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Guilford Quartz Monzonite

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The Guilford Quartz Monzonite is a Silurian or Ordovician quartz monzonite pluton in Howard County , Maryland. It is described as a biotite - muscovite - quartz monzonite which occurs as discontinuous lenticular bodies which intrude mainly through the Wissahickon Formation ( gneiss ).

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33-669: The extent of this intrusion was originally mapped in 1940 as the "Guilford granite". It was given its current name in 1964 by C. A. Hopson. Hopson grouped the Guilford Quartz Monzonite with the Ellicott City Granodiorite and the Woodstock Quartz Monzonite as "Late-kinematic intrusive masses." The Guilford Quartz Monzonite was described in 1898 as "perhaps the most attractive stone in the state" by Edward B. Mathews of

66-827: A radiometric date of the Woodstock Quartz Monzonite of 420 +/-50 Ma ( Silurian ). In 1998, A. A. Drake reported an age of 444 Ma ( Ordovician ), and suggested it may be comagmatic with the Guilford Quartz Monzonite . Woodstock granite can be found in the United States Capitol , Thomas Viaduct , "the Library of Congress , the inner walls of the Washington Monument , the Old Patent Office , and

99-605: A railroad two miles long to connect with the Baltimore and Ohio at Putney and Riddle's bridge, about one mile east of Woodstock. Their first contract of importance was furnishing stone for the Baltimore Custom House . They, however, continued the business only a few years. Extravagance and mismanagement caused the failure, and they were succeeded by Edward Green and Joshua B. Sumwalt, under the firm-name of Green & Sumwalt. The senior partner dying about 1849, he

132-628: A short while, when he associated with him Wm. H. Johnson, of Baltimore, and they soon after formed with George Mann, Hugh Hanna, Messrs. Grey & Sons, of Philadelphia, and Mr. Hamilton of Baltimore, a joint stock company, calling it the Guilford and Waltersville Granite Co. This company is now (in 1898) conducting the business. "The two largest quarries were Waltersville and Fox Rock. These and smaller quarries counted hundreds of stonecutters among their employees." The quarries near Granite were "most active after 1875." In 1966, G. W. Wetherill reported

165-561: 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. 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

198-508: Is evidently intruded into the gneisses, is entirely enveloped by them and sends no dikes or apophyses into the surrounding rock. That the gneiss is really older than the granite is shown by the great number of inclusions found within the latter. These are chiefly of gneiss, and they occur often in huge irregular blocks six to eight or even ten feet in size, showing narrow rims due to contact metamorphism. They are beautifully puckered and wrinkled and being much richer in ferro-magnesian silicates than

231-615: Is made of these quarries. It is not certain whether the quarry on the Baltimore county side or the quarries of the Howard county side furnished the first material for Baltimore, but it is clearly evident from the character of the rock furnished for the Catholic Cathedral , that the gneiss was the more important rock at that time. Local tradition assigns the source of the stone sometimes to the Baltimore county side and sometimes to

264-544: The Patapsco River . The rock on the eastern, or Baltimore County, side is "a fine grained mass, with a decided foliation or gneissic structure," while the rock on the western, or Howard County side, is "more uniform and granitic." The text also refers to the figure of the polished slab on the left: "Here it also has a porphyritic structure in consequence of the development of large flesh-colored crystals of feldspar which are disseminated somewhat irregularly through

297-547: The Smithsonian building , twice passed by these quarries and yet makes no mention of them. At the time of the Tenth Census the agent remarks that he "knows of no other place in the country where there are so many stone buildings in an area of the same size." Mathews described recent (c. 1872-1898) operations at the quarries: Of the quarries in operation at the present day those of Werner Bros, were opened as early as

330-906: The Wissahickon Formation and the Baltimore Gabbro Complex . In 1964, C. A. Hopson grouped the Ellicott City Granodiorite with the Guilford Quartz Monzonite and the Woodstock Quartz Monzonite as "Late-kinematic intrusive masses." In 1980, Crowley and Reinhardt of the Maryland Geological Survey remapped the Ellicott City Quadrangle and referred to this unit as the Ellicott City Granite, rather than granodiorite. Hopson reported

363-493: The "Waltersville" and "Fox Rock." The former is the principal one, and was at first called the "Branch." This rock developed into a fine ledge, surpassing all the granite around in quantity, quality and easy access, so that all the boulders in which Sweatt, Putney and Riddle were interested were at once abandoned. After working it for a year or two Putney and Riddle obtained a lease of this quarry for twenty years in August, 1835, from

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396-453: The Guilford Quartz Monzonite yielded an age of 362 +/- 3 Ma ( Devonian ). Ellicott City Granodiorite The Ellicott City Granodiorite is a Silurian or Ordovician granitic pluton in Howard and Baltimore Counties, Maryland. It is described as a biotite granodiorite along the margin of the intrusion which grades into a quartz monzonite in its core. It intrudes through

429-456: The Howard county side and the published information is equally conflicting and indefinite. When the Cathedral was constructed during the years 1806 to 1812 and subsequently from 1815 to 1821, the material was hauled from Ellicott City to Baltimore along the old Frederick road in huge wagons drawn by nine yoke of oxen . After furnishing the rock for this building, which must have been one of

462-427: The Maryland Geological Survey. Mathews described the mapped extent of the granite and inclusions of gneiss within it as follows: The granite mass as indicated by the map forms a more or less oval, isolated area of granite extending scarcely two miles northeast and southwest and a mile northwest and southeast. Although so small, it is one of the most important economic areas within the state. This mass of granite, which

495-469: The Maryland Geological Survey. He provides this detailed description of the granite: The rock of this area differs from all of the other granites of the state in the persistent presence of both light and dark colored micas . Thus, according to the German classification, it is the only "true granite" in the state. Other granites may have muscovite as a constituent, but it is not so abundant or typical as in

528-537: The Woodstock Quartz Monzonite with the Ellicott City Granodiorite and the Guilford Quartz Monzonite as "Late-kinematic intrusive masses." Woodstock granite has been used in the Capitol Building , the Library of Congress , and in buildings in Baltimore. The Woodstock Quartz Monzonite was described in 1898 as "perhaps the best granite in Maryland for general building purposes" by Edward B. Mathews of

561-415: The beginning of the century. In 1872 Charles J. Werner reopened a quarry, which since his death in 1888 has been operated by his sons, who purchased in 1890 a second quarry, which had previously been opened by Robert Wilson. These quarries became of some importance in 1893, when one of them is spoken of as the principal Ellicott City quarry, although it is now producing little or no building stone except during

594-508: The chemical composition (by %) of the Ellicott City Granodiorite from two locations. H7-A is on River Road, 0.3 miles east of the Patapsco River Bridge, Ellicott City, and H18-1A is on U.S. Route 29 , 200 yards south of U.S. Route 40 . The 1898 account of Edward B. Mathews of the Maryland Geological Survey of the quarries at Ellicott City begins with a statement that there were two quarries; one on either side of

627-473: The fall of the year when random rubble is quarried for local use. The output for the year 1896 did not aggregate over 200 perches . The most active quarry at the present is that operated by A. Weber. This quarry is situated on the Howard county side some distance below the station. The material has been furnished in recent years for some important buildings, as those of the Woman's College of Baltimore , but most of

660-475: The granite itself, their irregular outlines contrast sharply with the lighter background. Mathews described the granite itself as follows: The appearance of the Woodstock granite is well represented in ( the polished slab shown at right ) which reproduces the polished surface in natural size. The color of the rock is bright gray, with something of a luster imparted by the quartz and the unaltered feldspars ,

693-424: The largest individual areas in the rock mass, sometimes reaching 0.15-0.2 of an inch (4-5 mm.) in diameter, while the clear transparent grains of quartz average less than 0.01 of an inch (.03 mm.). The individuals are interlocked in a mosaic, which indicates that the rock can well withstand any pressure to which it may normally be subjected. The mica flakes are small and evenly disseminated, so that they do not injure

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726-478: 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

759-531: The local quarrying industry circa 1820." The 1898 account of Edward B. Mathews of the Maryland Geological Survey of the quarries at Granite (formerly known as Waltersville) begins with boulders attracting the attention of "several enterprising men from New Hampshire," (Sweatt, Putney, and Riddle) who commenced quarrying operations about 1832-33, and supplied stone to the Baltimore and Ohio Railroad. He continued: Although prospecting has been carried on ever since, only two ledge quarries have been discovered, viz.:

792-470: The material seems to be used for Belgian blocks , curbing and macadam . In 1973, M. W. Higgins reported a radiometric ( Rb-Sr age ) of 425 Ma, which placed the Ellicott City Granodiorite in the Silurian . In 1998, A. A. Drake revised the age to Ordovician based on the granodiorite's relationship with the Woodstock Quartz Monzonite . Woodstock Quartz Monzonite The Woodstock Quartz Monzonite

825-473: The most important stone structures in the United States at the time of its construction, the quarries evidently were worked only to meet local demands. In fact they have never since been of such relatively great importance. Dr. David Dale Owen , indeed, while studying the various building stones of Maryland at Cockeysville , Woodstock and Port Deposit , with the view of gaining all the information for

858-604: The naked eye. The polished surfaces, such as are represented in ( the same figure ), are darker than the rough or ashlar finished stone. Hopson reported the chemical composition (by %) of the Woodstock Quartz Diorite from the "Sylvan Dell Quarry" (probably the Waltersville Quarry) in Granite, Maryland, as follows: The Walters/Blunt family of Waltersville (later Granite, Maryland) "founded

891-503: The operations of Messrs. Matthew Gault and Sons, who commenced work in 1893, and by Messrs. Brunner and White, who opened a quarry of superior quality in March, 1895. A. A. Drake argued that the Guilford is of Ordovician age because it is probably comagmatic with the Woodstock Quartz Monzonite dated at 444 Ma. An earlier source gives the date of 420 +/-50 Ma. More recently, radiometric dating ( U-Pb - TIMS ) of zircon crystals extracted from

924-417: The outbreak of the civil war in 1860. During the succeeding twenty-five years the operations were of little account, and little work was done until the Guilford and Waltersville Granite Company attempted to develop the industry in 1887. This effort lasted but a short time as all of the machinery was removed from the quarries in 1889. The industrial life of the district has been revived somewhat in recent years by

957-529: The owner, Captain Alexander Walters, to whose family this quarry has belonged for more than a century. It is called in the lease and is still known as the Waltersville quarry, although the name of the village of Waltersville was changed to Granite about 1873-74, when the first post-office at the place was established. The lessees went to work vigorously, and besides many other improvements, built

990-677: The polish which may be given to the rock in preparing it for monumental purposes. Hopson reported the chemical composition (by %) of the Guilford Quartz Diorite from 1.5 miles west-southwest of Guilford along the Middle Patuxent River, as follows: The 1898 account of Edward B. Mathews of the Maryland Geological Survey of the quarry at Guilford (now within the town of Columbia ) is as follows: The quarries at Guilford were originally opened about 1834, and were worked almost continuously from that date until

1023-482: The present instance. Both of the micas are products of the original crystallization of the molten rock magma, and they are frequently in parallel growths. The biotite , which is especially rich in iron, possesses a very dark color, but shows no evident disintegration or decomposition. The feldspar is almost entirely microcline , which shows the cross- twinning very clearly, and appears clear and fresh with very few included flakes or small crystals. These microclines form

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1056-447: The rock, as shown in (the figure) ." Mathews continued with a description of their historical importance: The time of opening these quarries dates back probably into the last of the 18th century, but the details are entirely wanting. The beautiful appearance of some of the more uniformly porphyritic specimens early attracted attention, and in the earliest works which we have on this area, that by Dr. Hayden published in 1811, mention

1089-406: Was succeeded by his son Frederick, and the firm became Sumwalt & Green, who conducted the business until 1865, when Attwood Blunt, whose wife owned the property, took charge and continued the business until 1871, when the quarry was leased to Ansley Gill and James McMahon. After a lapse of about sixteen years, the firm was dissolved by the death of McMahon. Mr. Gill continued the business alone for

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