Monday, January 31, 2011

Good Weather for a Road Trip

Since January 1, 2011, the Engineering Geek and I have spent exactly three nights under the same roof. All of those nights were within the first two weeks of January. On New Year's Day, the CIT and I drove down through frigid sunshine on icy roads because he was due to start school on the 3rd. At that time, Cowboy J. and his wife Nurse A. were still living in the ranch house, and the CIT and I took up housekeeping in the Cabin. However, they have since moved to new digs, and we have one horse, three pregnant cows, two heifers, and one bull to care for, as well as the dogs. So as one of us stays at Ragamuffin House to prepare our move, the other is down here, looking after the CIT and Ragamuffin Ranch.

One of the few consolations for our hurried lunches at halfway points between the two places is that the weather had been good for roadtrips over the past month. Last Monday was one of the best days. The roads were completely dry, the sun was out and the temperature was in the 40's in the highlands and in the 50's in the Rio Grande Valley. And I was driving US 60 to Socorro and then up I-25 to Belen, where I was planning to meet the EG for lunch, so that we did not have to pass exactly like ships in the night. I took some good pictures of the geological features that day, for the sun was out and despite a stiff wind in the valley, the air was relatively clear. Here, then, are some pictures of the grandeur of New Mexico.

Peaks of the Sawtooth Mountains near Pie Town, NM, rise above the surface in these southern reaches of the Colorado Plateau. The Sawtooths are part of the Mogollon-Datil Volcanic Field, and are the sedimentary deposition of pyroclastics weathered from the volcanic action between 24 and 40 million years ago. The sedimentary layers also include breccias composed of large pieces of the country rock at the time, limestones and sandstones that were incorporated by the streams that deposited the weathered volcanics.

Looking southwest across the plains of San Augustin towards the San Mateo Mountains west of Magdalena. During the last ice age, a glacial lake resided within the downfaulted block between two upfaulted mountain ranges. The lake within this graben finally disappeared about 8,000 years ago. I was standing on an old beach bar of the lake that once was. The San Mateos are volcanic in nature, and the rock is composed of ash flow tuff and rhyolite flows that erupted during the Oligocene, about 28 million years ago. I find it easy to imagine the waters of a lake on the flat plain below the mountains.

The western front of the northern Magdalena Mountains, here seen from just west of Magdalena, NM. The mountains core consists of Precambrian igneous and sedimentary rocks that were upfaulted relative to the Precambrian sediments I was standing above while taking the picture. These mountains were later intruded and extruded by basalts and volcanics of the same age as the Rocky Mountains to the north, during the Laramide Revolution about 65 million years ago. These events account for the minerals , including silver and iron ore mined at Magdalena and Kelly during the early years of the 20th century. Highway 60 here joins a fault that defines the edge of the mountain range.

Looking slightly north of east across the Rio Grande Rift west of Magdalena. Behind me is the Magdalena fault that is resposible for the high valley upon which I stand. Across the rift are the upfaulted Los Pinos Mountains that define the eastern edge of the rift. The rift defines an area where the continent is being stretched apart, and the fault blocks on either side bound a graben. These faults are still active and the mountains are still rising relative to the valley floor. The Rio Grande Rift began pulling apart nearly 30 million years ago, and the maximum distance between Pennsylvanian Limestone at the top of the fault-block mountains and that same formation below the valley sediments is as much as 30,000 feet. The rifting is responsible for the activity of the Mogollon-Datil Volcanic Field to the west.

Here I am standing on the stabilized dunes of the Rio Salado north of Lemitar, within the Rio Grande Rift itself. The mountains in the background are rift fault block above the dunes to the southwest. They are composed of tertiary sedimentary rocks rising from the quaternary Santa Fe Formation. In the foreground, is a moving dune field just across the Rio Salado.

Here, I am standing on a terrace of the Santa Fe Group west of the Rio Grande at Belen looking across the rift to the Manzano Mountains that here define the Eastern boundary of the Rift. The steep side of the fault block, these mountains rise steeply, and form a rainshadow over the valley. The "green side" is the other side, that falls to the hinge of the fault block at a much gentler angle, and catches the rainfall.

The EG and I met and ate at a little railway car diner there on the edge of the terrace, that is open 24 hours a day. I recommend the Green Chile Burger.My trip took me on up the Rio Grande Rift to Albuquerque and then through the pass made by the Tijeras Fault to Ragamuffin House.

I thought I would be making another road trip from the Ragamuffin Ranch to Ragamuffin House this week, but the January thaw seems to have ended with the month, and today snow showers have become a steady snowfall here in the Western Mountains. It looks like I am here for the week, as the Continental Divide is expected to be difficult traveling. So I will look back with pleasure at the good weather and the road trip while I contemplate taking the 4WD ranch truck to the bus stop this afternoon to pick up the CIT.

We do need the snow. But the bitter cold that will follow, I could do without.


Chuck said...

A gentle chide aside. You said:

"....between 24 and 40 million years ago ....

Accuracy you can count on, that.

Seriously, I have read ahead to your blogs coming after this one and have enjoyed them a great deal. Same for this one, but I had to try to be funny ... sorry. ;>)

Elisheva Hannah Levin said...

Chuck--volcanoes are usually active for a short period--these had multiple eruptions and extrusions of lava, the layers of which were extruded over a period of 16 my plus or minus.