Montana’s autumn is my favorite time of the year to do field work. Daytime temperatures are usually cool enough to encourage one to keep moving and the lighting is simply gorgeous. It is also one of the best times to visit areas in and around Yellowstone National Park (YNP) because most of the tourists have gone home. So no huge bear traffic jams or jostling for parking spots at the better known thermal spots in YNP and surrounding environs – it’s just a wonderfully introspective time for field forays. What follows are several photos that chronicle some of my fall wanderings in the greater Yellowstone area, both in terms of wildlife and geology.
Some of my favorite sightings in YNP are bison at any time of the year. But the autumn snows bring on the bison’s technique of using its head to clear snow away from any vegetative food source. The result of their snow-clearing activity is a snow-masked face.
And where the snow hasn’t stacked up much, the YNP bison calmly graze and occasionally congregate on a ridge line to watch what remains of the YNP visitor traffic.
Geological features in YNP take on new dimensions with the golden low and slanting light of autumn. I’ve spent much time re-photographing geologic features at all scales that seem to glow in this season’s light.
The fall staging areas of sandhill cranes in southwestern Montana are mesmerizing. Staging areas are those locations where cranes annually congregate during late September into October, spend several days foraging through fields for food, and eventually continue on their migration southward from Montana to Colorado and the southwestern U.S.. The staging area that I usually go to is near Dillon, Montana, where hundreds of cranes can be viewed.
As I said initially, it’s hard to surpass a Montana/YNP autumn!
Over 100 wildlands fires are burning in the U.S., with most of them being in the western U.S. The California fires are exceedingly destructive, with Cal Fire officials calling this the new normal for the now extended and catastrophic fire seasons that we are experiencing. In the midst of all this, there’s a particularly good Ted talk on megafires done by Paul Hessburg at the TEDx event in Bend, Oregon, 2017. The video is well worth viewing:
Geologic field work is always fun, but especially so when it turns up something unexpected. Working on Eocene to Recent geology and vertebrate paleontology in the Gravelly Range, southwestern Montana promised to be enthralling because the volcanics, sedimentary units, and vertebrate fossils are at elevations of about 9,000 feet. But to come across extensive, unmapped calcareous spring deposits of probable Eocene age is topping off research efforts.
At this point, I’ll just say that our field team is still at work on the Tertiary spring deposits. We’ve found numerous leaf impressions including those of ginkgo, palm, metasequoia, Fagopsis (extinct member of Beech family), and alder – just to name a few. We’ve shown the plant assemblage collected to date to several paleobotanists, and, at least for age, their take is that the assemblage is probably latest Eocene in age, and bears many similarities to Florissant, Colorado fossil plant assemblages.
The spring deposits in the Gravelly Range are extensive, covering an area roughly 2 miles in length with deposits up to 120 feet in thickness. The springs are best characterized as travertine, although the spring systems’ edges contain clastic fluvial units and both the springs’ edges and pools have features such as plant impressions, root systems, and small travertine balls.
Because the Gravelly Range is so close to Yellowstone National Park, it is extremely interesting to compare its Eocene spring deposits to hydrothermal units at both the currently active Mammoth Hot Springs (which probably began its activity about 7,700 years ago), and to the fossil travertine found just north of Gardiner, Montana, that formed about 19.500 to 38,700 years ago (Fouke and Murphy, 2016: The Art of Yellowstone Science: Mammoth Hot Springs as a Window on the Universe).
The Gardiner travertine is fairly well exposed because it has been extensively quarried for several decades. Of interest for comparison are numerous plant impressions that occur within microterracettes. Fouke and Murphy (2016) suggest that these may be impressions of sage brush. A photo of the quarried wall with the plant impressions is shown below.
Other features in the Gardiner travertine, now partly covered by graffiti, include a quarry wall that shows terracettes and microterracettes that are outlined by darker lines within the travertine. These features are probably indicative of a proximal slope facies.
Jumping forward in time to the extensive spring deposits of Mammoth Hot Springs (just within the northeast park boundary of Yellowstone National Park), is mind boggling. As in any comparison with rocks as old as Eocene to active deposition, one realizes how much detail is lost over time. But it is still worthwhile to try to compare spring features, so I’ll show a few photos of the Mammoth Hot Springs that may match up with various features of the fossil springs.
Suffice it to say, that the upcoming field season should be a good one, with more work to be done on the Gravelly Range spring deposits. And – it’s always fun to get a trip in to Yellowstone!
It’s time for our yearly update talk on field work and data compilation for the Tertiary geology and paleontology of the central Gravelly Range project in southwestern Montana. The Madison Ranger District in Ennis, Montana (5 Forest Service Road) will be hosting my talk on Monday, April 2nd at 10am in the Madison Ranger District conference room. We have a project permit from the US Forest Service because our project area lies within the Madison Ranger District – and the USFS District people have been really helpful with our project logistics. Thus, this is the perfect way to let them know what we did this past field season and how the whole project is coming together. The Madison District just sent their public announcement for the talk:
Dr. Hanneman and Dr. Don Lofgren, PhD (Director, Raymond M. Alf Museum of Paleontology, Claremont, CA 91711) and their team have been executing a multiyear study in the Gravelly Range near Black Butte resulting in many interesting paleontological findings right here in our own back yard. Please join Dr. Hanneman and the Madison Ranger District for an update on this project and what they hope to unearth this year!
It’s a very intriguing project on high-elevation, mainly Eocene-Oligocene Tertiary geology and paleontology (mostly vertebrate and floral). So – anyone with an interest in this and who is in the geographic area, is welcome at the talk!
Within the last few weeks I’ve had several requests for available resources on Cuban geology. The requests, of course, have come from individuals outside of the U.S.A. Guess that they sense opportunities for working with and understanding Cuba’s geology that we are backing away from. In any case, I’ve sent the requests on to Manuel Iturralde-Vinet, the person who has worked and published an immense amount of information regarding Cuba’s geology. Manuel has now sent me back an updated list of resources and said:
Traveling to Ireland has been something I’ve wanted to do. So, when the opportunity came up to go to Scotland, I couldn’t leave the general area without seeing at least some of both Northern Ireland and the Republic of Ireland. I only made it as far south as Dublin, but I guess on the positive side, that leaves many places that I need to visit on a future trip.
I flew from Glasgow into Dublin, rented a car, and first headed for Northern Ireland which is the subject of this blog. The causeway coastal route in Northern Ireland (from the North Channel coast eastward to the Irish Sea coastline) is a drive that I wanted to try. I ended up driving only about half of it – from Ballycastle east to Port Stewart because I spent so much time stopping to look at rocks and scenery.
The total area of these flows is now much reduced compared to their original extent, but they still constitute, at 3,800km2, Europe’s most extensive lava field. Traditionally the lavas of the Antrim Lava Group have been divided into three main phases of activity, separated by two extended periods of quiescence or limited, local activity.
The two areas that I spent most time at during my coastal causeway drive are the Carrick-a-rede Bridge and the Giant’s Causeway. These areas are developed within the Lower and Middle Basalts of the Antrim Lava Group and contain an Inter-basaltic Bed of reddish-weathered regolith and paleosols. A photo tour of the two areas are shown below –
A rope bridge connects the mainland with Carrick-a- Rede island. The first rope bridge was built in 1755 to facilitate fishing of Atlantic salmon. The salmon fishery has since died out, but the bridge is maintained as part of National Trust lands.
The Giant’s Causeway is a UNESCO World Heritage Site. As noted on its UNESCO website:
The Giant’s Causeway lies at the foot of the basalt cliffs along the sea coast on the edge of the Antrim plateau in Northern Ireland. It is made up of some 40,000 massive black basalt columns sticking out of the sea. The dramatic sight has inspired legends of giants striding over the sea to Scotland.
Twenty-five years after the Union of Concerned Scientists and over 1700 independent scientists published their “World Scientists’ Warning to Humanity”, a new group of scientists (bolstered by 15,364 scientist signatories from 184 countries) have again issued a warning that humanity has not made significant progress in mitigating environmental challenges.
The recently published viewpoint of these scientists and signatories appears in the 11/13/17 issue of BioScience and can be read on line at “World Scientists’ Warning to Humanity: A Second Notice”. The authors review the 1992 warning of major environmental challenges and our response to it by:
we look back at their warning
and evaluate the human response
by exploring available time-series
data. Since 1992, with the exception
of stabilizing the stratospheric ozone
layer, humanity has failed to make
sufficient progress in generally solving
these foreseen environmental challenges,
and alarmingly, most of them
are getting far worse…
The newly published warning of our need to deal with these major challenges – catastrophic climate change, deforestation, agricultural production associated with farming ruminants for meat consumption, and a sixth mass extinction event (just to name a few of them) – makes the reading of this viewpoint critical. It takes less than 10 minutes to read this, and – if you are a scientist, then sign on to support it. More than signing, find a way to become active in really dealing with these challenges.
Siccar Point is unquestionably one of the most important geological sites in the understanding of geological time. It was here in 1778 that James Hutton, John Playfair, and James Hall contemplated the immensity of time needed to produce vertically oriented rocks overlain by gently-dipping rocks. The concept of geological time is so fundamental to the science of geology that I really wanted to explore the locality that gave rise to the idea of geological time. So I finally made the trip to Scotland and Siccar Point a couple weeks ago. Wow – what an amazing country! It was a fantastic trip, but for this blog, I’ll just post a few photos of Siccar Point – just enough, perhaps, to encourage geologic time enthusiasts to also make the trip.
Siccar Point is located on Scotland’s Berwickshire coast, about 40 km southeast of Edinburgh. It is not difficult to get there from Edinburgh if you’re willing to drive a few back roads, and also drive on the left side of the road – which for me was somewhat of an initial challenge (going left on the roundabouts was mind boggling to begin with!). The best directions that I found for getting to Siccar Point are given by Angus Miller, who also runs field trips there. Angus’s directions to Siccar Point and his contact information are found at his Geowalks website.
The pull-off for the hike to Siccar Point is well marked by signage. All that one needs to do is walk through the gate and then follow the fence lines south to the Siccar Point locality. There is a small sign on the entrance gate that advises you to beware of the bull. We happened to meet up with a local person while we were hiking through the fields to Siccar Point and she told us that the land owner posted the sign mainly because he’s at war with the hordes of people that tromp through his fields to get to Siccar Point (in Scotland there is the “right to roam”, so one can hike across private property). She also assured us that at the time we were there, the cows were off in another field, so not to worry about the bull. We then just followed the hiking instructions on the sign at the gate entrance, and found that it’s an easy walk to Siccar Point.
Once one arrives at the rock promontory that is Siccar Point, it is an amazing view looking down the cliff face. The vertical beds of Silurian graywacke outcrop beautifully below Devonian Old Red Sandstone. The “Hutton Unconformity” here marks an approximately 80 million year hiatus. Again, there is also good signage present at the promontory for an explanation of the unconformity.
A rope is attached to the fence at the promontory to help the climber down the cliff face. As it was a muddy and slick climb down to the North Sea, I was very glad to use the rope! Much thanks to whoever put the rope there!
It was fun to investigate the unconformity at the sea’s edge. The base of the Old Red Sandstone contained lags from the graywacke, some of which are cobble size.
I know that we were very lucky to have good weather for our Siccar Point excursion, but I would have gone there whatever the weather. It is really one of the great geologic sites and well worth traveling part way around the world to see. For a drone view of Siccar Point, take a look at the video done by the British Geological Survey which is posted in an earlier Geopostings blog: Siccar Point from a drone’s view.
I took part in a central California tectonics field trip a few weeks ago that the Association for Women Geoscientists (AWG) sponsored. Tanya Atwater and Art Sylvester, professors emeriti at the University of California Santa Barbara, Department of Earth Sciences, led the field trip. During the field trip, we made numerous stops between Los Angeles and Hollister at areas where the San Andreas Fault bounds the North American/Pacific plates. Interspersed with fault-specific localities, we explored associated geology such as turbidites around Point Lobos, marine terraces in the Morro Bay area, and pillow/flow basalt at Port San Luis. The final stop on the field trip was an overlook on Santa Barbara geology at La Cumbre Peak with Tanya’s explanation on the tectonic evolution of the Transverse Ranges. If you are not familiar with the tectonic history of this general area, go to Tanya’s web site (http://emvc.geol.ucsb.edu/) and download her visualizations on global/regional tectonics. There are also visualization downloads on ice-age earth and sea level changes, so treat yourself to some very worthwhile earth science information by downloading these visualizations, too.
The following photos are from what I think are field trip highlights, including a brief caption regarding the geology shown in each photo. More information on many of the photo localities can be found in “Roadside Geology of Southern California“, 2016, by Art Sylvester and Elizabeth Gans.