Historical Geology:Southern California RegionKristi Coy

Southern California RegionMost of Southern California’s geological history occurred during the Mesozoic and Cenozoic Eras. Due to high volumes of volcanic activity, much of this area formed during this time (“Geologic History of Southern California”).

There were many changes that occurred for California, such as mountain building, faulting, erosion sediment depositing and, of course volcanic activity (“Geologic History of Southern California”).

History: In the Southern California area, Tertiary and Quaternary volcanic rocks are the most commonly found, such as granite (Wagoner and Maldonado).

History and Conditions of Southern California

During the Quaternary Period, 2.6-.011 million years ago, California’s volcanic activity was subsiding and instead experienced uplift and erosion (Wagoner & Maldonado, 2014).

In addition, we had a lot of rivers and streams that moved sediment and deposited it. Later, in the Pliocene and Pleistocene eras, ice ages contributed to forming the valleys in which I took many of these photos (“Geologic History of Southern California”).

Conditions: The region I took these photos is a very dry climate with temperatures exceeding

105 degrees in the summer and below freezing temperatures in winter. It currently receives approximately 11” of rain per year, so it is considered to be a semiarid climate.

View of Lake Elsinore (Lake Elsinore, Wiki).

HummingbirdsApodeformes-Trochilidae

Photo Taken in Southern CA

Hummingbird nesting in my sister’s back yard in Southern California.

How and Why Did They Evolve?How? It is presumed hummingbirds

originated in Eurasia and went over to South America (Sanders, 2014).

Once in South America, they evolved to over 140 new species (Sanders, 2014).

Next, they went to North America and the Caribbean (Sanders, 2014).

The phylogenetic history connects them to swifts and treeswifts (“Classification”).

Why? The answer to this question is

still unknown. According to a study at UC Berkeley, it is still unknown “since they are dependent on plants that coevolved with them and developed unique feeding adaptions” (Sanders, 2014).

Because they feed on nectar, it is thought they possibly drive the evolution of the very plants they feed upon.

When Did They Evolve?When? Hummingbirds are said to

have arose in Eurasia 42 million years ago (“Evolution: Hummingbird Species”).

There are fossils dating back to 28-34 million years ago found in Europe and Asia that look similar to present day hummingbirds (Sanders, 2014).

Adaptions: Hummingbirds have

extreme abilities that allow them to hover during flight.

Their unique beak allows them to feed on nectar deep in a trumpeted flower.

They are an extremely diverse species with over 300 currently in existence and predicted to rise to over 700 in the years to come.

(“Evolution: Hummingbird Species”)

Sahara MustardBrassica Tournefortii

Mustard plant growing wild behind my house in Southern California.

Evolutionary History of the Mustard PlantThe Sahara mustard originally came from North Africa and the Middle East. Other areas it was known to exist was in southern Europe. Apparently, it was brought to southern California in the early 18th century and grows wild in fields or rocky areas (Sanders & Minnich, 2006).

Although I could not find a fossil record for this particular plant, it is a seed plant and therefore began to appear in the Late Devonian. It is most likely not an early seed plant, because it contains pollen chambers that release a sticky fluid. Earlier seed plants do not have this feature (“Seed Plants”).

This plant grows rapidly and produces anywhere from 750-9000 seeds during December-May (Sanders & Minnich, 2006). This can be a problem, because it grows and spreads so quickly, then dies off, it becomes a huge fire hazard in the southern California area.

Adaption: The leaves are small with incised margins which is perfect for the cool weather during their growth period (Monroe & Wicander, p.633).

California Quail

Species: Callipepla Californica

This photo is of a female quail sitting on a familiar rock with sagebrush in the background.

Habitat and Evolutionof the California QuailHabitat:The California Quail are frequently found in southern California areas that contain plants, such as sagebrush in which they can hide (Moore, 2014).

Evolution:They are considered to be New World quails, and were given their own family name of Odontophoridae, because the DNA shows they are not closely related to the Old World quail descendants (McIlvaine, 2000).

The California quail are thought to have an evolutionary history dating back to an earlier bird from 63 million years ago in South America. Some fossil analysis have been done and it is thought that the Odontophoridae appeared approximately 16 million years ago.Because the oldest genera were found in Mexico and further south, it is thought the New World quail originally appeared in tropical America (McIlvaine, 2000).

Granite Igneous Rock Comparison

Photo Taken in Southern CA

Granite Igneous Rock Comparison The picture shows uniquely

different granite rocks, which contain minerals causing them to be different colors.

The one on the left contains more biotite, which is black, causing it to appear darker whereas the three clustered on the right contain potassium feldspar that gives them the orange or pink look.

Both contain quartz and plagioclase feldspar which is the lighter white color (Monroe & Wicander, p.75)

How They Formed: Intrusive rock that is found

in volcanic arcs and mountain building areas (“Geology Rocks & Minerals”).

Comprised of minerals that crystallized from cooling molten rock matter or particulate matter ejected from volcanoes during explosive eruptions (Monroe and Wicander, p. 86).

Granite Rock with Lichen

Igneous RockPhoto Taken in Southern California

Igneous Granite Rock Covered in Lichen I think this is a granite rock,

because under the lichen, the rock is lighter in color than a rock such as grandodiorite.

In addition, it is usually found in mountain building, which is where I found this rock while hiking a hill behind my house.

It features several minerals including quartz and potassium feldspar and similar to my rock, is medium to coarse grained in its texture (“Geology Rocks & Minerals”).

Lichen is basically a fungus that are found in many bright colors clinging to rocks.

Lichen is commonly found on rocks in arid climates and could not survive on its own in the hot conditions of Southern California.

According to Wayne Armstrong, “the relationship is a kind of marriage where each member depends on the other for its survival” (Armstong).

Igneous Lava Rocks

Encased in a

Metamorphic

Foliated Gneiss

RockPhoto Taken in Southern CA

Details: Igneous Lava Rocks Encased in a Metamorphic Foliated Gneiss Rock

Type: Igneous - granite, plutonic:

contains visible minerals that reveals a slow cooling process (“Rocks and the Rock Cycle”).

How They Formed-Igneous Lava Rocks: Comprised of minerals that

crystallized from cooling molten rock matter or particulate matter ejected from volcanoes during explosive eruptions (Monroe and Wicander, p.86).

How They Formed-Metamorphic: Formed by heat, pressure

and chemical process while buried below the Earth (“Examples of Common”).

Two types of metamorphic rocks: foliated and non-foliated (“Examples of Common”).

Foliated look like they have layers or bands whereas non-foliated do not (“Metamorphic Rocks”).

Details: Igneous Lava Rocks Encased in a Metamorphic Foliated Gneiss Rock

How They Formed- Metamorphic Gneiss: Shale or granite are usually

the parent rocks (“Examples of Common”).

Formed by granular mineral grains (“Metamorphic Rocks”).

It has the greatest degree of metamorphism of all foliated rocks (“Examples of Common”).

Usually associated with major mountain building (“Examples of Common”) and I found this near a large hill.

Gneiss is a very common metamorphic rock (“Examples of Common”).

Close up of a portion of the rock to show detail.

RhyoliteFelsic Rock

Igneous Volcanic RockPhoto Taken in Southern California

Details Rhyolite Igneous Volcanic Rock:

I think this rock is a rhyolite, because it has a fine grained appearance also known as an aphanitic texture, which is smoother than most granite rocks.

Another feature of a rhyolite is that it is light gray or pink and when I compared this to samples online, it was a similar color (“Geology Rocks & Minerals”).

In addition, when observing this rock up close, it contains small rock fragments, and has a banded appearance which is indicative of a rhyolite rock (“The Rock-Rhyolite”).

Because there are so many granite rocks around this area and the rhyolite is related to granite, I think this could be a good fit.

This is a quick cooling rock (“Geology Rocks & Minerals”).

Granite Felsic Rock with Iron Deposits

Igneous RockPhoto Taken in Southern California

Details: Granite Felsic Rock

I think it is felsic versus mafic, because felsic are lighter in color due to the minerals.

I thought this rock was unique, because of the iron deposit on the surface. There were other similar rocks in the area that had been chipped and the iron deposit only appears on the surface.

Type: Igneous - plutonic: contains

visible minerals that reveals a slow cooling process (“Rocks and the Rock Cycle”).

Interesting Notes: This particular rock shows

oxidation which then runs into the soil. You can see how this has occurred only on the side exposed and unprotected from weathering.

Initially, I thought it might be a grandodiorite which is a type of granite, but decided against it, because of the pinkish colored grains observed on the side of the rock that are consistent with granite.

ReferencesArmstrong, W. The Desert’s Lichen Crust on Rocks. Retrieved June 13, 2015. Classification: Where Do I Fit In. April 25, 2008. Retrieved May 14, 2015. <http://bioweb.uwlax.edu/bio203/s2008/esser_kels/>. Evolution: Hummingbird species on the rise. (2014). Nature, 508(7495), 152. doi:10.1038/508152a Examples of Common Metamorphic Rocks. (n.d.). Retrieved May 17, 2015, from http:// www.rocksandminerals4u.com/metamorphic.html Geology Fieldnotes. (2005, January 4). Retrieved May 17, 2015, from http://www.nature.nps.gov/geology/parks/glac/ Geology Rocks & Minerals. (n.d.). Retrieved June 13, 2015, from http://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/grandodiorite.html Lake Elsinore, California. (n.d.). In Wikipedia.org. Retrieved June 13, 2015 from wiki:enwikipedia.org/wiki/Lake_Elsinore,_California

ReferencesMcIlvaine, J. (2000). The Biogeography of California Quail. Retrieved June 13, 2015 from http://online.sfsu.edu/bholzman/courses/Fall00Projects/Quail.html Metamorphic Rocks. (n.d.). Retrieved May 17, 2015, from http://geology.com/rocks/

metamorphic-rocks.shtml Monroe, J., & Wicander, R. (2012). Igneous Rocks and Plutons. In The Chaning Earth

Exploring Geology and Evolution (Sixth ed., p. 75, 86, 633). Belmont, CA: Brooks/ Cole, Cengage Learning. Moore, C. (2014). California Quail & Mountain Quail: Precocial Gallinaceous Galliformes. Retrieved June 13, 2015. Rocks and the Rock Cycle. (n.d.). Retrieved May 17, 2015, from http://geoscience.wisc.edu/~chuck/Classes/Mtn_and_Plates/rock_cycle.html Sanders, A., & Minnich, R. (2006). Invasive Plants of California’s Wildland. Retrieved June 13, 2015.

ReferencesSanders, R. (2014, April 3). Hummingbird Evolution Soared After They Invaded South America 22 Million Years Ago. Retrieved May 14, 2015. Seed Plants: Fossil Record. (n.d.). Retrieved June 13, 2015, from http://www.ucmp.berkeley.edu/seedplants/seedplantsfr.html Wagoner, D., & Maldonado, D. (2014). Generalized Geologic Map of California. Retrieved May 17, 2015.

All photos taken by Kristi Coy, unless otherwise indicated.