Earth Science Club of Northern Illinois - ESCONI

ESCONI Events June 2022

Field trips require membership, but visitors are welcome at all meetings!

Fri, June 10th	ESCONI General Meeting 8:00 PM Zoom - Topic: “Off-Axis Seamount Investigations at Siqueiros: The OASIS Expedition” by Dr. Patricia Gregg, University of Illinois. This meeting will be held via Zoom.  Zoom link
Sat, June 11th	ESCONI Junior Meeting - 7:00 PM at College of DuPage - Topic: "Our Juniors' Rock Viewing Microscope" Specifics of this meeting are available from Scott Galloway, 630-670-2591, [email protected]. The meeting will be in person at the College of DuPage Tech Ed (TEC) Building, Room 1038A (Map).
	ESCONI Paleontology Meeting - No Meeting in June... see you in September!

 

Trilobite Tuesday #40: Find the Trilobite! #fossil #paleontology #trilobite #trilobites #fossils #ordovician

ESCONI recently held a field trip to the St. Paul Quarry in St. Paul, Indiana.  As part of that trip, a few of us paid a visit to the famous St. Leon roadcut on Indiana Route 1 just off Interstate 74 at exit 164 for St. Leon.  The road cut is huge and loaded in fossils.  Head on over to The Fossil Forum for many trip reports.

As part of that visit, we went looking for trilobites.  Here you can see ESCONI President Keith Robitschek with Phil Anderson looking for interesting fossils.  The ground is littered with brachiopods, bryozoans, and other bits.

To have the best chance of finding a trilobite, you'll need to crawl on your hands and knees along the first bench in the "butter shale".  It was fairly wet when we were there, but with a little effort we all found a few complete trilobites - of the genus Flexicalymene.  You'll also see many pieces of a large trilobite called Isotelus.  Whole Isotelus have been found, but are rare.

Here is a few photos of trilobites in situ for a game we like to call "Find the Trilobite".  The first is a little easier and was found by Phil Anderson.

This one is more challenging.  It was found by Keith Robitschek.

Mazon Monday #114: Codonotheca caduca #fossil #paleontology #MazonCreek #MazonMonday #pollen #pollenorgan #seedfern #pennsylvanian

This is Mazon Monday post #114.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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Codonotheca caduca was named by Elias Howard Sellards (1875 - 1961).  He was a paleontologist, geologist, and anthropologist.  The Texas State Historical Association has a nice summary of his career, which spanned almost 60 years.

SELLARDS, ELIAS HOWARD (1875–1961).Elias Howard Sellards, geologist and paleontologist, was born in Carter City, Kentucky, on May 2, 1875, the son of Wiley W. and Sarah (Menach) Sellards. The family moved to Kansas during Elias's youth. He attended the University of Kansas, where he received his B.A. and M.A. degrees, and Yale University, from which he graduated in 1903 with a doctoral degree in paleontology. During his years as a graduate student in Kansas he discovered about 6,000 specimens of Permian insects, among the richest finds of its kind. After completing his doctorate he worked briefly at the Carnegie Museum in Pittsburgh and taught at Rutgers University for one year. In 1904 he was appointed professor of geology and zoology at the University of Florida. From 1907 to 1918 he served as state geologist of Florida, and in 1908 he attended the first Conference for the Preservation of Natural Resources in Washington, presided over by President Theodore Roosevelt. In 1918 Sellards moved to Austin, Texas, where he worked in the Bureau of Economic Geology at the University of Texas. He was commissioned by the Texas attorney general's office to research the history of the Red River and testify in a boundary dispute with Oklahoma (see BOUNDARIES). His evidence gained a settlement favorable to Texas. During his forty-three years in Texas, Sellards also made numerous significant finds, including early sculpture in East Texas, estimated to be 25,000 years old; Pleistocene deposits in Bee County containing the fossilized remains of elephants, camels, giant wolves, and three-toed horses; a twenty-five-foot sea lizard near the Gulf Coast; and brontosaurus tracks. Sellards was the author of numerous works, including Pliocene and Pleistocene (1906), The Geology of Texas (1933), and Early Man in America (1952), and was widely honored in his profession. He served a president of the Society of Economic Paleontologists and Mineralogists in 1938 and the Paleontological Society in 1942. He was assistant director of the Bureau of Economic Geology from 1925 to 1932 and director from 1932 to 1945. He was a longtime member of the Philosophical Society of Texas. Sellards married Anna Mary Alford on September 4, 1907. The couple had two daughters. He died in Austin on February 11, 1961.

C. caduca is believed to be the pollen organ of Macroneuopteris scheuchzerii.  It is considered rare and is only known from the Mazon Creek fossil biota, especially with deposits which are rich in M. scheuchzerii like the Mazon River locality.

The addition of the pollen organs and fertile forms is just one of the improvements Jack Wittry made in "A Comprehensive Guide to the Fossil Flora of Mazon Creek" over his previous plant book.  Finding information on these obscure plant parts tends to be fairly troublesome.  C. cadica appears on page 237.

1903. Codonotheca caduca Sellards: pls. 1-3, fig. 3A
1907. Codonotheca caduca Sellards: fig. 7
1925. Codonotheca caduca Sellards; Noé: pl. 43, figs. 1-3
1958. Codonotheca caduca Sellards; Langford: p. 303, figs. 566, 567
1969. Codonotheca caduca Sellards; Darrah: p. 163, pl. 17, figs. 1-4
1994. Codonotheca caduca Sellards; Drinnan and Crane: p. 236, pls. 1-3

DESCRIPTION: These are elongated and stalked pollen organs that are often borne in pairs. They consist of a swollen, bell-shaped, sterile portion near the stalk, from which hang six elongated and parallel-sided segments for 70 to 80 percent of the organ's length. Each segment contains a single sporangial cavity. The organs are variable in size, and most range from 30 mm to 50 mm in length. The surface of the pollen organ is often covered with dense hairs.

REMARKS: Codonotheca caduca is rare and known only from the Carbondale Formation of Illinois, most notably the Mazon Creek area, where it is the most common pollen organ found. Both Sellards and Darrah (from cuticular and stomata evidence, Darrah, 1937) believed this was likely the pollen organ of Macroneuropteris scheuchzerii, but no organic attachment has been found to date.

Specimens

From the Field Museum

Mazon River from ESCONI member Rhonda Gates

Mazon River from ESCONI member Marie Angkuw

Mazon River from ESCONI member Andrew Young

ESCONI at CGMA 2022 #gems #minerals #fossils #Chicago #Illinois #KaneCounty

Today is the last day of the 2022 Chicagoland Gems and Minerals Association show. It's at the Kane County Fairgrounds in St. Charles, IL.  There's lots of vendors, interesting displays, and good friends.... See you there!

Here are a few pictures of ESCONI at the show.

Juniors Table

Display photots

The first Australians ate giant eggs of huge flightless birds, ancient proteins confirm #fossil #Australia #paleontology #birds #eggs

Detail from an illustration of Genyornis being chased from its nest by a Megalania lizard in prehistoric Australia. Credit: Peter Trusler

Phys.org has a story about the extinction of the large flightless birds in Australia.  An international team of scientists have found evidence that the earliest humans to arrive on Australia ate the eggs of the large flightless birds that lived in Australia 47,000 years ago.  That evidence suggests humans had direct influence on the extinction.  The research was published in a paper in the journal Proceedings of the National Academy of Sciences.

Proteins extracted from fragments of prehistoric eggshell found in the Australian sands confirm that the continent's earliest humans consumed the eggs of a two-meter tall bird that disappeared into extinction over 47,000 years ago.

Burn marks discovered on scraps of ancient shell several years ago suggested the first Australians cooked and ate large eggs from a long-extinct bird—leading to fierce debate over the species that laid them.

Now, an international team led by scientists from the universities of Cambridge and Turin have placed the animal on the evolutionary tree by comparing the protein sequences from powdered egg fossils to those encoded in the genomes of living avian species.

"Time, temperature and the chemistry of a fossil all dictate how much information we can glean," said senior co-author Prof Matthew Collins from the University of Cambridge's Department of Archaeology.

"Eggshells are made of mineral crystals that can tightly trap some proteins, preserving this biological data in the harshest of environments—potentially for millions of years."

Fossil Friday #110: Sea Cucumber from Mazon Creek #fossil #paleontology #FossilFriday #seacucumber #MazonCreek

This is the "Fossil Friday" post #110.  Expect this to be a somewhat regular feature of the website.  We will post any fossil pictures you send in to [email protected].  Please include a short description or story.  Check the #FossilFriday Twitter hash tag for contributions from around the world!

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For this Fossil Friday, we have a very sweet sea cucumber (Achistrum sp.) from Mazon Creek.  For more information, we looked at these echinoderms back in Mazon Monday #29.  Holothurians appeared in Andy Hay's Creature Corner in May 1986.

Holothurians (sea cucumber)

As has been noted previously in these articles, the not uncommon fossil finds of Pit 11 are a great rarity in the fossil record of the rest of the world. So it is with the "sea cucumbers", more accurately the members of the class Holothuroidea which are found at this location.

In a recent journal it is stated "complete fossil Holothurians are rare". During the last 100 years only a few such specimens have been found. Following a page describing the complete specimens known, a paragraph much further on makes note of Dr. Eugene S. Richardson, Jr.'s study of "entire specimens of apodus holothurians" from Pit 11.

Holothurians possess leathery to gelatinous body walls, which are strengthened by Ossicles and spicules -tiny bone-like structures of various shapes. The body is more or less cylindrical, mouth at one end, anus at the other. Feeding tentacles surround the mouth. These tentacles are usually retractable. Some holothurians are burrowing creatures, ingesting the bottom sediment and filtering it for food.Others feed on tiny animals swimming by ensnaring them in the fan like tentacles. A calcareous ring of calcite plates joined together (often called radula by fossil collectors) is a support for the esophagus and body muscles. This ring plus the tiny "fish-hooks" (ossicles) are the field marks of Pit 11 sea cucumbers. During preservation, the sac-like body dries and cracks. Spaces being filled by calcite give the fossil body a septarian or mud-crack appearance. The various genera and species, one dozen plus or minus, are under study and will be described by S. Sroka (personal communication). Gelatinous body with few skeletal elements that could be preserved make the study of fossil holothurians difficult. Pit 11 holothurian specimens may change this condition.

This particular specimen was found by ESCONI member Sue Diblee.  She sent along this story to describe her discovery.

Here is the Achistrum sp. that you confirmed for me last Sunday.  I found the nodule on March 1, 2022.  The nodule opened by itself while it waited in line for some freezer time!  I initially thought it was a coprolite but it matched quite closely with Jack Wittry's description and photo in his Mazon Creek Fossil Fauna book.  The desiccation cracks and the circular mouth are essential features.  Dr. WIttry reminds us to avoid vinegar when cleaning a sea cucumber fossil because acid can dissolve the calcite in the cracks.

Thanks for the contribution, Sue!  That's a very nice fossil!  The mouth can be seen on the upper right of the bottom half shown below.

Throwback Thursday #112: April 1990 Field Trip to St. Paul and Brookville, IN #fossil #paleontology #silurian #ordovician #indiana #stpaul #brookville #TBT #history #ThrowbackThursday

This is Throwback Thursday #112.  In these, we look back into the past at ESCONI specifically and Earth Science in general.  If you have any contributions, (science, pictures, stories, etc ...), please sent them to [email protected].  Thanks!

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ESCONI has been visiting St. Paul, IN for Silurian fossils for a long time.  In 1990, there was a rather large field trip to St. Paul.  While down there, they decided to visit Brookville, IN and Ohio for some Ordovician fossils.

Earl Elliott announced the trip in the April issue of the newsletter... it was a three day affair - April 6th, 7th, and 8th. 

FIELD TRIP

ESCONI FIELD TRIP S-E INDIANA & S-W OHIO -

April 6-7-8

MEET: 8:00 A.M. sharp on Saturday April 7 (Eastern Time) PLACE: Super 8 Motel I74 and Route 9 Shelbyville, Indiana

Be ready for a full day of collecting. We have permission to collect in the Waldron Shale at a quarry in this area. This is a Silurian age quarry, where on our last trip we found some trilobites, crinoid heads and stems and numerous other fossils and micros, some of which are replaced by pyrite. Also, come calcite and other minerals are available. The quarry will close around noon and we will head further east to collect in areas around Brookville, Indiana for Ordovician age fossils and who knows what??? It should be fun.

Sunday morning we will collect Ordovician fossils in an area around Oxford, Ohio. I would suggest that Motel people try to stay at the lodge at Hueston Woods State Park. which is 7 miles north of Oxford. Plan to drive back home Sunday afternoon or Monday A.M. if you have an extra day off.

Reservations: Super 8 Motels 1-800-843-1991 (10% VIP Discount) Hueston Woods State Park Lodge 1-800-282-7275 (call A.S.A.P.) Hueston Woods Campground 1-513-523-1060 (call A.S.A.P.)

TO sign-up call Earl Elliott (Field Trip Chairman) 708-698-6246 For camping information call Don Auler (Second VP) 708-832-0479

Adult and junior members of ESCONI in good standing are welcome. Everyone must have a hard hat.

Earl Elliott Field Trip Chairman

April 6th was a travel day, with hotel accommodations at the Super 8 Motel in Shelbyville, IN, which is still there.

They met at 8:00 AM sharp for a full day of collecting.  The morning was spent in the St. Paul Quarry. 

For the afternoon, Brookville, IN was visited for Ordovician fossils.

On Sunday, they visited Hueston Woods in Ohio.  The site of a fossil park in Ohio.  Better maps are available online.

From the field trip report in the May 1990 edition of the newsletter, it sounds like everyone had a great time!

FIELD TRIP REPORT

We had a nice turn out for our Arpil field trip to Indiana and Ohio. 42 members of ESCONI were along on the trip.

During our two days of collecting we visited areas around Waldron Indiana, Brookville Indiana and Oxford Ohio. Some nice Silurian and Ordovician fossils were found along with some interesting mineral and micro specimens. The weather was good, a little cool but sunny. Everyone was having such a good time that nobody minded the cool weather. We also were very fortunate to have Dr. Gerrald Haddock along with us to help identify many of our fossil finds. I hope that our many new members that were along on this trip found it interesting and will join us again on our next trip. Field trips are an important part of our study of the Earth sciences and are open to all adult and junior members of ESCONI.

Earl Elliott Field Trip Chairman

Silurian fossils of St. Paul, IN

Ordovician fossils of Brookville, IN and Hueston Woods in Ohio

2022 Tate Geological Museum Lecture Series - 6:30 MDT on Mat 26th, 2022 #fossil #ammonites #paleontology #jurassic

The next installment of the 2022 Tate Museum Lecture Series will take place  Thursday evening, May 26th. Continuing with the ammonites theme, Kathleen Ritterbush of the University of Utah will present: “Adventures in the Jurassic Jet Propulsion Laboratory”. 

The Zoom will open at about 6:30PM Mountain Savings Time and the talk will start at 7PM. And here is the link:

https://caspercollege.zoom.us/j/84334489484?pwd=OFNuVVpmZWtLQ01yVkVNWTRIM2pXdz09

I am sending one email to all groups. Please pass this on to your members.

Recordings of the last two talks (David Peterman and Josh Slattery) can be found on the Tate Geological Museum’s YouTube channel:

https://www.youtube.com/channel/UCedShZzSLZPCa018d8T_3Jg

We failed to record the first talk (Russell Hawley) as we were still new at this.  With Kathleen’s permission, her talk should be out on the Tate’s YouTube channel a few days after the talk.  Rather than send out another mass email to announce that, I will leave it up to folks to look it up.  

BBC: Mary Anning: Lyme Regis fossil hunter's statue unveiled #fossil #paleontology #history #womeninscience #fossils #lymeregis #uk #england

Hundreds of people turned out to see the unveiling

The BBC has a story about the unveiling of a statue of Mary Anning in her home town of Lyme Regis, Dorset, England.  The unveiling was done on May 21st, which was her 223rd birthday.  She lived her whole life in Lyme Regis and supported her family by collecting and selling fossils from what is now known as the Jurassic coast.  She was the first one to discover a complete plesiosaur in 1823.  The poem "She sells sea shells by the sea shore" is widely attributed to her.

During the ceremony, crowds cheered as Prof Roberts said: "Mary Anning - welcome back to Lyme Regis."

She added: "It makes Mary Anning visible as a role model for any woman wanting to get into science. This is her place, where she was from and where she made all her discoveries.

"But she also represents the change we need in our society - we need to push further and bring more people into science," she said.

Anning, whose life inspired the feature film Ammonite, was never fully credited for her discoveries due to the fact she was woman and because of her social status.

Mazon Monday #113: Spring 2022 Braceville Field Trip Report #fossil #paleontology #MazonCreek #MazonMonday #coalmine #coal #mine

This is Mazon Monday post #113.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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Braceville Field Trip (Mazon Creek) May 14th and 15th

by Keith Robitschek

This spring’s field trip to the Braceville spoil pile started on Saturday with a warm cloudy day with a chance of rain. We had about five minutes of a cool light drizzle. To be honest, it was well timed and felt good. Near the end of the field trip, it got uncomfortably hot, reaching 88 degrees and humid.  We had 39 members show up which left 11 no-shows. Kids young and old alike enjoyed the fossil dump performed just before lunch. Sunday’s weather was a direct opposite from that of Saturday. Mostly cloudy for most of the day, with cooler temperatures.  There was about a minute of light mist midday.  Unfortunately, only 34 members turned out on Sunday.  For the weekend, nearly a third of members that signed up were no-shows. This did allow the guides to be much more personal by sharing knowledge with the participants that were there.

This spring’s fossil donations were provided by Andrew Young, Marie Angkuw, Rich Holm, Jeremy Zimmerman, Rob Coleman and myself... Thanks!  Everyone got to pick through them, ask questions, and take home a few handfuls of fossils.  The fossils giveaways came from all over the world, including England, Morocco, Indiana, Wyoming, and Iowa. Many of the donations can be seen at the feet of our young hunters in the picture below.

Here a video of the fossil dump on Sunday.

There was much success digging into the ridges, where concretions were being discovered in both eroded areas and in situ. Remember, when you find one concretion in situ, they usually come in small clusters relatively close to each other. The image below looks like we have plots subdivided under leases for excavation.

The top of the hill is the coolest place to be, along with a nice breeze.

Check the ESCONI website!  It has a wealth of information about Mazon Creek fossils. We have the weekly Mazon Monday series.  Mazon Monday #66 applies well to the Braceville spoil pile. 

 

Ancient Tooth From Young Girl Discovered in Cave Unlocks Mystery of Denisovans, a Sister Species of Modern Humans #fossil #paleontology #humans #denosovans #evolution

 

What links a finger bone and some fossil teeth found in a cave in the remote Altai Mountains of Siberia to a single tooth found in a cave in the limestone landscapes of tropical Laos? The answer to this question has been established by an international team of researchers from Laos, Europe, the US, and Australia. Credit: Flinders University

SciTechDaily has a story about the Denisovans.  The Denisovans are a closely related species of humans who lived in southeastern Asia around 150,000 years ago.  Their DNA had only known from the Denisova cave in the Altai Mountains of Siberia (Russia).  Now, the discovery of Denisovan DNA in a tooth from Cobra Cave in northern Laos links the modern occurrence of DNA with the ancient fossil DNA.  See the detail in a paper in the journal Nature Communications.

Lead Author and Assistant Professor of Palaeoanthropology at the University of Copenhagen, Fabrice Demeter, says the cave sediments contained teeth of giant herbivores, ancient elephants, and rhinos that were known to live in woodland environments.

“After all this work following the many clues written on fossils from very different geographic areas our findings are significant,” Professor Demeter says.

“This fossil represents the first discovery of Denisovans in Southeast Asia and shows that Denisovans were in the south at least as far as Laos. This is in agreement with the genetic evidence found in modern-day Southeast Asian populations.”

PBS Eons: The Curious Case of the Cave Lion #paleontology #archaeology #artifacts #cats #fossil #fossils

 

PBS Eons has a new episode.  This one is about large cats from ancient Eurasia.

A mysterious, large feline roamed Eurasia during the last ice age. Its fossils have been found across the continent, and it’s been the subject of ancient artwork. So what exactly were these big cats?

Fossil Friday #109: Tully Monster! #FossilFriday #fossil #tullymonster #paleontology #MazonCreek #vertebrate #pit11

This is the "Fossil Friday" post #109.  Expect this to be a somewhat regular feature of the website.  We will post any fossil pictures you send in to [email protected].  Please include a short description or story.  Check the #FossilFriday Twitter hash tag for contributions from around the world!

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Today, we have a Tully Monster that got a second chance.  It was found by ESCONI member Jeremy Zimmernan a while back deep in the wilds of Pit 11.  Someone had hammered it many years ago, thought it was a blank and left it to the elements.  Jeremy picked it up, made it part of his freeze/thaw process, and it rewarded him for his patience.  It's not the best Tully, but it's a Tully!   It needed some repair as can be seen on the back side.  For that, Elmer's Glue works wonderfully and gives you multiple chances if you make a mistake.

When you're out in the field collecting, don't overlook the discards from long ago.  Back then, the collectors had more concretions than you can believe.  They hammered them and then kept the better specimens with the least damage.  Use the freeze/thaw method, yes, it's slow, but gives the best chance for a nice opening... especially with the markedly reduced count of concretions available today!

Thanks for sharing, Jeremy!  And, thanks for passing on this valuable lesson in Mazon Creek fossil collecting!

Throwback Thursday #111: In Quest of Galena #rocks #fossil #TBT #ThrowbackThursday #history #galena #mineral

This is Throwback Thursday #111.  In these, we look back into the past at ESCONI specifically and Earth Science in general.  If you have any contributions, (science, pictures, stories, etc ...), please sent them to [email protected].  Thanks!

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This week, we are posting the story of a field trip from the March 1952 edition of the newsletter.  The story is by Alan D. Kattele, who was a member of ESCONI during the 1950's.  He writes of a trip to find galena in 1950 with his wife and three year old daughter in their 1936 Pontiac.  They have mixed luck, which includes a run in with a bunch of wasps.

In Quest of Galena

When a family of avid rock hounds are transplanted from their native rock strewn hillsides of New England to the barren prairies of Illinois, tensions are found to be built up, tensions that can only be relieved by the sight of masses of honest-to-goodness rock, rock that gleams with more than the pale shine of dolomite, with these thoughts in mind, and after due consideration of the endurance limits of a three year old daughter and a 1936 Pontiac, my wife, the aforementioned daughter and myself embarked one July night in 1950 from the pleasant suburb of LaGrange for the north-west corner of Illinois, and the famed deposits of galena in the Tri-State region.

The night ride west on Route 64 was uneventful, the daughter slept as we had hoped, and we eventually found lodgings in the wee hours of the morning in a hotel in Savanna, Illinois, Up reasonably early the next morning, our first sight of the Mississippi was a great thrill to us all. What boy weaned on Mark Twain wouldn't feel a sense of completeness when he stands on the banks of that great river? If he squints the least bit, he can soon make out a raft over by the far bank, and if he listens carefully, he can hear the paddles splashing as the packet from Cairo cuts up the channel below the bend.

It was a beautiful morning, and the road map showed the Mississippi Palisades Park to be nearby, so we headed for that. It turned out to be well worthwhile. There is a lovely trail that winds up to the Twin Sisters, an interesting formation of weathered limestone. Part of the trail is paved with limestone slabs, and one of these slabs stopped us in our ascent. Embedded in its surface were at least a dozen museum-quality fossils which I will have the temerity to call cephalopods. But cephalopods or brachiopods, only the utmost efforts of my wife and a few shreds of conscience restrained me from carrying the entire slab back to the car.

The swift passage of the morning recalled us to our original destination, and we pressed on to Galena. Once in town, we had the familiar experience of asking a number of people before we found one who could direct us to any mining operations in the vicinity. Our informant's directions led us to the Eagle-Pitcher mine, as I recall, not far out on the cutskirts of town. This mine and mill proved to be a very business-like and distressingly tidy place. No casual piles of ore, or even tailings. I finally screwed up courage to venture into the mine office, where to my surprise, no one pounced on me, in fact no one paid me the slightest attention! Eventually I sidled up to a busy clerk and asked him if he knew where I might find a specimen of lead or zinc ore. He said smilingly that he didn't know just what I wanted, but there was a chunk of ore down there on the floor holding the door open that I was welcome to if I wanted it. I thanked him, and eagerly carried off my loot. It proved to be an excellent specimen of both galena and sphalerite, or blende, arranged in concentric layers to form a nodular mass as big as a grapefruit. Meanwhile my wife and daughter had discovered a small pile of waste rock, and there we found some beautiful specimens of mixed crystalline calcite, pyrite, and sphalerite. We still didn't have any really pleasing specimens of nice shiny galena, so we decided to look for a new site.

Back in Galena, we secured directions to the Tri-State Mine, which proved to be way back in the hills at the end of five miles of very bumpy dirt road. This mine consisted simply of a steeply sloping road leading into a dark tunnel which disappeared into the hillside. In the hot July afternoon, a pleasantly. cool mist nrose gently from the mine entrance. As I busied myself on a pile of waste rock, my wife found a patch of wild mustard, which she proceeded to harvest. A couple of empty dynamite boxes seemed to make ideal containers for our specimens and our mess of greens, but for a few minutes both rocks and mustard were forgotten when it was discovered that a family of wasps had laid prior claims to the dynamite boxes. A few good specimens of galena were found. here, and soon the setting sun and the increasing irritability of the three year old urged us to make tracks for food and rest.

Starting home the next morning, we decided to cross over into Iowa, just so we could say we had been there. There are several quarries near Dubuque, but we failed to find anything of interest there. Turning east again, we drove through the pleasantly rolling countryside of southern Wisconsin. Both active and abandoned lead and zinc mines abound in this area, and while we did not find any specimens of truly museum quality, it is easy to obtain interesting samples of the typical ore minerals of this region.

-- Alan D. Kattelle --

Fossils of a Prehistoric Rainforest Hide in Australia’s Rusted Rocks #fossil #paleontology #rainforest #australia #spider #insect

An ancient spider, which Dr. Frese likens to “squishy bags of liquid.”Credit...Michael Frese

The New York Times Trilobites column has a story about the discovery of a fossil rain forest in the outback of Australia.  The deposit is located hundreds of miles northwest of Sydney in a place called McGraths Flat.  The fossils date to the Miocene Epoch when Australia was much wetter.  There's flowers, insects, spiders, and even a feather.  The discovery is documented in a paper called "A Lagerstätte from Australia provides insight into the nature of Miocene mesic ecosystems" published in the journal Science Advances.

Fifteen million years ago, a river carved through the jungle, leaving an oxbow lake (known as a billabong in Australia) in its wake at McGraths Flat. Nearly devoid of oxygen, this stagnant pool kept scavengers at bay, allowing plant material and animal carcasses to accumulate. As iron-rich runoff from nearby basalt mountains seeped into the billabong, the pool’s low pH caused the iron to precipitate and encase the organic material. As a result, the fossils at McGraths Flat are preserved in a dense, iron-rich mineral known as goethite.

This method of fossilization is uncommon, Dr. Hocknull said. Because quality fossils are rarely found in iron deposits, paleontologists often overlook them. However, the fossils from McGraths Flat illustrate that goethite, which is common in Australia, can yield remarkable fossils.

“There’s no shortage of goethite,” Dr. Hocknull said. “We’re essentially a rusting country.”

New armless abelisaur dinosaur species discovered in Argentina #dinosaur #paleontology #fossil #argentina

Guemesia ochoai could have looked similar to relatives such as Carnotaurus sastrei (pictured). Credit: Fred Wierum, licensed under  CC BY-SA 4.0 via Wikimedia Commons

Phys.org has a story about an armless therapod dinosaur.  Many of the large predatory dinosaurs had reduced arms and hands with Tyrannosaurs and South American Giganotosaurus and Carnotaurus as prime examples.  Now, a new species of abelisaur, Guemesia ochoai, has taken it a step farther.  G. ochoai lived about 70 million years ago in what is modern day Argentina.  All the details can be found in a paper by Frederico Agnolin et al in the Journal of Vertebate Paleontology.

A new dinosaur which formed part of an array of 'unusual' creatures has been discovered in Argentina.

The new species, Guemesia ochoai, could be the close relative of the ancestors of an armless group of dinosaurs, which roamed the southern hemisphere over 70 million years ago.

A partially complete skull uncovered in Argentina provides new evidence of a unique ecosystem during the Late Cretaceous.

Guemesia ochoai was a species of abelisaurid, a clade of carnivores which roamed what is now Africa, South America and India. Dating back around 70 million years, the dinosaur may have been a close relative of the entire group's ancestors.

The discovery of Guemesia ochoai's skull offers a valuable insight into an area which has very few abelisaurid fossils, and may go some way to explain why the area gave rise to such unusual animals.

Professor Anjali Goswami, Research Leader at the Museum and co-author, says, "This new dinosaur is quite unusual for its kind. It has several key characteristics that suggest that is a new species, providing important new information about an area of the world which we don't know a lot about.

"It shows that the dinosaurs that live in this region were quite different from those in other parts of Argentina, supporting the idea of distinct provinces in the Cretaceous of South America. It also shows us that there is lot more to be discovered in these areas that get less attention than some of the more famous fossil sites."

Mazon Monday #112: Concretion Shape from 1952 #fossil #paleontology #MazonCreek #MazonMonday #concretions

This is Mazon Monday post #112.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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Lately, we've been getting a bunch of questions about concretion shape, probably due to the Braceville field trip this past weekend.  It's an age old question that repeats again and again.  Back in March 1952, Stevens T. Norvell, a founding member of ESCONI and its first treasurer, wrote "Our Fossil Ferns - Why They Occur in Form-Fitting Pebbles" for the newsletter.   The information is still mostly relevant today. 

Our Fossil Ferns - Why They Occur in Form-Fitting "Pebbles" by Stevens T. Norvell

Why you may very well ask is it that the fossil ferns which we collect in the ' nearby strip mines are always inside of pebbles, and why is it that the size of the enclosing pebble is proportional to the size of the enclosed leaf, that is big fronds are inside of big pebbles, little leaves are inside of little pebbles and medium size leaves are in medium size pebbles. Likewise, long leaves are in long pebbles and round leaves are in round pebbles. This situation is indeed peculiar to say the least. It almost looks like the leaf itself had some thing to do with the size and shape of the pebble. Well, that is exactly right, the leaves did have a lot to do with the formation of the enclosing pebbles.

In the first place let us dispose of that word "pebble". These are not pebbles at all. Pebbles are pieces of rock broken from a large rock mass and then rolled along a stream-bed until they are nicely rounded. What we are dealing with here are not pebbles because they never were part of a large rock mass, and they did not become rounded by rolling along a stream-bed. So in stead of calling them pebbles we shall call them "concretions", meaning that they are masses of natural concrete. This is not a figure of speech. The rock crypts in which the fossils have reposed for millions of years are actually produced by silt or clay being cemented.

Now let us study this phenomenon by following in our minds eye, a leaf or a frond from the time it falls or is blown from the parent plant until we have it, in fossil form safely in our specimen cabinet. The falling leaf lands en or is blown onto the water of the nearby swamp. Here it floats for a day or so until it becomes "waterlogged" and then it sinks to the bottom. At that particular time the bottom of our swamp was clay or silt and more clay or silt was constantly settling from the roilly water. Soon our leaf was covered, buried in a layer of mud which was quite homogeneous. Probably there. was no definite mark to show where the surface of the mud happened to be when our leaf came to rest upon it. Now, in strictly fresh water the leaf would soon have decayed. But this was swamp water which is as you know quite another matter. Being deficient in oxygen as all swamp water is, this water was a pretty good bactericide, especially for bacteria that require much free oxygen, and the bacteria of decay are just such aerobic organisms. So decay did not take place. However certain anaerobic bacteria, bacteria that could get along without free oxygen, did have some effect on the leaf but not very much, just enough to cause the production of a comparatively small amount of organic acid. This acid gradually dispersed outward from its source, and as it did so it came into contact with the clay and with the iron-disulfide, FeS₂ (one atom of iron, F, to 2 atoms of sulfur, S) dissolved in the water. Between them they form a cement, and of course, the more acid there was the larger was the ball of cement that resulted. In other words a large frond produced more acid than a small one could produce and therefore, a larger ball of cement formed around a large frond than formed around a small leaf. This accounts for not only the size of the concretion but also for its shape which as we have already noted, pretty well follows the outline of the leaf. In fact, the margin around a leaf as it is exposed when the concretion is opened is a sort of a dispersion diagram. By studying it closely you can easily visualize and can mark with a pencil the various paths followed by the acid as it dispersed outward from the leaf.

Another question: Why is it that most of the concretions split just right to expose the fern to the best advantage? Well, since the leaf formed a sort of a partition between the cement above the leaf and that below, it created a plane of weakness. When you tap the concretion on the side (edge), the break occurs along this natural cleavage plane.

At the time the shovels bring the fossils up from the pit and dumps them on the tailing piles they are bluish-gray in color, same as all the rest of the debris. After being exposed to the elements for a few months the concretions begin to turn red. The reason for this is that the iron which was locked up at the time the concretions were formed is now turning to that well known form, the mineral hematite, Fe₂0₃. The concretions are readily seen now because their color makes them stand out against the blue-gray background. At the time the concretions formed at least 250,000,000 years ago there was just as much iron in the mud between the concretions as there was in the concretions, but that in the concretions was "locked up", chemically speaking, while that in the rest of the mud was not. As a result, down through the millions of years since then most of the free iron-disulfide has been leached out, carried away by percolating ground waters. That in the concretions could not be leached as it was bound up too firmly in the chemical compounds of the concretion.

For a more modern view try Gordon Baird, Steven Sroka, Charles Shabica, and Gerald Kuecher "Taphonomy of Middle Pennsylvanian Mazon Creek Are Fossil Localities, Northeast Illinois: Significance of Exceptional Fossil Preservation in Syngenetic Concretions" in Palaios in 1986.

Abstract

Mazon Creek area fossil localities (Pennsylvanian: Westphalian D) in northeast Illinois provide an extraordinary preservational "window" for the study of Late Paleozoic terrestrial, fresh-water, and estuarine marine organisms. Marine animals were killed by episodic pulses of turbid fresh water associated with flooding from distributaries, and terrestrial organisms were introduced into coastal waters from upstream sources. Rapid burial entombed remains, commonly before significant decomposition had occurred, and very early diagenesis ensured fossil preservation as molds and composite impressions within sideritic concretions. The taphonomy of these deltaic, fossil-bearing beds is complex. Episodic engulfment of organisms is indicated by animal escape activity and by the presence of upended plant fragments. Numerous, distinctive, cyclic repetitions of siltstone-claystone laminae, each recording a single tidal (flood-ebb) event, are observed in areas yielding marine organisms; these indicate that rapid but extremely regular deposition was also important. Concretion formation was probably influenced, but not necessarily triggered, by decay processes. Siderite precipitation reflects three key conditions: the availability of iron, rapid burial of organic material, and a low to nonexistent supply of sea-water sulfate to centers of interstitial microbial activity. A regional (seaward) decrease in the quality of fossil preservation is observed away from the coastal depocenter, and an interval of sparsely fossiliferous facies (a taphonomic discontinuity) occurs between the delta complex and shell-rich, normal marine deposits. The preservational significance of early diagenetic siderite is discussed; we argue that paleoenvironmental interpretations of analogous or similar nearshore deposits lacking fossiliferous concretions must be made cautiously. The potential value of Mazon Creek-type facies in the study of other Pennsylvanian nearshore deposits, including many superficially "barren" shales, is stressed. The association of the fossil-bearing concretions with inferred estuarine-deltaic fades points to the need for future actualistic studies of comparable modern coastal environments.

Or, Thomas Clements, Mark Purnell, and Sarah Gabbott in "The Mazon Creek Lagerstatte: a diverse late Paleozoic ecosystem entombed within siderite concretions" in 2018.

Abstract

One of the best records of late Paleozoic ecosystems, the Mazon Creek Lagerstätte is world famous for its striking flora and fauna preserved within siderite concretions. Distinct from other late Carboniferous concretionary Lagerstätten because of the remarkable fidelity of soft tissues and pigments that are frequently preserved, the Mazon Creek has seen a revival in investigations during the last 10 years using modern palaeontological techniques. However, many of these modern investigations build upon a literature that incorrectly interprets the palaeoenvironment of the Mazon Creek and the separate biotas: there is a lack of evidence to support a distinct freshwater fauna. Here, we present a detailed overview of the Mazon Creek Lagerstätte, including the palaeoenvironmental conditions, organisms present and the complex taphonomic processes involved in fossil formation. Investigation into the formation of siderite concretions and the complex taphonomic processes controlling soft-bodied preservation are still continuing but are reviewed in detail.

Or, S. Cotroneo, J. D. Schiffbauer, V. E. McCoy, U. G. Wortmann, S. A. F. Darroch, Y. Peng, and M. Laflamme in "A new model of the formation of Pennsylvanian iron carbonate concretions hosting exceptional soft-bodied fossils in Mazon Creek, Illinois"  in GeoBiology from 2016.

Abstract

Preservation of Pennsylvanian-aged (307 Ma) soft-bodied fossils from Mazon Creek, Illinois, USA, is attributed to the formation of siderite concretions, which encapsulate the remains of terrestrial, freshwater, and marine flora and fauna. The narrow range of positive δ34S values from pyrite in individual concretions suggests microenvironmentally limited ambient sulfate, which may have been rapidly exhausted by sulfate-reducing bacteria. Tissue of the decaying carcass was rapidly encased by early diagenetic pyrite and siderite produced within the sulfate reduction and methanogenic zones of the sediment, with continuation of the latter resulting in concretion cementation. Cross-sectional isotopic analyses (δ13C and δ18O) and mineralogical characterization of the concretions point to initiation of preservation in high porosity proto-concretions during the early phases of microbially induced decay. The proto-concretion was cemented prior to compaction of the sediments by siderite as a result of methanogenic production of 13C-rich bicarbonate—which varies both between Essex and Braidwood concretions and between fossiliferous and unfossiliferous concretions. This work provides the first detailed geochemical study of the Mazon Creek siderite concretions and identifies the range of conditions allowing for exceptional soft-tissue fossil formation as seen at Mazon Creek.

Construction Workers Uncover Massive 800-Year-Old Aztec Dwelling in Mexico City #history #archaeology #aztec #mexicocity

An electrical works project led archaeologists to uncover this Aztec-era dwelling.  Mexico's National Institute of Anthropology and History (INAH)

Smithsonian Magazine has a story about an accidental archaeological find in Mexico City.  Construction workers unearthed the remains of a large house while renovating an electrical substation.  The structure, which measures about 4300 square feet, dates to the late Postclassic period maybe 800 years ago.  It is fairly common to uncover Aztec ruins in Mexico City,  In 2017, renovations on a historic pawnshop led to the discovery of a palace built by Henan Cortes.

The house’s location itself is unique, as it borders two neighborhoods not far from Tenochtitlan, which became the Aztec capital around 1325 C.E. Based on modern-day standards, the residence is vast: The remains stretch over more than 4,300 square feet, archaeologists say.

The findings show that the area was not only an important place to live but to work using the chinampas farming technique typical of the time. The Aztec agricultural system relied on “floating gardens”—patches of seemingly self-sustaining land that appear to float along shallow bodies of water. A pier with wooden beams that stretch up to 130 feet and connected channels found at the site demonstrate how the location would have functioned as part of a larger whole.

Even today, some Mexico City residents still use this farming method, reported Conde Nast Traveler's Megan Zhang in 2021. The tactic, which allowed the Aztecs to claim fertile land from the area’s wetlands, is now used by organic farmers.

PBS Eons: When Ants Domesticated Fungi #fossil #ants #paleontology #insects #fungi #evolution

There's a new episode of PBS Eons.  This one is about one of Earth's first farmers... ants!

While we’ve been farming for around 10,000 to 12,000 years, the ancestors of ants have been doing it for around 60 million years. So when, and how, and why did ants start … farming?

TRIP FULL! - ESCONI Field Trip to a Belvidere Quarry Saturday, May 21st, 2022, 9:00 AM - 12:00 PM #ordovician #quarry #fossil #fieldtrip #illinois #belvidere #limestone

THE TRIP IS FULL!  It filled up in less than an hour!  We are still accepting requests, which will place you on the waiting list.  Please let us know if you can't make it, as it makes room for those on the waiting list.  Thanks!

There will be a field trip to a quarry near Belvidere, Illinois on Saturday, May 21, 2022, from 9 AM to 12 noon.

The rock is Ordovician, Galena Group. This is a "hard-rock" quarry (dolomite). If you like Hormotoma or Receptaculites, this is the place for you! The quarry has been active so there is new rock exposed.

If you are sick, have symptoms of Covid 19 or have tested positive recently, DON'T COME!

Rules

1. Everyone in your group MUST be an ESCONI member when you register for this trip.
2. Everyone in your group MUST be at least 18 years of age.
3. Everyone MUST have and wear a hard hat, safety vest, and sturdy boots while in the quarry. No sandals, tennis shoes, and the like. No claw hammers or roofing hammers - use only rock hammers. If you plan on hammering then bring eye protection and wear it.
4. Sign up by sending me (Dave) an email with the number of members attending and their names. My email is [email protected] No phone calls please.
5. I will acknowledge by return email. If you don't get a reply in 24 hours, send it again!
6. Maximum attendance by ESCONI members is 18. This is a shared trip with the Rock River Valley Gem and Mineral Society.
7. Please review the Code of Ethics and Conduct on the ESCONI website. You will be expected to check-in at the quarry. By doing so you agree to follow the Code of Ethics and the conditions on the ESCONI Liability and Waiver form (sent by email to those that sign up). You do not need to print out the ESCONI waiver form, just know what you’re agreeing to. There may be an additional waiver from the quarry.

The address of the quarry will be sent to those that sign up.

I will distribute the waiver forms by email to those signed up just before the trip.

Questions? Send me an email...