Exploring Wisconsin Geology
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UW Green Bay Lifelong Learning Institute January 7, 2020 Exploring Wisconsin Geology With GIS Mapping Instructor: Jeff DuMez Introduction This course will teach you how to access and interact with a new online GIS map revealing Wisconsin’s fascinating past and present geology. This online map shows off the state’s famous glacial landforms in amazing detail using new datasets derived from LiDAR technology. The map breathes new life into hundreds of older geology maps that have been scanned and georeferenced as map layers in the GIS app. The GIS map also lets you Exploring Wisconsin Geology with GIS mapping find and interact with thousands of bedrock outcrop locations, many of which have attached descriptions, sketches, or photos. Tap the GIS map to view a summary of the surface and bedrock geology of the area chosen. The map integrates data from the Wisconsin Geological & Natural History Survey, the United States Geological Survey, and other sources. How to access the online map on your computer, tablet, or smart phone The Wisconsin Geology GIS map can be used with any internet web browser. It also works on tablets and on smartphones which makes it useful for field trips. You do not have to install any special software or download an app; The map functions as a web site within your existing web browser simply by going to this URL (click here) or if you need a website address to type in enter: https://tinyurl.com/WiscoGeology If you lose this web site address, go to Google or any search engine and enter a search for “Wisconsin Geology GIS Map” to find it. There are other geology maps out there, but look for the one branded as the state outline with the rock hammer inside. Basic use instructions The GIS map is easy to use no matter what device you choose to use it on. Once you open the map/web site, you need just three basic skills to interact with it: 1) Zoom in to your area of interest a) On a desktop computer, your mouse wheel works great to ‘zoom in/out’. b) On a tablet or smartphone, you can “pinch to zoom” or tap the GPS button to zoom to your location. 2) Click or tap on the map to view popup information about the geology of the area a) Tap anywhere to view a popup summary of the bedrock and surface geology for that location. b) Tap specific map features such as outcrops to view information about it. 3) Use the map layer list to turn on or off map layers and to hone in on the geologic information that interests you the most. 2 Exploring Wisconsin Geology with GIS mapping That’s it! The basic functions are as easy to use as a Google Map. If you wish to dig deeper into the map, the Wisconsin Geology GIS map includes advanced features and tools (though none are difficult to use). Play with the buttons and see what happens, otherwise, you can read more about some of the advanced features in the appendix section of this document. Other tips, instructions, stories and news about this app can be found at my blog: https://wisconsingeology.blogspot.com GIS map link: https://tinyurl.com/WiscoGeology When first opened, the online GIS map will appear as shown below. 3 Exploring Wisconsin Geology with GIS mapping Course Goal The goal of this course is to look into the fascinating stories of Wisconsin’s deep past as told by geology. The instructor will speak of these stories and show you how to use the online GIS map as a new way to illustrate them. One idea behind this online mapping app is to let you discover the “geology of your backyard”. This map can serve as a field trip guide the next time you’re outdoors, even in your own neighborhood. The GIS map blankets the state with all sorts of geologic information that you may find interesting. This handout includes some topics we will explore in class. Neither this class nor this handout will cover everything there is to discover in the online GIS map (not even close!) The class and this document are intended to give you a start on how you can use the online GIS map on your own to learn much more about the state’s geology. The online map is a great companion to other books you might read about Wisconsin’s geology, including those recommended below. The instructor will ad-lib during class and dive into some topics not included in this handout. It is strongly encouraged that you use this GIS mapping app on your own after class to see what else it has to offer to you. Basic concepts and terminology: You may or may not have background knowledge of the geologic concepts and terms we will discuss in this course. The instructor will answer questions during class, but you are using the GIS map or reading this handout after class and you’re unclear of a concept or term, I suggest you use a search engine such as Google to learn more. Some of the terms used in this class and on the GIS map are specific to Wisconsin, others are more generic geologic terminology that you can find in standard textbooks. The online GIS map includes thousands of links to external resources as well. Some books that are beginner/intermediate level and focus on Wisconsin Geology: Great Lakes Rocks by Stephen Kesler, published in 2019 Wisconsin Rocks by Scott Spoolman published in 2018 Roadside Geology of Wisconsin by Robert Dott and John Attig published in 2004 Geology of the Lake Superior Region by Gene LaBerge published in 1994 4 Exploring Wisconsin Geology with GIS mapping Journey b ack through time For this course, we will start our journey in the present and work back through time, ending our journey through Wisconsin’s space and time in the Archean about 3 billion years ago. These Archean-age rocks are found in central Wisconsin and are are the oldest rock exposures you can find on the surface of the state (or almost anywhere on Earth for that matter). One reason to move in reverse order through time is because it is easier for most people to understand how the detailed landforms appear on the GIS app by comparing them to modern, familiar landscape features such as roadbeds and yard landscaping. Viewing these familiar features of the landscape first will help train your brain to see how landforms are abstracted and displayed in the GIS map. You’ll then be able to see and better understand natural landforms created by glaciers and other geologic processes. Older geologic landforms are usually less conspicuous on the GIS map’s LiDAR hillshade images than the new features because geological processes such as erosion had more time to erase evidence of past events. However, as you’re finding out, the GIS map has lots of underlying map layers and popups that will help you interact and understand these older and more obscure geological features as well. In this course, time is referenced using the Geologic Time Scale which is included in Appendix E of this document. Let the journey begin! 5 Exploring Wisconsin Geology with GIS mapping Cenozoic Era (Present → 66 million years ago) Quaternary Period (Present → 2.58 million years ago) Holocene Epoch 2 Present → 11,700 years ago. This is after the glaciers receded from our area. Many landform features visible on the LiDAR image on the Wisconsin Geology GIS map were shaped during the Holocene. This makes sense, since it is the most recent geologically-speaking. Humans have made a lot of changes to the topography. Some scientists have proposed the term Anthropocene as a new epoch which covers very recent time during which human activity has been the dominant influence on the environment (including geology and landforms). On the GIS map, we will explore the following features using LiDAR Digital Elevation Model (DEM) with the hillshade effect applied. Looking at these familiar topographic features on the GIS map will give you a sense of the detail the LiDAR data can reveal. Human-made landforms we will view on the GIS map in class: 1. City streets of Green Bay and the UWGB campus area 2. Quarries, freeway and septic (mound) systems along Church Rd east of Green Bay 3. Dredge spoils from the 1800s-early 1900s along the Fox River between Berlin and Princeton 4. Because people find this interesting, we’ll look at Native American effigy mounds. Use the Search function to find Koshkonong Mounds near Baraboo Does that give you a feel for how landforms appear on the GIS map? Let’s continue: Natural landforms from the Holocene or late Quaternary Period to view in class: 5. Lake level fluctuations, elevated shorelines including the Nipissing Great Lakes lacustrine features in Brown County a. Click the “Add Data” button then add the “Nipissing Shoreline in Wisconsin” map layer. Zoom and move around the map to explore the former Nipissing shoreline with the LiDAR elevation + hillshade. 6. In class we will discuss the history and formation of these and other landforms largely created during this time period, using the online GIS map as illustration. 6 Exploring Wisconsin Geology with GIS mapping Pleistocene Epoch 11,700 --> 2.588 million years ago. This is often referred to as the Ice Age. It is the most recent time that continental glaciers covered much of Wisconsin. On the GIS map, many landforms from the Pleistocene really stand out. Among them we will explore: 1.