This document discusses how climate and rock type impact the rate of weathering. It provides examples of the Hoffman Drainage Tunnel (concrete) and Cleopatra's Needle (granite) and how their appearance has changed over time and location. Specifically, it notes that Cleopatra's Needle, which was constructed in 1500 BC in Alexandria, Egypt and moved to New York City in 1881, shows more weathering in NYC due to the differences in climate between the two locations. It also discusses comparing the weathering of granite and marble gravestones from 1888 and 1885, noting that marble weathers faster.

1. Hoffman Drainage Tunnel (concrete)

4. Hoffman Drainage Tunnel
Record Observations:
What caused these changes?

5. Variables that impact
the Rate of Weathering
Climate
Rock Type
• Before moving on, discuss and record
hypothesize on how these variables would
impact the rate of weathering.

6. Cleopatra’s Needle (Granite)
3500+ years old, constructed ~ 1500BC
CLIMATE
Alexandria, Egypt – moved to NYC in 1881 100 years later: Central Park, NYC - 2005

7. Record Observations:
How would climate differ in New York City in comparison to Alexandria, Egypt?
How would these differences impact rates of weathering?
New York City
Alexandria, Egypt

8. ROCK TYPE
Same cemetery, different types of rock!
1888: Granite 1885: Marble
Record Observations:
Which type of rock weathers faster?
List evidence.

9. Field Trip Extension
• Visit a local cemetery OR
• Take a walk and observe building
materials.
– Do you see examples of some features that
have been weathered to a greater degree
than others? Record your observations.
– What can you hypothesize accounts for
differences in the rate of weathering among
these features?