Earth History Field Experiences
By Ashley Griffith, Bellingham School District, Washington

Field-based experiences are a meaningful part of any science curriculum. The FOSS Earth History Course lends itself toward local investigations. During the second investigation, Grand Canyon Rocks, students learn and practice how geologists make sketches of rock outcrops, record their observations and collect rock samples. As a follow-up to the investigation, I arranged for my sixthgrade students to visit a local rock outcrop to gather information about the geology of our local area and to apply the skills they had learned in class.

THIS STUDENT RECORDS HER OBSERVATIONS (COLORS, TEXTURES, ETC.) OF THE LAYERS IN THE ROCK OUTCROP.

Students sketched the outcrop and recorded observations of the different types of rocks, just like they did from the photos and samples in Investigation 2. Students observed and recorded the colors, textures, and other features of the rocks and tested them with hydrochloric acid. Based on their observations, students tried to identify the rocks as sandstone, shale, or limestone. This fieldbased experience gave students the opportunity to observe and learn about local rock formations following their classroom experiences. The students felt like professional geologists! Following the field trip, students compared their local rock samples with the Grand Canyon rock samples in the Earth History Course.

THIS GIRL USES HYDROCHLORIC ACID TO TEST THE ROCK LAYER FOR THE PRESENCE OF CALCITE.

To support students, each adult chaperone had a folder with field trip tips for adults, equipment safety sheet for the hydrochloric acid, a list of adjectives helpful for describing rocks, and a list of characteristics helpful for identifying the rock type. In addition, each adult was responsible for carrying a set of acid bottles, safety goggles, and magnifying lenses to the site and checking them out to students. Each student had a clipboard with two sheets—one for doing their sketch and the other for recording their observations. These sheets were later inserted into their composition books in the classroom.

AFTER DOING THE ACID TEST ON SOME ROCKS, THIS STUDENT RECORDS HIS OBSERVATIONS.

See the Web version of this article at http://lhsfoss.org/newsletters/index.html for more information about the materials and supporting documents described in this article.

Ashley Griffith
Bellingham School District
agriffit@bham.wednet.edu