Some winter days in Yellowstone National Park are so amazing with clear blue skies and sparkling snow that they just take your breathe away. Luckily enough, I just experienced several of these kinds of days which I packed full of cross country skiing, snowshoeing, and animal watching.
One of the groomed trails that held a good snow base until about early afternoon is the Blacktail Plateau Loop. The trail follows melt-water channels that are associated with “Retreat Lake”, which was formed by the Beartooth glacial ice mass blocking the lower end of the Grand Canyon of the Yellowstone during the Pleistocene.
The Tower ski trail provides access to the Grand Canyon of the Yellowstone area. A favorite stop of mine is the Calcite Springs overlook where the thermal springs lie south of the overlook, on the west side of the Yellowstone River and Pliocene/Pleistocene sediment and basalt are on the Yellowstone River’s east side.
A groomed ski trail also accesses the Upper Terraces of Mammoth Hot Springs. However, after a few days of spring-like temperatures, the snow was so melted back that I just used my snowshoes to trek through the icy slush. Some thermal features were still covered by snow and slush, but others appeared much more vibrant against the white snow/slush blanket.
Aphrodite Terraces lie a short way north of the White Elephant Back Springs:
My favorite thermal feature of the Upper Terraces is Orange Spring Mound. The spring is supported by a fissure ridge and is intermittently active. Because of its low water discharge and subsequent slow growth, it has built up a characteristic cone shape.
All in all, it was perfect wintertime fun trekking around in Yellowstone. Can’t wait to get back there when the bears come back out from hibernation!
During the 14th century, the Inca ruler Inca Pachacuteq (Tito Cusi Inca Yupanqui) transformed the central Andean area of present-day Cusco, Peru into a major urban center. The city became the capital of the Inca empire, containing religious and administrative areas that were surrounded by fertile agricultural expanses. In the 16th century, the Spanish conquered Cusco, building their Baroque churches and palaces atop the remnants of the Inca city. Today about half a million people live in Cusco. The city is now known for its amazing indigenous population and as a mecca for tourists that travel on to the Sacred Valley and Machu Picchu.
Cusco Historic District
Cusco was declared a UNESCO World Heritage site in 1983 and the boundary for the site is mostly what is known as the Historic District (link here for a map of the UNESCO inscribed property). I did tour some of the buildings within the Historic District, my favorite being the Convent of Santo Domingo. The Spanish built this church on the remains of Qurikancha, a revered Incan temple for the Sun God Inti. The Inca stonework is the foundation for the cathedral and it is truly enthralling to see. Interestingly, numerous earthquakes have extensively damaged the cathedral, but the Inca stone walls still stand largely undamaged.
The Vino Canchón Market
The markets of Cusco – now they are an experience that can’t be missed. If you love food, Vino Canchón in the district of San Geronimo, is the place to go. This is the largest market in Cusco, supplying families as well as businesses with all kinds of produce, hardware, flowers, and many other items. It is also a market where the traditional Quechua language dominates the conversations. The Vino Canchón market is open daily and vendors are happy to talk with customers and the inquiring tourist.
Saqsaywaman and Its Geologic Puzzle
Saqsaywaman is the ruins of a fortified complex located at the northern edge of Cusco, on a hilltop that overlooks the city. As briefly summarized by Lake and others (2012):
“Most of the complex was demolished by Spanish settlers, who used the Incan stone to rebuild Cusco into a Spanish colonial town. What remains of the Saqsaywaman complex are large limestone blocks along with some shales, plasters and limonites which were too large for the Spanish settlers to easily remove. Some of these blocks are over 125 tonnes. Chroniclers state, that the construction ofSaqsaywaman was initiated by the ninth Inca, Pachacutec and was continued by his son Tupac Yupanqui Inca, between 1431 and 1508. The construction of Saqsaywaman is testament to the stonework engineering ability of its builder architects: Huallpa Rimachi Inca, the first and main Builder, followed by Maricachi Inca, Acahuanca Inca and Calla Cunchuy Inca. The remaining walls lean inward, which according to current theory allowed the Inca to create a more earthquake resistant structure, and are comprised of mortar-less joints so closely interlocked that even a single sheet of paper cannot fit between the blocks.”
The Geologic Puzzle at Saqsaywaman
On the north side of the Saqsaywaman Archeological Park is a strange outcrop. The outcrop is andesite, but it is marked with north-east trending grooves. It is so deeply grooved in fact, that it’s known as “El Rodadero” – the roller coaster.
In a quick scan of the geologic literature, it appears that ideas for groove formation have ranged from glacial grooves, to faulting, and to the andesite being plastic to partially molten as it was extruded and basically corrugated due to the overlying wallrock. The consensus on groove formation appears to be that of the viscous flow model, but here are links to the references I found, so decide for yourself: