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Wooster’s Fossil of the Week: A conulariid revisited (Lower Carboniferous of Indiana)

July 31st, 2015

Conulariid03 585

This summer I’ve been updating some of the photos I placed in the Wikipedia system (check them out here, if you like; free to use for any purpose). I was especially anxious to replace a low-resolution image I had made of an impressive conulariid (Paraconularia newberryi) from the Lower Carboniferous of Indiana. The new version is above. Since I used the same specimen as a Fossil of the Week exactly four years ago to the day, I thought I’d take advantage of a slow summer and update that earlier text for this week:

I have some affection for these odd fossils, the conulariids. When I was a student in the Invertebrate Paleontology course taught Dr. Richard Osgood, Jr., I did my research paper on them. I had recently found a specimen in the nearby Lodi City Park that was so different from anything I had seen that I wanted to know much more. I championed the then controversial idea that they were extinct scyphozoans (a type of cnidarian including most of what we call today the jellyfish). That is now the most popular placement for these creatures today, although I arrived at the same place mostly by luck and naïveté.

The specimen above is Paraconularia newberryi (Winchell) found somewhere in Indiana and added to the Wooster fossil collections before 1974. A close view (below) shows the characteristic ridges with a central seam on each side.

Conulariid01 585Conulariids range from the Ediacaran (about 550 million years ago) to the Late Triassic (about 200 million years ago). They survived three major extinctions (end-Ordovician, Late Devonian, end-Permian), which is remarkable considering the company they kept in their shallow marine environments suffered greatly. Why they went extinct in the Triassic is a mystery.

ConulataThe primary oddity about conulariids is their four-fold symmetry. They had four flat sides that came together something like an inverted and extended pyramid. The wide end was opened like an aperture, although sometimes closed by four flaps. Preservation of some soft tissues shows that tentacles extended from this opening. Their exoskeleton was made of a leathery periderm with phosphatic strengthening rods rather than the typical calcite or aragonite. (Some even preserve a kind of pearl in their interiors.) Conulariids may have spent at least part of their life cycle attached to a substrate as shown below, and maybe also later as free-swimming jellyfish-like forms.

It is the four-fold symmetry and preservation of tentacles that most paleontologists see as supporting the case for a scyphozoan placement of the conulariids. Debates continue, though, with some seeing them as belonging to a separate phylum unrelated to any cnidarians. This is what’s fun about extinct and unusual animals — so much room for speculative conversations!

References:

Driscoll, E.G. 1963. Paraconularia newberryi (Winchell) and other Lower Mississippian conulariids from Michigan, Ohio, Indiana, and Iowa. Contributions from the Museum of Palaeontology, The University of Michigan 18: 33-46.

Hughes, N.C., Gunderson, G.D. and Weedon, M.J. 2000. Late Cambrian conulariids from Wisconsin and Minnesota. Journal of Paleontology 74: 828-838.

Sendino, C., Zagorsek, K. and Taylor, P.D. 2012. Asymmetry in an Ordovician conulariid cnidarian. Lethaia, 45: 423-431.

Van Iten, H.T., Simoes, M.G., Marques, A.C. and Collins, A.G. 2006. Reassessment of the phylogenetic position of conulariids (?Vendian–Triassic) within the subphylum Medusozoa (Phylum Cnidaria). Journal of Systematic Palaeontology 4, 109–118.

 

Glacier Bay 2015

July 30th, 2015

Guest Blogger: Dan Misinay

This summer Dr. Wiles, Nick, Jesse Wiles, and myself traveled to Glacier Bay National Park and Preserve. We spent our six days in upper Muir Inlet at Wolf Point. Our purpose this summer was to bridge a crucial gap in the tree ring record around 1700-2000 years B.P. As well as bridging the tree ring record gap, we are aiming to provide a better glacial history for the region. While we were there, we collected 22 sections and 13 cores. The sections and cores are sitka spruce and mountain hemlock. We collected samples from McBride Inlet, Wolf Point Creek, Nunatak Mountain, White Thunder Ridge, and Stump Cove. We also scouted some other promising areas for future projects. All pictures used in this blog were taken by Jesse Wiles.

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Our first day in the park at McBride Inlet. The large icebergs in the background are everywhere in the inlet due to the constant calving of McBride Glacier.

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More icebergs that are washed up on shore during low tide at McBride.

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A large spruce stump in situ in a large delta at McBride with Nick for scale. McBride Glacier is faintly visible in the background around the corner.

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Me searching for logs and taking note of the sedimentology of the delta at McBride.

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Our second day led us on a strenuous trek through wolf point to get to a promising lake. On the way to the lake we found a nice moose shed in a creek.

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Me crashing through the young alder at the shore of the lake at Wolf Point.

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After determining that the lake was too much for us to cross in a day, we headed back through a decent size stream. Me knee deep preparing to go back into the brush because of a large set of rapids ahead.

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Once the clouds and rain subsided, the days and evenings were very clear and the alpine glow on the mountains was a nightly occurrence.

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Days 3 and 4 were spent at the Nunatak Mountain and fan because on our  first attempt we were unable to cross a stream to access the alluvial fan. Nick and I walking along a stream and glacial moraine.

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When we finally made it to the Nunatak Fan on day 4 we found a nice selection of detrital logs through out the fan. Nick and Dr. Wiles core a detrital log while I watch.

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Since day 5 fell on the Fourth of July, Dr. Wiles decided to have tourist day. We went up the inlet and visited Riggs Glacier. We kayaked around 12 miles up and down the inlet.

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Before we made it to Riggs Glacier, we stopped at an alluvial fan along the inlet at White Thunder Ridge. We found some nice logs. This is an example of a section that was taken from White Thunder Ridge.

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Day 6, which was our final full day in the field, we went to Stump Cove. This is a picture of the delta at the bottom of the alluvial fan at stump cove.

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Nick taking a core of the only other in situ stump we found. The stump was about half way up the large delta at Stump Cove.

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One of the grizzly bears we saw while in the park. This was a smaller bear that we saw at Stump Cove walking the shore line. The bears usually came out at low tide to feed on any organisms that got washed up on the shore. They also flip rocks to find food like this bear was doing in the picture.

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A nice picture of a humpback whale tail we saw on the last day while boating back to the National Park station. While boating in the the inlet, we saw a lot of humpback whale fins and breaches. However, we did not see any orca (killer whale).

Wooster’s Fossil of the Week: A calcareous sponge from the Lower Cretaceous of England

July 24th, 2015

Raphidonema faringdonense 070715a 585One of my favorite fossil localities is a gravel pit in Oxfordshire, England. Gravel pits are not usually good for fossil collecting given their coarse nature and high-energy deposition, but the Lower Cretaceous (Aptian) Faringdon Sponge Gravels are special. They are tidal gravels sitting unconformably over Jurassic rocks that have an extraordinary diversity and abundance of marine fossils, both from the Cretaceous and reworked from the Jurassic below. I have previously described in this blog bored cobbles, bryozoans, ammonites and a plesiosaur vertebra from this unit. Above is one of the most characteristic fossils from Faringdon, the calcareous sponge Raphidonema faringdonense (Sharpe, 1854).
Raphidonema faringdonense 070715b 585This is a view of the upper surface of this sponge. Like most sponges it was a filter-feeder sitting stationary on the seafloor. This one was probably attached to a cobble in the gravel. It is in the Class Calcarea because it has a fused network of calcitic spicules making up its skeleton. This is why it has remained a very resistant, rigid object long after death. It probably spent some time rolling around in those gravels with the tidal currents.
Sophie Faringdon 2007The Faringdon Sponge Gravels are a member of the Faringdon Sand Formation. They are cross-bedded gravels that have been mined for construction purposes since Roman times. Above is Wooster Geologist Sophie Lehmann (as a student) when she and I visited one of the gravel pits in 2007. For the record, this sponge comes from the Red Gravel, 5.5-8.5 meters above the disconformity with Oxfordian limestones, in the Wicklesham gravel pit on the southeast edge of Faringdon, Oxfordshire (51.647112° N, 1.585094° W).

after Maull & Polyblank, photogravure, circa 1856

Daniel Sharpe FRS (1806-1856) named Raphidonema faringdonense in 1854. He was born in Marylebone, Middlesex, England. His mother died shortly after his birth and he was raised by his uncle Samuel Rogers, a literary figure of some merit. He entered the mercantile business as an apprentice when he was 16, and he stayed connected with trading the rest of his life. His first research as a geologist (and this was very early in the discipline of geology) was examining geological structures around Lisbon, Portugal. He then studied the strata of north Wales and the Lake District of England. Sharpe was an early opponent of Adam Sedgwick in a dispute over the Cambrian, which brought him some notoriety among English geologists. His most prominent geological work was sorting out what rock cleavage meant in regard to stress and strain, using distorted fossils as part of his evidence. He died as the result of a riding accident in 1856, shortly after he had been elected president of the Geological Society of London.

Sorting out the taxonomic history of Raphidonema faringdonense is more complex than I would have expected for such a simple fossil. I’m using the most common version of the name, but we also see “farringdonense“, “faringdonensis” and farringdonensis“. (I know. Who worries about such things?)
Manon farringdonense Sharpe figuresManon farringdonense description 1854Above are Sharpe’s original figures of Raphidonema faringdonense, along with his description (and the nice bryozoan Reptoclausa hagenowi below). We can see that he spelled the species name with a double r in keeping with a common spelling of the village’s name then. I don’t know when we lost one of those letters.

Just to add to the complexity, Raphidonema is also the genus name of a filamentous green alga. Since it is not an animal, though, there is no legal problem with having the name also refer to a sponge. (There should be a rule against such homonymy, but there’s not.)

References:

Austen, R.A.C. 1850. On the age and position of the fossiliferous sands and gravels of Faringdon. Quarterly Journal of the Geological Society of London 6: 454-478.

Lhwyd, E. 1699. Lithophylacii Britannici Ichnographia. 139 pp. London.

Pitt, L.J. and Taylor, P.D. 1990. Cretaceous Bryozoa from the Faringdon Sponge Gravel (Aptian) of Oxfordshire. Bulletin of the British Museum, Natural History. Geology 46: 61-152.

Sharpe, D. 1854. On the age of the fossiliferous sands and gravels of Farringdon and its neighbourhood. Quarterly Journal of the Geological Society of London 10: 176-198.

Wilson, M. A. (1986). Coelobites and spatial refuges in a Lower Cretaceous cobble-dwelling hardground fauna. Palaeontology, 29(4), 691-703.

Team Columbia returns in high spirits with bountiful samples!

July 22nd, 2015

I.S. students, Kaitlin and Maddie enjoying the sunshine and representing Wooster below a fascinating ice tunnel.

I.S. students, Kaitlin and Maddie enjoying the sunshine and representing Wooster below a fascinating ice tunnel.

Guest Bloggers: Maddie Happ and Kaitlin Starr (Girdwood, Alaska)

Team Columbia is back from an exciting 8 days in the field.  Dr.Wiles, Nick Wiesenberg, Maddie Happ and Kaitlin Starr traveled via helicopter to Columbia Bay, Alaska beginning July 15th and returning July 21st. The first half of the trip was spent on the West Branch of Columbia Bay. Despite rainy days and blustery winds, we accomplished quite a bit of work! During our time on the West Branch, the team updated an old growth site, known as the Rock Tor, and collected samples from another living tree site near Kadin Lake. In addition to these living tree samples, the team collected cores and cross sections from newly exposed wood that were killed during the initial advance of Columbia Glacier.

    Kaitlin recording sample numbers and GPS locations at our first site.

Kaitlin recording sample numbers and GPS locations at our first site.

On July 18th, we were transferred across the bay to a location known as the Land Lobe. The team created base camp on the Great Nunatak side of the Land Lobe, as opposed to past years when groups were limited to the moraine due to the previous glacier terminus. Finally, the weather gods were on our side, and abundant sunshine allowed for productive days. We collected samples from the fans surrounding our base camp. On our last night in Columbia, we climbed to the tree line to update another living tree site titled the Son of the Great Nunatak. The alpine forest made for a wonderful last dinner in the Alaskan wilderness. On our final morning (with great weather still hanging on), Dr.Wiles and Nick recieved helicopter support to jump across the river to the other side of the Land lobe, where they collected newly exposed samples to complete a previously sampled site.

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Team Columbia enjoying sunshine and exploring sites at our second camp near the Great Nunatak.

Team Columbia encountered a few minor setbacks throughout the trip, including gritty oatmeal, killer porcupines, and constant stumbling (particularly near waterfalls); however, it was a fabulous adventure overall! I.S. students, Maddie and Kaitlin are excited to return to the Wooster Tree Ring Lab and begin exploring the great stories behind these logs.

    Photo of the East Branch of Columbia Glacier captured from the helicopter.

Photo of the East Branch of Columbia Glacier captured from the helicopter.

Wooster’s Fossil of the Week: A coiled nautiloid from the Middle Devonian of Ohio

July 17th, 2015

Goldringia cyclops Columbus Ls Devonian 585The above fossil is a nautiloid cut in cross-section, showing the large body chamber at the bottom and behind it to the left and above the phragmocone, or chambered portion of the conch (shell). It is a species of Goldringia Flower, 1945, found in the Columbus Limestone (Middle Devonian, Eifelian) exposed in the Owen Stone Quarry near Delaware, Ohio. It is a nice specimen for both what it shows us about a kind of nautiloid coiling and for clues to its preservation.

This specimen was originally labelled Gyroceras cyclops Hall, 1861. In 1945, Rousseau Flower designated this taxon the type species of Goldringia. I can’t tell if we really have G. cyclops here or some other species, so I’m leaving it at the genus level. The old name lingers, though, in the term for this kind of open coiling: gyroceraconic. It is one of the earliest examples of the nautiloids having the phragmocone positioned above the body chamber, presumably for stable buoyancy.
Pentamerid embedded 071315I like the clues to the early history of this conch after death. The chambers are entirely filled with sediment, a fossiliferous micrite. You can see places where the original shell was broken and larger bits infiltrated, like the whole brachiopod shown above. This brachiopod appears from its cross-section to be a pentamerid. Also visible are strophomenid brachiopods and gastropods.
Winifred GoldringRousseau Hayner Flower (1913–1988) described Goldringia in 1945. He doesn’t directly say who he named it after, but he thanks “Dr. Winifred Goldring of the New York State Museum” in the acknowledgments. We can tell Flower’s story later (and it’s a good one), but this gives us a chance to introduce Winifred Goldring (1888-1971). She was the first paleontologist to describe the famous Gilboa fossil flora (Devonian) in upstate New York, and she was the first woman State Paleontologist of New York (or anywhere, for that matter). (Now there is Lisa Amati in this prestigious position. Congratulations, Lisa!) Goldring grew up near Albany, New York, one of nine children in a very botanical family. She graduated from Wellesley College in 1909 with a bachelor’s degree in geology (very unusual for a woman at the time). She stayed at Wellesley to earn a master’s degree (1912). She also taught geology courses at Wellesley. In 1913 she studied geology at Columbia University with the famous Amadeus Grabau. In 1914, Goldring joined the scientific staff at the New York State Museum as a “scientific expert”. She worked her way up through the many ranks there to become State Paleontologist in 1939. She is best known as a paleontologist for her work with the fascinating Gilboa fossil forest, bringing her early upbringing by botanists to full circle. Along the way she was the first woman president of the Paleontological Society (in 1949) and vice-president of the Geological Society of America (in 1950). A hero of paleontology.

References:

Flower, R.H. 1945. Classification of Devonian nautiloids. American Midland Naturalist 33: 675–724.

Goldring, W. 1927. The oldest known petrified forest. Scientific Monthly 24: 514–529.

Koninck, L.G.D. 1880. Faune du Calcaire Carbonifere de la Belgique, deuxieme partie, Genres Gyroceras, Cyrtoceras, Gomphoceras, Orthoceras, Subclymenia et Goniatites. Annales du Musee Royal d‘Histoire Naturelle, Belgique 5: 1–333.

Wooster’s Fossil of the Week: A small lobster from the Lower Cretaceous of North Yorkshire, England

July 10th, 2015

Meyeria ornata fullMae Kemsley (’16) found this little beauty during her Independent Study fieldwork last month on the Speeton Cliffs of North Yorkshire. It is Meyeria ornata (Phillips, 1829), a decapod of the lobster variety, from the Speeton Clay. It is relatively common in Bed C4, so much so that it is referred to as “the shrimp bed”. Mae is the only one of our team of four who found one, though, so it is special to us. The above is a lateral view, with the head to the left and abdomen on the top of this small concretion.
Dorsal Meyeria ornataHere is a dorsal view looking down on the abdominal segments.
Screen Shot 2015-07-01 at 9.14.03 PMSimpson and Middleton (1985, fig. 1b) have this excellent diagram of Meyeria ornata in life position. The scale bar is one centimeter. “Details of pleopods, third maxillipeds and first antennae of M. ornata unknown. Dashed line represents length of extended abdomen. Symbols: a branchiocardiac groove; c postcervical groove; e cervical groove; m3 third maxilliped; p pereiopod; pi pleopod; t telson; u uropods; x ‘x’ area; r rostrum; al first antennae; a2 second antennae; ar antennal ridge; sr suborbital ridge; 1,2,3. branchial ridges.”

According to Simpson and Middleton (1985), Meyeria ornata actively crawled about on the muddy substrate like modern lobsters. They did not have true chelae (large claws), so they were likely scavengers in the top layers of the sediment rather than predators.

3 Mae working 060915Mae at work.

References:

Charbonnier, S., Audo, D., Barriel, V., Garassino, A., Schweigert, G. and Simpson, M. 2015. Phylogeny of fossil and extant glypheid and litogastrid lobsters (Crustacea, Decapoda) as revealed by morphological characters. Cladistics 31: 231-249.

M’Coy F. 1849. On the classification of some British fossil Crustacea with notices of new forms in the University Collection at Cambridge. Annals and Magazine of Natural History, series 2, 4, 161-179.

Phillips, J. 1829. Illustrations of the geology of Yorkshire, Part 1. The Yorkshire coast: John Murray, London, 184 p.

Simpson, M.I. and Middleton, R. 1985. Gross morphology and the mode of life of two species of lobster from the Lower Cretaceous of England: Meyeria ornata (Phillips) and Meyerella magna (M’Coy). Transactions of the Royal Society of Edinburgh: Earth Sciences 76: 203-215.

Classifying the unknown: the lunar edition

July 7th, 2015

New York, NY – [Guest Blogger Annette Hilton]

This summer I have the privilege of working and living in New York City at the American Museum of Natural History. I, along with several other students, have the opportunity to work with the museum’s researchers through an REU (Research Experience for Undergraduates) program funded by the National Science Foundation.

Front entrance of the American Museum of Natural History (AMNH).

Front entrance of the American Museum of Natural History (AMNH).

Entrance to the Earth and Planetary Sciences Department, AMNH.

Entrance to the Earth and Planetary Sciences Department, AMNH.

As a geologist, I am working in the Earth and Planetary Sciences Department. I am under the mentorship of Dr. Juliane Gross, a research associate at the museum. Together we have been working with a small sample from an unnamed lunar meteorite found in Northwest Africa. Our goal for the end of the summer is to classify and name this mysterious lunar meteorite.

Photo from: http://www.nasa.gov/sites/default/files/moon_and_earth_lroearthrise_frame_0.jpg

Photo from: http://www.nasa.gov/sites/default/files/moon_and_earth_lroearthrise_frame_0.jpg

Meteorites are undoubtedly cool, but why should we care so much about the Moon? According to the Giant Impact Hypothesis, around 4.5 Ga proto Earth collided with another planetary body called Theia. Though an extremely violent impact, Earth quickly reformed and the remaining debris circled our planet, eventually forming the Moon. This theory is generally accepted but still under reform. We know that the Moon and Earth are extremely similar in composition, making their dual formation likely.

What the formation of Earth and the Moon may have looked like.  Photo from: http://www.dailymail.co.uk/sciencetech/article-2650130/How-moon-formed-Researchers-reveal-new-evidence-Earth-hit-giant-object-4-5-billion-years-ago.html

What the formation of Earth and the Moon may have looked like.
Photo from: http://www.dailymail.co.uk/sciencetech/article-2650130/How-moon-formed-Researchers-reveal-new-evidence-Earth-hit-giant-object-4-5-billion-years-ago.html

Because the Moon and Earth are so similar, we can study the Moon to gain information about our early solar system and early Earth. If we want to know more about how Earth formed, how old it is, and what the proto-material was like, we can turn to our closest neighbor in the solar system. Because the Moon is no longer geologically active, it has preserved information from the span of over 4.0 Ga. This is a sharp contrast to Earth, whose original material has all since been recycled.

Before the Apollo and Luna missions, lunar information was all theory. We had no data to put lunar theories into context and were unable to classify lunar meteorites because we had nothing to compare them to. From all of the Apollo missions, only ~382 kg of lunar rocks and soils were brought back. Because of logistical reasons, all of the lunar missions landed and collected samples in the same relatively small area: the lunar mare.

Mapped image of the Moon with Apollo and Luna missions landing sites.  Photo from: http://www.lpi.usra.edu/science/kring/epo_web/moon/moon_image7.jpg

Mapped image of the Moon with Apollo and Luna missions landing sites.
Photo from: http://www.lpi.usra.edu/science/kring/epo_web/moon/moon_image7.jpg

Later, data collected by satellites would show this area to be a chemical anomaly in comparison to the rest of the Moon. The lunar mare largely contains higher levels of elements including rare earth elements (REEs) in comparison to the rest of the Moon.

Elemental map of the Moon showing high levels of Thorium in areas of Apollo and Luna landings.  Photo from:  https://upload.wikimedia.org/wikipedia/commons/9/93/Lunar_Thorium_concentrations.jpg

Elemental map of the Moon showing high levels of Thorium in areas of Apollo and Luna landings.
Photo from: https://upload.wikimedia.org/wikipedia/commons/9/93/Lunar_Thorium_concentrations.jpg

So now we know that the samples collected from the Moon aren’t representative of its entire body. Much of what we consider to know and understand about the Moon today were based on Apollo, Luna samples and information. Because these samples aren’t representative, it is necessary to take a critical look at our current understanding of the Moon. Until we return, our only source of lunar rocks that come from places other than where the Apollo/Luna samples were collected are meteorites. So if we want to gain a clearer understanding of what the Moon is really like, we must study them.
You may be wondering how lunar meteorites arrive on Earth in the first place. Lunar meteorites come from the ejecta during an impact event on the Moon. When a meteoroid or other asteroidal body hits the Moon’s surface, lunar crust is displaced and gets ejected into space, eventually becoming trapped in Earth’s gravity field, allowing it to come to our surface.

Diagram of a meteoroid impact. Photo from: http://explanet.info/images/Ch04/04_03.jpg

Diagram of a meteoroid impact.
Photo from: http://explanet.info/images/Ch04/04_03.jpg

Meteorites are usually collected in deserts, like the Sahara or Antarctica, because they are easily located and preserved well in these areas. Teams of scientists search for meteorites each year in key locations and may at best return with some hundreds of samples.

Among those, only a small fraction may be lunar. On the whole, lunar meteorites are very rare–there have only been a total of 110 total unpaired lunar meteorites ever found.

Image of meteorite, exhibiting fusion crust, in Antarctica.  Photo from: https://earthandsolarsystem.wordpress.com/2013/01/21/ansmet-meteorite-hunting-2012-2013-season-draws-to-an-close/

Image of meteorite, exhibiting fusion crust, in Antarctica.
Photo from: https://earthandsolarsystem.wordpress.com/2013/01/21/ansmet-meteorite-hunting-2012-2013-season-draws-to-an-close/

Even though samples are limited, each new lunar meteorite gives us another chance to learn more about the Moon and expand our understanding of it.

In order to learn about our meteorite, my advisor and I have been studying our sample through chemical analysis and elemental x-ray mapping, which is done with an Electron Probe Micro-Analysis (EPMA). The machine can be programed to map the element distribution of the entire sample or just specific areas, but depending on the size of the area to be mapped the analysis can take several days. By analyzing single minerals within the sample we can get mineral chemistry in oxide weight percent, which has helped us to understand the mineralogy and petrography of our sample.

Annette Hilton (‘17) programing analysis of the unknown lunar meteorite in the EPMA, located in the Earth and Planetary Sciences Department at AMNH.

Annette Hilton (‘17) programing analysis of the unknown lunar meteorite in the EPMA, located in the Earth and Planetary Sciences Department at AMNH.

Soon we will be conducting LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry) on the sample to get data on trace and REEs that might be in our meteorite but are too minute for the EPMA to detect. This finer analysis will allow us to compare our sample more comprehensively to other lunar samples, and perhaps even hypothesize crystallization history. Currently we are working to calculate the bulk composition of our sample, which would enable us to use whole rock analysis as another comparative tool. Looking forward, we also hope to use the presence of different pyroxenes in the sample to calculate crystallization temperature, which could help us further understand our sample’s formation history.

By the end of the summer at AMNH we hope to submit a classification for the meteorite and work to publish about the sample. I am incredibly grateful for this exciting and valuable opportunity to learn and contribute towards lunar work.

SEM (Scanning Electron Microscope) image of our unknown lunar sample. Shown above is a terrestrial alteration crack, several melt veins (from shock impact), and plagioclase grains outlined by a matrix of olivine and pyroxene grains.

SEM (Scanning Electron Microscope) image of our unknown lunar sample. Shown above is a terrestrial alteration crack, several melt veins (from shock impact), and plagioclase grains outlined by a matrix of olivine and pyroxene grains.

Thank you to AMNH, NSF REU Program for Physical Sciences, Dr. Juliane Gross, and of course our wonderful professors at Wooster (particularly Dr. Meagen Pollock, professor of Mineralogy and Petrology).

 

References:

Gross, J., Treiman, A.H., and Mercer, C.N., 2014, Lunar feldspathic meteorites: constraints on the geology of the lunar highlands, and the origin of the lunar crust: Earth and Planetary Science Letters, v. 388, p. 318–328.

Joy, K.H., and Arai, T., 2013, Lunar meteorites: new insights into the geological history of the Moon: Astronomy & Geophysics, v. 54, p. 4–28.

Korotev, R.L., 2005, Lunar geochemistry as told by lunar meteorites: Chemie der Erde-Geochemistry, v. 65, p. 297–346.

Taylor, S.R., Taylor, G.J., and Taylor, L.A., 2006, The moon: a Taylor perspective: Geochimica et Cosmochimica Acta, v. 70, p. 5904–5918.

Treiman, A.H., Maloy, A.K., Shearer, C.K., and Gross, J., 2010, Magnesian anorthositic granulites in lunar meteorites Allan Hills A81005 and Dhofar 309: Geochemistry and global significance: Meteoritics & Planetary Science, v. 45, p. 163–180.

Inspiring young female scientists through B-WISER

July 6th, 2015

Wooster, OH – [Guest bloggers Chloe Wallace and Mary Reinthal]

When thinking about geology, people tend to think first about rocks. We do love our rocks, preferably pillow basalts, but when Wooster’s campus hosted hundreds of young women science enthusiasts, we wanted to teach them a practical field skill: pace and bearing. Buckeye Women In Science, Education, and Research, or B-WISER got the chance to learn and apply an important skill for geologists. This type of outreach is important because it reminds students that science is fun.

B-WISER girls focus intently on measuring distances on the academic quad with their paces.

B-WISER girls focus intently on measuring distances on the academic quad with their paces.

For five days, girls ranging in ages from 14-16 were engaged in different fields of science hosted by departments around campus. The geology department was fortunate to have over thirty girls participate in a variety of super-awesome orienteering activities for two days. Each of the girls was supplied with packets outlining the daily activity and a compass to help them orient themselves. Even poor weather could not damper spirits, and inside activities were met with laughter and good energy.

By the end of the workshop, the budding geologists were able to make (and follow) their own scavenger hunt maps!

By the end of the workshop, the budding geologists were able to make (and follow) their own scavenger hunt maps!

 

Mary records bearing data from two young women geologists.

Mary records bearing data from two young women geologists.

 

On the first day, students were taught how to take a compass bearing and orient themselves to pinpoint a location. They learned their pace and how to use it to calculate distance. Professor of all things geology, Dr. Meagen Pollock, along with her summer research students Chloe Wallace, Julia Franceschi, and Mary Reinthal, guided activities and often participated alongside the students.

Wooster’s Fossils of the Week: An Upper Ordovician cave-dwelling bryozoan fauna and its exposed equivalents

July 3rd, 2015

1 Downwards 063015This week’s fossils were the subject of a presentation at the 2015 Larwood Symposium of the International Bryozoology Association in Thurso, Scotland, last month. Caroline Buttler, Head of Palaeontology at the National Museum Wales, Cardiff, brilliantly gave our talk describing cryptic-and-exposed trepostome bryozoans and their friends in an Upper Ordovician assemblage I found years ago in northern Kentucky. They were the subject of an earlier Fossil of the Week post, but Caroline did so much fine work with new thin sections and ideas that they deserve another shot at glory. We are now working on a paper about these bryozoans and their borings. Below you will find the abstract of the talk and a few key slides to tell the story.

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Trepostome bryozoans have been found as part of an ancient cave fauna in rocks of the Upper Ordovician (Caradoc) Corryville Formation exposed near Washington, Mason County, Kentucky.

Bryozoans are recognized as growing from the ceiling of the cave and also from an exposed hardground surface above the cave. Multiple colonies are found overgrowing one another and the majority are identified as Stigmatella personata. Differences between those growing upwards and those growing down from the roof have been detected in the limited samples.

The colonies have been extensively bored, these borings are straight and cylindrical. They are identified as Trypanites and two types are recognised. A smaller variety is confined within one colony overgrowth and infilled with micrite. In thin section it is observed that the borings follow the lines of autozooecial walls and do not cut across. This creates a polygonal sided boring, suggesting that the colonies were not filled with calcite at the time of the boring. The second variety has a larger tube size and its infilling sediment has numerous dolomite rhombs and some larger fossil fragments including cryptostomes, shell and echinoderm pieces. These cut through several layers of overgrowing bryozoans. Some of the borings contain cylindrical tubes of calcite similar to the ‘ghosts’ of organic material described by Wyse Jackson & Key (2007).

Very localised changes in direction of colony growth due to an environmental effect are seen.

Bioclaustration in these samples provides evidence for fouling of the colony surface, indicating that the bryozoans overgrew unknown soft-bodied organisms.

Reference:

Wyse Jackson, P. N., and M. M. Key, Jr. (2007). Borings in trepostome bryozoans from the Ordovician of Estonia: two ichnogenera produced by a single maker, a case of host morphology control. Lethaia. 40: 237-252.

2 Title 0630153 Location 0630154 Strat position 0630155 hdgd up 0630156 hdgd down 0630157 Growth up 0630158 Growth down 0630159 Stigmatella 06301510 Cartoon 06301511 Boring A 06301512 Boring B 06301513 Ghosts explanation14 Ghosts 06301515 Overgrowths 06301516 Further questions 063015

Link to posts from Wooster Geologists in the United Kingdom in June 2015

June 29th, 2015

11 Mae Meredith Filey BriggI spent 25 days in England, Scotland and Wales this month, 12 of them with these two happy Senior Independent Study students, Mae Kemsley (’16) and Meredith Mann (’16) — dubbed “Team Yorkshire”. We had to delay our blog posts until today. You can see all of them by clicking the UK2015 tag. It was a spectacular expedition. Thanks again to Paul Taylor, Jen Loxton, Joanne Porter, Tim Palmer, Patrice Reeder and Suzanne Easterling for the parts they played in this adventure. Thank you as well to Mae and Meredith who were not only sharp field paleontologists, they were great companions as well. They are shown above on the tip of Filey Brigg in North Yorkshire. (N54.21560°, W00.25842°; Google Earth image below. Cool study site!)

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