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Norcross Quarry, Dorset, Vermont.  

Rock to Stone — Assignment   110316

Reading

Granites

Introduction

Use of the dimensional stone may range from random rubble or roughly coursed ashlar for foundations; to trimwork for splash courses, window and door openings, and steps; to entire exterior walls ranging from random rubble to coursed ashlar; to roofing slate – and many other applications.

The stone may be any rock type: igneous, metamorphic or sedimentary. Or you may select sediments, aggregate, products from the regolith used in building construction.

Rock

  1. Research mid-19th-centuryand late-20th-century state geological maps and publications (annual; special, industry-specific issues; maps of statewide surveys); U.S.G.S maps, historic annual reports, special reports.
    1. A main source for bedrock maps is geologic maps of US states, USGS. Go to a state, scroll down to "view" and download the <.klm> file to open in Google Earth.
  2. Select an area with information available about:
    1. bedrock or
    2. surficial geology
  3. View examples of examining outcrops, roadcuts, quarries.
    1. Marble,Cockeysville, Maryland, Geoblog, NVCC
      1. Use in construction of the Washington Monument, USGS
    2. Tonalite, Port Deposit, Maryland, Geoblog, NVCC
  4. Access a location of the source rock in the area (ideally the source for the building stone)
    1. Research the area geology and rock type(s) in advance.
    2. The location may be a quarry or gravel pit (abandoned or operating), outcrop, and/or roadcut that exhibits a similar rock type to that which was quarried and used.
    3. You will likely need a mason's hammer and chisel to obtain a sample.
    4. Wear protective eyewear whenever obtaining samples.
    5. Keep away from high and steep faces of rock (quarries, roadcuts, etc.), especially in the springtime as weathering during the winter may cause rocks to fall—on you.
    6. Develop your own hand-written description of the lithology w based on the selected site(s). Include:
      1. beds (if present)
      2. structure (folding, faulting, fracturing. etc.)
      3. weathering and erosion
      4. other factors affecting its appearance and condition
      5. large-scale description of the source
      6. close-up description of the rock (for use below for petrographic description)
      7. Include written description in report.
    7. Sketch location. Include sketch in report.
      1. Indicate major lithographic features
      2. Indicate photographed areas
    8. photograph the location/rock. Include:
      1. large-scale images of the source
      2. detailed images of the rock
      3. use a scale in the photographs. (No commercial products. Best to use a sclae/ruler, hammer.)
      4. Identify the views, including compass direction
    9. Obtain a representative hand sample.
      1. Sample size to be approximately 4" x 6" x 2".
      2. If necessary, obtain more than one sample.
      3. Shape sample on site so it exhibits a weathered surface and freshly exposed surface.
      4. Provide a label noting location, collector, date.
      5. Note: Do not plan of taking sample as carry-on baggage on any flight as it may be confiscated by TSA.
  5. Identify the location on:
    1. Google Earth or Google Maps, capturing a 640x480 image.
    2. Locate by latitude/longtitude
    3. Include select geological maps, citing the source
    4. Image captures to be at least 640x480 pixels; ideally 1024x786.
  6. Note mesoscopic (between microscopic and macroscopic; here: foliation and lineation, ussc) characteristics
    1. Identify Lithology w and Petrography w / w, including cited references as needed.
      1. Rock type w
      2. Grain/clast size w
      3. Mineralogy w / w
      4. Color(s) w, using Munsell Soil Chart
      5. Fabric w / w
      6. Texture w / w
      7. Small-scale structures w
      8. Weathering and erosion
      9. Surficial lithology w (as needed)
      10. Petrography w / w
        1. Mineralogy w
        2. Texture w
    2. Spatial and temporal identification
      1. Geological unit w
      2. Group name
      3. Formation name w
      4. Commercial name(s), if applicable
      5. Age w. Include:
      6. Era
      7. Period, with approximate date(s)
    3. Reference specific maps, scientific literature; cite source
  7. If applicable, note quarrying operations, name of quarry, owner and/or contact person.

Stone

  1. View examples of examing building stones, in situ.
    1. Building Stones of our Nation's Capitol, USGS
  2. Undertake a visual survey of masonry buildings in the area. Note:
    1. what local rock is employed
    2. how is it employed as a building stone
  3. Select at least one masonry bulding that exhibits characteristic treatment of local stone.
    1. Identify site/buildings by:
      1. name, historic and, if available name on National Register nomination
      2. address
      3. latitude/longtitude
      4. date of construction (and changes, if relevant)
      5. architect and builder, and
      6. other historical information
    2. Write a brief (one paragraph) architectural description of the structure. If listed in the National Register (or state survey) a description is available; Use and cite this resource, or others, as needed.
    3. In detail, describe the characteristics of the stone as it is employed for architectural purposes. Note:
      1. elements employing the stone (foundation, lintels, sills, quoins...)
      2. dimensions of stock
      3. quarrying (plug-and-feather...) and
      4. finishing techniques (quarry faced, pitched, patent hammer...) indicated by toolwork
      5. architectural and physical relation with design intent and construction of building
      6. physical condition (noting ways in which the material may be failing; and the causes). Note how the following affect performance:
      7. lithology
      8. structure: foliation, cleavage, fracturing, jointing afftects performance
      9. photograph, use scale in images
    4. Look around the neighborhood, town to see what other buildings employ the same stone. Talk to people in the community: local historians, craftspeople, monument dealers (who see stone monumental stone from all over the world, but who may still know a lot about historic stone industries in the area). Is there a "Quarry Steet," or other streets leading to historic industries?
  4. Look for local historic resources indicating quarries (reference citations, images, other sources; repositories):
    1. geological surveys
    2. maps (Henry F. Walling maps, Beer's Atlas, Sanborn Fire Insurance maps)
    3. postcards
    4. photographs
    5. surveys
    6. other resource

Report

  1. Prepare a report (for presentation) to include all the material above including, but not limited to:
    1. presentation graphic, to be plotted out
    2. written report with images (captioned, cited), footnotes, bibliography
    3. photographs of site work
    4. image captures of geological or topographic maps, historical materials and maps
    5. rock sample, with geological and topographical identification
    6. provide in digital form.

Presentation

  1. Bring in:
    1. report
    2. presentation graphic, to be plotted out
    3. rock sample(s), labeled