A Geology Field Trip to the Local Mountains and Desert (yes, GEOLOGY)

I am taking a Physical Geology course at Mesa College, as a pleasant diversion from the life sciences. San Diego County is chock full of fascinating rocks and minerals and interesting land forms. More than I ever imagined!

On March 19th, we took a day-long field trip to the Laguna Mountains, and then the local desert. Terri Groth (friend and neighbor) accompanied me. About 13 people were on the adventure, including fellow classmates and the instructor, Don Barrie.

The photos below are from Canyon sin Nombre ("canyon without a name"), not far from Indian Gorge where we camped the weekend before.

This canyon was full of fascinating geological formations and types of rocks, including igneous, sedimentary and metamorphic - a little of everything we are learning about in the class at the moment.

Varied landscape near the entrance to Canyon sin Nombre. Much of the dark brown rocks are schist, a metamorphic rock.

More of the unusual swirls and strange rock patterns.

A big dike of light-colored igneous rock filling an ancient crack.

Contrast between the darker (what I believe is schist) and the felsic, light-colored igneous rock of the dike.

Some really nice gneiss (pronounced "nice"), another metamorphic rock, the result of ultra-high temperatures and pressures deep in the Earth.

Amphibolite, another metamorphic rock. 

Schist, a metamorphic rock with course grains, and foliation (a "layered" look), the result of intense pressures.

Folding in sedimentary rocks in the Olla Formation.

A Short Diversion to Indian Gorge in the Anza Borrego Desert

From March 11 - 13 (2016), we camped with friends in Indian Gorge, a canyon in the southern portion of the Anza Borrego State Park.

We have camped there before around this time of year, and on the last trip were toasted in unusually hot temperatures (low 90s), but this year things were cooler (with a little rain on Friday night even). Some flowers were blooming from earlier rains, but it has not turned into an "epic" flower season, sadly (the El Nino rains have not materialized for southern California in the way we had hoped).

Here are a few of the highlights from this trip:

"Palm Bowl" group of native palms (Washingtonia filifera). This was one canyon south from Indian Gorge.

Desert Iguana (Dipsosaurus dorsalis), also in the canyon to the south of Indian Gorge and Indian Valley (as is the iguana below).

This one allowed a very close approach!

This very pale (felsic) granite is everywhere in the area. It has nicely formed mica embedded in it.

A pottery shard, from the earlier inhabitants of the region - the first I have seen in the Anza Borrego Desert. Indian Gorge.

Oncerimetopus nigriclavus (a small true bug with a BIG name!). In Torote Canyon, which is an off-shoot from Indian Gorge. Torote is Spanish for Elephant Tree, and a few of these trees (twhich are more abundant in Mexico) occur in this small canyon.

The Red-eared Blister Beetle (Lytta auriculata). This was the main beetle seen. NO tenebrionids (darkling beetles) were seen at all - very unusual. Possibly due to the cool temperatures.

Lytta auriculata feeding on Brittlebush.

More Lytta auriculata (MAKING more Lytta auriculata).

An ichneumon wasp, one of the few (non-moth) visitors to the black light that I set out on Saturday night.

A nocturnal mutillid (velvet ant - which is actually a wasp). At the light.

Ready to demolish Tokyo!!! Well, maybe not (it's less than a centimeter long...).
This appears to be a nymph of the planthopper Orgerius sp. Just about the most photogenic creature to appear at the light.

Another view of Orgerius sp.

Some Insects and Other Arthropods from San Felipe Creek

We took a short trip down to San Felipe Creek in the desert, and encountered some interesting arthropod fauna after dark.

A small orb weaver with wrapped-up prey. This specimen was only about 9-10 mm in body length. Will do some searching on-line to try to identify it. This spider had it's web in a mesquite.

Dinacoma marginata. Have seen these in this spot before in a prior year.

These two males came to the flashlight beam as we walked a dirt road after dark.

Eleodes sp., as identified on Bugguide. This is the very large, robust, shiny species that seems abundant in the San Felipe Creek area. They tend to be about 30 mm in body length.

Looks like Euthysanius. E. lautus? Much smaller than the E. lautus we see in the Cuyamaca Mountains in summer. This one was about 17 mm long, and others seen were smaller.

My best guess as to identity for this clerid is Enoclerus quadrisignatus.

Our 2014 Diversion to Coyote Canyon, in the Anza Borrego Desert

Last year around this time, Gary and I made a little trip to Coyote Canyon in the Anza Borrego State Park. We were so intrigued by the riparian area in the middle of the arid desert that we decided to return this last weekend, this time with several friends.

This year was drier even than last (which is saying something, as last year was pretty parched). But Coyote Creek was running steadily, if not very high, and some flowering trees, shrubs and forbs were to be found. Beetles were here and there, but not numerous. The majority were tenebrionids found on the ground after dark. The stars of the show were the tree frogs, of two species (the California Tree Frog, Pseudacris cadaverina and the Pacific Tree Frog, Pseudacris regilla). The California Tree Frogs seemed by far to be the most numerous. They were calling day and night, in hopes of making more frogs, and any stroll near the creek would reveal little hoppers here...there...everywhere.

This will surely be a spectacular spot to visit in a wet spring!

The weekend before, we made a short day trip to the area to check out access to Sheep Canyon, further up from where we camped in Lower Coyote Canyon. The steep part of the access road had been "cleaned up" by the State Park, and we were actually able to creep up it slowly in 4WD low. This would have been impossible the spring before, as it truly was "Boulder Alley" then, and only the most capable four-wheel-drive vehicles could make it.

This weekend we only hiked to the lower lush "forest" and not all the way to Sheep Canyon. Many endangered Least Bell's Vireo were nesting in the thick willow-dominated woodland.

Sheep Canyon, from our visit on March 9. Native California Fan Palms are visible scattered throughout the rich forest.

Coyote Creek. Many tracks of coyotes (of course), bobcats, raccoons, squirrels and others were near the life-giving water. On Sunday morning VERY early (before dawn) three of us thought we heard a distinct "meow" sound near our camp. After later investigation, it did sound quite a bit like a certain vocalization that bobcats make.

California Tree Frog, Pseudacris cadaverina, the most commonly seen frog species for this trip. All the remaining frog images below are of this species, except the last photo. This one was seen (along with many of his friends) on a night hike Gary and I took on Friday evening.

I couldn't manage to capture an image of a fully inflated throat sac - those frogs were a bit too shy for the camera.

On Saturday, during the day, several of us walked over to the nearby creek from our camp, with chairs, and settled in by the trickling waterway for relaxing time. I never did encounter my fellow humans, but where I settled in there were plenty of frogs, and they slowly emerged from hiding and proceeded to do frog things as I sat quietly nearby. These two croaked and crawled on each other (but never mated) and then hunkered down under this tiny overhang, to escape the heat.

A pretty little frog amongst the fallen blossoms.

A nice classic pose.

I guess there can be no such things as too many frog photos!

I saw very few Pacific Tree Frogs, which is the more common species in Cuyamaca Woods. But this one is unmistakeable, with the dark eye-stripe and less blotchy markings.

Asbolus verrucosus. We saw about a dozen total on the trip, which I thought was quite a lot for the Anza Borrego Desert.

Acmaeodera sp. on Apricot Mallow. Still waiting to identify to species.

Edrotes ventricosus, a small fuzzy darkling beetle. We saw several on our evening hike.

What appears to be Sphenophorus sp., a billbug (a type of weevil). It was on the sandy road just adjacent to the rich riparian area.

Cerenopus concolor, a darkling beetle.

Pupa of...? This was right next to the creek, and when I knelt down nearby to photograph a track in the mud, it started wiggling and whipping back and forth!

I tried to take a short video of the wiggling pupa, but operator error prevented my getting a movie (just this still image)! In other words, I forgot how to do THAT on this camera! This image still sort of conveys the action, though.

Raccoon tracks in the mud. Last August and September there were massive monsoonal floods that ripped through the canyon, and I think some of these tracks may date back to that time (we've had virtually no rain in the local desert since).

The Guys, posing with a huge metal THING we found sitting in the middle of the desert! This THING isn't going anywhere soon, I suspect. It was impressive, though.

A Re-Visit to Scissors Crossing and Vicinity, Post-Monsoonal Rains

I made a short trip to the area around Scissors Crossing in the Anza Borrego Desert today, to see what the heavy rains have yielded, about a month after they fell (the last trip was on August 30th). The most dramatic change since the last visit was a massive explosion of White-lined Sphinx Moth larvae, and many yellow composites blooming on the desert floor. There were not many beetles to be found, with the exception of quite a few Lytta vulnerata, a large, colorful blister beetle, and a new species for me.

The old corral area, a little west of Shelter Valley. The reddish plants on the ground were heavily nibbled by the caterpillars. Ravens and crows were busily eating the caterpillars.

The find-of-the-day: Lytta vulnerata. A "life-beetle" for me!

"Rabbit Brush," upon which the Lytta were found (other Lytta vulnerata were found on a different yellow composite that I have not yet identified).

A small pile of White-lined Sphinx Moth caterpillars. It was difficult not to step on them, they were so numerous. No caterpillar hunters (Calosoma or Callisthenes) seen, though.

A Diversion to the Anza Borrego Desert: About One Week Following the Local Monsoonal Rainfall

Some excellent rain has fallen in the Anza Borrego Desert in the past couple weeks, with spectacular flash flooding in some areas about one week ago.

I took a little day trip down there this Friday, August 30, to see what sort of flowering and insect activity might have been triggered by the rain.

The Scissors Crossing area clearly received quite a bit of precipitation, and about one mile west of Shelter Valley, the ground was very moist still, and mushrooms were popping up all over the landscape! Not too much flowering was occurring, and not too many insects were out and about, but that might change in the days and weeks to come. A lot of green growth was starting to appear on the damp landscape, though.

Below are some photographs of beetles found, and the wonderful mushroom "bloom."

Acmaeodera gibbula, Scissors Crossing, Anza Borrego Desert, August 30, 2013.

Plionoma suturalis pair, Scissors Crossing, Anza Borrego Desert. This female did not seem to enjoy being bitten in the face during copulation, and struggled to leave while I watched the pair. When this photo was taken, the male was trying to restrain her. In seconds she wriggled free and flew off, closely followed by the male. August 30, 2013.

Plionoma suturalis pair, Scissors Crossing, Anza Borrego Desert. August 30, 2013.

This white species of mushroom was the most abundant about one mile west of Shelter Valley. August 30, 2013.

A young, fresh pair of the species shown above. August 30, 2013.

Another undetermined mushroom species. One mile west of Shelter Valley. August 30, 2013.

A mystery-fungus. I'm not even completely sure that this IS a fungus! There were several of these hemispherical growths on the ground. They had no real stalk penetrating into the ground. The "hemisphere" sat on top of the fibrous mat seen below it here. August 30, 2013.

NOTE: Euphoria fascifera WERE flying associated with mesquite trees near Shelter Valley, but they were all flying too fast and high to photograph. I had seen this species in this location in late August 2007, in similar post-monsoonal conditions.

Euphoria fascifera from 2007, near Shelter Valley, Anza Borrego Desert.