Posts tagged GLC Programming
Geo Tour at Gratiot Lake
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Two pontoon sessions were needed to accomodate the number of participants for GLC board member and geologist Daniel Lizzadro-McPherson’s geo-tour at Gratiot Lake.

From the pontoon boat and at the GLC Preserve participants viewed the amazing topography of Gratiot Lake, a 10,000-year-old glacially formed plunge pool carved out of 960-million-year-old Jacobsville sandstone. The lake’s mountain-backed northeastern shoreline marks an important geologic boundary, the Keweenaw Fault. One-billion-year-old lava flows (known as the Portage Lake Volcanics) sitting high above the Gratiot Lake have been thrust up and over the younger Jacobsville sandstone. The Keweenaw Fault is inferred from the sharp change in topography and bedrock.

From the boat, Daniel was able point out the evidence of powerful forces that formed what on that summer day seemed a placid landscape. The group also visited the Gratiot Lake Conservancy land to identify shoreline pebbles and boulders and to picnic at the Noblet Field Station.

Daniel is in the process of mapping this specific segment of the fault as part of his Master’s thesis at Michigan Tech. He has done work on Keweenaw GeoHeritage, fieldwork on the Keweenaw fault to enhance the USGS EdMAP, and is a GIS analyst at Michigan Tech’s Great Lakes Research Center.

 

Part of the tour was put on YouTube by participant Robin Mueller and can be viewed at
https://youtu.be/adNNmZ1V3Bs


Below are related sources

Geologist Bill Rose’s Geoheritage website page about Gratiot Lake:  http://www.geo.mtu.edu/KeweenawGeoheritage/The_Fault/Gratiot_Lake.html

Geologist Bill Rose’s Geoheritage website page about Gratiot Lake:
http://www.geo.mtu.edu/KeweenawGeoheritage/The_Fault/Gratiot_Lake.html

How the Rocks Connect Us: A Geoheritage Guide to Michigan’s Keweenaw Peninsula and Isle Royale  , by Bill Rose and Ericka Vye with Valerie Martin.  This handbook is a comprehensive overview of underlying geologic features and their influence on human life and the history of the region. It has lots of photos and maps that clearly illustrate information presented. The text is concise and understandable so a geology degree is not required to understand it. Handy links to further information on the geoheritage website are with each topic and location highlighted. This book is available at some local stores, at the Keweenaw National Historical Park Visitor Center in Calumet, or from the Isle Royale & Keweenaw Parks Association at  https://irkpa.org/ .

How the Rocks Connect Us: A Geoheritage Guide to Michigan’s Keweenaw Peninsula and Isle Royale,
by Bill Rose and Ericka Vye with Valerie Martin.
This handbook is a comprehensive overview of underlying geologic features and their influence on human life and the history of the region. It has lots of photos and maps that clearly illustrate information presented. The text is concise and understandable so a geology degree is not required to understand it. Handy links to further information on the geoheritage website are with each topic and location highlighted. This book is available at some local stores, at the Keweenaw National Historical Park Visitor Center in Calumet, or from the Isle Royale & Keweenaw Parks Association at https://irkpa.org/.

Limnologist, Erick Elgin, Exotic Aquatic Plant Watch training at Gratiot Lake

For about 18 years GLC has participated in Michigan Cooperative Lakes Monitoring Program (CLMP). Since 2006 Dorothy Jamison has been taking readings of lake transparency on average 14 times a year. Every one to two years a water sample from the lake is sent to the state lab to detect the amount of phosphorus present. Overall at Gratiot no major changes have been noted in this monitoring data over the years.

In 2005 and 2006 botanist Janet Marr undertook a comprehensive survey of aquatic vegetation at the lake. The survey revealed that Gratiot Lake was home to good array of beneficial native aquatic plants. As a baseline that survey provides data for comparison in the future. Native aquatic plants provide food and habitat for a healthy community of animals in the lake, including a variety of fish, so the richness and variety of plant species found was a good health indicator for the lake. Janet even discovered one plant that is endangered in Michigan: Subularia aquatica, water awlwort. She didn’t find any aquatic exotic plant species, but recommended that the lake be monitored from time-to-time for any invasive plants before they become problematic.

In July, limnologist Erick Elgin, a water resource educator from Michigan State University Extension Service, came to Keweenaw County to lead an Exotic Aquatic Plant Watch (EAPW) training at Gratiot Lake. GLC recently joined this monitoring effort through the Cooperative Lakes Monitoring Program. CLMP provides this hands-on Exotic Aquatic Plant Watch training so that those interested in lake monitoring to protect their lake can learn how to do just that. This program targets five plant species that pose the biggest threat to Michigan waters: Eurasian watermilfoil, curly-leaf pondweed, hydrilla, European frog-bit, and starry stonewort.

The night before the training, Erick stopped by the GLC Members Meeting held in Eagle Harbor to give an overview of this monitoring program. EAPW is a yearly check-up for the potential entry into inland lakes of invasive aquatic plant species. Of this list, Eurasian watermilfoil is the most immediate threat to Keweenaw lakes.

You can view more info about EAPW on the MiCorps.net website. Go to the “Lake Monitoring” drop- down menu at the top of the page and click on “Lake Training.” Then click on “Exotic Aquatic Plant Watch.”

No invasive species were noted during the training or in sampling done afterwards.

After the EAPW training, Erick presented a lake issues Q&A program in Eagle Harbor. Most questions were about shoreline erosion, lake levels, dams, and floods, especially with regards to Lake Superior shoreline. Although no easy solutions for homeowners were presented, Erick provided the links below.

Pictured above are Erick Elgin (at right) and Keweenaw Invasive Species Management Area (KISMA) Coordinator Sigrid Resh and members of the KISMA weed crew sampling aquatic vegetation with a “weed rake” at Gratiot Lake during the EAPW training.

Pictured above are Erick Elgin (at right) and Keweenaw Invasive Species Management Area (KISMA) Coordinator Sigrid Resh and members of the KISMA weed crew sampling aquatic vegetation with a “weed rake” at Gratiot Lake during the EAPW training.

Sample for benthic flora species using the double headed rake tossing sampling method, aka the ‘weed rake"'.

Sample for benthic flora species using the double headed rake tossing sampling method, aka the ‘weed rake"'.