|Spring 2002 Volume LVII NO. 1|
2003 BOARD OF DIRECTORS
Paul Martin, President
Ken Barklind, Vice President
Judy Hamilton, Secretary
Ted Chura, Treasurer
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Kimball Memorial Banquet
Monday, May 5, 2003
***LOCATION NOT YET DETERMINED***
LOCATION TO BE ANNOUNCED AT THE LECTURES OR CALL
STEVE ERICKSON 651-501-9851 IN APRIL, FOR THE LOCATION
Dinner 5PM, Program 7PM
Topic: Role of Minerals in the Cultural
History of Minnesota
Speaker: Mark Jirsa, MSc
Minnesota Geological Survey
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“One of the Ely greenstone’s strangest characteristics is the presence of large ellipsoidal shapes in the body of the rock, like eggs embedded in aspic. Geologists know that this ellipsoidal structure is typical of lava flows that solidify under water, so we have strong reason to believe that the greenstone began its existence on the floor of some long-departed Minnesota Sea.”
~ Minnesota’s Rocks and Waters: A Geological Story, University of Minnesota Press, 1954
[Do you think they meant ‘pillow lava’? –Ed.]
1.Which sea is a back-arc basin?
a) Sea of Cortez, b) Sea of Galilee, c) Sea of Azov, d) Sea of Japan.
2.Where is earth’s crust the thinnest?
a) Continental Margins, b) Mid-Ocean ridges, c) Volcanic provinces, d) Impact craters.
3.Which element is strongly concentrated in the earth’s crust?
a) Thorium, b) Oxygen, c) Silicon, d) Platinum
4.What is the most common mineral in the earth’s crust?
a)Quartz, b)Illite, c)Olivine, d)Feldspar
5.What is the most abundant rock on earth?
a)Granite, b)Basalt, c)Shale, d)Limestone
6.What is the largest of earth’s lithospheric plates?
a)Pacific, b)African, c)Eurasian, d)Indian-Australian
7.What is the waste rock around an orebody called?
a)Groundmass, b)Graywacke, c)Gangue, d)Grit
(answers are listed after “Worms with a Copper Smile”)
The remaining lectures in the 2002-2003 series will be held in the Electrical Engineering & Computer Science Bldg. (EE Comp Sci) Room 3-210, just a few steps N.E. of Amundson Hall.
LABS will be held at the Minnesota Geological Survey office:
2642 University Ave. W., Saint Paul.
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Institute on Lake Superior Geology
49th Annual Meeting
May 7 – 11, 2003
The Institute on Lake Superior Geology is a non-profit professional society with the objectives of providing a forum for exchange of geological ideas and scientific data and promoting better understanding of the geology of the Lake Superior region. The 49th Annual Meeting will be held in Iron Mountain, Michigan. A two-day technical session will be held between pre- and post-meeting field trips. Geology students and interested non-professionals are welcome to attend. For information on registration, costs, field trip topics, and more, go to: www.ilsgeology.org
Or contact Laurel Woodruff, U.S. Geological Survey at firstname.lastname@example.org
Notes from the Board…
As the incoming president, I thank outgoing president Steve Erickson for his hard work and dedication during 2002. I am counting on his advice during the coming year as I attempt to live up to the high standards he and previous presidents have established. I also thank those outgoing board members for their service. They are: Katy Paul, William Robbins, Gail Marshall, and Steve Erickson. I am pleased to report that all of these will remain active in GSM . We welcome a number of new or returning board members: Cindy Demers, Marlys Lowe, Bill Farquhar, Ken Barklind, and Tom Smalec.
One of the main ways we reach the public at large occurs during the Minnesota State Fair. I doubt we have ever counted the number of people who visit our booth in the Education Building, but it must be hundreds per day! The booth is crucial to our program, and must be maintained and strengthened.
One of our goals this year is to update the booth, and we are very grateful to Don and Nora Mattson for donating $1000 to help jump-start this project! If any members have ideas on how the booth can be made better, ( more informative, more eye-catching, and more interesting ) please contact me or Tom Schoenecker, who presently chairs the State Fair committee.
Another vital part of what we do is the popular series of lectures and labs between October and May each year. These are in addition to the three or four field trips which we organize annually.
The success of these programs over the last two decades, and more, is due in large part to the work of Rick Uthe. Rick takes ideas and topics suggested by board members and forms them into a very coherent organized series of lectures. Kudos to Rick, and thanks to the board for recognizing how vital he has been to GSM. As many of you know, the 2002 board voted to give Rick an honorary lifetime membership. At our January 13 meeting, a certificate was presented to Rick, which said in part : “We are grateful for the vital work which he has done for us during the last twenty-plus years, and hope he will continue to be an active member in the future.” Thanks Rick for all you do!
~Paul Martin, President
Southern Minnesota Well Water Turns Black
Wells throughout southeastern Minnesota and adjacent areas of Wisconsin and Iowa suddenly began producing black water in early November, 2002 -- an effect that may be related to a Richter 7.9 earthquake in Alaska on November 3.
While no shaking was felt by people in the region, well drillers and environmental monitors interviewed by the Mankato Free Press blamed the water change on manganese released from the area’s sandstone, limestone and dolomite bedrock by waves from the Alaskan tremor. One well-driller quoted by the newspaper said a similar effect occurred in the region following the historic Good Friday Alaska quake of 1964, adding that the Good Friday quake also caused some wells in the Owatonna-Waseca area to dry up and old wells to start flowing again.
Val W. Chandler, Acting Director of the Minnesota Geological Survey, said quakes of magnitude 8 or higher are well known to cause changes in groundwater thousands of miles from the epicenter.
“Unusually large earthquakes produce very low-frequency oscillations or waves that travel world-wide at the earth’s surface, and these waves can essentially squeeze aquifers like a sponge as they pass through,” Chandler explained. “Distance from the epicenter and the intervening structure of the crust and mantle may also play a role in focusing this very low frequency energy, so that the effects may not necessarily be evenly observed.”
Reports of discolored water in the Mankato area were in fact spotty and inconsistent. While in some localities all the wells were affected, in other areas the discoloration was found in only a few wells. Black water was reported across a wide swath of southeastern Minnesota, northeastern Iowa and southwestern Wisconsin, but not in the Twin Cities area.
Mankato-area residents said they normally do not see any effects in their wells from major California quakes, and Chandler said that was because California earthquakes aren’t as strong as those in Alaska.
“Magnitude and total energy released is probably the major factor,” Chandler said. “At least part of the reason that no water well effects have been observed in association with California quakes is that (thankfully) no magnitude 8 events have occurred there in recent history.”
State officials recommended that people not drink the discolored water or give it to livestock. Well experts said allowing taps to run for a day or two usually cleared the black water from home and farm systems.¨
NEW GSM ROCK AND MINERAL COLLECTIONS
The GSM is excited to announce it has two new additions to its growing family of rock and mineral collections: the St. Louis County, Minnesota Bedrock Collection, and the Ashland County, Wisconsin Bedrock Collection. These collections are perfect for the beginner or the veteran looking for hands-on material.
The Ashland County, Wisconsin Bedrock Collection contains six rock specimens from outcrops in the county. It includes a fine example of an intrusive breccia, and beautiful black gabbro
Banded jasper, and the infamous Ely Greenstone are just two examples of the six specimens included in the St. Louis County, Minnesota Bedrock Collection.
Both collections are packaged with a descriptive key in a handsome, six-compartment polystyrene box.
Other rock and mineral collections available both to members and non-members are the Stearns County, Minnesota Granite Collection, and the Common Minnesota Minerals #1 Collection.
The price of each collection is $10 for GSM members and $15 for non-members. (Shipping and tax are included.)
If you would like to own one or all of these collections, send your order along with a check payable to the GSM to:
Geological Society of MN
c/o Bruce Goetteman
16125 Delarma Drive
Carver, MN 55315
If you have questions, Bruce can be reached by phone at this number: (952) 448-5422. Or e-mail at: email@example.com
WOMEN IN GEOLOGY: Florence Bascom
Although Florence Bascom (1862-1945) was known as "the first woman geologist” in this country, she was the second woman to earn a Ph.D. in geology in the United States. (Mary Holmes earned a Ph.D. in geology from the University of Michigan in 1888). Bascom was the first woman hired by the U.S. Geological Survey (1896), the first woman to present a paper before the Geological Society of Washington (1901), the first woman elected to the Council of the Geological Society of America (elected in 1924; no other woman was elected until after 1945), and the first woman officer of the GSA (vice president in 1930). She was an associate editor of the American Geologist (1896-1905) and a four-starred geologist in the first edition of American Men and Women of Science (1906), which meant that her colleagues regarded her as among the country's hundred leading geologists. After joining the Bryn Mawr College faculty, Bascom founded the college's geology department. This site became the locus of training for the most accomplished female geologists of the early 20th century.
Bascom was an expert in crystallography, mineralogy, and petrography. Trained by leaders in metamorphism and crystallography including Roland Irving and Charles Van Hise (University of Wisconsin), George Huntington Williams (Johns Hopkins), and Victor Goldschmidt (Heidelberg, Germany), she worked in these fields during their infancy. Her earliest contribution was her dissertation, in which she showed petrographically that rocks previously considered sediments were metamorphosed lava flows (Aldrich, 1990; Bascom, 1893). An expert on crystalline rocks of the Appalachian Piedmont, she published more than 40 research papers, including USGS Bulletins and Folios. Additionally, she published research on Piedmont geomorphology, particularly the provenance of surficial deposits.
This is the text of another new geological marker erected in 2002
Located in Nobles County, 19 miles W. of Worthington on westbound I90 at the Adrian Rest Stop.
GEOLOGY OF THE ADRIAN AREA
The landscape along Interstate 90 between Austin and Adrian varies from a flat to a gently rolling plain. This topography was shaped beneath a thick lobe of glacial ice. About 14,000 years ago, glacial ice advancing through the Manitoba region followed the lowlands of the Red River valley and the Minnesota River valley and reached south into central Iowa. At its maximum, the ice lobe’s western margin deposited glacial sediment (clay, silt, sand, gravel, and boulders) as it melted, producing a broad belt of low hills called a moraine, which extends to the northwest and upon which this rest stop was built. Streams to the east of this moraine drain into the Mississippi River system, whereas streams to the west, like Kanaranzi Creek just south of here, drain into the Missouri River system. Thus, the moraine is now a drainage divide.
Farther westward and just north of Luverne, there is a bedrock upland called Blue Mound. Blue Mound can appear bluish from a distance, but it is actually composed of a reddish-pink-to-whitish rock called quartzite. One theory for the bluish appearance is that it is caused by the lichens that cover the quartzite outcrops. This quartzite formed from a quartz sand whose grains, over time, were cemented by silica and partially recrystallized, making a solid, hard rock that is resistant to erosion. The color shades of the quartzite are due to iron oxides that exist as thin films around and between the quartz grains. The quartzite of Blue Mound has probably been a high point on the landscape for much of the time since its formation 1.7 billion years ago. It was an island when shallow seas covered this area 97 million years ago. The surrounding rocks contain fossils of animals that lived in these waters: sharks, turtles, sponges, and even mosasaurs—large fish-eating lizards related to the modern monitor lizard.
The area west of here was also glaciated, but much earlier—at least a half million years ago. Blue Mound was not high enough to escape the great thickness of ice that covered this region at that time. The hard quartzite bears the scratches left by those passing glaciers.
Erected by the Geological Society of Minnesota in partnership with the
Minnesota Department of Transportation and the Minnesota Geological Survey
☺ ☺☺ WORMS WITH A COPPER SMILE ☺☺☺
The rare mineral atacamite--Cu2(OH)3Cl--is named after the Atacama Desert in Chile, one of the few places where it is found. A team of U.S. and Austrian scientists has now found another source: the teethlike jaws of the marine bloodworm Glycera dibranchiata.
The discovery by research associate Helga C. Lichtenegger of the department of chemistry and biochemistry at the University of California, Santa Barbara, and co-workers, adds to the relatively short list of about 70 minerals that animals make to form structures such as shells, teeth, and bones. Atacamite is the first of these biominerals known to contain copper [Science, 298, 389 (2002)].
Lichtenegger and her colleagues used a combination of X-ray diffraction, electron microscopy, and other techniques to determine the chemical composition and mechanical properties of the worm's jaws. The carnivorous worm uses the hard, sharp-tipped structures to bite and inject venom into its prey.
The tip region of the jaws contains layers of polycrystalline atacamite fibrils dispersed in a protein matrix, the researchers find. The fibrils which align with the jaw's outer contour. They are concentrated toward the center of the tip, while the base region is devoid of fibrils. The hardness and stiffness of the jaw increases from the base to the tip and from the surface to the interior, which correlates with the increasing degree of mineralization.
Cross-sectional maps of copper and chloride concentration confirm the elemental distribution in the jaw and show that the Cu-Cl ratio is higher than that found in atacamite, suggesting that free copper ions are present. Copper is known to cross-link polymers and protein scaffolds, the researchers point out, and the excess copper in the worm's jaw could be playing that role.
The jaw's impressive structural stability and resistance to abrasion approaches that of human tooth enamel, the team notes--even though atacamite makes up only 4% of the worm's jaw, while hydroxyapatite, Ca5(PO4)3OH, makes up 96% of tooth enamel. This toughness is needed to protect the jaw from wear and tear as the worm burrows through gritty marine sediment where it may chomp indiscriminately on bits of gravel.
G. dibranchiata appears to exhibit strict chemical control to consistently produce only atacamite, rather than any of the other three known Cu2(OH)3Cl polymorphs. The selectivity for copper rather than other elements such as calcium, silicon, and iron commonly found in biominerals suggests that copper may play an additional role, such as activation of the worm's venom during injection, the researchers say.
"The marriage of protein with copper mineral as well as with copper ions is an intriguing concept per se, but may serve as a design prototype for new materials that need to be hard, lightweight, and durable," the researchers write.☻
[Answers to the GeoQuiz on cover: 1. Sea of Japan, 2. Mid-Ocean ridges, 3. Thorium, 4. Feldspar, 5. Basalt, 6. Pacific, 7. Gangue]