A Little Lakes Basin Geology

Glacial Polish and the Sierra Buttes

Geology isn't something that grabs my interest even though it surrounds me!  I guess I prefer to study living organisms!  However, I often see evidence of glacial polish when I'm hiking in the Lakes Basin. So I did a little research and here's what I learned.

The following information is from the website https://hikemtshasta.com/.

"In a broad perspective, the northern Sierra Nevada can roughly be defined as that part of the Sierra Nevada that begins at Carson Pass, includes the Lake Tahoe Basin and continues north 120 miles to Lake Almanor. Compared to the parts of the Sierra Nevada that lie further to the south, this area is typically more subdued and less wild than the vast wilderness of jagged mountains that is the signature of California’s signature mountain range. While there are some fantastic mountains around Lake Tahoe, the subdued trend becomes more evident the further north you go. Despite this, the Lakes Basin area appears to be an island of craggy, glacially carved terrain. It is surrounded by decidedly less rocky, less rugged mountains in nearly every direction.

Geologically the area is something of an island as well. Most of the exposed rock in the Lakes Basin area is composed of quartz porphyry. This is situated between an extensive area of marine sediment to the west and a large granite pluton to the east. The confused geologic structure of this area is common in the northern Sierra Nevada. Rather than consisting of a single granite pluton like most of the range to the south, the mountains in this region are a seemingly random mixture of a variety of rock types. In spite of this, the composition of the cliffs at the Lake Basin area are distinct, with few other examples of it anywhere nearby. It is the quartz porphyry that gives the cliffs their white to pink range of colors and the area’s visual distinctiveness."

 Mud Lake (foreground) - Long Lake (background)

"Strictly speaking, the Lakes Basin proper lies at the northern end of this glaciated area, focused on the basin containing Long Lake. However, the area is geologically cohesive and glaciation and lakes abound, making the name Lakes Basin appropriate to the whole area. In total, there are 6 primary lakes basins here. From north to south, these are the Jamison, Lakes Basin (proper), Gold Lake, Salmon Lake, Packer Lake and the Sardine Lake basins. Worth noting, the Lakes Basin proper, which is around Long Lake, is the centerpiece of the Lakes Basin Recreation Area."

There are approximately 50 lakes in the Lakes Basin, and I've hiked to 46 of them!  They range from clear, rock-bound lakes, to murky pond-like lakes. Each one is unique and beautiful!  Not all of them are named, so we sometimes create our own names for them!  One lake was bone-dry when we first encountered it, so we named it "Not a Drop Lake". We've been back to that lake, and even swam in it, since then!  Unfortunately, I can't show you a photo of it as my new computer doesn't have a CD reader.  RATS!  Here's a collection of photos of some of the Lakes Basin lakes I've visited this past summer!

 Big Bear Lake

Long Lake

Round Lake

Veronica Lake

Upper Tamarack Lake

Un-named Lake

Eye Gnat - Liohippelates pusio

(photo from www.fliesonly.com)

It's HOT out there!

This week the temperatures have been in the high 90's and low 100's!  TOO HOT!  Clouds have been extremely rare.  Occasionally we've had breezy days which help with the heat, but not the dry conditions. No rain is in the forecast.  We try to go for our neighborhood walk in the morning, but gnats have been flocking to our noses, mouths, eyes, and ears! 

 The type of gnats that are currently plaguing us are female Eye Gnats (Liohippelates pusio). They are very small, true flies, and are non-biting. They need the proteins found in human and animal secretions to produce their eggs. They do not pierce the skin of the host to obtain this material, but rather scrape up a pool of mucous with their hind legs and suck it up with their spongy mouth parts! These female gnats can be active anytime the temperature is over 70 degrees, with the most activity occurring when temperatures reach into the 90's. Unfortunately that is happening right now!  

Male Eye Gnats are rare, and do not feed on secretions. Females will lay their eggs in loose soil. It can take 11-30 days for the larvae to become adults. Larvae feed on plant material, not secretions. Multiple generations can occur each year. Our only hope is rain and cold temperatures, which will get rid of these gnats. However, our forecast is for HOT temperatures and no rain, so the gnats are here to stay for awhile!

View north from the Steel Bridge - 9/1/22

Sierra Valley in Late August

Some dear friends of mine were visiting last week, and since one of them was laid up with a foot problem we decided to drive over to Sierra Valley.  It was very DRY and HOT over there, but a breeze kept us from boiling.  All the canals were dried out, and the small ponds were reduced to puddles.  Nevertheless there were still some birds to watch and scenery to enjoy!

American Kestrel (male) - Northern Harrier (female) 

Falco sparverius - Circus hudsonius

Interestingly we saw a few raptors while we were there. On most of my previous trips to the valley, raptors were conspicuously absent!  We saw several American Kestrels, and one Northern Harrier!  Such beauty!

American Kestrels are the smallest falcon in North America, measuring 9" in length, with a wingspan of 22", and a weight of 4.1oz. They prefer to hunt in wide open, grassy fields. Their diet consists primarily of insects and small rodents such as: grasshoppers, beetles, dragonflies, scorpions, spiders, butterflies, moths, voles, mice, shrews, bats, snakes, lizards, frogs, and small songbirds! These beautiful little falcons can be seen in Sierra Valley year-round.

Northern Harrier (female) - Circus hudsonius

We were thrilled to watch a Northern Harrier hunting nearby! After flying over the grass for awhile, it dropped down into the grass with its legs outstretched and ready to grab some prey. It was probably successful in its hunt, as we didn't see it fly up out of the grass!  Northern Harriers typically fly low, skimming over the grasses, tules, and sagebrush while hunting for prey. They are a medium size raptor, measuring 18" in length, with a wingspan of 43", and a weight of 15 oz. They eat medium to small birds and mammals, as well as reptiles and frogs. Unlike other raptors, they rely on auditory clues from their owl-like facial disc of feathers, which helps them locate prey acoustically! They can be found in Sierra Valley year-round.

Sandhill Cranes (adults) - Antigone canadensis

Over the course of the day we saw about 6 Sandhill Cranes! They must have raised their young in Sierra Valley this year, which is the southernmost area that Sandhill Cranes are known to nest. Most of the Sandhill Cranes that overwinter in California breed farther north in Idaho, Oregon, and Washington. They will be leaving for California's Central Valley in the Fall. I love seeing these beautiful large birds, that are 4' tall and have a wingspan of 7' 7".

View north from the Marble Hot Springs Road

Damp Earth Art

Once again, more HOT weather has come in this week with no rain in sight. Please join me in my continuing hope for precipitation! Perhaps our collective efforts may help it happen.

I'm going to keep posting rain inspired writings, art, etc. on my blog at dampearthart.blogspot.com. Any submissions would be greatly appreciated.

What kind of rock formation is this?

What's happening on the River?

Check back next week for the answers to these questions and more!

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