State of Maryland MARYLAND GEOLOGICAL SURVEY DEPARTMENT OF NATURAL RESOURCES Emery T. Cleaves, Director Educational Series No. 10 A GEOLOGIC WALKING TOUR OF BUILDING STONES OF DOWNTOWN BALTIMORE, MARYLAND by Sherry McCann-Murray with contributions and photography by the Environmental Geology and Mineral Resources Program of the Maryland Geological Survey October 2001 CONTENTS STATE OF MARYLAND Parris N. Glendening Kathleen Kennedy Townsend LIST OF WALKING TOUR STOPS AND ROCK TYPES ........................................ 1 Governor Lieutenant Governor INTRODUCTION .................................................................................................. 3 A message to Maryland’s citizens: STOP 1: THE GALLERY ........................................................................................ 5 The Maryland Department of Natural Resources is committed to educational STOP 2: LEGG MASON TOWER .......................................................................... 6 outreach and an informed public. The Maryland Geological Survey’s Educational Series supplements school curricula and provides general public information on a STOP 3: BANK OF AMERICA BUILDING ............................................................ 8 wide range of topics in the geosciences. STOP 4: 120 EAST REDWOOD STREET BUILDING ............................................ 9 Parris N. Glendening Governor STOP 5: MERCANTILE TRUST & DEPOSIT COMPANY BUILDING .................. 9 STOP 6: CALVERT STREET MONUMENTS ....................................................... 11 DEPARTMENT OF NATURAL RESOURCES STOP 7: CITY HALL AND VICINITY .................................................................. 13 J. Charles Fox Karen M. White Secretary Deputy Secretary STOP 8: WAR MEMORIAL BUILDING SCULPTURES ...................................... 13 STOP 9: DISTRICT COURT BUILDING .............................................................. 14 MARYLAND DEPARTMENT OF NATURAL RESOURCES 580 Taylor Avenue STOP 10: CITY OF BALTIMORE POLICE HEADQUARTERS ............................ 15 Annapolis, Maryland 21401 General DNR Public Information Number: 1-877-620-8DNR STOP 11: PARKING GARAGE ............................................................................ 15 http://www.dnr.state.md.us STOP 12: LOMBARD STREET SCULPTURES ..................................................... 16 MARYLAND GEOLOGICAL SURVEY SELECTED REFERENCES ................................................................................... 18 2300 St. Paul Street Baltimore, Maryland 21218 ACKNOWLEDGEMENTS ................................................................................... 19 General MGS Telephone Number: 410-554-5500 http://www.mgs.md.gov COMMISSION OF THE MARYLAND GEOLOGICAL SURVEY 2001 M. Gordon Wolman, Chairman ................................................................. Baltimore F. Pierce Linaweaver .................................................................................. Baltimore Robert W. Ridky ................................................................................... College Park James B. Stribling ............................................................................... Owings Mills © 2002 Maryland Department of Natural Resources i List of Maps and Figures Map 1. Maryland’s physiographic provinces........................................................ 3 Figure 10a. Polished “Rainbow Gneiss” on the west wall of the City of Baltimore Map 2. Route of the walking tour in downtown Baltimore. .................................... 4 Police Headquarters (Stop 10); photo width corresponds to a distance of about 12 feet. ............................................................................................... 15 Figure 1a. The Gallery entrance (Stop 1)................................................................ 5 Figure 10b. A close-up of the “Rainbow Gneiss” showing the banding and color Figure 1b. Fossiliferous limestone tiles on the lobby floor (Stop 1). ...................... 5 contrast of the metamorphic rock (Stop 10). .................................................. 15 Figure 1c. Granite on the outside wall of The Gallery. Rough “flamed” texture left; Figure 11. Man-made aggregate at the parking garage on Gay Street (Stop 11). .. 16 polished surface right (Stop 1). ....................................................................... 5 Figure 12a. Stone sculpture composed of light and dark gray Cambrian limestone Figure 1d. Pink granite (lower right) and gneiss (upper left) on the lobby floor of from Tennessee (Stop 12). ............................................................................ 16 111 South Calvert Street (Stop 1). ................................................................... 6 Figure 12b. Close-up of limestone sculpture in 12a, showing light gray calcite Figure 2a. Precambrian pink granite on the exterior plaza and portions of the Legg alternating with dark gray dolomite (Stop 12). ............................................... 16 Mason Tower (Stop 2). ................................................................................... 7 Figure 12c. Stone sculpture composed of gray and pink Ordovician limestone Figure 2b. Travertine on the exterior walls (plaza level) of the Legg-Mason Tower from Tennessee (Stop 12). ............................................................................ 17 (Stop 2). .......................................................................................................... 7 Figure 12d. Close-up of limestone in Figure 12c showing irregular contacts called Figure 3. Indiana Limestone (also known as Salem Limestone) on the exterior of stylolites (Stop 12). ....................................................................................... 17 the Bank of America building. ......................................................................... 8 Figure 4. Fine-grained granite showing two contrasting finishes: a smoother “bush hammered finish” (left) and a “rough point finish” (right); weathering of granite also shown at the corner of the smoother block (Stop 4). ............... 9 Figure 5a. Front of the Mercantile Trust & Deposit Company building (Stop 5).. 10 Figure 5b. “Seneca Red” sandstone in a textured layer between red bricks and as basal blocks of the Mercantile Trust & Deposit Company building (Stop 5). 10 Figure 5c. A “Spy Step” (Stop 5). ........................................................................ 10 Figure 6a. Battle of North Point Monument in Calvert Street (Stop 6). ................ 11 Figure 6b. Close-up of Cockeysville Marble used in the low stone wall surrounding the Battle of North Point Monument (Stop 6). .............................................. 11 Figure 6c. Wall of Georgia gneiss in small park north of the Battle of North Point Monument (Stop 6)....................................................................................... 12 Figure 6d. Monument to Negro Heroes of the United States (Stop 6)................. 12 Figure 6e. Dark gray granite on the pedestal of the monument (Stop 6). ............. 12 Figure 7. City Hall, faced with Cockeysville Marble (Stop 7). .............................. 13 Figure 8a. One of two horse statues made of Indiana Limestone (Stop 8)............ 13 Figure 8b. A typical worm burrow in the Indiana Limestone (Stop 8). .................. 14 Figure 8c. A burrow resembling one produced by modern “Callianasa,” a burrow- ing shrimp, in the Indiana Limestone (Stop 8); (Fayette Street side of the base of the south statue at the War Memorial Building). ...................................... 14 Figure 9. Anorthosite, a Precambrian-aged building stone from Minnesota, along the base of the District Court Building (Stop 9). ........................................... 14 ii iii LIST OF WALKING TOUR STOPS AND ROCK TYPES Stop 1 The Gallery East Pratt Street Lobby (interior) Sedimentary rock — tan and black limestones Building Exterior Igneous rock — pink to red granite Calvert Street Lobby (interior) Igneous rock — pink to red granite Metamorphic rock — gneiss Stop 2 Legg Mason Tower Igneous rock — pink granite Sedimentary rock — travertine Stop 3 Bank of America Building Sedimentary rock — Indiana Limestone (Salem Limestone) Stop 4 120 East Redwood Street Building Igneous rock — fine-grained gray granite Stop 5 Mercantile Trust & Deposit Company Building Sedimentary rock — “Seneca Red” sandstone Stop 6 Calvert Street Monuments Battle of North Point Monument Metamorphic rock — Cockeysville Marble Monument Park Metamorphic rock — Georgia gneiss Monument to Negro Heroes of the United States Igneous rock — dark gray granite Stop 7 City Hall and Vicinity Fayette Street Sidewalk (on the route to City Hall) Sedimentary rock — sandstone City Hall Metamorphic rock — Cockeysville Marble War Memorial Plaza Sedimentary rock — Indiana Limestone (Salem Limestone) Stop 8 War Memorial Building Sculptures Sedimentary rock — Indiana Limestone (Salem Limestone) iv 1 INTRODUCTION Stop 9 District Court Building Igneous Rock — anorthosite A rock is formed naturally on or inside the earth and is made up of one or more minerals. It is called a building stone once the rock is used in construction. Rocks Stop 10 City Police Headquarters are divided into three major groups—sedimentary, igneous and metamorphic—on Metamorphic Rock — Rainbow Gneiss the basis of how the rock formed. Sedimentary rocks are formed from sediments, such as gravel, sand, clay, or organic material, that have become cemented to- Stop 11 Parking Garage gether