Geological and Archaeological Park at Timna

June 5th, 2010

Cambrian sandstone exposures at Timna Park, southern Israel.

MITZPE RAMON, ISRAEL — Our last stop on our shabbat trip today was at Timna Park north of Eilat, Israel.  Here we saw a combination of geology and archaeology.  The porous sandstones exposed in the cliffs have been mineralized along fault and joint planes by a green copper ore.  The world’s oldest underground copper mines, dating back 6000 years, are here, along with hundreds of more “modern” mines hand-dug by Egyptians between the 14th and 12th centuries BCE.  The sandstone itself is rich with geological information, including cross-bedding, channels, and a very prominent honeycomb weathering.

Micah Risacher and Andrew Retzler at Timna Park.

Micah and Andrew are well protected in this complicated part of the world! No worries.

Blogger’s note: We have only limited internet access on this trip, so we may not be answering our personal email very often.  I send these posts in pre-written bursts when we get some internet time.

Dr. Whitey Hagadorn presents “The First Animals on Land” for the 29th Annual Osgood Memorial Lecture at Wooster

March 24th, 2010

WOOSTER, OHIO–This evening Dr. Whitey Hagadorn, an assistant professor of geology at Amherst College, gave the 29th Annual Richard G. Osgood Memorial Lecture to a large crowd of students, faculty and community members in Wishart Hall at The College of Wooster.  His topic was “The First Animals on Land”, which was an account of research he and his students did with remarkable Cambrian trace fossils (tracks, trails and burrows) in sandstones in Wisconsin.

Sedimentary structures In Upper Cambrian sandstones, Wisconsin, USA. On the left are ripples with raindrop imprints; on the right is an intertidal channel. Photographs courtesy of Whitey Hagadorn.

Dr. Hagadorn showed in his presentation how he and his team first recognized ancient shoreline deposits by tracing sedimentary structures such as ripples, channels and raindrop imprints on extensive sandstone bedding planes in quarries.  They could then follow trace fossils of mollusks, worms and arthropods out of the water onto what were sandy beaches in the Cambrian.  Some of those organisms seem to have been carrying shells with them as protection from desiccation in the dry air.  Dr. Hagadorn answered many questions after his lecture from the audience and from a good crowd at the following reception.  We were impressed not only with the beautiful trace fossils and what they tell us about early land life, but also how such significant work could be done with simple tools and clever analyses.

Trace fossils in Upper Cambrian sandstones, Wisconsin, USA. Photographs courtesy of Whitey Hagadorn. More details are available on his website linked in this post.

Dr. Hagadorn will be leaving Amherst College this summer to become the Curator of Earth Sciences at the Denver Museum of Nature and Science.  We wish him well.

The Richard G. Osgood, Jr., Memorial Lectureship in Geology was endowed in 1981 by his three sons in memory of their father, a paleontologist with an international reputation who taught at Wooster from 1967 until 1981. Funds from this endowment are used to bring a well-known scientist interested in paleontology and/or stratigraphy to the campus each year to lecture and meet with students.

Wooster geologist at Lake Louise, Banff National Park, Canada

August 10th, 2009

LAKE LOUISE, ALBERTA–On our free day the IPREP study group (this apparently means “International Paleontological Research Exchange Program”) drove to the spectacular Lake Louise in Banff National Park for a hike up the valley to the “Plain of Six Glaciers”. It was one of those many places where I know just how fortunate I am to be a geologist. The weather could not have been better, and there was even a tea house near the end of the trail for sandwiches, peachade, and perfect chocolate cake!

Lake Louise as seen from its outlet looking up the valley. Our hiking trail proceeded from here along the right side of the lake and up the valley almost to the ice of the hanging glaciers.

Lake Louise as seen from its outlet looking up the valley. Our hiking trail proceeded from here along the right side of the lake and up the valley almost to the ice of the hanging glaciers.

We could not help but be delightfully distracted by these brilliant trace fossils in the rocks along the lake shore. The bilobed structure which looks like a deer footprint is an excavation made by a trilobite -- the trace fossil itself is called Rusophycus. The sinuous tubes are trails made by burrowing worms. These features protrude form the rock surface because they are actually on the bottom of the bed. Sediment filled the original holes and is now preserved as ... wait for it ... convex hyporeliefs.  You knew we had a name for it! (Middle Cambrian, Gog Formation).

We could not help but be delightfully distracted by these brilliant trace fossils in the rocks along the lake shore. The bilobed structure which looks like a deer footprint is an excavation made by a trilobite -- the trace fossil itself is called Rusophycus. The sinuous tubes are trails made by burrowing worms. These features protrude form the rock surface because they are actually on the bottom of the bed. Sediment filled the original holes and is now preserved as ... wait for it ... convex hyporeliefs. You knew we had a name for it! (Middle Cambrian, Gog Formation).

The water of Lake Louise has a pastel emerald color because it is loaded with very fine sediment called "glacial flour". It is produced by glacial ice finely grinding the rocks in the highlands above. This sediment fills the streams to near capacity and makes an extensive delta at the inlet to the lake.

The water of Lake Louise has a pastel emerald color because it is loaded with very fine sediment called "glacial flour". It is produced by glacial ice finely grinding the rocks in the highlands above. This sediment fills the streams to near capacity and makes an extensive delta at the inlet to the lake.

Looking down the valley to Lake Louise from one of the many glacial moraines. This unsorted sediment was pushed here by glacial ice when it filled this valley.

Looking down the valley to Lake Louise from one of the many glacial moraines. This unsorted sediment was pushed here by glacial ice when it filled this valley.

The glacial ice above the Lake Louise valley. This is a classic hanging glacier. We had the privilege of seeing (and mostly hearing) a large piece of ice break off and crash into the valley below on this warm and sunny day.

The glacial ice above the Lake Louise valley. This is a classic hanging glacier. We had the privilege of seeing (and mostly hearing) a large piece of ice break off and crash into the valley below on this warm and sunny day.

Middle Cambrian stromatolites high in the Canadian Rockies

August 9th, 2009

FIELD, BRITISH COLUMBIA, CANADA–Our study group was fortunate to meet Whitey Hagadorn (Amherst College and Denver Museum of Natural History) and Sally Walker (University of Georgia) for a hike to an exposure of stromatolites in the Pika Formation (Middle Cambrian) near Lake Helen and Lake Katherine in Banff National Park. A stromatolite is a finely-laminated sedimentary rock produced by mats of cyanobacteria in a shallow sea collecting and trapping thin layers of sediment. They are relatively common features in Precambrian sediments (the oldest of fossils, in fact) and become significantly more rare in younger rocks (although they are still around today). These Cambrian stromatolites are interesting because of what they can tell us about Cambrian marine conditions, including tidal dynamics, bioturbation, and grazing herbivore pressures.

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Stromatolites exposed as domal structures in this eroding outcrop of the Pika Formation (Middle Cambrian) above Helen Lake in Banff National Park.

A natural cross-section of the Pika Formation stromatolites showing their laminated nature and sediment which has accumulated around their heads.

A natural cross-section of the Pika Formation stromatolites showing their laminated nature and sediment which has accumulated around their heads.

A hardground (light unit) exposed in cross-section in the sediment between stromatolite heads.  This is a layer of carbonate sediment which was cemented on the seafloor and then eroded by currents.  The dark sediment was deposited later on top of the scoured surface.  The hardground layer had been previously burrowed when still soft.

A hardground (light unit) exposed in cross-section in the sediment between stromatolite heads. This is a layer of carbonate sediment which was cemented on the seafloor and then eroded by currents. The dark sediment was deposited later on top of the scoured surface. The hardground layer had been previously burrowed when still soft.

Beautiful folds in the rocks above the Pika Formation stromatolites.  They are nearly recumbent in some parts.  I'll leave their interpretation to my structural geologist colleagues Sam Root and Shelley Judge!

Beautiful folds in the rocks above the Pika Formation stromatolites. They are nearly recumbent in some parts. I'll leave their interpretation to my structural geology colleagues Sam Root and Shelley Judge!

A marmot on the banks of Helen Lake.  Not at all camera shy, this little guy.

A marmot on the banks of Helen Lake. Not at all camera shy, this little guy.

Mt. Stephen Trilobite Beds (Middle Cambrian)

August 8th, 2009

FIELD, BRITISH COLUMBIA, CANADA–After a very steep and long climb, our little field party visited another restricted quarry of famous Middle Cambrian fossils: the Mt. Stephens Trilobite Beds. Charles Walcott also collected from this site when he was working on the Burgess Shale. The fossiliferous unit is about a million years old (more or less) than the Burgess Shale itself, and it has a rather different fauna dominated by large trilobites. One of the most exciting new ideas is that these fossils may represent an ancient cold seep community associated with methane degassing from the sediments.

Our Canadian guide (and paleontologist) Paul McNeil and our trip leader Matthew James in the Mt. Stephen Trilobite Beds Quarry.

Our Canadian guide (and paleontologist) Paul McNeil and our trip leader Matthew James in the Mt. Stephen Trilobite Beds Quarry.

A view from the Mt. Stephen Trilobite Beds down the mountain to Field and the Trans-Canada Highway. Note the steepness.  Nearly did me in!

A view from the Mt. Stephen Trilobite Beds down the mountain to Field and the Trans-Canada Highway. Note the steepness. Nearly did me in!

Trilobites in the Mt. Stephen Trilobite Beds. (I know -- I should have had a Canadian quarter for scale!)

Trilobites in the Mt. Stephen Trilobite Beds. (I know -- I should have had a Canadian quarter for scale!)

A beautiful complete trilobite. Very common here.

A beautiful complete trilobite. Very common here.

An appendage of one of the most famous Middle Cambrian fossils: Anomalocaris. The Mt. Stephen Trilobite Beds also have soft-bodied preservation.

An appendage of one of the most famous Middle Cambrian fossils: Anomalocaris. The Mt. Stephen Trilobite Beds also have soft-bodied preservation.

The wondrous Burgess Shale

August 7th, 2009

FIELD, BRITISH COLUMBIA, CANADA–I stepped on Paleontological Holy Ground when I visited the Burgess Shale earlier this week. It is often cited as the most important fossil locality ever. I felt the historical as well as the scientific vibrations in the Walcott Quarry, the site where the extraordinary Charles Walcott began his explorations of the unit in 1909.

The Walcott Quarry of the Burgess Shale.

The Walcott Quarry of the Burgess Shale.

There are numerous websites illustrating the famous Burgess Shale Fauna. I’ll just share some of the favorite fossils I found. (We could pick up and examine any fossil, but collecting, of course, is strictly forbidden.)

The humble sponge Vauxia. I like the less charismatic taxa in the Burgess Shale. The fancy arthropods get plenty of love!

The humble sponge Vauxia. I like the less charismatic taxa in the Burgess Shale. The fancy arthropods get plenty of love!

The primitive mollusc Scenella on the left and a trilobite on the right. The Burgess Shale fauna has plenty of skeletonized fauna along with the soft-bodied forms.

The primitive mollusc Scenella on the left and a trilobite on the right. The Burgess Shale fauna has plenty of skeletonized fauna along with the soft-bodied forms.

This is an odd breccia at the base of the Burgess Shale. The white parts are limestone fragments and the black is calcite. This may be an indication of carbonate hardgrounds -- features I study.

This is an odd breccia at the base of the Burgess Shale. The white parts are limestone fragments and the black is calcite. This may be an indication of carbonate hardgrounds -- features I study.

It is a tradition among paleontologists to pose with Charles Walcott at his famous quarry! I lack the knickers, though.

It is a tradition among paleontologists to formally pose with Charles Walcott at his famous quarry. I lack the knickers, though, and that certain set of jaw.

The Walcott Quarry of the Burgess Shale on a beautiful day

August 6th, 2009

FIELD, BRITISH COLUMBIA, CANADA–We have a small group of seven people for this expedition organized by Matthew James of Sonoma State University in California. Everyone is from California except me (although I was invited through my California roots). Our guide to the Walcott Quarry didn’t show up yesterday morning, so we joined a much larger group from Chevron — an interesting and productive mix of industry professionals and academics. Here is a movie of our exploration in the quarry:

Our Burgess Shale group.  Clockwise starting with the guy in the orange shirt: Matthew James, Howard Adams, Rebecca Perlroth, Mark Wilson, Bob Rubin, Bob Davies, Kurt Burmeister.

Our Burgess Shale group. Clockwise starting with the guy in the orange shirt: Matthew James, Howard Adams, Rebecca Perlroth, Mark Wilson, Bob Rubin, Bob Davies, Kurt Burmeister.

Wooster geologist at the Burgess Shale

August 6th, 2009

FIELD, BRITISH COLUMBIA, CANADA–I’ve been waiting to write those words! More later when I get better wireless access. The summary: my colleagues and I successfully made the long hike to the Walcott Quarry of the famous Middle Cambrian Burgess Shale today (5.5 hours to get there); it rained all morning, and then the sun appeared in time to dry out the outcrop before we arrived; we saw many wonderful fossils on this iconic outcrop.

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Walcott Quarry of the Burgess Shale in the lower right, with Emerald Glacier and Mount Wapta in the background. Stunning in all respects!

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