science

How we add to the sum of the world’s knowledge.

Cave Formations Show Evidence of Fire

stalactites inside a cave

Drip water in Yonderup Cave contains evidence of an aboveground fire. Credit: Andy Baker/U. New South Wales

Stalactites and stalagmites form in caves when water that contains dissolved minerals (such as calcium carbonate) drips from the ceiling. Scientists can analyze the 18O/16O ratios (isotopes of oxygen) in the stalactites and see how the temperature changed as they were formed. A team led by Andy Baker, Gurinder Nagra, and Pauline C. Treble of the University of New South Wales, Australia discovered that Yonderup Cave had a lot more 18O than they expected. Since having more 18O is associated with higher temperatures at the time of formation[1], it could have been interpreded as one of the largest climate changes in the last 2 million years.

But, there was a wildfire in 2005 and a large tree died right on top of the cave. Baker’s team believes that this is what actually caused the increased 18O concentration. This is important for anybody else trying to use these oxygen isotopes to determine ancient temperatures, because if they get a very warm result it might have been caused by a forest fire instead.

[1]It’s a little more complicated than that. Read the whole article here: http://cen.acs.org/articles/94/i30/Cave-dripwater-contain-fire-evidence.html and check Baker’s website for more interesting stuff about how he researches caves to learn about past climates.

Spring 2017 Lectures

Lectures presented by the Association of Earth Science Clubs of Greater Kansas City

Friday, March 10, 2017

3:00 p.m. “Opal Down Under”, Ron Wooly, Owner of Dreaming Down Under

Saturday, March 11, 2017

1:00 p.m. “Earth Science… Facts, Frauds and Scams”, Mark Sherwood, Independence Gem and Mineral Society

2:00 p.m. “The Life and Hard Times of the KU T. rex”, Dr. David Burnham, Research Associate, University of Kansas, Lawrence, Kansas

3:00 p.m. “Medullary bone in Tyrannosaurs: a question of chickens, eggs and possibly more”, Dr. Josh Schmerge, University of Kansas, Lawrence, Kansas

4:00 p.m. “History of Gold Mining”, Doug Foster, Show-Me Gold, Missouri

Sunday, March 12, 2017

2:00 p.m. “The Life and Hard Times of the KU T-rex”, Dr. David Burnham, Research Associate, University of Kansas, Lawrence, Kansas

3:00 p.m. “Islands in the sun: Eocene fossil mammals from Turkey”, Dr. Chris Beard, University of Kansas, Lawrence, Kansas

Scholarship

The Association has a scholarship for students studying earth science. The value will be between $250 – $1000. To apply, fill out this form on the Association website here and mail it to Molly Stinemetz. The application says 2015 but it is good for 2017. The scholarship happens every year.

Deadline: February 28, 2017

Requirements:

  • Be a student at an accredited college or university in Missouri or Kansas
  • Must have completed your sophomore year, or be a grad student
  • Major in a field related to earth science
  • Be a legal resident of the United States
  • Complete the application honestly and on time
  • Include a recommendation from a professor
  • Include a transcript
  • If you are selected as a finalist, you must attend the auction at the Kansas City Gem Show on Saturday, March 11, 2017 at 7:15pm.

Special Exhibits 2017

KANSAS CITY GEM SHOW SPRING 2017 FEATURE EXHIBIT

ROCK ART –Stone Quilt Design; Susan Judy; Denver, CO and WKP Accent Tables; Bill Peterson; Boulder, CO
Colorado artists Judy and Bill have brought some of their creations to the Kansas City Show.  Judy inlays natural materials in a stone mosaic to create pictures and Bill uses natural materials to create tables.

INVITATIONAL EXHIBITS (more…)

Collagen Found in Dinosaur Bones

Paleontologists at the University of Toronto just found collagen in a 195 million year old fossil. This makes it the oldest protein that has ever been found. Previously, the oldest protein sample was only 80 million years old (it was also collagen, from a dinosaur bone). They also found hematite crystals in the fossil, which possibly came from the blood. The dinosaur was a Lufengosaurus that lived in Yunnan Province, China.

Some other paleontologists didn’t like the new, non-invasive methods that the team used used to identify the collagen, but other scientists thought the methods were fine. Read the whole article here https://cen.acs.org/articles/95/i6/Collagen-found-195-million-year.html and let me know what you think.

Gem Show Pictures Fall 2016

KCI Expo Center outside building

The Gem and Mineral Show was once again at the KCI Expo Center

selling rocks and books convention customers

The view from behind the Association booth.

yellow keokuk geode

This yellow geode is from Keokuk in St. Francisville. They call it “Lemoness”.

crinoid Scyphocrinites elegans fossil from Morocco

This huge crinoid (Scyphocrinites elegans) fossil is from Morocco.

kansas fossils

There were also fossils from Kansas available.

tiny beads in tubes

Plenty of beads for sale at the show.

fossilized starfish britlestar ophiura morocco

Fossil Brittle Star from Morocco, sold by Schooler’s Minerals. Fun fact: a brittle star is from the class Ophiurida and starfish are from the class Asteroidea, so they are not really related to starfish at all.

official-apron

Bob models an official Association apron and holds a pufferfish.

pufferfish

The preserved pufferfish close up. It is hollow and light as a feather. I don’t think anyone bought it so it will be for sale again in March.

books about minerals and gem cutting for sale

Some of the mineral, fossil, and jewelry-related books we had for sale this year.

carved mineral skulls

Carved skulls made of semi-precious minerals.

dino agate.JPG

Is this a giant dinosaur showing off a giant agate, or a very small dinosaur with a tiny agate?

potter with pots and bowls oklahoma dirt shirt

Martin selling pottery that he made

men packing items for storage

Everything is packed up into our big blue cube until the next show.

Congratulations Scholarship Winners

Every year, the Midwest Federation offers scholarships to students studying geology or earth science related fields at the college or post-graduate level. If you purchased anything at the Scholarship Auction at the March Gem & Mineral Show in Kansas City, or at the auction at the Association Picnic in August, then you contributed to these scholarships. Thank you!

Dr. William S. Cordua is a retired professor from the University of Wisconsin. Dr. Cordua is the chair of the Geology committee of the Midwest Federation of Mineralogical and Geological Societies. Dr. Cordua has chosen the two students:

Ms. Kari Wolfe is pursuing her Masters degree in Nitrate Pollution in Tile Water in Dead Zones in the Gulf of Mexico, through the University of Wisconsin in Minneapolis.

Ms. Colleen Hoffman is pursuing her Ph.D. degree in Mineralogy and Biogeochemistry of Deep Sea Hydrothermal Vents, through the University of Wisconsin in Minneapolis.

For more information about the scholarships, including how to apply: http://www.amfed.org/mwf/federation/scholarships.html

How Amethyst Cathedrals are Formed

purple amethyst cathedral in a museum with other minerals

Amethyst cathedral at the Sutton Museum. Photo by Stephanie Reed

Article by Dr. Bill Cordua, University of Wisconsin-River Falls

Have you ever been to a show and seen enormous amethyst geodes or crystals 3-5 feet or more in height? The tubular geodes are lined with deep purple gemmy amethyst crystals. How do such wonders form?

These excellent geodes come from a region along the Brazil-Uruguay border. The genesis of deposits on the Brazil side of the border has recently been extensively researched by an international team of geochemists lead by H. Albert Gilg of Techniche University Munchen in Germany (Gilg, et. al., 2003). The geodes are mined from several lava flows belonging to the Parana Continental Flood Basalt Province. This was one of the largest outpourings of basalt lava known. An estimated 800,000 cubic kilometers of lava extruded over an 11 million year time span. For comparison, this would be enough to cover Minnesota with a pile of basalt lava over 2 miles high. The lava outburst occurred as part of the opening of the South Atlantic Ocean during Cretaceous time about 130 million years ago. Of all these flows, however, only a few are known to host amethyst cathedral geodes.

Gilg et al. proposed a 2-stage model for their formation. In the first stage the large hollows form. This was caused as volcanic gases were released from certain lavas as they cooled. Not every lava has enough dissolved gas to form such big openings. As gas bubbles emerged from the congealing lava (much as bubbles emerge when beer or soda pop is poured) they coalesced as they rose. The lava was cooling fast too, and soon became so thick and sticky that bubbles quite rising and were trapped. The bulbous to tubular shapes thus point towards the top of the flow, a fact easily seen when the geodes are in place in the mines. These cavities, though, were empty of crystals.

The second stage was the formation of the amethyst, plus celadonite, calcite and gypsum fillings. An important clue to this event is the presence of small gas and liquid bubbles (called fluid inclusions) trapped within these minerals. These are samples of the mineral-forming liquids caught as the crystals grew. Fluid inclusions are treasure troves of information when studied with sophisticated instruments. Analyses of the fluid inclusions in the amethyst, calcite and gypsum show them to be filled with slightly salty water. This water had a temperature of no more than 100 degrees C, and possible less than 50 degrees C, during mineral formation. These cannot be fluids related to the magma that formed the lavas.

What was the source of these fluids? An amazing story unfolds from the radiometric dating of the minerals. The basalts formed about 130 million years ago, but the green celadonite, which makes up the rinds of the geodes, formed about 70 million years ago. For 60 million years these enormous cavities sat empty of crystals. Trace element data from the fluid inclusions gives another important clue to the source of the mineral-forming fluid. Below the lavas is a large aquifer (the Botucatu aquifer) filled with ground water that closely resembles the fluid inclusion liquids. Uplift and tilting of the area about 70 million years ago would force water out of the aquifer into the porous areas of the overlying lava. In the lava flow these waters would have found volcanic glass. Glass breaks down over geologic time and makes silica and other chemicals available in a form that is readily soluble in water soaking through the rocks. The water carried these chemicals into the cavities, where the amethyst and other minerals grew due to cooling and pressure release.

The special combination of geologic circumstances, unfolding over millions of years, is not often duplicated. Understanding the process gives geologist tools to prospect more efficiently for these wonders.

Reference:
Gilg, H. et. al, 2003, “Genesis of amethyst geodes in basaltic rocks of the Serra Geral Formation (Ametista do Sul, Rio Grande do Sul, Brazil): a fluid inclusion, REE, oxygen, carbon, and Sr isotope study on basalt, quartz and calcite” Mineralium Deposita vol. 38, p. 1009-1025.

The Glacial Drifter 08/2011, The Gemrock 06/2015

Curb Showing Hayward Fault is Replaced

Hayward, California is the home of the Hayward Fault, which is a break in the Earth’s crust. Geologically speaking the Hayward Fault moves very fast. You can see that the tectonic plates are always moving when you look at the roads. Since it only moves a few millimeters a year, the roads and/or curbs don’t crack but instead gently wiggle apart at the seams.[*] See how this curb at Rose and Prospect has moved over time?

curb a few inches offset hayward fault

This is how the curb looked in 1974. It has already drifted several inches from where it was originally. Photo from http://www.geologyfieldtrips.com/haywardresidential.htm

hayward fault curb 2012 with people standing on top

This is how the curb looked in May 2012. See how far this piece has moved away? Photo by Andrew Alden at oaklandgeology.wordpress.com

If you want to go to California and see it for yourself, you are out of luck. The city has just replaced the curb. This is probably the first time that road work has made it into the New York Times. Read the article here: A Curb is Repaired and a Seismic Marker is Lost

[*]Note: Cracks in the road are not caused by plate tectonics. They are caused by thermal expansion/contraction, road salt, heavy trucks, and degredation of the road bed.