Maryland’s Pink Granite - Woodstock Quartz Monzonite
Please visit our related Earth Cache - In Guilford, Howard County near Rt 32 & I-95
y Maryland’s Granite - Guilford Quartz Monzonite GCAMVQ7
Welcome to our Earthcache. We hope you will enjoy the area here at Patapsco Valley State Park- McKeldin Area, find something you may not have known was here, and learn about a unique rock. Why? Well we like rocks and minerals from basic to exotic. There is a lot of relavent information here so to make it easier for handheld caching, the logging requirements are listed here at the beginning. This is not a test, so have fun and do your best. Send us the answers and then log your Find.
1. Visit the posted Coordinates and tell us why you think there is a lake here? Yes, it is simple!
2. Do you see any pieces of Woodstock granite here? Describe the colors you see and estimate the grain size. Visible to the naked eye or not?
3. At Reference Point #1, North Pile, - Observe the pile of rocks. Do you see any marks that would indicate how they were separated? What are the marks caused by, if you see any? Enjoy the view! (If your are viewing this on a computer with the background photo showing, look to the right, here>>>>>>>>>)
4. At Reference Point #2, West Boulder Field - Observe the boulders piled here and look for the famous pink granite. If you can find any, is it easy to see or faint? What gives the granite this pink?
5. Post in your Log a picture of yourself (face not required) or a personal item at the cache location.
Maryland’s Pink Granite
What is Granite? Granite is a dense igneous rock, formed as molten rock slowly cooled and crystallized. It is a mixture of feldspar, quartz, and mica (or biotite). These minerals create flecks of light and dark on a gray background, but the colors can range from black to pink. Granite sold by the Guilford and Waltersville Granite Co. was pink-toned granite, primarily from the Waltersville and Fox Rock quarries. It was renowned for its beautiful appearance and use in many fine local structures such as the Baltimore Customs House, Court House, old Post Office, and the Maryland Revolutionary War Monument. Woodstock granite can also be found in the United States Capitol, Thomas Viaduct, "the Library of Congress, the inner walls of the Washington Monument, and the Old Patent Office.
Woodstock Granite is thought to be the the best in Maryland. Woodstock Granite is a little darker in color than the Guilford granite that is only found in the Guilford and Atholton areas of Howard County, including an area around the Middle Patuxent River. These granites differ only slightly from the Ellicott City granite which is described as “Ellicott City Granodiorite” and also dates to about 420 million years ago. Ellicott City granite is found in both Baltimore and Howard Counties.
The Woodstock Quartz Monzonite is a Silurian or Ordovician quartz monzonite pluton in Baltimore County, Maryland. It is described as a massive biotite-quartz monzonite which intrudes through the Baltimore Gneiss at a single locality surrounding the town of Granite, Maryland. (see above)
The extent of this intrusion was originally mapped in 1892 as the "Woodstock granite". It was given its current name in 1964 by C. A. Hopson. Hopson grouped the Woodstock Quartz Monzonite with the Ellicott City Granodiorite and the Guilford Quartz Monzonite as "Late-kinematic intrusive masses."4
The color of the rock is bright gray, with something of a luster imparted by the quartz and the unaltered feldspars, the latter often giving an additional faint pink tone. The mica occurs in evenly disseminated fine black flakes which emphasize the grain of the rock and only slightly subdue the bright fresh aspect of the stone. The size of the constituent grains which varies from 0.05-0.2 inches in length, and from 0.01-0.10 inches in breadth, for quartz and feldspar, is little marred by the less resistant mica wearing away and leaving small depressions, that are scarcely discernible to the naked eye. The polished surfaces, such as are represented in (the same figure), are darker than the rough or ashlar finished stone.
The chemical composition (by %) of the Woodstock Quartz Diorite from the "Sylvan Dell Quarry" (probably the Waltersville Quarry) in Granite, Maryland is in the chart below.
| Chemical |
% |
Chemical |
% |
| SiO2 |
71.01 |
CaO |
2.32 |
| TiO2 |
0.30 |
Na2O |
3.59 |
| Al2O3 |
14.46 |
K2O |
4.38 |
| Fe2O3 |
1.17 |
H2O+ |
0.62 |
| FeO |
1.44 |
H2O− |
0.03 |
| MnO |
0.04 |
CO2 |
0.10 |
| MgO |
0.70 |
P2O5 |
0.12 |
Fox Rock Quarry was opened in 1836 on land then owned by Nicholas Owings. A couple of stone cutters from Baltimore named John Emery and Cyrus Gault leased the quarry for a term of 6 years, beginning on November 10th, 1840. To pay the lease, they agreed to quarry at minimum 40,000 cubic feet of stone each year and pay 1.25 cents per cubic foot. The principal early demand was from the Baltimore and Ohio Railroad for stone stringers, dressed to correspond to the flange and tread of the car wheels. Early in the lease Nicholas Owings died and the land was passed to his son. Many legal issues evolved from the death and debts owed. In the end Emery and Gault worked the quarry for about 10 years and built a railroad from the quarry, acrocss the Patapsco, and connected to the B&O's Old Main Line. After Emery and Gault abandoned their activity, the quarry sat idle for several years and the railroad spur and bridge deteriorated, never to be repaired. In 1866 the land was part of a purchase by the Jesuits as the site for a seminary named Woodstock College. The main building was constructed entirely of stone from Fox Rock and opened in 1869. The campus buildings still exist less than a mile southwest of here and are now used as a Job Corps training center. The College then sold the quarry location outright and it passed through several hands including William and Matthew Gault who formed the Woodstock Granite Company. The quarry operated under various owners through the 1920's. 2
The first four "granites" and gneisses below were frequently used in buildings around Baltimore. In descriptions of buildings,these stones have often been confused, but with careful observation, the differences between them can easily be noted.
1. Port Deposit "Granite"..... a coarse-grained, granite gneiss with an obvious foliation produced by black mica. The rock was used in early days by colonial settlers, but commercial use did not occur until about 1816 when stone was needed for the abutments to the Susquehanna River Bridge. A quarry was established at Port Deposit and by the 1830's much of the stone was being shipped to Baltimore. Other quarries were opened in Cecil County as the stone gained acceptance. Some of the buildings in which this popular stone was used are: Fort Carroll, Fort McHenry, the Naval Academy in Annapolis, Haverford College in Philadelphia, and part of the old Goucher College in Baltimore. It is now quarried north of Havre de Grace by the Arundel Corporation for use as crushed stone.
2. Baltimore Gneiss..... any of several similar looking banded gneisses in a variety of colors, texture, and composition that were quarried along the Jones Falls and Gwynns Falls in Baltimore City. It is thought that the first buildings of Baltimore in the 1700's used stone quarried from the Jones Falls gneiss, near the old Mount Royal railroad shops. Many of the tone buildings, foundations, roads, and curbstones in Baltimore were built of rock from both the Jones Falls and Gwynns Falls quarries. The blue-gray color of fresh stone caused the term "blue stone" to be used by the quarrymen. The last building stone quarry in Baltimore closed in 1958.
3. Ellicott City "Granite"..... a porphyritic gneiss that was first quarried in the late 18th century. It was used in building the Basilica of the Assumption in Baltimore, which was erected during the period 1806 to 1821. Material was hauled from the Ellicott City area to Baltimore by huge wagons drawn by nine yoke of oxen. After 1892, the stone was used primarily in foundations and as paving stone. Little building stone was produced from this area after 1896.
4. Woodstock Granite..... a pinkish-toned, coarse-grained, gray granitic rock that was quarried near the town of Granite in Baltimore and Howard counties. This rock was first quarried in 1832 and was used intermittently until the 1920's. It was employed as a monument stone as well as being used for building exteriors. Buildings made from this stone include: parts of the Capitol building and the Library of Congress in Washington, D.C., the Baltimore Customs House, and the old Baltimore County Court House. Many curbstones, paving blocks and bridges are made of this stone.
5. Cockeysville Marble... a white, crystalline, metalimestone, most famous for its use in the Washington Monument in Washington, D.C. The first 152 feet of the monument, built between 1845 and 1854, were faced with Cockeysville stone from a quarry near Texas, about 12 miles north of Baltimore. When funds were depleted, work ceased for 25 years and was resumed again in 1879 using a marble from Lee, Massachusetts. Four courses of this stone were used; however, it proved too costly and the remainder of the structure was faced with marble from a quarry in the Cockeysville area. The marble was also used in the construction of the Washington Monument in Baltimore City. By the 1840's-1850's, the marble was very popular and readily available for use in building the stone front steps of many of the older row houses in Baltimore. The Beaver Dam quarry at Cockeysville furnished marble used for the 108 columns in the wings of the National Capitol at Washington, D.C. Today, quarries work the Cockeysville Marble primarily for crushed stone and high-purity calcite.
6. Slate..... a bluish-gray, thin-bedded, fade resistant slate was quarried from the Peach Bottom-Cardiff area in Harford County and, to a lesser extent,from the Ijamsville area in Frederick County. The Peach Bottom area was worked as early as 1750 for local use. The first commercial Peach Bottom quarry opened in 1812, about the same time that work began in the Ijamsville area. The Ijamsville slates did not achieve the popularity afforded those from Peach Bottom because of their dullness and softness or lack of "ring," and operations closed in 1892. Slate was quarried from Peach Bottom as late as 1957 for granules in composition roofing shingles.
7. "Seneca Red" Sandstone..... a reddish to purplish brown, fine-grained, arkosic sandstone or "Brownstone" was quarried extensively along the Potomac River in Montgomery and Frederick Counties. This Triassic stone was initially used for the "Potowmack Canal" built around 1774 and again for the C & O Canal in the early 1830's. In 1847, it was used to build the Smithsonian Institution Building in Washington, D.C. The stone is readily carved and chiseled when first quarried but later hardens on exposure to air. There is a tendency of the rock to spall if laid "on edge," therefore, careful placement was required.
8."Potomac Marble"..... also known as "calico rock" or "Potomac Breccia," is a multi-colored conglomerate of Triassic age and is composed of rounded quartz and limestone pebbles cemented in a calcareous matrix. Benjamin Latrobe first reported finding this rock in 1815. This stone, probably quarried from Montgomery County, was used for the twenty-foot columns in the old U.S. House of Representatives (now Statuary Hall). The stone was quarried primarily in Frederick County, most extensively along the Potomac River, near Washington Junction.
9, Wakefield Marble..... a variegated marble used for altar fronts and interior decorations was quarried in Carroll and Frederick Counties. The colors range from "deep red," "salmon," "lavender veined," "undulated pink and white," "ruby" to black to white. The marble's variety of color was its drawback, as it was neither consistent nor predictable. The marble was worked around the turn of the 20th century.
10. Serpentinite..... a patterned rock occurring in various shades of green from pale leek to greenish black that has been used both as a building stone and as a sawed and polished ornamental stone. Serpentinite from Baltimore County was used to build the Mount Vernon Place Methodist Church in Baltimore City. Cut and polished, it is also known as "Maryland Green Marble" or "verde antique." Stone from Broad Creek was shipped to New York and was used in the Empire State Building in New York City.
11. Sykesville Gneiss..... a dark gray, often schistose gneiss with a roughly rectangular fracture pattern is currently being quarried near Potomac in Montgomery County and was at one time used extensively in the Washington, D.C. area for foundation and rubble stone. The stone was first worked commercially as "granite" about 1850. The early settlers in the Washington area used many of the schists and gneisses found along the Potomac River. This Sykesville stone may be what was once known as "Potomac Bluestone."
12. Setters Quartzite..... a thinly layered tan quartzite that has been used for many years as a flagstone and as building material. Tourmaline crystals are often present on cleavage surfaces. The stone has become popular in recent years for use in many of the houses and buildings in Towson and Baltimore. It is currently being quarried near Marriottsville in both Howard and Baltimore Counties.
13. Paleozoic Sandstones..... four sandstone beds which range in age from Silurian to Mississippian have been quarried in Western Maryland for use in that area. The Tuscarora sandstone has been used for foundation stones and trim in many of the older buildings at Cumberland. The Oriskany, a yellow to buff sandstone was also widely used there; however the stone is soft and tends to disintegrate with time. Currently, both the Pocono, a thin-bedded brown sandstone, and the Pottsville, a massive gray conglomeratic sandstone, have limited use for flagstone, building facing, and rubble stone.
Many other rock formations were used throughout Maryland for building material. Often these were simply rocks picked up near the site of construction and are termed "fieldstone." Initially, most building stone was obtained this way, but about 1825 technology and transportation had developed to the point that it was feasible to quarry stone at specific sites. 6
Permission received from the Eric Mottola Patapsco Valley State Park Maryland Department of Natural Resources for this cache.
* The listed trailhead does not have parking but is great if you are on foot or being dropped off. This trail runs just outside a hunting area.
* The Church Trail trail head is nearby on Old Court Road and the church may allow parking. The longest route in is from the park.
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CONGRATULATIONS - First To Find - _bw_
Second To Find - ???????
Third To Find - ???????
Sources:
1 https://en.wikipedia.org/wiki/File:MDGeoReg.PNG
2. https://www.geocaching.com/geocache/GC2YD2P
3. httpsearthathome.orghoemapsne#maryland
4. https://en.wikipedia.org/wiki/Woodstock_Quartz_Monzonite
5. Maryland Geological Survey - Resource Assessment Service - Maryland Department of Natural Resources
6.http://www.mgs.md.gov/geology/building_stones_of_maryland.html
