Monday, October 27, 2008

Interesting tree.....?

Joining in on the mini-meme about trees. I thought about what beautiful trees I could think of off the top of my head. I love the ancient bristlecone pines, the tall coastal redwoods, the valley oaks and the massive sequoias, but this one tree along Highway 50, is the first tree that came to mind. It is not beautiful but interesting and is dubbed "The shoe tree". I first came upon this tree in 2004 during my field camp days at UNR. What would cause people driving, to pick this one random tree in the middle of Nevada to stop and throw a pair of old shoes within its branches? My first thought is that non geologists get bored traveling along the highway, which in no way is boring to a geologist. There is not many trees along this stretch of road in Nevada, so why damage the only shade for miles. My reasoning on why people can do something like this turn into puzzling and angry thoughts, it shows the great American way, if one person does it then another must and then another until you have a tree full of old shoes. This is disrespecting nature and in my views not needed, I don't care if is it in the middle of nowhere or next door to my house.

Also a natural history stop

Prisoners Rock is also known as Petroglyph Point and is protected as a small portion of Lava Beds National Monument. The below picture is the western cliff of the tuff cone that reveals numerous wave cut benches that formed when Tule Lake (Modoc Lake) was at a higher level. The Tule Lake basin was filled with water until 1905, after which the lake was drained for agricultural use. Also in the picture is the fence that protects the petroglyphs from being defaced.

There are over 5,000 different petroglyphs that date around 4,500 to 2,500 years ago. So why the petroglyphs at this locations and who completed the rock art? It is believed that the Modoc people used canoes to cross Tule Lake to the island and then complete the petroglyphs unlike other Great Basin rock art. Below are some of my favorite petroglyphs.

Tread lightly if ever visiting Prisoners Rock or

"Someday Kamookumpts will surely wake up and look out over the world he made. He may be angry at how things have changed and bring the water back to cover Tule Lake again, changing the world to be like it was when he first made it."

Sunday, October 26, 2008

Tuff Cones!

The photos in today's blog are my traverse on top of Prisoners Rock.

This photo shows some of the palagonitic rock (orange rust color). Palagonite is a hydration and oxidation of volcanic rocks.

This is the view across the entire tuff cone. The vent area is buried somewhere out in the middle.

This is a piece of juvenile lava that was erupted out. When dealing with phreatic eruptions, it sometimes is problematic to determine if the lava erupted is juvenile or non juvenile. A clue is that juvenile lava is very fragile and has a cauliflower texture.

This is a view to the north showing The Peninsula, a bigger tuff cone in the distance.

Here is the entire view of The Peninsula. It is roughly the same age as Prisoners Rock, but once the tuff cone was above lake level, a small lava lake formed and is represented by the small ledge in the left middle of the photo.

Friday, October 17, 2008

It was cold!

Like I said in the previous post, I knew it was going to be cold on my trip and indeed it was! The advanced volcanology class had to arrive at the Devils Homestead flow lookout in Lava Beds National Monument by Saturday noon, which meant me leaving Modesto at 4AM to get to Sacramento by 5:30AM and after we got the van packed, we left Sac State at 6AM. Traveling by Interstate 5 to Weed, because I was map girl and instructed we could not go over the Medicine Lake Highland. Mt. Shasta was beautiful with a fresh covering of snow and surrounded by clouds. MacDougal and Dorris on Highway 97 are unchanged. There wasn't many birds in the Klamath Basin Preserve, but of course it was hunting season, so I would want to be there either! Arriving in Lava Beds around 11AM and not able to find the undergrad volcanology class (we actually did look), we went to the visitor center, but having been an organizer for a conference last fall at Lava Beds I was wanting to wonder around. The biggest change I noticed was that Cave Loop road was closed from sunset to 8AM, but I was so tired, I didn't get to do any lava tubing.

The undergrads found us and they were sent home and our field trip started. We spent the rest of the day at Prisoners Rock (also called Petroglyph Point for thousand of petroglyphs that are present). Prisoners Rock is a tuff cone that formed approximately 270,000 years ago. Types of hydrovolcanic deposits include armored lapilli (second photo), beds dipping 25-40 degrees from the vent area, lithic clasts, juvenile lava, and massive deposits (fourth photo). The third photo is an interesting feature that was unknown to any of us and not described in any papers we had with us.

It was very windy and a little cold, but I could of been warmer because I was only wearing a pair of workout pants. It got in the lower 20's for the night. The weather made me sleep in a tent for the first time in several years and I was glad I bought it. I had three blankets, lots of heat warmers and a nalgene bottle with hot water at the bottom of my sleeping bag. It was the best I had ever slept in cold weather. So I will leave you with a photo of a freshly covered Mt. Shasta from on top of Prisoners Rock.

Friday, October 10, 2008

I will be on the road again this weekend....

but I am going to freeze my behind off! My advanced volcanology class is taking a trip to Lava Beds National Monument-Tule Lake basin area and High Rock Caldera in northwest Nevada. The caldera is suggested to be the oldest volcanic area in the Yellowstone hotspot track, so that basically means it is out in the middle of nowhere and has not been studied very much. I just was checking temperatures, it is going to be a nice warm toasty 50 degrees in the daytime and 20 degrees at night. At least we will have a lot of firewood! The focus of the trip is hydrovolcanism, so I when I get back I hope to post a bunch of interesting photos, that is if we aren't frozen to the Nevadan high desert!

Wednesday, October 8, 2008

"In Search of the Old Ones"

In Search of the Old Ones is a book by David Roberts that I am currently reading. I am really enjoying the book, he shares his experiences of traveling the southwest looking for Anasazi sites and understanding their culture. Some influential people in locating Anasazi sites were the Wetherill brothers. They found sites like Cliff Palace in Mesa Verde and Chaco Canyon in New Mexico, but they are many other important archaeological sites of the Anasazi that are just important, for instance the Grand Gulch area of Cedar Mesa.

Which brings me to my photos. In a previous entry, I said that Cedar Mesa was one of my favorite places I traveled to this summer in my southwest journeys. After spending the night on the mesa at Muley Point, one of the planned stops the next day was Mule Canyon. Located on the northeast side of the mesa, this was my first chance to see ruins not in a touristy nature like Spruce Tree House at Mesa Verde. The above photos are some of the Anasazi ruins located in the North Fork of Mule Canyon.

I am looking forward to the time I can travel back to the area and do more exploring and learning about the Anasazi.

Tuesday, October 7, 2008

Hydrovolcanism within the Mono Basin

On my eastern Sierra trip, I saved the best hydrovolcanism for last. Mono Lake is a remnant of Pleistocene age Lake Russell. If you are a bird watcher, the lake is an important pit stop for birds on the flyway and three times saltier than the ocean. Over 13,000 years ago the lake was more than 800 ft deeper than present when Black Point (second photo) erupted. Black Point received its name for obvious reasons since it produced basaltic lava. I wish I had time to venture out to the area, but I did not. So I will just have to make another trip to see the fissures and palagonitic soil.

The current lake level is regulated because starting in 1941, the Los Angeles Department of Water and Power (LADWP) began diverting water from streams that filled the lake, this dropped the lake level dramatically, enough so to damage the gull population at the lake. So to make a long story short, LADWP, must now allow some water to be released back into the lake. For the full story, I recommend the book, Storm over Mono Lake, by John Hart. Instead my focus on Mono Lake for this blog entry is Paoha and Negit Islands. Negit Island (photo 3) is a 1,600 year old andesitic volcano that has had activity as recently as 270 years ago. Paoha Island (photo 4) is problematic, made up of lake mud sediments, it may be a bulge from unerupted magma or could have been caused by local faults in the area. Anyways, it dates around 300 years old.

My first photo is Panum Crater, the youngest volcano in the Mono Craters chain that erupted around 600 years ago. It is a type of volcano known as a tuff ring. Usually tuff rings are monogenetic but the geologic history of Panum Crater is more complex. The eruption started with a tuff ring, then a dome was built, but collapsed sending a debris avalanche into Mono Lake, then a second dome formed. In my photo, I show the place where the dome collapsed through the tuff ring into the lake. If ever in this area, there is a short trail that can be taken to the top of Panum Crater. The reward is great views of Mono Lake, the Mono Craters and the June Lake/Mammoth Lakes Area and a hike through obsidian.

Also recommended when in Lee Vining is the Mono Lake Committee store and the National Forest Visitor Center, which has great exhibits on Mono Lake and a balcony to view the lake. If hungry when passing through and wanting an old style burger or ice cream cone, eat at the Mono Cone. If gourmet food is in order, then stop at the Whoa Nelli Deli, try the fish tacos, they are tasty.

Wednesday, October 1, 2008

Class Project: Hydrovolcanism on the East side of the Sierra

After enjoying geologic sites around Mammoth Mountain, the main purpose of my trip was to add photos of hydrovolcanism. Below is a Google Earth map showing the relationship between the Inyo Craters and Mammoth Mountain. Mammoth Mountain is in the southwest corner covered with ski trails and the Inyo Craters are the two little lakes located near the top middle part of the map. So why did I want pictures of the Inyo Craters for my class presentation? The Inyo Craters are a type of hydrovolcanism known as phreatic eruptions that produce structures called maars.

The below picture is the biggest of the three maars that comprise the Inyo Craters. The size of the crater is 600 ft wide and 200 ft deep and there is a permanent lake at the bottom of the crater. The second maar is just a little to the northeast and not quite as wide and 100 ft deep. The third maar is located on top of Deer Mountain. A maar forms when magma comes in contact with groundwater and produces violent steam explosions. Magma never reaches the surface, but the result of the steam explosion leaves a sizable crater. The eruptive phase tends to last anywhere from days up to a month. The Inyo Craters are some of the youngest volcanic features in California erupted around 550 years ago. A shallow dike is the most likely cause for the eruptions.

The next photo reflects the type of deposits that are deposited by a phreatic eruption. These deposits are coarsely layered and exhibit poor sorting of ash to gravel size. In phreatic eruptions it is hard to determine juvenile magma, because the steam eruption will also cause non juvenile clasts to be ejected.

This photo shows the northeast trending relationship of all three craters, but the third crater is hidden in the trees on top of Deer Mountain. The craters are believed to have erupted in sequence from north to south.

Below is the deposits of the second biggest crater. Distinct characteristics exist between the two maars other than size. The second maar contains a smaller lake and mature trees located within the crater.The craters are that way! This is the trail marker at the end of the 1.2 mile dirt road. To get to the Inyo Craters: take the Mammoth Lakes Scenic Loop and travel several miles and look for the Inyo Craters sign, turn left if coming from Mammoth Mountain and follow the signs to the craters. There are many dirt trails that you could potentially get lost, always choose to the right.