Archive for December 19th, 2014

Wooster Geologist in Yorkshire

December 19th, 2014

1 Spaunton Quarry 121814LEEDS, ENGLAND–It was my good fortune to attend this week the 58th Annual Meeting of the Palaeontological Association in Leeds, Yorkshire, this week. I very much enjoy these meetings because of the high quality of the talks and posters, the collegiality, the field trips, and my chance to meet new colleagues and learn more about fossils and the history of life. This year I was here as a representative of the Paleontological Society and one of the Palaeontological Association’s North American Representatives. The last such meeting I attended was in Dublin in 2012.

One of the main attractions of any geological meeting are the associated field trips. Today a busload of hardy paleontologists had a field trip to the moors of northeastern Yorkshire to see Upper Jurassic limestones and fossils. The image above is from Spaunton Quarry (see below). It is no accident that this scene looks a bit stark — there was a cold wind blowing all day. Yorkshire in December is not surprisingly a bit chilly. We avoided the usual rain, though, and had a splendid day.

Betton Farm South QuarryAll our outcrops were in the Cleveland Basin, a depositional center in northeastern Yorkshire during the Late Jurassic (Oxfordian Stage). Our first stop was in the disused South Quarry at Betton Farm, where the Betton Farm Coral Bed and Malton Oolite Member is exposed (N54.25517°, W000.46503° — that cool “W000” means we are almost on the Prime Meridian). Above you see the old quarried walls in this small excavation.

Western Face SQ 121814This is the western face of the quarry showing flat bedding of a coral-rich carbonate sand facies. To the right, out of view, is a contemporaneous coral reef (see below).

Coral Few Borings 121814This is the upper surface of the scleractinian coral Thamnasteria concinna, with a few bivalve borings (Gastrochaenolites). I would not be a happy paleontologist if I had to study these poorly-preserved corals. For contrast, you might remember the Jurassic corals of southern Israel. There’s a lot to be said for desert weathering and protective layers of marl.

BBQ 121814We had a wonderful lunchtime barbecue set up for us in the quarry. Who would guess we’d have an outdoor feast in December in northern England?

Ravenswick Quarry 121814Our second stop was at another abandoned quarry, Ravenswick (N54.25517°, W000.46500°). The Malton Oolite, which was exploited as a building stone, is exposed here. You can see the flat bedding and jointing of this rock that made it good for construction materials.

Ravenswick Rhabdophyliia phillipsiAbove the Malton Oolite is the Coral Rag Member. The branching corals shown above are Rhabdophyllia phillipsi. Since they were originally aragonitic skeletons, their later recrystallization into calcite has reduced the amount of fine detail preserved.

Sheep Spaunton 121814Our final stop was in the sheepiferous Spaunton Quarry (N54.27846°, W000.89128°). The Coralline Oolite Formation is shown above. You may again note the structural features that make this a good building stone.

Tomasz Spaunton 121814My Polish friend Tomasz Borszcz is shown above with the Coralline Oolite Formation and, immediately above, the Upper Calcareous Grit Formation. Fossils were not common here, but we did see an ammonite in the grit and some echinoid fragments in the Oolite.

Thank you very much to Dr. Crispin Little of the University of Leeds for leading this great field trip. I enjoy seeing Jurassic rocks anywhere, but they were especially attractive on the rolling moors of Yorkshire.

 

 

Wooster’s Fossils of the Week: Beautiful trace fossils from the Upper Ordovician of southern Ohio

December 19th, 2014

Trace fossils Bull Fork Ordovician OH 585Every year we highlight at least one of the fossils found and studied by Wooster’s Invertebrate Paleontology class as part of their field and laboratory exercises. This year it is this nice slab of trace fossils collected by Curtis Davies (’15) on our August 31 field trip to the emergency spillway in Caesar Creek State Park. I didn’t even notice it at the time Curtis picked it up. I only saw its full glory when he photographed the rock as part of a paleontological essay.
CurtisGalen083114aCurtis Davies is the smiling, bearded guy in the back (with Galen Schwartzberg) at the Caesar Creek outcrop. The rain had finally stopped and everyone was happy.

The traces are exposed here on the bottom of a bed of argillaceous limestone. They are preserved in what trace fossil workers (ichnologists) call convex hyporelief, which means simply that they stick out on the base (or sole) of the rock slab. These were tunnels originally excavated in soft mud by worm-like animals. The tunnels were filled with sediment that cemented up more resistant than the surrounding matrix, and thus were weathered in this relief.
Taenidium serpentinum Heer, 1877Most of the trace fossils here are the simple unlined burrow called Planolites, one of the most common traces in the Ordovician of the Cincinnati area. The trace labelled with the red “T” above, though, is rare here. Note that it is formed by a series of pulse-like movements that produced segments in the sediment infill. My estimate is that this trace can be classified as Taenidium serpentinum Heer, 1877. It is not common in the Ordovician.
Heer, Oswald, 1809-1883Oswald Heer (1809-1883), the scientist who named Taenidium serpentinum, was a Swiss geologist and botanist. As was the case for many educated Europeans, he started as a clergyman, even signing up for holy orders. The natural world captivated him, though, and starting with insects he worked his way up to become a naturalist and professor of botany at the University of Zürich. He was one of the key figures in the establishment of paleobotany (the study of fossil plants).
Taenidium serpentinum Heer, 1877 image 585Here is Heer’s figure of Taenidium serpentinum from Plate XLV in his 1877 book, Flora fossilis Helvetiae (Fossils Plants of Switzerland). You see the irony already. Heer described this trace fossil as a plant, inadvertently becoming one of the early figures in ichnology, the study of trace fossils.

Oswald Heer published many books and papers, becoming well known for his geological and paleontological explorations and descriptions. He was awarded the prestigious Wollaston Medal from the Geological Society of London in 1874. He was an earlier advocate of using fossils to sort on problems of paleogeography. He knew, for example, that Miocene fossils in Europe and North America were very similar, so he suggested in those days before Plate Tectonic Theory that the two continents were connected by a “land bridge“. This was called the “Atlantis Hypothesis”, and you can imagine the confusion that name caused among various cranks and pseudoscientists looking for Plato’s mythical continent. Heer died in Switzerland in 1883.

References:

D’Alessandro, A. and Bromley, R.G. 1987. Meniscate trace fossils and the Muensteria-Taenidium problem. Palaeontology 30: 743-763.

Heer, O. 1877. Flora fossilis Helvetiae: Die vorweltliche flora der Schweiz. Zürich, J. Wurster & Company. 182 p.

Keighley, D.G. and Pickerill, R.K. 1994. The ichnogenus Beaconites and its distinction from Ancorichnus and Taenidium. Palaeontology 37: 305-338.

Keighley, D.G. and Pickerill, R.K. 1995. Commentary: The ichnotaxa Palaeophycus and Planolites: Historical perspectives and recommendations. Ichnos 3: 301-309.