Monday, January 30, 2012

Wild cucumber, or manroot, of North America



Wild cucumbers of the Marah genus (gourd family, Cucurbitaceae) are found on the west coast of North America. The common name “manroot” refers to the large underground tubers that can weigh up to 100 pounds [1]. From these tubers, wild cucumbers sprawl or climb as vines with the help of tendrils that attach the growing plants to shrubs and trees. Most striking (and pricking) are the eye-catching spiny balls, one to two inches in diameter. Sometimes they are dangling from a vine—as in the pictures herein, showing a plant along the Ojai Pratt Trail through chaparral-like habitat south of Santa Barbara in California. The unripe, green fruits typically ripen into non-edible, yellow to brown fruits. The large leaves are palmetedly lobed, with five to seven lobes.

In a recent Bay Nature article entitled “Cool as a Cumber,” Jake Sigg features the two Marah species (M. fabaceus and M. oreganus) that grow in shrublands around and beyond San Francisco Bay [2]. He describes their emergence from summer dormancy with the advent of autumn rains. The best time to admire the spiny fruits is winter. With the beginning of the dry season in spring, the herbage turns yellow-brown and dies back to the tuberous root.

Like with all species in the gourd family, the flowers of the Marah are unisexual [3]: individual flowers are either male or female. But both sexes can be found on the same plant (monoecious plants), on which male flowers fertilize the female ones.

References and more to explore
[1] wiseGEEK: What Are Wild Cucumbers? [http://www.wisegeek.com/what-are-wild-cucumbers.htm].
[2] Jake Sigg: Cool as a Cucumber. Bay Nature January-March 2012, page 10. Also see Sigg's Wild Cucumber (Marah) article at collective roots and his San Francisco Natural Areas contribution.
[3]  Gourd Family (Cucurbitaceae) - Biology of Gourds: science.jrank.org/pages/3083/Gourd-Family-Cucurbitaceae-Biology-gourds.html.


Tuesday, January 24, 2012

Concentric thinolite layers at Winnemucca Lake


Winnemucca Lake in Nevada is like Pyramid Lake a remnant of the Pleistocene Lake Lahontan. Winnemucca Lake is separated from Pyramid Lake by the Lake Range, but almost meets it at Dago Bay, north of where the Truckee River flows into Pyramid Lake. Winnemucca Lake is mainly a dry lake now: the top picture shows its playa at New Year's Eve 2011. Depending on the day light, it may look like salt or snow. But a hike into the playa confirms that it is sand and soil (which may be covered by snow on some rare, snowy winter days). 

The Pyramid-Winnemucca landscape is rich in natural tufa sculptures including Popcorn Rock, Indian Head Rock and the towers and deposits at The Needles. Spectacular tufa formations can be explored at the south end of Winnemucca Lake. There, assemblies of thinolite rolls are scattered along the side of a gentle slope. Getting close to these unusual rocks, one can see crystalline tufa forming concentric layers, as seen in the picture above. How did calcium carbonate deposit and align into these mysterious, round-shaped megaliths?

Getting there
From I-80 at Wadsworth near Fernley take Route 447 north. This route enters the Pyramid Lake Indian Reservation along the Truckee River and leads to Nixon. From there, Route 447 continues north to Gerlach and the Black Rock Desert. The site of interest is about five miles north, just past the left-side intersection with the dirt road going to the east shore of Pyramid Lake, the Great Stone Mother & Basket and the scenic Pyramid rock (currently closed).  The thinolite tufas are on the right side, off Route 447, which leaves and reenters the Reservation there.



Sunday, January 22, 2012

The steam geyser of Lake Pyramid's Needles area



The tufa structures of the Needles Rocks area at the north end of Lake Pyramid in Nevada make a fascinating landscape for hiking and hanging around. Between the shoreline and the tufa mounds is a steam geyser, spraying hot water over 25 feet high. The hot water is running down into the lake and green plants can be seen thriving and bending in the flow of warm water.


While relaxing at the geyser fountain, enjoying its splashing sound and the sun-light reflections in the falling water droplets, one's thought may go back in time and imagine (diving) this place during the days of Lake Lahontan: instead of ejecting into the air, the hot and calcium-rich water would have mixed with the lake water and initiated chemical reactions causing calcium carbonate (CaCO3) precipitation and tufa formation.

Saturday, January 21, 2012

Hiking between tufa pinnacles and mushroom castles



Tufa deposits of various sizes and shapes can be found in California and Nevada, typically along the shores of Pleistocene lakes and their present remnants (often dry lakes or valleys today) such as Honey Lake, Pyramid Lake, Mono Lake, Indian Wells Valley,  Panamint Valley, Searles Lake and the Salton Sea [1]. An impressive diversity of tufa mounds and cementations can be explored at the north end of Pyramid Lake in Nevada. This location is often referred to as “the Needles.” The Needles Rocks, like Popcorn Rock and Indian Head Rock, were built in the past during times of higher water levels, when upwelling calcium-laden spring water entered the lake along fault zones and mixed with colder, carbonate-rich lake water [2].

The tufa formations in the Needles area include spread-out mounds composed of interlocking spheres and barrels and tall mounds (towers) reaching elevations 100 m above lake level [3]. Tufa is mainly calcium carbonate, but some tufa deposits contain cells of algae. The variation in composition, density, porosity and crystallinity results in a multitude of forms including encrusting, fiber-forming and branching tufa. Many can be discovered between and around the Needles. 

Getting to the Needles
Route 445 along the west side of Lake Pyramid ends at Warrior Point as a paved road and continues on as Indian Land Route No. 2. The dirt road to the Needles has been closed. The “tufa incarnation of the first President of the United States of America,” George Washington Rock, about five miles north of Warrior Point, is a good location to view Wizard Cove and the Needles. Depending on your time, you may start anywhere along the shore and hike north. The tufa mounds can be seen from far away. But remember that you are in desert country: features that look like they are nearby, may still be miles away. Also, you may sink or break in by stepping onto unstable ground, what will further delay your approach.    

References and more to explore
[1] Tufa on pages 116-118 in California Geology by D. R. Harden. Second Edition. Pearson Education, Inc., Upper Saddle River, NJ, 2004.
[2] Tufa on page 145 in the guide book Geologic and Natural History Tours in the Reno Area by J. V. Tingley, K. A. Pizarro, C. Ross, B. W. Purkey and L. J. Garside. Nevada Bureau of Mines and Geology Special Publication 19, University of Nevada, Reno, 2005.
[3] Larry Benson: The Tufas of Pyramid Lake, Nevada. USGS, Circular 1267, last updated 2004 [plpt.nsn.us/geology/index.html].

Wednesday, January 18, 2012

Indian Head Rock at Pyramid Lake

Indian Head Rock next to the shoreline of the lower west side of Pyramid Lake is—like Popcorn Rock—an eroding tufa mound. This complex of deposited calcite (calcium carbonate) showcases various forms of tufa such as coralline and crystalline-layered tufa. Differently rounded and coated parts of the ludicrous-looking mound are interlocking with each other. The picture below shows a thinolite arch at Indian Head's base with crystalline tufa forming concentric layers of fibrous and branched calcite structures.




Finding Indian Head Rock
Indian Head Rock is located along Route 446 between its intersection with Route 447 at Nixon and its intersection with Route 445 a few miles further north. From the rock complex, it is only a short walk to Indian Head Beach.

Tuesday, January 17, 2012

Pyramid Lake: pouched fishermen

The American White Pelican (Pelecanus erythrorhynchos) roosts on sandbars and small islands [1]. Such an island is Anaho Island, located south of the tufa pyramid of Pyramid Lake in northwest Nevada. This island features a 600-foot-tall rock off the lower east side of the lake [2]. It is a National Wildlife Refuge, protecting the nesting grounds for shorebirds including the white pelican.


Anaho Island is visible from most places around Pyramid Lake such as the Popcorn Rock site, from where a group of lake visitors (see picture) was trying to zoom in on birds and the island on New Year's Eve 2011. The Popcorn Rock viewing area is the place of choice to learn about white pelicans: an interpretive panel informs about the pouched fishermen. The enormous orange pouched bill, orange-red legs and black wing tips make it easy to recognize these fish-eating waterbirds. The panel explains that Anaho Island supports the largest American White Pelican nesting colony in the western United States, with as many as 20,000 birds in some years. The island is a nesting habitat free from predators and human disturbance.   

The pelicans typically spend the winter in southern California and Mexico. According to the panel, they begin to arrive at Pyramid Lake in early March. New Year's Eve is not the time for pelican watching at Pyramid Lake, although this winter's weather pattern does not seem very different from that of mid-March and early spring.

References
[1] David Allen Sibley: The Sibley Field Guide to Birds of Western North America. Alfred A. Knopf, New York, 2003; page 47.
[2] Deke Castleman: Nevada.Compass American Guides, Inc., Oakland, California, 2000; page 226.

Saturday, January 14, 2012

Popcorn Rock at Pyramid Lake


Popcorn Rock is a tufa structure at Pyramid Lake.The natural composition of round-shaped rocks, built from calcareous substances and partially eroded, gives the appearance of a giant popcorn.

Popcorn Rock and other tufa structures have been formed by precipitation of calcium carbonate. When water levels were much higher than they are now and Pyramid Lake was part of Lake Lahontan during the ice age, the sites, which exhibit tufa towers and mounds today, were under water. Many tufa features line up along fault zones. It is assumed that, in the past, warm calcium-laden spring water spilled out into the colder water of Lake Lahontan: tufa features, such as Popcorn Rock, formed at this interface where mineral water of different temperature and composition combined [1]. Gradually diverse calcium carbonate sculptures were deposited and agglomerated into today's shapes around and beyond the current reach of Lake Pyramid.

Finding Popcorn Rock
Popcorn Rock is located at the southern end of Pyramid Lake (near the Guanomi Mine) along Route 446 between its intersection with Route 447 at Nixon and its intersection with Route 445 further north. See the section Getting to Pyramid Lake in the previous post, describing how to get to the lake from Wadsworth (near Fernley) or from Reno and Sparks.

Popcorn Tufa Reference
[1] Tufa on page 145 in the guide book Geologic and Natural History Tours in the Reno Area by J. V. Tingley, K. A. Pizarro, C. Ross, B. W. Purkey and L. J. Garside. Nevada Bureau of Mines and Geology Special Publication 19, University of Nevada, Reno, 2005.



Friday, January 13, 2012

Pyramid Lake


Pyramid Lake is a desert lake in Nevada [1], located about 30 miles northeast of  Reno and Sparks. The lake was named by John C. Fremont (nicknamed the Pathfinder of the West, who visited the lake with his party in January 1844) for the shown pyramid-shaped tufa formation on the eastern shore. Pyramid Lake is part of the land of the Paiute people and was established as a reservation in 1873 by Ulysses S. Grant [2].

Pyramid Lake is a popular fishing lake [3]. Hiking along the shore, one can see—all year round—fisherman who wade out deep to cast their lines. Bird watchers and tufa enthusiasts also enjoy the lake shores. If you don't mind the alkaline water and are prepared for sudden dangers such as undercurrent, cold water pockets and uprising mud patches, the lake is great for floating and swimming on hot-summer days.

Getting to Pyramid Lake
From Sparks take Route 445 (Pyramid Highway) north. From Wadsworth (north of I-80 near Fernley) east of Sparks go north on Route 447. You need a permit for day use, camping, fishing, boating, jet skiing and other activities. The permit can be obtained online (Pyramid Lake Permits) or along the way; for example, at the Nixon store at the intersection of Route 447 with 446 (when coming from Wadsworth) or at the Texaco station at the intersection of Eagle Canyon Drive and La Posada Drive with Route 445 (when coming from Reno/Sparks and getting to Spanish Springs).
Unfortunately, the area near the pyramid has recently been closed to the general public until further notice due to respectless vandalism of cultural sites and natural beauty. The above picture was taken in March 2008, when the Pyramid surroundings could still be accessed via a dirt road off Route 447. Arriving at the lake via Route 445 over Mullen Pass, you'll have an excellent view of the lake with The Pyramid and Anaho Island right in the center of the scenery.

References and more to explore
[1] Sessions S. Wheeler: The Desert Lake - The story of Nevada'd Pyramid Lake. Caxton Press, Caldwell, Idaho, Seventh Printing 2001.
[2] Nevada > Destinations > Paiute Tribe: travelnevada.com/destinations/pyramid-lake/paiute-tribe/.
[3] Lee Allen: Fishing Pyramid Lake. Lahontan cutthroat trout go from threatened to plentiful in ancient Northern Nevada lake. Nevada Magazin, July/August 2011 [www.nevadamagazine.com/issues/read/fishing_pyramid_lake/].