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Initial Publication Date: December 12, 2013

Introduction to the Black Canyon City Landslide

Kaatje Kraft (designed with Robin Paarlberg Fergason at Arizona State University for her Preparing Future Faculty Project)
Mesa Community College


Intended Audience: Community College students in introductory physical and environmental geology classes

Location:

Black Canyon City, AZ

Summary:

On this one day field trip, students will be exposed to some general introductory field methods by examining an active landslide. They will examine the relative ages of the units involved as well as identify the types of materials involved (bentonite, basalt, colluvium and alluvium). They will make an assessment as to what type of motion is occurring as well as a prediction for what types of hazards this may pose to the surrounding community.
Students examining an outcrop at the first stop of the field trip. (Fall 2004)

Context:

This field trip is designed for introductory level students (it works well with a balance from physical (101) and environmental (110) geology students). This trip can work for any number of students from 6-20, ideally pairing up students from the two different classes.

This field trip was an extra credit option for the students after the 101 students have been introduced to relative dating principles and geologic structures and the 110 students have been introduced to mass wasting processes.

This trip does require some bushwacking and steep ascents in portions. As a result, it is limited to people that are comfortable walking at least 2 miles. This is not on a marked trail, and can lead to interactions with aggressive vegetation and possible interactions with snakes and insects. Students with SEVERE fear of heights are discouraged from attending, however, students with some fear of heights have succesfully completed the field trip with minimal stress.

Goals:

By the end of the field trip, students should be able to answer (or, at the very least predict) the following questions:

  • What is causing this landslide to occur?
  • Is the landslide currently active?
  • Is this feature a threat to Black Canyon City?

Students share their ideas with the other participants on the trip and also have a better understanding of how geologists do work in the field.

Design:

Students stop at several locations along the trip. At the first few stops, they are asked to identify the different materials present in this landslide and describe them as well as sketch them. They also examine the relative age relationships to determine what is on bottom and what is on top (a little tricky as they're walking up section with faults intersecting).

After they're familiar with the materials, we ask them to determine which material is the most likely to cause motion.

At our final stop, they measure the fractures and describe the relationship to the vegetation. We also have an overlook to be able to see Black Canyon City below. We ask them to defend their positions of the type of motion (after a mini-lecture on the types of landslides--slump block vs. rotational) and predict the effect on the surrounding community.

Students completing assignments at stop three. (Fall 2004)

Notes and Tips:

I try to make sure that student are aware of rest stops (we stop at a local supermarket before we go out into the field, and we stop on our way home in case a flush toilet is needed) and encourage them to use the "outdoor facilities" if needed. A full itinerary is provided ahead of time.

The group is required to stay close together since it is not on a marked trail and it is easy to get lost. As a result, students stick together, help each other out, and have a more "bonding" experience overall.

Students are not allowed on the trip if they do not have appropriate (close-toed) footware and some water. It's also nice to have some cold water/gatorade waiting back at the van.

The "trail" follows a stream channel. Since it is a desert climate, it is dry most of the time. If a heavy rainfall has occurred or is likely to occur, this may not be safe.

This area continues to be developed and may become less accessible in the future.

Assessment and Evaluation:

Students hand in their field trip packet at the end of the trip--it is graded for accuracy and effort.

Materials and Handouts:

Field Guide (Microsoft Word 90kB Jun29 06)
Topographic map (Acrobat (PDF) 545kB Jun29 06)

References to Supplement Field Guide:

Excellent additional resources are available on the Arizona State University website.