Visualizing Geology: A Case Study of the Baraboo Ranges, Wisconsin

Sunday 7:45am-5:00pm Baraboo Field Trip

Leaders

Stephen Marshak, University of Illinois at Urbana-Champaign

Tim Shipley, Temple University

Scott Wilkerson, DePauw University

A field trip to the Baraboo Ranges provides much more than a show-and-tell opportunity. It provides a unique opportunity to help students understand how to visualize geologic relationships at regional and personal scales, how to see what a geologist sees when looking at an outcrop, how to convey information about geology through the use of outcrop sketches, and how to relate geologic features to landscape features. During the course of the day, we will see excellent examples of: various rock types (quartzite, phyllite, breccia, conglomerate, and sandstone); a regional-scale asymmetric fold; spaced cleavage and cleavage refraction; primary sedimentary structures; small faults; veins; crenulation and kinks; parasitic folds and joints; the Great Unconformity (the Paleozoic/Precambrian contact); and glacial deposition and landscape modification.

Logistics

Departure: 7:45 a.m. from Weeks Hall (Univ. of Wisconsin)
Return: 5:15 p.m. to Weeks Hall
Equipment Needed: sturdy shoes (boots preferred / no sandals); notebook and pencils; sunscreen and insect spray; raingear; water; hardhats and lunch will be provided.
Releases: All participants will need to sign liability releases.

Location

The Baraboo Ranges are a classic geology field-trip destination for colleges and universities from throughout the upper Midwest (Dott and Dalziel, 1970; Mederis et al., 2011; Goodwin et al., 2013). The Ranges (a set of low hills that outline a bathtub-shaped basin) expose the Baraboo Syncline. This structure is a 35 km-long doubly plunging syncline that involves Proterozoic Baraboo Quartzite (a 1200 m-thick succession of quartzite and phyllite). Paleozoic strata were deposited unconformably on the Precambrian rocks, and a Pleistocene glacier flowed over the eastern half of the syncline and deposited a terminal moraine. Each year, hundreds of students visit the ranges to study aspects of general geology, stratigraphy, structural geology, and geomorphology.

Strategy

We will try to visit 6 outcrops during the course of the day. At each, participants will be asked to visualize and sketch the geologic features visible, with a focus on stratigraphy and structure. Then, we will discuss visualization issues, and teaching approaches to support student sketching and learning from sketching. Before leaving each outcrop, we will review geologic features and bring participants up to date on research concerning these features. At relevant stops during the day, we will discuss approaches to help students piece together outcrop-scale observations to yield a regional-scale tectonic synthesis. We will also discuss (and demonstrate) how to incorporate Google Earth™ and digital elevation maps (DEMs) into the field study and geo-visualization.