The Distribution Pattern of Obsidian around Glass Mountain

1
The Distribution Pattern of Obsidian around Glass
Mountain

• By, Alexander Titus Jack Preston
• 6th Grade
• 3rd Quarter
• Robert Louis Stevenson Middle School

2
Introduction

• Background Information
• Glass Mountain was a volcano a long time ago.
  When it erupted the lava soon cooled and formed
  obsidian.
• Obsidian is a black, shiny rock that almost looks
  like glass. Wappo Indians, a native tribe, used
  obsidian by carving it into a point called an
  arrowhead.
• Glass Mountain is on N Silverado Tr. Its just
  passed Deer Park Rd. Many people have passed it
  going to Calistoga on Silverado Tr.

3
Introduction Cont.

• Testable Question
• What is the distribution pattern of obsidian
  around Glass Mountain?
• Hypothesis
• Our hypothesis is that the most obsidian will be
  on the east side of Glass Mountain. (on Deer Park
  Rd.)We think this because its the steepest slope
  and all the obsidian will tumble to the bottom of
  the hill.

4
Introduction Cont. 2

• Experimental Variables
• The experimental variables are the different test
  sites.
• Constant Variables
• The constant variables are Glass Mountain and the
  amount of the samples.

5
Materials

• Shovels
• Compass
• Double-sided plow
• Gloves
• Scale
• Plastic bags
• Sharpie/ pencil
• Metal sieve
• Big metal spoon
• Binder paper
• Newspaper
• Map

6
Procedure

• 1)Map out area.
• 2)Indentify study sites.
• 3) Collect at least 1 kg. of test soil into the
  bag.
• 4) Label the bag with the place the sample was
  taken.
• 5) Repeat procedures numbers 2-4 until there are
  nine soil samples including the control.

7
Procedure Cont.

• 6) Dry the soil samples in the sun for 24 hours
  to get rid of excess moisture.
• 7)Use a kitchen scale to weight 1 kg of each soil
  sample.
• 8)Filter each soil sample using 1 centimeter
  square metal sieve to separate the obsidian.
• 9) Weigh the obsidian left in the sieve.
• 10) Repeat steps 7-9 for each sample.
• 11) Record results.

8
Observation and Data
Date Soil Sample Total Weight Weight Of Obsidian of Obsidian in soil
3/18 Titus Vineyards 1 kg. 0.25 25
3/18 South-East Glass Mountain 1 kg. 0 0
3/18 North Side Glass Mountain 1 kg. 0.67 kg. 67
3/18 Hillside- Lodi Lane 1 kg. 0.06 6
3/18 End of Swanston Rd.- hilltop 1 kg. 0.05 5
3/18 East Deer Park 1 kg. 0 0
9
Observation and Data Cont.
Date Soil Sample Total Weight Weight of obsidian of obsidian in soil
3/18 North-West Swanston Rd. Hillside 1 kg. 0.125 12.5
3/18 North-west wall, front of Duckhorn winery 1 kg. 0.750 75
3/18 Control Markham Vineyards West of Napa River 1 kg. 0 0
10
Data Graph
11
Data Analysis

• One of our observations based on the soil samples
  is that not all sides of Glass Mountain have the
  same concentration of obsidian.
• We found that two of the highest samples of
  obsidian were found at the North-West side of the
  mountain.
• Soil samples and visual observations on the North
  West side showed that Glass Mountain has
  contributed to the distribution of obsidian
  spreading towards the Napa River.
• We found no obsidian in the East and South-East
  of Glass Mountain.
• Our control soil sample, west of the Napa River,
  on Markham Winery did not have any obsidian.

12
Conclusion

• From analysis of the soil samples we discovered
  that our hypothesis was incorrect. Our hypothesis
  was that most obsidian would be found on the east
  side of Glass Mountain. It turned out obsidian
  was found mostly at the North West side of the
  mountain. We think this is because a) there is
  more concentration of obsidian on the North side
  of Glass Mountain b) the north side of Glass
  Mountain may be more susceptible to weathering
  and erosion and thus, obsidian is found at the
  upper soil surface c) construction or human
  activity on the East side caused it to be moved
  or turned under the soil.
• We think this project has contributed to a better
  understanding of a) the distribution of obsidian
  at Glass Mountain b) the importance of Glass
  Mountain as a source of obsidian and its
  influence in the settlement of local Native
  Americans.
• Were we to repeat this experiment we would make
  sure to include more soil sampling and interviews
  with local historians and geologists.

13
Acknowledgement and Thanks

• Works-Cited-
• Google Maps. March 10, 2009. http//maps.google.
  com
• United States Geological Survey. March 10,
  2009. http//geomaps.wr.usgs.gov
• Stone Quarries and Beyond. March 10, 2009.
  http//quarriesandbeyond.org
• CA HomeTownLocator. March 10, 2009.
  http//california.hometownlocator.com
• We would like to thank Pierette Titus for all
  of the many things she helped us with. This
  experiment wouldnt have been possible with out
  her.