Your are required
to attend one of the field trips.
Dates: May 7-9
or May 14-16
Each student must attend
one (and only one) of the two field trips. The field trip is to
Grand Canyon and surrounding areas in Arizona. It will familiarize
you with a broad range of concepts covered in lecture, lab and on
the problem sets. The first day will include examination of Sunset
Crater, AZ, a recently active volcano, and walking through the Permian
Coconino, Toroweap and Kaibab Formations that rim Grand Canyon.
The second day will include examination of igneous and metamorphic
rocks and an ancient erosion surface called the Great Unconformity
west of Seligman, AZ, followed by study of a volcanic formation
called the Peach Springs Tuff near Kingman, AZ, which records a
gigantic, explosive volcanic eruption that occurred 18 million years
ago. More details are provided below.
View
of Grand Canyon, from the South Rim, looking northwest, near the first
stop on the 2009 Ge 1 field trip this May. The horizontal layering
are strata deposited during the Paleozoic Era, between 543 and 250
million years ago. The dark cliffs in the deepest part of the canyon
in the lower left part of the photo are the eroded remains of a mountain
belt that formed 1.7 billion years ago.
Background:
The primary activities at each stop on the field trip will be:
(1) to listen to the instructor introduce the geologic features
and phenomena at each stop;
(2) mark on your copy of the Geologic Map of Arizona with the
location of the stop, and
(3) take a photograph of at least two of the features at each
stop, as listed on the itinerary below, with a total of not
less than 20 photos.
Your field report will be 12 pages total, including
(1) your annotated copy of the map;
(2) a ten-page section including two photographs on each page
presented in the order of the stops, with a caption of less
than 50 words below each photo; and
(3) a 1-page essay (<250 words) on the significance of
one stop of your choosing. Each photo caption should include
the stop number, geographic location, direction of view, description
of scale (for view shots where scale cannot be included),
the names and ages of key rock formations if they are defined,
and lastly a very brief explanation of what appears in the
photo. Where appropriate, you should annotate the photo itself,
either by hand or using Photoshop or equivalent.
2010 Field Trip Itinerary
Friday
09:30 p.m. Depart from Arms Circle on the Coconino Redeye Express
Stop 1-3, Intermediate Volcanism
(San Francisco Peaks, AZ)
5. Stratovolcano
6. Caldera
Stop 1-4, Erosion and Sedimentation (Grandview
Point, South Rim of Grand Canyon, AZ)
6. Disconformity (Redwall on Muav)
7. Angular unconformity (Tapeats on Unkar)
8. Nonconformity (Tapeats or Unkar, on Vishnu)
Stop 1-5, Sedimentation and Stratigraphy
(Hermit Trail, Grand Canyon, AZ)
9. Chert nodules in dolostone
10. Sponge (Actincoelia sp.) preserved in chert nodule
11. Productid brachiopod (Penciculauris sp.)
12. Spar-filled vug
13. Convoluted bedding in evaporite
14. Conformable contact between sandstone and dolostone
15. Eolian cross stratification
16. Wavy-bedded cross stratification
DAY 2 (Sunday)
Stop 2-1, Intrusion and
Metamorphism (Cross Mountain Road on-ramp to I-40, AZ)
17. Amphibolite gneiss
18. Metamorphic foliation and lineation
19. Porphyritic gneiss
20. Pegmatite
21. Intrusive contact (porphyritic gneiss into amphibolite
gneiss)
22. Intrusive contact (leucogranite into amphibolite gneiss)
23. Intrusive contact (pegmatite into leucogranite)
Stop 2-2, Weathering,
Erosion, Unconformities (I-40 roadcuts near Cross Mountain,
AZ)
24. Fluvio-marine cross-stratification in sandstone
25. Graded bedding
26. Nonconformity (sandstone on leucogranite)
27. Spherical weathering of granite
28. Pyroclastic fall (air-fall tuff)
29. Angular unconformity (pyroclastic fall on sandstone)
30. Basalt flow
