Franklin Canyon is located within the Santa Monica Mountains, which have a complex geological history spanning over 16 million years. The mountains were formed by plate collisions and volcanic activity, and contain diverse rock formations from basalt to sandstone. The climate is Mediterranean with hot, dry summers prone to wildfires due to flammable chaparral vegetation. Hiking trails allow visitors to see native plants like yucca and animals like squirrels, birds, and potentially rattlesnakes within the mountain ecosystem.

1. A Look at Franklin Canyon in the Santa Monica MountainsField Assignment Lucia Rodriguez Geology 103, LTCC Professor Mark Lawler July 21, 2011

3. Overview of the Santa Monica Mountains

4. Geological history

5. Climate

6. San Andreas Fault

7. Rock examples

8. Flora

9. Fauna

10. References2

12. Franklin Canyonrests on 605 acres of land. It is one of the parks in the Santa Monica Mountain System, and it sits close to the South Eastern end of the system.

13. On this presentation I will give an overview on the Santa Monica Mountains geology and environment, and specifically on Franklin Canyon, based on my observations and research.Map courtesy of Mapquest Map courtesy of Santa Monica National Recreation Parks

14. 4 Overview Franklin Canyon is in the Santa Monica Mountains system, which is a part of the Transverse Ranges. The transverse ranges sit on top of the colliding North American and Pacific Plates. Geographically, the Santa Monica Mountains run along the Pacific through Los Angeles and the San Fernando Valley. Climate is Mediterranean and ecosystem is rare and wide in variety. Vegetation consists of chaparral, grasslands and oak woodlands. There is a three-acre lake, a duck pond and over five miles of hiking trails.(LA Mountains, 2011) The Santa Monica Mountains have lived through many fires, due to the chaparral and coastal sage brush. These mountains are 46 miles long and eight miles wide. Volcanic Sandstone Peak, at 3,111 feet above sea level is the highest point in the park. (National Parks Service, 2011)

15. 5 Geological history About 16 million years ago the Santa Monica Mountains started to emerge from the ocean. Much volcanic activity took place and the Mountains continued to grow for the next 3 million years, reaching 10,000 feet high. (National Parks Service 2011). The range contains rock 154 to 200 million years old. Transverse ranges ofSouthern CaliforniaMountains run in an East-West direction instead of North-South. There is faulting, uplift, and erosion which is all taking place now. There has been periodic uplift in the area since the Oligocene collision of the Pacific and the North American Plates. The rocks exposed date from the Jurassic to the Quaternary. Santa Monica Mountains National Recreation Area contains one of the most diverse fossil assemblages of fossil with at least 2,300 known fossilLocalities. (Santa Monica Mountains National Recreation Area, 2011). Unfortunately I wasn’t lucky enough to find one. Photo courtesy of National Parks Service

16. 6 Geological make -up This chart shows the diverse make-up in the geology of these mountains, including extensive areas of volcanic intrusions, and recent sediments (in red and grey, respectively). The range was created by repeated episodes of uplifting and submergence by the Raymond Fault that created complex layers of sedimentary rock. There are thick marine sedimentary sequences of sandstone, siltstone, and mudstone, as well as volcanic deposits. Chart courtesy of The Santa Monica Mountains National Recreation Area.

17. Climate 7 With a chaparral biome, there is a very wet winter and also a very dry summer. The summers can be dry enough to create a drought, and this dry period can extend for up to five months out of the year. These dry conditions make the risk of fires breaking out very high. Many of the plants found in the chaparral biome have leaves that are made from highly flammable materials. That is why the fires are able to spread so quickly rather than just from the dry conditions.Those are also the plants that have the ability to withstand the fires. They have heavy bark and deep roots so it isn’t long after the fire that they are able to thrive again. (Bio expedition, 2011)

19. Besides the constant change in its environment due to fires and its volcanic history, here is another aspect that makes this range so interesting and constantly mobile.

20. Uplift of the Santa Monica Mountains continues today at a gallop: one inch every thousand years. (Collier, 1999)San Andreas fault. Photo from waterencyclopedia.com

21. 9 Rock example #1 Basalt is a common extrusive, igneous, mafic rock. Extrusive or volcanic rocks form from lava, which cooled on the Earth's surface. We know that the ocean crust is predominantly composed by basalt. This rock may have arrived here in different ways. It could possibly be the result of the many volcanic eruptions that took place over time, or it might have been exposed from the ocean crust in the collision of plates.

23. Fragments of sediment laid down by water or wind become compressed or cemented over time.

24. They tell us the locations of ancient sedimentary environments such as seas, reefs, deltas, beaches, rivers, lakes deserts, glaciers, and mountains.

25. As you can see on the photo, leaves are already becoming part of this sedimentary rock.

26. Sedimentary rocks contain the fossil record, which preserves the evolving story of life on Earth over the eons. Unfortunately I didn’t run into any fossils on my trip, but I was able to find an example from the Santa Monica Mountains (see photo on the right, below.) Photo courtesy of National Parks Services

27. 11 Flora I encountered a lot of examples of the Chaparral flora, as well as a lot of conifers (gymnosperms), sycamores, oaks, and a wide variety of flowers , including what I believe was a California yucca (perennial shrubs and trees in the family of Asparagaceae, see below) which I later learned is a cousin of the Joshua tree (Wikipedia, 2011) The chaparral biome is one that is found in areas of every single continent, many people don’t realize it is the same. A chaparral biome iscreated when cool water from an ocean merges with a landmass that is at a high temperature. The major chaparral biomes are found along the coast of Baja and California. They are also found in various areas around the Mediterranean Sea.(Bio expedition, 2011)

28. 12 Flora example #1 – The Sacred Datura The Sacred Datura (Datura wrightii)is avascular plant, herbaceous perennial belonging to the Solanaceae family. It is poisonous and sometimes used as a hallucinogen. Its flower is divided in five symmetrical lines and it is usually white or purple. Datura is found in desert areas, in coastal sage scrub, and in joshua tree woodland. It is very common and blooms from April to October. (Calflora, 2011) Vascular plants evolved before the Middle Silurian, some have been found from Middle to Upper Ordovician rocks.

29. 13 Fauna Fauna that populates the Santa Monica Mountains include: Birds: Mandarin ducks (migratory birds), hummingbirds, etc. Mammals: Deer, bobcats, mountain lions, squirrels, etc. Amphibians: Pacific tree frog, salamanders, toads, etc. Insects: Swallow-tail butterflies, bees, etc. Reptiles: lizards, rattlesnakes, turtles, etc. Fish: Californian grunion, kelpfish, etc. More than 450 vertebrate species occur in the park. The relatively intact wildlifeis impressive considering their proximity to one of the largest urban areas in the United States.”(National Park Service, 2011) I ran into a good amount turtles and koi fish in the pond. I learned later that the pond was man-made, so for the purpose of this presentation I looked at other examples of native fauna.

30. 14 Fauna Example #1: The Pacific Rattlesnake Fortunately (or unfortunately), I didn’t run into a rattlesnake on this trip, however I have, many times in past hikes and I would like to present it briefly. Rattlesnakes are dangerous, but important to our environment; without them, rodent populations would rise causing an imbalance in the ecosystem. Rattlesnakes seek areas in their body temperature range from 64 to 89 degrees (McAuley, 1990), which means they show up mostly in the heat of the summer. The Pacific Rattlesnake or Crotalus oreganusis a reptile of the Viperidae family. Reptile diversification began during the Mississippian Period. From this basic stock of so called stem reptile, all other reptiles (as well as birds and mammals) evolved. (Monroe and Wicander, 2006) Picture courtesy of Ken J. O’Brien

31. 15 Fauna Example #2: The Squirrel Squirrels are small and they live in almost every habitat from the rainforest to the desert. Squirrels' diet consists of a wide variety of plant food, including nuts, seeds, conifer cones, fruits, fungi and green vegetation. (Wikipedia, 2011) The squirrel is a mammal of the Rodentia order, and the Sciuridae family. It evolved from the Therapids, in the Permian Period, from which all mammals evolved. Then in the early Cretaceous, mammals diverged into two branches: triconodonts and monotremes. Monotremes include marsupial and placental mammals, the squirrel is a placental mammal. The divergence of marsupials and placentals may have taken place in the Early Cretaceous but undoubtedly both were present by the Late Cretaceous. (Monroe and Wicander, 2006) Squirrel next to the pond, July 2011

33. Jaffe, M. , and Gamache, T. The Santa Monica Mountains: Range on the Edge. (2006)

34. Los Angeles Mountains. (2011). Retrieved from: http://www.lamountains.com/parks.asp?parkid=14

35. National Parks Service. (2011). Retrieved from: http://www.nps.gov/samo/naturescience/naturalfeaturesandecosystems.htm, (retreived from: http://www.nps.gov/samo/naturescience/animals.htm)

36. The Santa Monica Mountains National Recreation Area. (2011). Retrieved at: www. http://www.nps.gov/samo/naturescience/geologicformations.htm

37. Bio Expedition. (2011). Retrieved from: http://www.bioexpedition.com/chaparral-biome.html

38. Collier, M. A Land in Motion: California’s San Andreas Fault. (1999)

39. Wikipedia. (2011). (Retrieved from: http://en.wikipedia.org/wiki/Yucca) (Retrieved from: _http://en.wikipedia.org/wiki/Squirrel)

40. Calflora. (2011). (Retrieved from: http://www.calflora.net/bloomingplants/sacreddatura.html)

41. McAuley. Guide to the Backbone Trail. (1990)16