Central California Tectonics Field Trip

Deformation associated with the San Andreas Fault along Highway 14, near Palmdale, California. The strata in the roadcut are lower to middle Pliocene  gypsiferous, lacustrine rocks of the Anaverde Formation (a sag-pond deposit). Undeformed Pleistocene gravel unconformably overlies the Anaverde Formation.

 

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.

Pallet Creek trench site, near Juniper Creek, consists of sag pond deposits that developed atop the San Andreas fault during the past 2000 years. These strata now underlie a terrace adjacent to Pallet Creek. In the late 1970’s, Kerry Sieh pioneered the idea of trenching strata along a fault to determine age constraints on fault movement at this locality.
On Tejon Pass, near Gorman, CA, it’s possible to place your feet on both the Pacific and the North American plates with little stretching effort. In this locality, the Pacific plate consists of quartz monzonite that is separated from the sandstone-silt strata of the North American plate by a zone of black-colored gouge developed along the San Andreas Fault.
Wallace Creek, a drainage from the Tremblor Range of the North American plate, takes a right-angle bend where it crosses the San Andreas Fault and enters the Pacific plate, The current offset is approximately 100 yards. Check out the aerial photo at http://epod.usra.edu/blog/2006/12/aerial-photo-of-wallace-creek-and-san-andreas-fault.html for a great view of the offset.
Cholame Creek near Parkfield, CA, delineates the trace of the San Andreas Fault. The plate boundary is well marked here and a similar sign is placed where one goes from the North American back to the Pacific plate.
The Parkfield Experiment is an earthquake research project focused on the San Andreas Fault. The USGS and the State of California are the primary agencies involved in this project. For more info on the project, go to https://earthquake.usgs.gov/research/parkfield/index.php.
Late Mesozoic Franciscan rocks along the Parkfield Grade are a chaotic assemblage of blocks of pillow basalt, chert, blue schist in a graywacke matrix. Note the scattered blocks of these rocks on the hillside and the blue schist block downslope in the foreground of this photo.
Pinnacles National Park contains remnants of the approximately 23 million-year old Neenach Volcanics. This volcanic area developed atop the San Andreas Fault system, and some Neenach rocks are now displaced northward on the west side of the San Andreas Fault system about 320 km.
In Old Town Hollister, CA, near Park Hill, a street curb is offset along the Calaveras fault.
Creep is occurring along the Calaveras fault in Old Town Hollister.
A building at the DeRose Vineyards near Hollister exhibits buckling due to movement along the San Andreas Fault.
A concrete drain ditch at DeRose Vineyards shows about 1 meter offset along the San Andreas Fault.
The San Juan Bautista mission west of Hollister is built adjacent to a straight hillside which is the San Andreas Fault scarp (located downslope from the white fence in the photo).
The Weston Beach area at Point Lobos, Monterrey Peninsula, has turbidite strata (the Paleocene Carmello Formation) that are contained within a submarine canyon that is cut into Silurian granitodiorite.
The Paleocene strata at Weston Beach are well know for their trace fossil assemblage. One of the more interesting, Hillichnus (shown in the central part of this photo), probably represents a feeding trace of a deposit-feeding bivalve.
The Tertiary volcanic rocks on Pinnacles National Park’s west side are also part of the Neenach volcanics originally located further south near Lancaster, CA. As noted above, the volcanics in Pinnacles National Park have been displaced about 320 km northwards along the San Andreas Fault system.
The Balconies Cave is a talus cave developed within the Tertiary volcanics on the west side of Pinnacles National Park.
Morro Rock is part of the Morro Rock-Islay Hill Complex. The complex is a series of 27-23 million-year old volcanic plugs that stretch for 29 km southeast of Morro Rock.
We stopped at the Montana de Oro State Park beach to see marine terraces (there are 6 terrace levels here). Unfortunately, because of the incoming marine layer, it was hard to see anything except an outcrop of the Miocene Monterrey Formation topped by Quaternary sediment.
Pillow basalt (23 million years in age) occurs at Port San Luis.
Pillow basalt is surrounded by shattered glass fragments at Port San Luis.
Pillow basalt is topped by ropy basalt flows at Port San Luis.
A view of Santa Barbara, CA, from La Cumbre Peak in the Transverse Ranges.  La Cumbre Peak tops out at 3,997 feet within the Santa Ynez Mountains north of Santa Barbara, California. The peak consists of  Eocene Matilija Sandstone. The existence of the Transverse Ranges is a topic that Tanya and her accompanying visualizations explain well. So once again – go to Tanya’s visualization web page and download her work on the Tranverse Ranges.
We are ready for the concert at La Cumbre Peak!! Great way to end a fantastic field trip.

 

Canadian Rockies – Alberta Badlands Geology Guidebook

The Canadian Rockies to Alberta Badlands geology guidebook is published by the Association for Women Geoscientists.

The Association for Women Geoscientists (AWG) published their first geology field trip guidebook in late 2016 and it is now available for sale to the general public. This guideboook is a collection of geology road logs, associated geological information, and local cultural history of areas within the Canadian Rockies and the Alberta Badlands. The following text is a brief summary of the guidebook:

“TECTONICS, CLIMATE CHANGE AND EVOLUTION – SOUTHERN CANADIAN CORDILLERA: Road Log and Accompanying Narratives From: Calgary – Lake Louise – Icefields – Field – Revelstoke – Fernie -Dinosaur Provincial Park – Calgary”, published by the Association for Women Geoscientists, 2016.

This field trip guidebook is written by Katherine J.E. Boggs and Debra L. Hanneman, and edited by Janet Wert Crampton and Stephanie Yager. It is the AWG’s first fully published field trip guidebook and is a field-tested guide from their two-week 2014 field trip through the Canadian Rockies and Alberta’s Badlands area.

The guidebook is a 209-page geology tour through many of the well-known parts of the Alberta Canadian Rockies, including the Front and Main Ranges of the Canadian Rockies and the Columbia Icefields. The Burgess Shale’s Walcott Quarry, the Okanagan Valley vineyards, and the Rocky Mountain Trench are trip highlights for geo-tours in British Columbia. The field trip guidebook ends with a geology tour of the Crowsnest Pass area on the British Columbia/Alberta border, and with field stops in Alberta’s Dinosaur Provincial Park and at the Royal Tyrrell Museum, Drumheller, Alberta.

The field guide is printed on double-sided 8.5″ x 11″ pages with the guide cover on 100 lb paper and the text on 80 lb paper. It has black wire-o binding and a clear acetate front and a black acetate backing for improved field durability. The guidebook’s cost is $55 USD (which includes shipping), and can be purchased at the AWG online store or by phoning the AWG main office at 303-412-6219.

Geological Travels In Cuba

A part of the Vinales Valley in western Cuba – a UNESCO World Heritage Site.

If you’ve ever thought about Cuban geology, now may be the time to get serious about actually going to Cuba and looking at it. As a U.S. citizen, it’s been extremely difficult to legally go to Cuba. I went there in March of 2013 as part of an Association for Women Geoscientists’s geological field trip that we did through the travel company Insight Cuba. It was a very good trip. Our geological guide was Manuel Iturralde, a retired curator from the National Museum of Natural History in Havana and current President of the Cuban Geological Society. Manuel’s knowledge of Cuba’s geology is immense and consequently the geology part of the trip was amazing. But – because I am a U.S. citizen, my travel at that time was done under the U.S. trade embargo on Cuba, initially imposed in 1960. That meant to be fully legal I had to travel to Cuba via a licensed “people-to-people” travel agency. The people-to-people visits involve booking a full-time schedule of educational exchange activities for each traveler that will bring about a “meaningful interaction” between the travelers and Cubans – and hence the time for geology is limited. Additionally, the places one can go in Cuba were also limited. For example, U.S. citizens could not visit “tourist” areas, and thus areas of geological interest such as most beach geology was off limits during my tour.

President Obama’s 12/17/2014 announcement on easing of Cuba travel restrictions may well help out those interested in seeing Cuban geology. According to the White House Fact Sheet – Charting A New Course on Cuba -, “general licenses will be made available for all authorized travelers in 12 existing categories”, two of which – professional research and professional meetings and educational activities – will help for improving the quality of travel for earth scientists. However, I talked with a person from Insight Cuba today about the new travel requirements, and they said, “a traveler still needs to get a license from OFAC (U.S. Office of Foreign Assests Control), and it still might take about 2 months to get the license”. Unfortunately, in the Insight Cuba rep’s opinion, not much has yet changed for travel to Cuba. I guess we’ll just have to wait and see on what transpires with this in the near future.

But – as I said earlier in this blog, it still may be a good time to think about geology-based travel to Cuba. Manuel Iturralde recently emailed me an announcement for The Cuban Society of Geology’s VI Cuban Convention on Earth Sciences and Exhibition of Products, Services and New Technologies – GEOEXPO 2015 – May 4 – 8, 2015, in Havana. This should be a excellent convention and good way to be introduced to Cuba’s geology.

Just to mention a couple other earth science resources for potential travelers:

  • 2013/2014 Yearbook of the Cuban Society of Geology (Volume 1, No. 1, 2013. ISSN 2310-0060, Scientific Journal of Geosciences, Havana – now this is the July 2014 version) is online. As described from the website:

    This version of the Cuban Digital Library of Geosciences brings together some 3700 references, 2091 in digital format, most of the published contributions, unpublished lesser extent, the existence of which the authors are aware. The topics cover the various branches of Earth Sciences, with emphasis on geology, geophysics and mining Cuba, or in any way relevant to the best knowledge of Cuban territory, although centrally relate to other geographies. These contributions include books, monographs and scientific articles, a few summaries and maps dating from 1535. Some very important unpublished documents are referenced as are available at the National Bureau of Mineral Resources (ONRM), the Centre National Geological Information ( CNIG ), the map library and collection of science in the National Library José Martí; and library (1989), Institute for Geophysics, University of Texas at Austin. In the year 2012 was published a list of Information Centers Geosciences across the country and how to access them.

  • Journeying Through Cuba’s Geology and Culture: This is a brief article that I wrote for the “Travels in Geology” section of Earth magazine (published July/August 2013) about my trip through western and central Cuba with the Association for Women Geoscientists in March 2013.

 

One of the towering limestone hills locally known as “mogotes” of the Pinar del Río Province in far western Cuba. This mogote is known as Abra de Ancón and it is famous for the site where Manuel Fernández de Castro first found Jurassic marine invertebrate fossils in the late 1800’s.
One of the towering limestone hills locally known as “mogotes” of the Pinar del Río Province in far western Cuba. This mogote is Abra de Ancón and it is famous for the site where Manuel Fernández de Castro first found Jurassic marine invertebrate fossils in the late 1800’s.

Canadian Rockies AWG Field Trip – A Summary

The AWG 2014 Canadian Rockies Field Trip took place from August 28 to September 7, 2014, with a Calgary-area geology pre-trip for early arrivals on August 27.  The main part of the field trip commenced with a mid-morning departure on the 28th from Calgary, and we all headed west along Canada Highway 1 to Lake Louise. After spending two days in the Lake Louise area, we drove north to the Columbia Icefields. A few of us continued further north the next day, on an side trip to Jasper. From the Icefields we toured south to Field, British Columbia, over to Revelstoke, and ended our British Columbia time in Fernie. We then drove east, back into Alberta, and spent time at Dinosaur Provincial Park near Brooks and at the Royal Tyrrell Museum of Palaeontology in Drumheller. The trip ended with our group once more back in Calgary, Alberta.

There were 22 people as full-time field-trippers and two more people on the trip during the Icefields to Field, B.C. part of the trip. Two of the full-time trip participants were students and one of the additional, part-time trip participants, was a student. All of the students on the field trip are from Mount Royal University in Calgary and are students of our field trip leader, Katherine Boggs. Paul Hoffman and Mindy Brugman also helped out for a day or so during the trip. Marcia Knadle and Debra Hanneman did the trip budget and logistics. We had a great field trip guidebook, thanks largely to Katherine Boggs’ efforts. The field trip guidebook, “Tectonics, Climate Change, and Evolution: Southern Canadian Cordillera” will be on sale at the AWG online store soon.

Some of us took to the water and canoed around Moraine Lake near Lake Louise, Alberta. Moraine Lake is located within the valley known as the “Valley of the Ten Peaks” which was once featured on the Canadian twenty dollar bill.
Some of us took to the water and canoed around Moraine Lake near Lake Louise, Alberta. Moraine Lake is located within the valley known as the “Valley of the Ten Peaks” which was once featured on the Canadian twenty dollar bill.
Katherine Boggs talks to the field trip crew about area geology at a stop along the Icefields Parkway in Alberta.
Katherine Boggs talks to the field trip crew about area geology at a stop along the Icefields Parkway in Alberta.
Our intrepid field crew hikes the Athabasca Glacier, one of the six major glaciers of the Columbia Icefield.
Our intrepid field crew hikes the Athabasca Glacier, one of the six major glaciers of the Columbia Icefield.
Paul Hoffman explains features of the Neoproterozoic Old Fort Point Formation near Jasper, Alberta.
Paul Hoffman explains features of the Neoproterozoic Old Fort Point Formation near Jasper, Alberta.
Some of the field trip group took the arduous hike up to the famous Walcott Quarry that is developed within the Cambrian Burgess Shale near Field, British Columbia.
Some of the field trip group took the arduous hike up to the famous Walcott Quarry that is developed within the Cambrian Burgess Shale near Field, British Columbia.
A member of our field trip group shows us one of the Burgess Shale’s trilobites from the Walcott Quarry.
A member of our field trip group shows us one of the Burgess Shale’s trilobites while at the Walcott Quarry.
One of the trip’s frequent rainy days – but we still had fun by the Kicking Horse River at its confluence with the Columbia River, near Golden, British Columbia.
One of the trip’s frequent rainy days – but we still had fun by the Kicking Horse River at its confluence with the Columbia River, near Golden, British Columbia.
Our field trip group poses by Columbia Lake, which forms the headwaters for both the Columbia and Kootenay rivers, and lies within the enigmatic Rocky Mountain Trench near Canal Flats, British Columbia.
Our field trip group poses by Columbia Lake, which forms the headwaters for both the Columbia and Kootenay rivers, and lies within the enigmatic Rocky Mountain Trench near Canal Flats, British Columbia.
The Frank Slide was a must-stop as we drove along the Crowsnest Highway near Blairmore, Alberta. The slide happened on April 29, 1903, when about 82 million tons of limestone fell off of Turtle Mountain.
The Frank Slide was a must-stop as we drove along the Crowsnest Highway near Blairmore, Alberta. The slide happened on April 29, 1903, when about 82 million tons of limestone fell off of Turtle Mountain.
Part of our field trip group discusses Centrosaur Bone Bed 43 during our guided hike at Dinosaur Provincial Park, Alberta.
Part of our field trip group discusses Centrosaur Bone Bed 43 during our guided hike at Dinosaur Provincial Park, Alberta.

Notes From the Field – The Rest of the 2014 AWG Geology Field Trip

The 2014 AWG Canadian Rockies Geology Field Trip did actually end last Sunday (9/7) and we did indeed make it back to Calgary largely unscathed. As many of you probably know, when lodging amenities state that WiFi is included, it most likely means that one can check email – not post blogs with photos of any size, or maybe not even post blogs without photos. Anyways, we did run out of somewhat viable WiFi in our remaining travels. So – this blog is a brief summary of what other adventures awaited us on the road from Revelstoke, B.C. to Fernie, B.C., and then eastward to Dinosaur Provincial Park near Brooks, Alberta, and finally to the amazing Royal Tyrrell Museum at Drumheller, Alberta.

Dutch Creek Hoodoos at mouth of Dutch Creek along Highway 93/95 south to Cranbrook, B.C.. The hoodoos are calcite-cemented Quaternary deltaic foresets deposited at edge of Glacial Lake Invermere.
Dutch Creek Hoodoos at mouth of Dutch Creek along Highway 93/95 south to Cranbrook, B.C.. The hoodoos are calcite-cemented Quaternary deltaic foresets deposited at edge of Glacial Lake Invermere.

 

 

 

 

 

 

 

 

View southeastward of the Rocky Mountain Trench along Highway 93/95 South where Columbia Lake forms the headwaters to both the Columbia and Kootenay Rivers.
View southeastward of the Rocky Mountain Trench along Highway 93/95 South where Columbia Lake forms the headwaters to both the Columbia and Kootenay Rivers.

 

The Three Sisters as viewed from Fernie, B.C.. All the rock units are upside down, with the Devonian Palliser Formation comprising the top of the far left "sister" and the Mississippian Rundle Formation overlying the Triassic Spray River Group (in the lower right of photo and occurring mostly in tree-covered slopes) via the Hosmer Thrust.
The Three Sisters as viewed from Fernie, B.C.. All the rock units are upside down, with the Devonian Palliser Formation comprising the top of the far left “sister” and the Mississippian Rundle Formation overlying the Triassic Spray River Group (in the lower right of photo and occurring mostly in tree-covered slopes) via the Hosmer Thrust.

 

The Frank Slide, located east of the towns of Coleman and Blairmore, Alberta, in the Crowsnest Pass area. The slide occurred on 4/29/1903. when 82 million tons of limestone fell off Turtle Mountain, burying part of the town of Frank, Alberta.
The Frank Slide, located east of the towns of Coleman and Blairmore, Alberta, in the Crowsnest Pass area. The slide occurred on 4/29/1903. when 82 million tons of limestone fell off Turtle Mountain, burying part of the town of Frank, Alberta.

 

Dinosaur Provincial Park near Brooks, Alberta - the darker colored unit, the Dinosaur Park Formation sits atop the lighter colored, Oldman Formation. Both units are placed within the Cretaceous (Campanian) Belly River Group.
Dinosaur Provincial Park near Brooks, Alberta – the darker colored unit, the Dinosaur Park Formation sits atop the lighter colored, Oldman Formation. Both units are placed within the Cretaceous (Campanian) Belly River Group.

 

Centrosaur bone bed located near the central part of Dinosaur Provincial Park. Our group had an amazing guided tour to this bone bed which occurs in the Dinosaur Park Formation.
Centrosaur bone bed located near the central part of Dinosaur Provincial Park. Our group had an amazing guided tour to this bone bed which occurs in the Dinosaur Park Formation.

 

Finally - the Royal Tyrrell Museum at Drumheller, Alberta. The museum has fantastic displays, and of course I spent much time in their Burgess Shale faunal reconstruction display!
Finally – the Royal Tyrrell Museum at Drumheller, Alberta. The museum has fantastic displays, and of course I spent much time in their Burgess Shale faunal reconstruction display!

 

Notes From The Field – Revelstoke to the Okanagan

Finally we had a mostly sunny day! We began the day with a tour of the Revelstoke Dam. This dam was one of the last Canadian dams built within the Columbia River watershed. The dam area is really interesting because just across the highway from the dam is the Columbia River Fault zone – a Early to Middle Eocene crustal-scale, east-dipping, extensional fault zone that follows the Columbia River Valley near Revelstoke. Now that was a bit disconcerting for me as I looked at the zone while standing on the top of the dam structure. Our group split up after the dam tour, and I went with the group to the Okanagan Valley. Among our stops were: 1. Three Valley Lake for a look at the hanging wall of the Monashee decollment, Craigellachie, where the last spike of the Canadian Pacific Railway was set in 1885, and the Okanagan-Eagle River Fault zone. Below are some of the day’s photos….

Revelstoke Dam spillway
Revelstoke Dam spillway

 

Mass wasting in rocks cut by the Columbia River Fault Zone near the Revelstoke Dam.

 

Rocks of the Three Valley assemblage – pelitic gneisses and mica schists – are cut by mafic dikes.
The last spike cairn at Craigellachie.
The last spike cairn at Craigellachie. Note the coal train in the background going by the cairn.

 

Quest for the Eagle River fault zone.

 

Notes From The Field – Lake Louise and Moraine Lake

I’m backtracking somewhat here by posting on our trips to both Lake Louise and Moraine Lake. Both are so gorgeous that I didn’t want to exclude them from the postings, but my SD card with their photos was not accessible when I did the initial postings. Suffice it to say that hikes and canoeing in these areas was great. The sun broke through long enough that afternoon that we had a very pleasant time at Lake Louise. We arrived at Moraine Lake in the morning so we could get there before the parking lot filled and we were greeted by heavy mist just starting to lift off the lake. Here are photos of both areas:

Lake Louise is a glacial cirque lake dammed by a recessional moraine.
Lake Louise is a glacial cirque lake dammed by a recessional moraine.
Moraine Lake lies in the Valley of the Ten Peaks - a scene that was once featured on the Canadian twenty dollar bill.
Moraine Lake lies in the Valley of the Ten Peaks – a scene that was once featured on the Canadian twenty dollar bill.
Skolithos, a trace fossil with the form of vertical burrows, is found in the Cambrian Gog quartzite present in this area.
Skolithos, a trace fossil with the form of vertical burrows, is found in the Cambrian Gog quartzite present in this area.
The “Rockpile” near the parking lot at Moraine Lake. Great views are to be had – if it is not raining.
Discussion time near Laggan's Mountain Bakery , Lake Louise.
Discussion time near Laggan’s Mountain Bakery , Lake Louise.

Notes From The Field – Field, B.C. to Revelstoke, B.C.

The AWG field trip continued along the Trans-Canadian Highway 1 from Field, B.C. to Revelstoke, B.C. – again in the rain. But at least the rain stopped several times for us to have fun at our trip stops. We followed the Kicking Horse River to its junction with the mighty Columbia River at Golden, B.C.. We had our first look at the Rocky Mountain Trench – we could sort of see it through the mist at an overlook near Golden. Then up over Roger’s Pass and into Revelstoke brought us to the day’s end. As can be seen in the photos below, we had alot of fun at the meeting of the Columbia and Kicking Horse waters….

Delta complex exposed at side of Kicking Horse River near Golden - note the large-scale cross-beds.
Delta complex exposed at side of Kicking Horse River near Golden – note the large-scale cross-beds.
Nora - one of our intrepid AWG field trippers- points out at side channel of the Kicking Horse River near its confluence with the Columbia River.
Nora – one of our intrepid AWG field trippers- points out a side channel of the Kicking Horse River near its confluence with the Columbia River.
The confluence of the Columbia and Kicking Horse rivers near Golden, B.C.. Note the differnt water colors as the Kicking Horse River flows in from the right side of the photo to mix with the Columbia waters.
The confluence of the Columbia and Kicking Horse rivers near Golden, B.C.. Note the different water colors as the Kicking Horse River flows in from the right side of the photo to mix with the Columbia waters.
Again at the Columbia/Kicking Horse rivers confluence. We couldn't pass  up a skipping stone contest...
Again at the Columbia/Kicking Horse rivers confluence. We couldn’t pass up a skipping stone contest….
Heather Hill debris flow near Roger's Pass on the Trans-Canadian Highway 1.
Heather Hill debris flow near Roger’s Pass on the Trans-Canadian Highway 1.

Notes From The Field – Icefields Parkway

After more rain and no wifi, we’re finally in Revelstoke, British Columbia where we still have rain, but finally have some wifi. We had a great trip from Lake Louise (I will post a few photos of scenes from Lake Louise later as my camera flash card for that part of the trip is still in my truck) up the Icefields Parkway to the Athabaska Glacier. Most of us ended up staying at Hostel International’s Rampart Creek Hostel for the night. If ever traveling up the Parkway, I do recommend staying at Rampart – Ken is a wonderful host and the setting is marvelous. Anyways, here are a few of the spectacular scenes that we saw…..

Crowfoot Glacier.
Crowfoot Glacier.

 

Lower Paleozoic rocks of the Parkway.
Lower Paleozoic rocks of the Parkway.
Mazama and Bridge River volcanic ashes exposed in bank cut near Saskatchewan Crossings.
Mazama and Bridge River volcanic ashes exposed in bank cut near Saskatchewan Crossings.
The toe of the Athabaska Glacier.
The toe of the Athabaska Glacier.

Notes From The Field

The first full day of the AWG Canadian Rockies Field Trip opened to pouring rain by the time we reached the Canmore, Alberta area – about 66 miles west of Calgary. So no grand views of the impending Front Ranges or sights of Triangle Zone structure. Once in a while during lunch we could vaguely see the break in slope that marks the McConnell Thrust at Mount Yamnuska. But even in the downpour, our intrepid leader Katherine Boggs got us out of the vehicles to look at and talk about the Kananaskis Dam and its geology.

Pouring rain does not deter the AWG field trip discussions.
Pouring rain does not deter the AWG field trip discussions.

The Upper Cretaceous Cardium Formation is the bedrock at the dam. Extensional faulting – late Cretaceous/Paleocene in age and expressed as a series of grabens and horsts – cuts the Cardium at the dam site. I took a long look at those structures knowing that that’s probably the last I’ll see of extensional faulting for awhile.

Extensional faulting in the Upper Cretaceous Cardium Formation at the Kananaskis Dam near Canmore, Alberta.

 

The downpour started to break a few miles east of Lake Louise. It was really spectacular to see the clouds begin to part around Castle Mountain. The Castle Mountain Thrust is at the base of the mountain and it delineates the boundary between the Front Ranges and the Eastern Main Ranges. Flat-lying Cambrian carbonates comprise Castle Mountain as opposed to generally west-dipping Devonian/Mississippian carbonates of the Front Ranges The weather forecast sounds better for tomorrow… we’ll see. Tomorrow brings hikes around the Lake Louise-Moraine Lake areas, so some clear skies would be welcome.

Castle Mountain finally breaks through the clouds.