darkness when all of lights were turned off.  Because I had to give all of my flashlights out to those not equipped with lights, I remained just inside the cave opening in case there was a problem.  After 45 minutes, I heard voices as the crew was coming out.  They all came climbing out of the opening with smiles and their  faces and muddy.  They actually worked together as a team conquering what some were fearful of, crawling through water and mud ands squeezing through tight spots.

It is always fun to take families on fieldtrips.  You never know how people will react when they find a fossil.  I still remember when a 12 year old found a worm tube fossil.  The expression on her face was priceless.  You would have thought that she just won $1 million.  That is a quite rewarding feeling to see those reactions.  I have said it before that when you break open a rock and expose a fossil, you are the first person to see that particular specimen.  Now that is cool!!

I worry about the new standards coming out for the secondary school level.  I am uncertain just how much earth and space will be included.  The rapid scientific discovery going on with Mars and the remarkable pictures taken by the Hubble Space Telescope certainly keep astronomy in the headlines.  But what about geology?  Perhaps some people look at geology as a low priority.  Just what can we do on a computer to teach the subject.  That appears to be the theme these days,  No more  field trips looking at rocks, mineral and fossils, but look what a computer can model when working with a theory.  In my book, that doesn’t sound like fun.  Remember, earlier, I said that the best way to teach geology is go out and touch it.  I don’t think you get the same experience when moving your mouse back and forth across the computer screen.  Time will tell where the priorities will be with the new standards.

I teach because I enjoy it.  Even talking to senior citizens is really cool.  If you are senior citizen and looking for some enrichment in education, check out the OLLI program at Penn State York.  What a great program with a wide assortment of classes offered.  If you can’t find anything in their catalog that hits a nerve, you better start reading the catalog from the back to the front.  The fee to belong to OLLI and course registration is only about the same amount as you and a spouse going out to eat at a fancy restaurant.  I teach every fall for several weeks   a geology class of some sort.  This coming fall I will be doing several of my favorite “canned” PowerPoint programs in geology and astronomy.   I will also be teaching an experimental course on  “Geology of Tourist Attractions” in the East.

Specialty Granules quarry

Point of Interest A Native Copper Mines in South Mountain Location: From near Mt. Hope southward to Pa. Rte. 16, mostly associated with Copper Run. Once belonging to the P. H. Glatfelter Company of Spring Grove, PA as one of their tree farms, many of the mines are today situated within the Michaux State Forest. Several mines were known on the property of Specialty Granules as well as near the “Underground Pentagon.” The first copper operation was reportedly opened in 1833 and became one of the country’s leading copper districts in the late 1800’s. The last major mining operations shutdown in the 1920’s. Occasional attempts and rumors to start new mining continued into the 1960’s. The area became known to “rockhounders” after several reports were published by geologists in the early 1900’s. The district was also publicized in the “Mineral Collecting of Pennsylvania” published in 1976 by the Pennsylvania Geological Survey. An assortment of minerals, including native copper, have been found on the mine dumps. It was reported that native copper was found during the construction of the “Underground Pentagon.” Specialty Granules also finds native copper during quarrying. Native copper is common within volcanic rocks. The Keweenawan copper deposits in Michigan is geologically similar to South Mountain. Most of the copper is found within the metabasalt and quartz veins associated with this rock. The green color of the metabasalt is not from the copper, but rather epidote and chlorite. The copper was formed from deep groundwater containing the native element, which leached toward the surface rocks undergoing hydration. Weathering of the surface rock created secondary minerals such as malachite, azurite and cuprite. The quartz veins were formed in similar fashion where silica and copper ions crystallized from hot groundwater caused by metamorphism. The groundwater found it’s way into cracks within the metabasalt, cooled and formed the copper-bearing veins. For a detailed description on the history of this copper district, go to http://www.pennminerals.com/Chronicles2.htm.

Jeri and Roxann at the Reed Hill copper mine near Mt. Hope

Point of Interest B Devil’s Race Course, Fort Richtie Road, Franklin County Location: Parking area is located on the west side of Ritchie Road about 0.75 mile north of the intersection of Md. Rte. 491 (Raven Rock Road). Although there is a similar occurrence with the same name just northwest of Specialty Granules, we are going to drive past this Maryland occurrence. Although time does not permit us to stop, please come back and visit this geologic feature. The Devil’s Race Course is known as a boulder field composed of boulders of the Weverton quartzite. The feature is approximately 0.70 mile long and 80-130 feet wide. The boulder field was formed by intense weathering and erosion during the “Ice Age.” These boulders were once part of large outcrops of the Cambrian-age quartzite (metamorphosed sandstone) which got broken into boulders and brought down the valley. A stream can still be heard running under the boulders.

Stop 2. Panning for Gold East Branch of Antietam Creek (need permission) Washington County Solid Waste and Recycling, Bikle Road in Smithsburg, MD. The art of panning for gold has intrigued humans for many years. Since the discovery of gold near Charlotte, NC in 1803 which led to the first commercial gold mine in the United States to the gold rush at Sutter’s Mill, CA, people always get excited when they hear “gold.” Although the author has never panned for gold in this vicinity, you can still learn the how’s and why’s in this short stop. The East Branch of the Antietam Creek flow off of the west side of South Mountain and actually originates within the Catoctin Formation metabasalt. Gold, like copper, forms within volcanic rocks. However, with my experience as well as other recreational panners, gold within South Mountain in Pennsylvania appears to be almost non-existent. It appears that gold within the Catoctin Formation is not very common. The area of our panning is underlain by the Cambrian Tomstown Formation, composed entirely of limestone. You will be instructed here on how to fill your gold pan with sediment and using the water, have the heavy minerals settle to the bottom of the pan and the other “junk” rock washed out of the pan. Heavy minerals would include magnetite (black sand), garnet and possibly gold. We will supply you with a small container if you would like to take your “heavy” minerals home for a souvenir or closer look. History of Gold in Maryland: The following is taken from “Gold in Maryland written by Karen Kuff (1987) published by the Maryland Geologic Survey. Maps and more information can be obtained at http://www.mgs.md.gov/esic/brochures/gold.html “Although gold was first reported in 1849 on Samuel Ellicott’s farm near Brookville, Montgomery County, no production was recorded. There are numerous versions of the first discovery of gold in the Potomac area. In 1861 during the Civil War, a Private McCleary (or McCarey) of the 71st Pennsylvania Regiment (or “1st California Volunteers”) was stationed outside of Washington, D.C. While encamped in the vicinity of Great Falls, he discovered gold. It is reported that the gold was found while washing skillets in a stream near McCleary’s hilltop camp overlooking the old Anglers Club. By 1867 the first shaft was sunk near the site of the Maryland Mine.” “Gold has been mined, panned or prospected intermittently since that date. Active mining ended prior to World War II in 1940 and the last recorded production from prospecting was 21 ounces found between 1950-51. The accompanying graph shows gold production in Maryland from 1868 to 1940. Prospecting continues even today. There is a surge of gold panning interest every few years, especially following an increase in the price of gold.“ “No great fortunes were made by Maryland gold miners. In 1890, Emmons stated that there was little likelihood of any new ventures that would result in sure riches for the operator.“ “On all of this belt …there is no record of any great mine the product of which can compare with the few enormously productive mines…in the west, and there seems to have been a very large proportion of disastrous failures among the many gold mining enterprises that have been undertaken here. There is some reason to assume that many of these failures have been due to ignorance and bad methods of working…the depth to which the rocks have been rotted and decomposed…has tended to make the surface showing underly rich; and has been an important factor in preventing systematic and successful mining in depth.” “Not all gold was obtained as ore from mine shafts; much was found by prospecting with trenches, or panning in local streams. The area around Great Falls has yielded most of the gold found in Maryland. Individuals hoping to find gold in Maryland are still looking in this area. Gold recovered by panning is mostly very fine grained but can range up to coarse sand size. Rarely, nuggets were found, some weighing as much as 4 ounces.”

Gold on top and magnetite on bottom of pan

Stop 3 George Washington State Park, Alt. Rte. 40 Boonesboro, MD Monument (Milk Bottle) composed of Weverton Quartzite If you have or never visited this first monument constructed in honor of our first President of the United States, it is always worth a visit. Each time you walk the short trail up to the monument you see something different. Closely examine the quartzite that composes the monument and enjoy the scenic view from the top of South Mountain. New landmarks are seen every time. Quartzite is a metamorphic rock, once a sandstone that has undergone heat and pressure associated with crustal collisions. The rock did not change chemically, but only texturally. Quartz is still the dominate mineral in the rock. Quartzite is coarser-grained due to the grains welding themselves together to make a larger quartz grain. The rock is hard (7.0 on the Moh’s Hardness Scale). Walking up the trail, float of quartzite are lying all over the ground. Examining the rock in the monument you can trace some indication of bedding. No fossils are present. Also, use your keen eye to pick up several quartzite blocks that appear to have 2 directions of bedding (layering) in the rock. This is known as cross-bedding which represents two directions of wave action at a beach when the rock was beginning to form as sandstone. The Weverton quartzite was used in many of the area’s historical buildings. Because of its durability and blocky shape, it is considered a long-lasting stone for buildings. Although rather hard to cut, the rock would be pretty polished after being cut. Ever wonder where the rock came from when you view a historic building? Chances are that the rock originated close by and hard by horse and wagon. For example, in the case of the Washington Monument, the rock came from right here. As we exit the park and return to Alt. Rte. 40, check out the church on the left side just before we travel down off of South Mountain. From the overlook, you are able to see at least 38 miles. Sidling Hill located on Interstate 68 west of Hancock appears as a notch in the mountain to the west. This section is known as the Valley and Ridge Providence or also called the Appalachian Mountains. This famous mountain range is composed of sedimentary rocks such as limestone, sandstone and shale ranging in age from Ordovician to Pennsylvanian. The wide valley below us is the Great Valley Section of the Valley and Ridge. The reason it is a valley is because the rock is mostly limestone and dolomite with some shale beds. Limestone and dolomite are rather soft, not holding up to the elements of weathering and erosion well, thus underlying valleys. Check out the framed photographs of the scenery on top of the tower which has landmarks indicated.

View looking west from Washington State Park

Point of Interest C Middletown Gneiss Exposure on MD Rte. 17 east of the Catoctin Creek, south of Middletown, MD With time restraints we are not able to show you this roadcut, but we have supplied enough samples for everyone to take home probably the oldest sample you have collected. This rock is known as gneiss, a metamorphic rock that illustrates to geologists just how intense the heat and pressure can become during a metamorphism event. This rock underlies much of the Middletown Valley, but exposures are rather obscure. The gneiss was originally a piece of a granitic crust making up a part of an ancient supercontinent known as Rodinia. The rock has been dated at about 1 billion years old. The rock was later involved in the pulling apart of Rodinia, the collision of a volcanic island arc to the east and the great African-North American collision to form Pangaea. Only if the rock could talk, what a story it could tell!! Gneiss is the highest grade metamorphic rock known. If the rock would have had more heat and/or pressure added, the material may have returned back into magma. When the rock was undergoing metamorphism, the white-colored minerals grouped themselves in a zone and the dark colored minerals gathered into their own zone, giving the gneiss a banded appearance. This rock is also believed to be the oldest rock found deep within South mountain and Catoctin Mountain in Maryland. Enjoy your gneiss!!

Point of Interest D Limonite (Goethite) from an area iron mine Again, because of time restraints, we will supply you with a sample of limonite, a.k.a. goethite. This ore was removed from a number of 19th century iron mines in this region and used in nearby furnaces to manufacture iron. We will see one of those furnaces at our last stop. Most of the mines were open pit, not requiring deep shafts to extract the ore. Much of the ore was laying loose in the clay which only required it to be washed and not removed from bedrock. Pick and shovel were about the only required tools. Horse and wagon removed the ore to its processing station or transported it to the furnace. Where blasting was required to dig into the bedrock, dynamite was not used commercially until 1890. Black powder was the main way to loosen the rock prior to 1980. Be careful, your hands will get dirty handling the limonite.

Stop 4 “Potomac Marble” exposure on Ballenger Creek Pike near the Substation 1.17 north of Points of Rock Road Rock Type: Breccia (Sedimentary) but known as a Fanglomerate due to its origin Age: Triassic Period With my experience of regional geology in southeastern Pennsylvania and now into Frederick County, Maryland, This is the nicest exposure of this rock that I know of. I read about this exposure in a book on Frederick County and Richard Gottfreid, professor geology at Frederick Community College suggested this stop. I have seen the fanglomerate quarried, sawed and polished from a farm in Lancaster County, Pennsylvania and wow, is it ever a pretty rock? Imagine that, seeing the large limestone angular boulders set in a reddish clay matrix, glued together. Yes, the rock has been used in several locations as an ornamental stone. The most famous is for pillars inside the National Capitol in Washington, D.C. I am sure there are smaller uses for the rock such as coffee table tops, chair molding in a room or around a fireplace. Just how did this rock form? The rock is considered Triassic in age. During this time, the area was located at about the same latitude as Miami, FL. The climate was tropical with abundant rainfall. It was also the time that the supercontinent Pangaea was beginning to split apart into the world as we know it. We are standing in what was a rift valley, similar to today’s example of the Red Sea. Land to our west was trying to go with North America and the crust to the east was going with Africa. The land here was sinking during the rifting and the valley walls were very steep. As streams flowed from the east into the rift valley, the streams had plenty of velocity coming down the valley slope and were able to carry larger rock fragments. Once the stream flowed out onto the valley floor, the stream’s velocity dramatically slowed and was forced to drop all of the boulders of limestone. As boulders were deposited on top of older boulder layers, as viewed from the air, the sediment appeared as a fan shape, thus known as an alluvial fan. In a dictionary, the rock would be classified as a breccia (rock containing angular fragments). Since we know the specific origin of the rock as an alluvial fan, the rock is known as a fanglomerate. Notice how the limestone is slightly more resistant to weathering and erosion than the reddish clay. The boulders are a little higher off of the surface. Let’s see who can find the largest limestone boulder!! It is hard to determine any bedding in the rock since the deposition was massive. The fanglomerate is estimated to be about 200 feet thick and exposures are localized. You will see the rock lying on the surface more often than in actual outcrops. Another factor is that these alluvial fans were not continuous along the end of a rift basin, but were spotty. It was reported by the Fredrick County School District website dealing with a geologic guide of the county that fanglomerate was encountered and dug out when the Pier 1 store along U.S. Route 40 was constructed in the last several years.

A pillar inside the National Capitol building in Washington, DC compsed of fanglomerate

Stop 5 Vulcan Materials Quarry – Buckeystown Pike north of Buckeystown (need permission) Frederick formation – limestone – Cambrian age Grove formation – Limestone – Late Cambrian to Early Ordovican Our second quarry of the day is operated by Vulcan Materials Company. According to their website, here is an introduction to Vulcan Materials: “Vulcan Materials Company is the nation’s largest producer of construction aggregates—primarily crushed stone, sand and gravel—and a major producer of aggregates-based construction materials including asphalt and ready-mixed concrete. Our coast-to-coast footprint and strategic distribution network align with and serve the nation’s growth centers. We are headquartered in Birmingham, Alabama.” “Over 300 Vulcan sites produce construction aggregates, and about 200 facilities produce asphalt and/or concrete, which also consume aggregates. All of these are located in the U.S. except for our large quarry and marine terminal on Mexico’s Yucatán Peninsula. The products from this facility are primarily exported by ship to the U.S. Gulf Coast, where quality stone cannot be mined locally For more information on this company go to www.vulcanmaterials.com.” “What we produce is used in nearly all forms of construction. In particular, large quantities of aggregates are used to build and repair valuable infrastructure such as roads, bridges, waterworks and ports, and to construct buildings both residential and nonresidential, such as manufacturing facilities, office buildings, schools, hospitals and churches.” Here the limestone is used primarily for aggregate purposes, for asphalt roads, concrete roads, road base, lightweight block, rip-rap for slope stabilization, stone driveways, construction, etc. The basics of the operation is laying out blasts or shots, blasting rock, loading rock into haul trucks to take to the plant where the various rocks are crushed, screened, and separted into their appropriate sizes. Of course, knowing the geology and having a good mine plan are also important. At one time the rock was mined for use to make cement, however the chemistry is not quite high enough in calcium carbonate as Essroc like so they don’t get rock for that purpose any longer. Some customers use the rock for out of spec AG lime. Two limestone formations occur in this area. The Frederick formation is found within the quarry while the Grove formation lies to the east. Based on stratigraphy of these formations, each limestone unit can be divided further into members. From west to east, they are: Rocky Springs Station member, Adamstown member and Lime Kiln member, all belonging to the Frederick formation. The Grove formation can be divided into the Ceversville member and the Fountain member (west to east). You will be permitted to collect off of a pile of limestone here. Watch for white, yellow or other colors in veins or crystals. This will be calcite, the primary mineral that composed limestone. It has a hardness of 3 on the Moh’s Hardness Scale, has 3 directions or cleavage and forms rhombohedra or dog-tooth shaped crystals. Calcite will react with vinegar with made into a powder or more readily with muriatic acid.

Aerial geologic map of the Buckeystown quarry

Stop 6 Catoctin (Isabella) Furnace in Cunnigham Falls State Park near Thurmont 18th and 19th century iron furnace The historical marker states: ”Catoctin Furnace: An important iron furnace during the Revolution owned by Governor Thomas Johnson and his brothers. Furnished 100 tons of shells used at Yorktowne.” The Johnson Furnace was a cold-blast operation. It operated from 1776 to 1795, and then was idle until 1803. The furnace operated again between 1803 and 1811 with substantial improvements. Early production consisted of household implements, tools, cast iron stoves, etc. The works were purchased by by John Brien in 1831 and modernized. The furnace operated until it was shut down and dismantled in 1880. The site of the Johnson stack was probably in about the middle of the retaining wall behind the existing (Isabella) stack. Another owner built the Isabella Furnace in 1856. Both the Johnson and Isabella stacks were 33 feet high, but the Isabella was supplied with a steam-powered hot blast mechanism. The Isabella operation was a advanced design for a charcoal furnace. It might have been capable to use anthracite or coke, but neither were available. The Isabella is the remaining stack on display. A third stack, the Deborah, was built in 1873 about 140 feet south of the Isabella. It was a water or steam-powered hot-blast furnace which used coke or coal with a daily capacity of 35 tons of pig iron. It operated until 1903 and was then dismantled. In the late 1800’s, when the complex was at its heyday it consisted of: 80 houses for workers, a saw mill, a grist mill, a company store, farms, an ore railroad and 3 furnace stacks. Production was 9,000 tons of pig-iron annually. A magnetite (iron) mine was located on a hill to the southwest and continued to mine until 1912. Today, we should have time to visit the stack area and walk east to see the remains of the ironmaster’s house. Further walking on the trail will take you past slag heaps a raceway and dam for the waterwheel for the Johnson furnace.

Portal of the Catoctin Furnace

The finding of a fossil is always a cool experience.  You are the first person to ever see that particular specimen and you probably know, each specimen is unique in appearance.   Some of you have probably experienced that feeling while fossil hunting.  Just think now if you find a fossil that has never been described before and you know that your find could be very important.

This is the case of Samuel S. Haldeman.  Samuel was born on the homestead just at Locust Grove, now Bainbridge, Lancaster County in 1812.  His father was a  great business man having interests in furnaces, a grist mill and .    He attended a classic school in Harrisburg and then spent two years at DickinsonCollege, although he did not receive a diploma.

The Haldeman homestead at Locust Grove as it appears today.

After his marriage in 1835 to Mary A. Hough of Bainbridge, he moved to a new residence at the base of Chickies Rock, Marietta. Not only did he design the stately home built by his father, he laid out the grounds with native specimens of trees and shrubs gathered from the surrounding woods, and some foreign varieties, all of which were planted with his own hands.

For a time he managed a saw mill. In 1836 Henry D. Rogers, having been appointed state geologist of New Jersey, sent for Haldeman, who had been his pupil at Dickinson, to assist him. A year later, on the reorganization of the  Pennsylvania Geological Survey, Haldeman was transferred to his own state, and was actively engaged on the survey until 1842, preparing five annual reports, and personally surveying the counties of Dauphin and Lancaster.   In 1840 he began the publication of his monograph on the “Fresh-Water Univalve Mollusca of the United States,” in which he described the Scolithus linearis, a new genus and species of animal fossil, the most ancient organic remains in Pennsylvania. During the year 1842/3, he gave a course of lectures on zoology at the Franklin Institute.

Samuel Haldeman circa 1850

In 1852, Haldeman was appointed professor of the natural sciences in the University of Pennsylvania. In 1855 he went to DelawareCollege, where he filled the same position. While there, he also lectured on geology and chemistry in the state agricultural college of Pennsylvania. In 1869, he returned to the University of Pennsylvania as professor of comparative philology. He remained there until his death, which occurred at Chikckies Rock, Pennsylvania.

Scolithus specimen found in the York area

Haldeman was an earnest advocate of spelling reform. He was a member of many scientific societies, was the founder and president of a Philological Society, and one of the early members of the National Academy of Science.

Samuel loved many aspects of the natural sciences.  He built and lived in a mansion at the north end of Chickies Rock.  He studied the plants living there and discovered Scolithus fossils.  Not certain of its origin, Samuel sent a letter to Charles Darwin in an attempt to identify the specimen.  Although I haven’t seen the correspondence or even sure if a letter still exists, historians have stated “that the fossil is Scolithus, a worm borrow of an ancient animal.”  Samuel continued his communication with Charles, helping Charles write the final pages of the classic “The Origins of Species.”  It was determined that Scolithus was a relatively short lived species of only several million years.  The age was placed on the Precambrian and Paleozoic era boundary, on today’s geologic time scale as 545 million years.  Because of its short life span was a species, any rock containing Scolithus can be dated at 545 million years old.  This is known tov a geologist as an index fossil, used as a dating tool.

Samuel Haldeman in his later years

Samuel died in September, 1880 at his mansion.   He left behind 200 publications covered six disciplines he had studied.  Samuel Stehman Haldeman gave his life to his scholarly pursuits, and his influence, though largely unnoticed, is astounding. Many of the most famous and influential scholars of the past were directly influenced by Haldeman both personally and professionally. Haldeman was able to aid in progressive research on many fronts, both scientific and linguistic. The fact that Haldeman was constantly on the cutting edge of every field he studied suggests that he was a man who challenged convention, a man who truly thought for himself. Samuel Haldeman was not only one of the greatest American scholars, but also one of the greatest American thinkers.

Samuel’s mansion he designed and his father built at the north end of Chickies Rock where he died in 1880.

What brought this blog to mind was that I finally visited the HaldemanMansion in Bainbridge this past Sunday.  I was the speaker at the Annual Meeting of the Haldeman Mansion Preservation Society and had a chance to see some of Sanuel’s specimens in his collection.  I even assisted members with identifying several of the artifacts they had questions about.  This society has done much work on the mansion and are still looking for funding to do more, for example, installing a new roof.   This is a great place to visit during the summer when they have open houses and appreciate some of the history of a great person in our local history.

One of those case recently arose.  I had met a gentleman who is very interested in local minerals and has indeed discovered some “cool” stuff on his expeditions in the YorkCounty.  One of his great pieces is petrified wood from Manchester.  Well preserved and rather large for a specimen, I must have looked like a dog waiting for my supper when you showed me that one!!  Certainly one of the best pieces of local petrified wood I have seen from YorkCounty.  Not to get off track, this person had a friend from the Newville, CumberlandCounty area who has done his own research of that area.  With his research he had some questions about items he recovered from the GreatValley region of central Pennsylvania.   So we made arrangements to meet on a Sunday afternoon since that was the only time I had available in the next few weeks and off we go to the Newville area.

I have done very little research in the GreatValley but had time to do some preliminary reading on maybe I should expect to find out there.  I studied the geologic maps since this person gave me an address to check out including Goggle Earth to get a picture of the lay of the land.  With hammer and camera in hand, we met at the designated location (thanks to the GPS) and he gives me some background of what he is doing and has found.  It turns out that much of his research is not geologically related but archaeologically based and certainly I still felt comfortable in that realm.

Float of limestone laying in the field close to the quartz crystals

During the preliminary discussion, I was told what my goal was for the day.  In the rolling hills of the western GreatValley area, this friend uncovered hundreds of small six-sided shaped quartz crystals almost resembling the famous Herkimer diamonds from upper New York state.  Wow, what I had to decide was if these crystals were really transported in from Herkimer for some sort of trading goods from previous residents of the valley or were rthey native to that area?

Again, I did not have much experience of mineral collecting from this portion of CumberlandCounty but I think I would have heard about these clear quartz crystals.  I should have seen some of these crystals for sale at a local rock and mineral show or even a rock swap, but I never did.  After he took me to an area where you has unearthed many of these crystals, I soon drew a conclusion that these crystals were native, weathering out of the limestone.  Wow, so cool and just walking through the freshly dug excavation, these crystals were abundant.  My guide and his friend even have perfected finding these at night using flaahlights at a low angle to the ground to detect their reflection.  Very creative!!!!

Quartz crystals recovered from the Newville area

I wanted to see more of the  immediate area to look at the available rock exposures and loose rocks in the fields.  Upon walking more of the property, I was shown a cave with a vertical entrance which apparently has been known by local cavers for many years.  I knew I was in sinkhole and cavern area knowing the rock formations for which laid under my feet.  Sure enough, with the topography, I located a solution valley that was created when two of more sinkholes combined to make one large sink and later became inactive, forming a narrow, elongated valley.  Other sinkholes were spotted around the edge of this property where residents brought their old metal and disposed of it in the sink.

Anoither sampling of the quartz crystals

Our last stop was at a small inactive quarry where the limestone was well exposed.  A great outcrop to see the structure of the limestone and maybe some more quartz crystals.  Although we didn’t find any of the clear quartz crystals, we did locate a cavity of white quartz crystals.  No other minerals were detected but seeing these clear quartz crystals native to the limestone and having great fellowship with my guides for the day was certainly worth the trip.

Limestone exposed in the abandoned quarry

After I got home and knowing exactly where I was on the trip, I went to my library again to find out if these fine quartz crystals were every reported by a geologist.  Sure enough, when I went to the classic book “Mineralogy of Pennsylvania” by Samuel Gordon in 1922 and I turned to CumberlandCounty, what did I see?  Not one listing of clear quartz crystals but two in the county.  After locating these locations on the CumberlandCounty map and referring to the geologic maps, both of those locations were in the same limestone formation as I visited earlier.  It is hard to believe that among my rockhounding friends that have explored CumberlandCounty, they never said a word about the quartz.

Milky quartz crystals from the abandoned quarry.

Harpers Formation phyllite and quartzite

Located between Hyde and INdian Rock Dam Rock, Spreing Garden Township

1. Harpers Formation derived from Harpers Ferry, WV
2. Southern 33% of YorkCounty is composed of metamorphic rocks
3. This ridge (Country Club Ridge) is just south of the dividing line between the Piedmont Lowlands Section (PLS) and the Piedmont Uplands Section (PUS).
4. Walk a portion of the exposure and notice what appears to be layering.  Actually this rock has undergone heat and pressure where bedding has become obscure.
5. What you believe is layering is known as foliation – a feature only found in metamorphic rocks where platy minerals in the rock align themselves to produce a flat plane.
6. Notice any folding in the exposure?
7. We are situated very close to a north-south fault.  Although most of the rocks in the PUS are folded, these rocks have been more tightly folded with the influence of the fault.
8. Find isolated beds of quartzite.  Quartztite is thicker “bedded” than the phyllite and more resistant to erosion.
9. There are small quartz veins also found here.
10. Notice how some of the tree roots anchor themselves into the bedrock and are accelerators in weathering of the rock.

Folding in the metamorphic rocks at Hyde

STOP 2.  Stoney Brook Diabase Dike

Diabase and Conestoga Formation limestone

Along the Railroad just west of the Pleasant Acres Road, Springettysbury Township

1. Diabase is an intrusive igneous rock giving the rock a coarse-grained appearance.
2. All diabase in Pennsylvania is Jurassic in age.
3. A dike is a narrow intrusion of magma in this case only measuring about 20 feet wide, but is about 35 miles in length
4. This magma was believed to be about 1100º C. and baked the surrounding rock into a metamorphic rock named as a hornfels.
5. Larger intrusions have formed mineral resources in southeastern Pennsylvania such as the Cornwall Iron Mines, LebanonCounty and Dillsburg magnetite deposit, York       County.
6. The magma intruded the Conestoga Formation composed of limestone.
7. Ripple marks have been found in this thinly-bedded limestone.
8. What is the direction and angle of dip of the limestone?
9. The Conestoga Formation is one of several limestone/dolomite units in the YorkValley, all forming on a continental shelf off the coast of ancient North America known as        Laurentia.
10. This limestone is now considered Cambro-Ordovician in age.

Stoney Brook Dike just west of Pleasant Acres Road

STOP 3.  Accomac Metabasalt

Catoctin Formation

Located along the south side of Accomac Road just west of the intersection with River Road, Hellam Township

1. Formed as a result of rifting of the supercontinent Rodinia about 620 mya.
2. Basalt forms on an oceanic crust (i.e. mid-oceanic ridge)
3. Look for quartz pods (filled-in gas bubbles) sometimes showing a trace of copper
4. Grass-green mineral is epidote and darker green mineral is chlorite
5. Notice crystal size – extrusive meaning it cooled quickly and is fine-grained
6. Fractures in the rock are known as joints (fractures where no movement has taken place)  Geologists can take measurements of joints and calculate direction of pressures
7. Notice one area where bedrock is missing with a small drainage ditch – a possible fault?
8. Across the road notice the erosion taking place as the stream crosses over the bedrock
9. The rock has gone at least one period of heat and pressure – metamorphism (meta)
10. Potholes are well developed in the metabasalt

Accomac road cut exposing the Catoctin metabasalt

STOP 4. Rocky RidgeCountyPark

Chickies Formation – Hellam Member

Located at the end of Deininger Road, Spring Gettysbury Township.  Proceed to the Oak Timbers North Overlook

1. Rock containing rounded pebbles is known as a conglomerate
2. Rock fragments of mostly quartz with occasionally darker fragment of metarhyolite
3. Can you detect any bedding?
4. Notice how the fragments are more resistant to erosion – standing higher than rock
5. Any theories on how this rock formed (include a continental shelf, IapetusOcean and other bodies of water in your thinking)
6. York, Lancaster, Lebanon and Berks counties can be seen from the overlook
7. Can you recognize any familiar landmarks?
8. Harder rocks underlie ridges and softer rocks underlie the valleys, i.e. sandstone and quartzite ridges; limestone and shales in the valleys)
9. We are at an elevation of about 940 feet above sea level
10. We can see a distance of 52 miles to the northeast on a clear day

Hellam Conglomerate exposed at Rocky Ridge County Park.

STOP 5. Sheep Bridge Road

Gettysburg Formation shale and sandstone

Located on the west side of Sheep Rock Road just north of the Conowego Creek, Newberry Township

1. Sandstone has thick bedding and shale has thin bedding. Grain size also varies.
2. Which of the two rocks is more resistant to erosion?
3. These rocks were laid down in an “Everglades” environment as Pangaea was rifting apart
4. Fossils in the area include petrified wood, ferns, dinosaur footprints and reptilian remains
5. The thickness of the New Oxford and Gettysburg formations are at least 25,000 feet thick
6. Can you detect the angle of dip and direction?
7. These rocks are undeformed and positioned nearly the same as when they were deposited
8. The red color of the rock was created when the sediment was above water level and exposed to the atmosphere
9. Clam shrimp found in this formation in DauphinCounty indicates fresh water environment
10. Which layer in this road cut is the oldest?

Sheep Bridge road cut exposing Triassic sedimentary rocks

STOP 6. Pinchot State Park Toboggan Run Area

Diabase Exposure

Warrington Township

1. This is one of the best exposures of diabase in YorkCounty
2. Compare this diabase with that seen at Stoney Brook
3. This diabase formed in a sill (a lenticular body of magma) formed at least one mile beneath the surface
4. In a sill, the magma closest to the outside will cool quicker than the middle
5. This event was the last stage of the rifting of Pangaea
6. Igneous rocks weather in a characteristic rounded shape boulders (spheroidal weathering)
7. Notice the cracks on the rocks – these are believed to be cooling cracks as the magma cooled now magnified by weathering
8. One could have fun here recreating how the boulders were all connected at one time
9. The rock develops a reddish-brown weathering rind
10. How do you think this rock would be for having a good groundwater supply?

Diabase exposed at Toboggan Run at Pinchot State Park

STOP 7.  Rossville   Road Cut

Diabase and Gettysburg Formation hornfels

Located on the east side of Old York Road, 0.50 and 0.75 miles north of Rossville, Warrington Township

1. Check the diabase at the lower road cut for grain size – positioned in the middle or on the edge of the sill?
2. White veins in the diabase of composed of a mineral group known as zeolites.  Heulandite and stilbite are present here in crystals
3. In the upper road cut, this rock was originally rocks similar to what we saw at Sheep Rock Road but these have been heated by the magma now known as hornfels
4. Can you detect the direction of the bedding?
5. A chemical reaction here formed a small amount of native copper to form in the rock
6. Upon weathering of the rock, native copper will adjust to the new conditions forming azurite (blue and malachite (green)
7. This rock has no economic value and only occurs on the joint surfaces
8. Other minerals formed in this method include garnets and opal
9. Gold is found in area streams, mostly washing out of the diabase
10. Collect your pieces of samples for the coffee table!

Azurite and malachite exposed in the upper road cut along Old York Road

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.

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.

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

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.

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.