Last (full) day of field tripping! After familiarizing ourselves yesterday with the stratigraphic relations of units of the La Garita caldera, we worked our way into the Creede caldera, one of the most well preserved calderas of the central San Juans. Named for the small mining town on its north end, the Creede Caldera occupies the center of the immense (75 x 35 km) La Garita nested caldera system. Creede is a beautifully well preserved example of caldera collapse and resurgent doming. This site provided some of the most spectacular views of caldera collapse structures we’ve seen since the Valles Caldera. Not to mention the turning Aspens and constantly changing weather to improve the views!
-
- Treasure Mtn. Tuffs and Conejos Lavas adorn the flank of Platoro Caldera (some artistic liberties taken in this image)
-
- Ignimbrite stratigraphy of the Platoro and La Garita calderas laid out
-
- Looking Tuff
-
- Prof. Marli Miller (UO) recording observations
-
- Biology was pretty nice too
-
- Other fans of the Chiquito Tuff
-
- Chiquito peak tuff (with columns) on fluvial or mudflow deposits. And a giant boulder topping it all
-
- Prof. Paul Wallace (UO) discussing with the USGS team about the effect of volatiles (probably) on all aspects of magmatism
-
- Impressively large lithic in the Chiquito Peak ash flow tuff. Photo by Prof. Marli Miller (UO)
-
- Rain doesn’t slow down Mike Dungan (UO). Photo from Prof. Marli Miller
-
- The topographic La Garita caldera wall is somewhere around here: LEt the pointing begin! Photo by Prof. Marli Miller
-
- Anothe rbout of rain makes a discussion about the scale of the La Garita Caldera and Fish Canyon Tuff even more memorable
-
- Leah Morgan sporting USGS gear, against a backdrop of multiple (cryptic) old caldera walls
-
- Realizes is missing lecture; quickly mobilizes
-
- Now inside the Creede Caldera, the geological perspectives and scales descriped by Mike Dungan (UO) and Ren Thompson (USGS) feel much more real
-
- The very impressive resurgent dome (Snowshoe Mtn.) of the Creede Caldera, as viewed from the northern caldera wall
-
- Densely welded resurgent dome of intracaldera Carpenter Ridge tuff is cut by the northern wall of the later Creede Caldera. Photo from Prof. Marli Miller
-
- Rheomorphic, devitrified intracaldera Carpenter Ridge tuff makes up the country rock in the Creede mining district
-
- Old mining works of Creede, CO, with a backdrop of densely welded Carpenter Ridge Tuff. Photo by Prof. Marli Miller
-
- Galena, chalcopyrite, sphalerite bearing ore in tailings from the Creede mining district
-
- Lacustrine deposits that formed in the intracaldera lakes of the Creede Moat, as seen from our final dinner locality
Reaching the capstone moment of our trip, the UO crew admires the very impressive, and aspen-accented, resurgent dome (Snowshoe Mtn) of Creede Caldera
Thus, our trip is formally concluded; however the rocks seen, lessons learned, and friendships and collaborations formed will live on throughout our entire careers.
Thank you to Mike Dungan, Paul Wallace, and the UO Staples fund for putting on such a wonderful trip! And a La Garita-sized (ie., huuuge) THANK YOU to our USGS colleagues who shared their time and expertise with us!