Field AssignmentBishop’s Peak and Leaning Pine Arboretum

Amanda NelsonGEL 103

Professor Lawler

ContentBackground and LocationsBishop’s Peak

◦ Geological History of the Peak◦ Rock Example◦ Peak Rock Example

Leaning Pine Arboretum◦ Geological History of Cal Poly Land◦ Rock Example◦ Animal Example◦ Plant Example◦ Fossil Example

ConclusionWorks Cited

Background and LocationsI chose to venture near and around our

Cal Poly campus for this Field AssignmentPlaces I went to:

◦Bishops Peak◦Leaning Pine Arboretum

The photos are taken from my visits to both locations

Identifications are done using brochures, Sierra Club’s website on the Nine Sisters of San Luis Obispo, Cal Poly resources, and online databases

Bishop’s Peak

Bishop’s Peak Geological HistoryAccording to the Sierra Club San Luis Obispo and Gary

Felsman(1) Bishop’s Peak has an elevation of 1,559 feet It formed from the plug of long-extinct volcanoes It has been inactive for 20,000,000 years

By the look of the mountain, there is another mountain that has formed around Bishops. It seems as though there are faults present and a fold has occurred

Bishop’s peak is primarily composed of dacite. Over 20 million years ago, magma welled up underneath a layer of softer rock and solidified. The softer overlying rock has since eroded away, leaving a distinct rugged shape. (2)

1. Felsman, Gary (2008). Sierra Club San Luis Obispo- The Nine Sisters of San Luis Obispo County. Retrieved from http://santalucia.sierraclub.org/ninesis.html#bishop2. Wikipedia- Bishop’s Peak. Retrieved from http://en.wikipedia.org/wiki/Bishop_Peak_%28California%29

Igneous Volcanic Rock- Dacite

Igneous Volcanic Rock- Dacite DescriptionI found these rocks at the bottom of the

mountain. I expect these volcanic rocks are evidence of a landslide that has occurred

They were an interesting red and grey color and many were located off to the side as though they had fallen

Dacite primarily forms from lava flows, dikes, or massive intrusions (3)

3. Dacite. (2011). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/EBchecked/topic/149437/dacite

Bishop’s Peak- Igneous Volcanic Rock- Dacite

Bishop’s Peak- Igneous Volcanic Rock- DaciteWeather conditions has cut and widened cracks

into gaps on their surfaces. (4)This makes the top of Bishop’s Peak appear like a

montage of boulders. Bishop’s peak is a great example of dike

injections of magma. (5)It also displays the movement of magma that

persisted long ago and shows that weather conditions have created erosion

4.Felsman, Gary (2008). Sierra Club San Luis Obispo- The Nine Sisters of San Luis Obispo County. Retrieved from http://santalucia.sierraclub.org/ninesis.html#bishop5. Felsman, Gary (2008). Sierra Club San Luis Obispo- The Nine Sisters of San Luis Obispo County. Retrieved from http://santalucia.sierraclub.org/ninesis.html#bishop

Leaning Pine Arboretum

Leaning Pine Arboretum Geological HistoryCal Poly land was once part of an ocean floor20 million years ago, the Pacific Plate pushed

against the North American Plate and broke the oceanic crust apart, leaving behind sediments of rocks and minerals (6)

Cal Poly land is full of nature and life, but most of all, it is full of history

It has changed over time, but remains from history’s past still exist

6. Cal Poly Land- Geology and Soils. Retrieved fromhttp://polyland.calpoly.edu/overview/archives/derome/geology.html

Metamorphic Sedimentary Rock- Serpentinite

Metamorphic Sedimentary Rock- Serpentinite Description Walking around this location, I found many rocks of this

kind and I predict they have been around for many years because they show signs of different weathering conditions

The theory is that serpentine is created through a high pressure and low temperature metamorphism of mantle rock or oceanic crustal rock (7)

Pre-existing rocks undergo metamorphic changes in a solid state to create new minerals from rearrangement of mineral components within the surrounding rocks or material (8)

Serpentine is the most common rock found on Cal Poly Land

7. Cal Poly Land- Geology and Climate. Retrieved from http://polyland.calpoly.edu/topics/Geology/index.html8. Cal Poly Land- Geology and Climate. Retrieved from http://polyland.calpoly.edu/topics/Geology/index.html

Western Fence Lizard

Western Fence Lizard Description Kingdom: Animal Phylum: Craniata Class: Reptilia Order: Squamata Family: Phrynosomatidae Genus: Sceloporus This black and brown blotched reptile is active on Cal Poly

land during spring and summer and can grow between 10 and 15 centimeters long (9)

They may not have naturally evolved in California, but they locate themselves here because they need to be in the sun in places with rocks and fences as much as possible because they are cold blooded (10)9. Cal Poly Land- Reptiles and Amphibians. Retrieved from

http://polyland.calpoly.edu/topics/florafauna/studentsites/2006b/Blue-Bellied%20Lizzard.htm10. Wikipedia- Western Fence Lizard. Retrieved from http://en.wikipedia.org/wiki/Western_fence_lizard

Buckeye Californica Tree

Buckeye Tree Description Kingdom: Plantae Order: Sapindales Family: Sapindaceae Genus: Aesculus Species: Californica This tree can survive in a variety of conditions, though

losing its leaves in mid-summer, and acts as a soil binder, preventing erosion in hilly regions (11)

Based on these facts, this tree could be found useful in areas such as San Luis Obispo because we are surrounded by mountainous regions

Historically, the seeds of the Buckeye Californica Tree were used by the Native Americans for food

11. Wikipedia- Aesculus Californica. Retrieved from http://en.wikipedia.org/wiki/Aesculus_californica#Distribution_and_habitat

Fossil

Fossil DescriptionI found this fossil as we were leaving the Arboretum (I

do not know where it was first located)There is no identification, but my best prediction is

that it is the head of a deer or another similar animalThe fossil seems to be cleaned up but untouched for

quite sometime because of the cobwebs insideThe age is unknown, but if this were a deer, the head

has become longer over time and eye sockets are slightly smaller

The nose of this fossil confuses me because it is very different then that of a deer that would exist today

Conclusion/ What I LearnedI found this field assignment to be very

interesting, not only because it furthered my knowledge of local San Luis Obispo geological features, but also because I learned about how the land around me has changed and evolved since its beginning

I never knew that Bishop’s peak had once been a volcano and how the Cal Poly land had formed from the Pacific Plate and North American Plate pushing together

I walk around my campus now being able to identify certain rocks and other features, and having a deeper understanding of their history

Works Cited Aesculus Californica (2011). Curbstone Valley Farm. Retrieved from http://curbstonevalley.

com Cal Poly Land- Geology and Climate. Retrieved from

http://polyland.calpoly.edu/topics/Geology/index.html Cal Poly Land- Geology and Soils. Retrieved fromhttp

://polyland.calpoly.edu/overview/archives/derome/geology.html Cal Poly Land- Reptiles and Amphibians. Retrieved from

http://polyland.calpoly.edu/topics/florafauna/studentsites/2006b/Blue-Bellied%20Lizzard.htm

Dacite. (2011). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/EBchecked/topic/149437/dacite

Felsman, Gary (2008). Sierra Club San Luis Obispo- The Nine Sisters of San Luis Obispo County. Retrieved from http://santalucia.sierraclub.org/ninesis.html#bishop

Wikipedia- Aesculus Californica. Retrieved from http://en.wikipedia.org/wiki/Aesculus_californica#Distribution_and_habitat

Wikipedia- Bishop’s Peak. Retrieved from http://en.wikipedia.org/wiki/Bishop_Peak_%28California%29

Wikipedia- Western Fence Lizard. Retrieved from http://en.wikipedia.org/wiki/Western_fence_lizard