Volume 43 | Number 2 | Spring 2013

Paul Link and Diana Boyack, geosciences digital mapping lab supervisor and long-time geotechnical advisor, on production of the Idaho geology map.

ISU Photographic Services/Susan Duncan

Man-Hours Make A Map

Spring 2013 Issue | By Andrew Taylor

The new geological map of Idaho, a work of both "art and science," was released last fall from the Idaho Geological Survey and was created with extensive input from Idaho State University.

The first geologic map of Idaho in 35 years, called "a perfect wall poster" by one of its creators, the map has been compiled from nearly 100 sources, including work from Idaho State University, the U.S. Geological Survey (USGS), Idaho Geological Survey and the University of Idaho.

"This map updates our understanding of Idaho geology," said Idaho State University geosciences Professor Paul K. Link. "It is a map that is of poster size, can hang on walls in schools and classrooms and makes Idaho geology accessible to the general public."

Geologic maps — in addition to showing regular features like mountains, rivers, plains, towns and roads — include details on the distribution, nature and age relationships of rocks, faults and strata.

The map, its graphic cross sections of the Earth's crust and accompanying booklet on rock layers and layering represent 12 years of compilation and editing by Link, former ISU graduate student Sean P. Long (now at the University of Nevada Reno), Reed S. Lewis and Loudon Stanford of the Idaho Geological Survey at the University of Idaho in Moscow.

Link noted that ISU's input was critical in creating the map. The new map has its roots in ISU's Idaho Digital Atlas project, which was an ISU project that created new geological maps for counties in Southern Idaho. The initial compilation for the Digital Atlas of Idaho was funded by an Idaho State Board of Education Technology Incentive Grant and a National Science Foundation grant to Link.

For the new geologic map of Idaho, Link was responsible for creating the portion of the map that covers most of southern Idaho. He was assisted by Long, who was responsible for compiling the geology south of Pocatello in the Malad area.

"Long's work was totally new. We had never compiled a geologic map of the geological feature, the Malad City Sheath," Link said. "He put together unpublished data to make a coherent map sheet that became part of this project. We had a bunch of ISU graduate students who worked on it and it helped develop their careers."

Long was a master's student from 2002 to 2004 under Link's advisement. He mapped an area southeast of Malad City for his master's project. After graduation he stayed on at ISU as an adjunct instructor, and worked on several other mapping projects with Link and other ISU geosciences faculty members, including David Rodgers, associate dean of the College of Science and Engineering, and former ISU geosciences chair.

"There were several new maps that came out in the few years preceding this, in particular a series of USGS maps of central Idaho, so I sized them to fit our compilation, simplified the map units to fit the compilation and traced out the line work," Long said. "The end product of my work was a substantially-revised draft of the geology of southern and eastern Idaho."

Other ISU students played lesser, but still valuable roles in the map's creation. One who contributed is James Blair, who is now a geoscientist working for the Bureau of Land Management in Delores, Colo. Blair was an ISU graduate student from fall 1998 to December 2001. During that time he helped create the geologic map of Wakley Peak Quadrangle in Southeast Idaho with Link and another student, Arron Pope.

"This map contributed a tiny fraction of the geology that wound up in the new state geologic map of Idaho," Blair said. " I also worked on the Digital Atlas of Idaho in 2001 as I was finishing my thesis. Most of the work I did on the Digital Atlas was digitizing, computer tracing existing geological maps of Idaho counties at an appropriate scale. I never had any idea at the time that the work I was doing would be used to help compile a new geologic map of Idaho."

At first glance, a casual onlooker might not be cognizant of how much work went into creating the new map.

"The map represents a summary of several tens of thousands of person-hours of work by hundreds of field geologists on dozens of smaller maps, each with a slightly different opinion of what is going on," Blair said. "Making the edges of each map line up with its neighbor is a tremendous undertaking.

"Just how difficult is hard to understand unless you have done it," continued Blair. "Deciding what to take out was just as tough as what to leave in. The level of detail on this map is great, without making it too busy. Aesthetically, the map is great too, one of the best I have seen. It is truly a work of both art and science. Few states are geologically as interesting as Idaho, and now Idaho has a geologic map that really does it justice."

Link said the map should be of interest to a wide variety of people.

"Anybody that is doing anything with natural history or geological hazards, from rivers to earthquakes, needs to refer to this map," Link said. "It contains the most recent information on a lot of these issues."

The new map is available in both print and GIS formats, the latter of which allows online users to query the map's database to locate such features as active faults and specific types of rocks. A booklet of explanatory information accompanies the map and includes an index of the map's many sources, which can be consulted for more detailed geologic information.

The new Idaho Geologic Maps may be purchased through the Idaho Geological Survey. Cost is $20, plus any shipping and handling if mailed.

For more information, visit www.idahogeology.org, send an email to igs@uidaho.edu or call (208) 885-7991.

It can also be purchased at the Idaho Museum of Natural History.