A surprising bit of Permian in central Sicily

Mark Wilson June 7, 2013 11:55 pm

1. Sicilian Mountains 060713MARSALA, SICILY, ITALY–This morning the pre-conference field trip of the International Bryozoology Association headed into the mountains of central Sicily. The roads were steep and windy, as one would imagine, and the views of mountainsides, villages and fields spectacular. We were high enough to be in some small woods and scrub forests. Our goal was to see some mysterious blocks of Permian limestone seemingly out of place on an island dominated by Cenozoic sediments.
2. Palermo Geologists 060713We met a team of friendly geologists from the University of Palermo in the Sosio Valley near Palazzo Adriano. They were well prepared to tell a complicated story of tectonics in the classic geological manner: maps and charts held by students as a professor lectures. It was very effective, aided by the superb weather and amazing views.
3. Geological cross-section 060713In this geological cross-section, the Permian rocks are shown as blue. Already you see something odd with the same color of rock above and below the blue, showing that it is tectonically bounded. It is part of a melange (in the geological sense) of blocks of rock broken and thrust about during the tectonism of the Miocene. The Permian rock was recognized as such by its fossil content, which includes distinctive conodonts, fusulinids, brachiopods, bryozoans and corals. It sits surrounded by much younger Miocene sediments, demonstrating the complex tectonics leading to this unusual setting.
4. Permian melange fragment MioceneAbove is the Permian outcrop in the Sosio Valley. It stands out as very different from its surroundings by its lithology alone. I admire the geologists, though, who found diagnostic fossils within it — I saw just a very few highly recrystallized fusulinids and corals.
5. Museum Palazzo Adriano 060713For lunch we went to the city museum in Palazzo Adriano and had delicious sandwiches and cakes. There we saw some of the best fossils from the Permian outcrops on display.
6. Palazzo Adriano Church 060713This is one of the churches in Palazzo Adriano on the city square. It looks to be neglected on the exterior, but inside …
7. Palazzo Adriano Church Interior 060713… it is elaborate and well-maintained.

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Pliocene marls white as snow in southern Sicily

Mark Wilson June 6, 2013 11:55 pm

6. Pliocene Cliff 060613SCIACCA, SICILY, ITALY–Our last stop of the day on this International Bryozoology Association pre-conference field trip was to a massive outcrop of foraminiferan-rich marls known as the Trubi. A view of the cliffs with the sun setting behind them is above.

7. Hans Arne Pliocene 060613My colleague (and roommate on this trip) Hans Arne Nakrem is serving as a scale to show the regular cyclicity of these marls. Appropriately, he is from snowy northern Norway. These sediments were deposited immediately after the Messinian Salinity Crisis when the entire Mediterranean was reduced to a shallow series of evaporitive ponds. These marls mark the opening of the Strait of Gibraltar which flooded the Mediterranean Basin with normal seawater (the Zanclean Flood) 5.33 million years ago.

8. Pliocene Cliff 060613I wish I had better lighting to show just how brightly white these rocks are. They are now used as the base type section of the Zanclean Stage.

SicilyBeachSandHere is a late addition to this post (June 23, 2013). I collected some sand from the beach in front of these chalky rocks. A close-up image is shown above. Note that the chalk itself is eroded so quickly that it leaves no trace in the sand. We see here mostly rounded quartz grains and shell fragments.

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Mountain lions and deformation bands: just another day in Utah

sjudge June 6, 2013 11:05 pm

Guest Blogger:  Tricia Hall

SIXMILE CANYON, UTAH — After a couple of days seeing a good number of mountain lion footprints, Shelley and I have decided that it is best to turn the attention of my I.S. toward using our new Trimble GPS to track mountain lion movements. We have heard from the local residents that the lions are low in the mountains, and have even ran across a potential “lion den”. Along the way, just in case this project does not pan out, I have measured a few deformation band orientations so that I don’t fail I.S. Just kidding! Here’s what we’ve really been up to the past couple of days….

Yesterday, we tackled the faulting and joint sets within the Flagstaff Limestone to the west of the Sixmile Canyon Formation exposure. The Flagstaff unconformably overlies the Sixmile, and the faulting and jointing relationships will be key in interpreting the deformation bands within the Sixmile Canyon Formation. We made good use of the Trimble to map the Formation and the fault (to the best of our ability). The resulting map, even without postprocessing, shows normal faulting within the Flagstaff complete with drag folds.

Above is the jointed Flagstaff Limestone looking to the north. We measured several units of this formation to determine the offset of the faults. In addition to the Trimble, we used the brand new Laser range finder! It was either the range finder or eye heighting up the mountain...I was all for the former.

Above is the jointed Flagstaff Limestone looking to the north. We measured several units of this formation to determine the offset of the faults. In addition to the Trimble, we used the brand new Laser range finder! It was either the range finder or eye heighting up the mountain…I was all for the former.

After a long day yesterday, we made it out to Sixmile Canyon this morning with the intention of measuring the major joint sets in the morning followed by deformation band measurements in the afternoon. The joint sets were harder to find than we thought, but hopefully after we go through today’s data after I’m done blogging we’ll find that we’re okay on joint sets. The afternoon was pretty warm, but there was work to be done. It was finally deformation band time! We began measuring orientations, collecting samples, and yes, we broke out the Schmidt Hammer. Schmidty proved most effective and will be put back to work tomorrow. We’re well on our way to our self-imposed 300 Schmidty hits!

Schmidty was phenomenal on the deformation band shown above.

Schmidty was phenomenal on the deformation band shown above.

We’ll check in later, back to Sixmile Canyon tomorrow!

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A cultural day in southern Sicily

Mark Wilson June 6, 2013 11:01 pm

1. Noto Duomo 060613SCIACCA, SICILY, ITALY–Most major conference geological field trips have a portion devoted to the culture and history of the region being explored. You can imagine the delights of this nature possible on a Mediterranean island. Today we started with the main square in the city of Noto in southern Sicily. This city had been destroyed by a 1693 earthquake and was completely rebuilt. The Noto Cathedral (above) was finished in 1776. It is such a classic of Baroque architecture that it was declared a World Heritage site by UNESCO. It is striking, especially since it is hemmed in by other buildings and so provides a sudden surprise when turning a corner. Hard to believe parts of it collapsed from disrepair in 1996.

2. Noto Street 060613A Noto street leading to a church. The many balconies are characteristic of the city. Since the city center was rebuilt in one go, it has a consistent architectural theme.

3. Casale Mosaics 060613Our second visit of the day was to an archaeological site revealing the astonishing remains of a 4th Century Roman building called Villa Romana del Casale on Mounte Mangone near the Gela River. This huge complex is most famous for its exquisite mosaic floors, the details of one shown above (“The Little Hunt”). This features a theme throughout the structures: hunting. This is another UNESCO World Heritage site. Such culture vultures we geologists are.

4. Female Pentathalon 060613Certainly the most photographed of the mosaics is this scene popularly known as “Girls With Bikinis”. It is more properly described as “women participating in the female pentathalon” because of the distinctive athletic activities shown.

5. Giant Mosaic 060613My favorite mosaic is probably the most violent: a series of giants killed by Hercules with poisoned arrows. Note that the dying giants have snakes for feet. It is astonishing what these craftsmen could do with millions of tiny colored stones — and that their art has survived so vividly.

 

 

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A familiar hydrozoan with a beautiful name

Mark Wilson June 6, 2013 6:57 pm

Velella_velella_060613_Sicily_585SCIACCA, SICILY, ITALY–Far too late today for more than a short post. For the first time I met in real life an animal I speak about in my Invertebrate Paleontology course: the colonial hydrozoan Velella velella. We found thousands of them on Marjate Beach on the south coast of Sicily (see below). These organisms are commonly known as By-The-Wind Sailors, and they are found throughout the world’s oceans. They are characterized by a thin vertical sail over a shelf of downward-directed polyps. The sail scoots them along very effectively across the sea surface, but once they reach a lee coast they are helplessly stranded on the beach. They are striking in their tragedy as the thin purple tissues wilt in the sunlight as if they were flowers.

Velella_vella_strew_060613More posts from this very interesting day after I get some sleep!

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A Sicilian rocky coast

Mark Wilson June 5, 2013 11:55 pm

9. Calcari di Siracusa Miocene 060513NOTO, SICILY, ITALY–Our last stop of the day on this International Bryozoology Association field trip was on the southeastern coast of Sicily just north of Syracuse at Scala Greca. There are several very small bays here which have been used for fishing boats since very ancient times. The whote rock is the Calcari di Siracusa (Miocene).

10. Rhodoliths060513The rock is made predominantly made of little algal and bryozoan spheres called rhodoliths. They rolled around on a shallow, warm seafloor and are quite common in some parts of the tropics today (although with fewer bryozoans).

11. Pillbox Scala Greca 060513This part of Sicily was an invasion area by the Allies in World War II. This grim German pillbox overlooking the coast is a reminder of those times. More on this later.

OctopusDinner585Finally, I wish to record part of my dinner this evening! I ate every piece of octopus in my large shell bowl. I saw it as a duty.

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A shelly bonanza from the Pleistocene of Sicily

Mark Wilson June 5, 2013 11:45 pm

5. MegaraDitch060513NOTO, SICILY, ITALY–Our second stop of the day on this International Bryozoology Association field trip was in an unimpressive ditch (above) near Megara. But, of course, there is paleontological gold here: an assemblage of extremely well-preserved marine fossils.

6. AndrejMegara060513Colleague Andrej Ernst is examining a layer of shells extending the length of the drainage ditch.

7. SerpulidsMegara060513Her are some beautiful pectinid bivalves (scallops) with the treat for me: abundant serpulid worm tubes. There is an extensive sclerobiont (hard substrate dwelling) community on these shells.

7a. TurritellidsMegara060513Turritellid gastropods (snails) are extremely common in this assemblage. Note that several of these specimens have small holes drilled in them by predatory gastropods. We found naticid gastropods here too, which were probably the culprits.

8. HornedQuadrupedsMegara060513This mother lode of fossils was guarded by a herd of horned beasts. This one had a bell on it, so I assumed it was the most dangerous and stayed far away. (Love this new zoom lens!)

 

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Spectacular shrimp burrows from the Miocene of Sicily

Mark Wilson June 5, 2013 10:14 pm

Siciliancountryside060513NOTO, SICILY, ITALY–The first stop on our International Bryozoology Association field trip today was a newly-opened quarry near Cugni di Rio in the dry southeastern countryside of Sicily, a view of which is above. New quarries are always interesting to geologists — a new view of the Earth’s bones.

OphiomorphaAshcontact060513This is a portion of the quarry wall with the inevitable volcaniclastic unit of ash and marine sediments shown as the greenish layered unit above and below limestones dated as Tortonian (Upper Miocene). On top of the ash you can see what look like tubes sticking out of the brownish layer of sediment.

OphiomorphaSlab1_060513When that brownish layer is exposed as the underside of the bedding plane, it looks like this. These branching features are infilled tunnels made by marine shrimp. The walls of the tubes are ornamented by pellets placed there by the shrimp in their frenetic activity. Combining these pellets with the branching style we can place this trace fossil in the venerable ichnogenus Ophiomorpha.

OphiomorphaSlab2_060513This is a closer view showing the branched galleries and maybe a bit of the pitted surface showing where the pellets were attached. These tunnels are completely filled, so we refer to this preservation as full relief.

I know, I know, I should be recording the bryozoans from this stop, but they were far from photogenic!

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20 Bags, Two Geologists, Plenty of Mountains

sjudge June 4, 2013 11:22 pm

EPHRAIM, UTAH — After no sleep, Tricia Hall (’14) and I had to get up at 3 am to catch our early flight to Utah.  It is a good thing that we arrived at the airport in plenty of time (thanks, Patrice, for the schedule!!), because one of our many equipment bags was searched several times.  Apparently the Schmidt Hammer (“Schmidty”) caused some concern.  But, it is not always that you have concrete strength testing equipment in your carry-on.

After a good night’s sleep, we were bright-eyed and ready for “reconn day” up Sixmile Canyon, just east of Sterling, UT.  Tricia will be working on her I.S. within the Cretaceous Sixmile Canyon Formation, which is exposed in all its glory near the mouth of the canyon.  Her focus is to investigate the wonderful deformation bands within the formation and their relationship to local structures.  To get a good overall perspective of some of the deformation in the area, we investigated two major faults that are exposed near the base of the formation.

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Here’s Tricia, admiring the fault plane and noticing the upturned Flagstaff Limestone on the downthrown block.

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After examining the faults, we decided to have some lunch.  Our view of the Sanpete Valley was gorgeous.  The sun was warm, with few clouds…and there was just enough breeze to make lunch very relaxing.  Take a look at the photo above, which shows a view toward Ninemile Reservoir and the infamous Arapien Shale that forms the core of the Sanpete-Sevier Valley Anticline.

DSC00205_585

The photo above is of the Sixmile Canyon Formation, which contains deformation bands of various types and sizes, along with traditional joints.  The formation at this locality is a medium- to even coarse-grained sandstone that shows the obvious impacts of fluid flow and iron-stained surfaces.

DSC00206_585

We had a great reconn day.  However, in the photo above, Tricia is looking out for mountain lions, which apparently are a little problem in the canyon!!  Lucky for us, we were able to get access to a southern exposure of the formation and had a great conversation with the landowner about all of the bears and mountain lions and recent “kill sites” that he has seen in the area.  We are psyched.

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Sicilian fossils at last!

Mark Wilson June 4, 2013 4:14 pm

FieldStopOne060413CATANIA, SICILY, ITALY–After lunch our International Bryozoology Association field trip actually collected fossil bryozoans. We visited a quarry exposure of Lower Pleistocene cemented marls rich in the bryozoan Celleporaria palmata (Michelin), along with many other species. These were apparently from a thicket of bryozoan colonies broken up in a storm and deposited as a debris flow down slope. The location is south of Catania at Pianometa.

Celleraria060413Lower Pleistocene Celleporaria palmata fragments at Pianometa. This was a very rapid-growing, branching bryozoan colony easily fragmented by storm currents.

Volcaniclastic060413Below those bryozoan-loaded beds is this unusual sequence. The darker layered units are volcaniclastic sediments derived from early eruptions from the Mount Etna complex. Occasionally boulders would roll downslope and be deposited as xenoliths (“foreign rocks”) Later the cemented sediments cracked repeatedly due to the intense earthquake activity associated with this tectonic boundary between the European and African plates. Those cracks filled with marly sediment from above.

SheepCheeseFarm060413The last visit of the day was to a sheep cheese farm. One sheep produces about a liter of sheep’s milk. The cheese we sampled (some more than others) is very soft — like cottage cheese without the lumps, or a soft ricotta. Interesting (and unpasteurized). We watched four rams beat each other bloody in an ongoing context monitored by large black dogs. I suppose it is part of the herding process, grim as it is.

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