Fallen Leaf Lake

Brooks MartinGeology 103Spring, 2015

www.Stanfordsierra.com

www.steveandkim.us

ContentsMapGeologyJeffrey PineGolden Mantle Ground squirrelOsprey5 Rocks

GranodioriteSiltstoneQuartzMetamorphic Glacial Till

GeologyPaleozoic: Carbonate platform of passive continental margin.Mesozoic: Emplacement of granitic plutons at depth with contact metamorphism.Cenozoic: elevation of the plutons with tilt, creating steep East face, sloping west face, and eroding off up to 10 kilometers of surface material.South west corner of the lake lies along the West Tahoe Dollar Point fault zone, where the western side rose by several thousand feet relative to the east. (Konigsmark, 2011)

geosphere.gsapubs.org

Aboutlaketahoe.com

--------Fault line-------

4 episodes of glaciation flowing down Glen Alpine Creek route from Desolation Wilderness.Most Recent:Tahoe: 150-74,000 BPTioga: 26-19,000 BP

Created:U shaped valleysSharp peaksGlacial striationsLateral morainesTerminal moraineRecessional moraines

Laketahoequest.com

Laddish.net

Lateral moraineTerminal moraine

Geosphere.gsapubs.org

Terminal moraineLateral moraine

Recessional moraines

Lateral moraine

Lidar: Light detection and Ranging

Laser based technique for visualizing ground structure even through vegetation.

Multiple recessional moraines are seen at the far endMultiple lateral moraines are seen on the sides.Both of these are created as the glacier recedes, then stops for a period of time, depositing till.

(Valentine, 2014)

Recessional lateral moraine

Lateral moraine

En.wikipedia.comStephenkharper.com

Conifers.org

Jeffrey PinePinus jeffreyiOregon to BajaHigh AltitudeLong needles in 3Inward barbs on cone3 years to make seedsUp to 130 feet tallVanilla odor:

n-heptane

Evolution: Gymnosperms, Angiosperms and pine

Carboniferous: Gymnosperms made the final jump to terrestrial status by separating from the need for as much water: by pollen fertilization, and by seed, which allowed wider dispersal. (Wiki Pinophyta)

Triassic: Gymnosperm dominance short lived, as angiosperms took over because of adaptations like: Animal Pollination Faster reproductionSeed dispersal by animals (seed dropped in a pile of fertilizer)Faster growth (tulane) Spread by RhizomesBetter self fertilization by leaf breakdown (Berendse)

Soon, pines relegated to borderline ecological conditions (cold, snow, dry or fire)

Became fire avoiders, fire tolerator, fire embracer, or fire refugee strategy (Keeley, 2012)

Pines started in Mesozoic, spread across Laurasia.Now pines are limited to the Boreal forests of the north, high

altitude, dry areas or fire prone areas.

Adaptations:Thick waxy cuticle to prevent water lossStomata in row underneath needle, covered by surface cells

(sunken stomata) to limit water lossWinter and snow: conical shape of tree, with down ward bending branches to shed snow.Hardening by changing biochemistry of leaves to prevent freezing in winter.Resin: helps fight fungus and insectsDark color leaves for more light absorption.(Wiki pine)

OspreyPandion halietusDiurnal, fish eating RaptorAll continents except AntarcticaOne species world wideNest re-used for years

Adaptations: Talons rounded, not grooved.Only Osprey and Owl can reverse their outer toe so they have two in front, two in back for grasping.Backward scales on talon act to help grasp fish.Closable nostrils to keep out water

(Wiki Osprey)

theguardian.com

En.wikipedia.org

EnantiornithesRocek.gli.cas.cz

Evolution of OspreyFrom Therapod Dinosaurs, clade ParavesReduction of anatomical parts for weight: tail sizeMesozoic:Enantiornithes, clawed wings and teethCretaceous:Rigid ribcage, carina and shoulders for flight, still had teethAsteroid at KT:Neornithes survived, toothless birdsThree groups:Paleognaths: flightless birds, like ostrichNeognaths Galloanserae:Ducks and FowlNeognath Neoave: all other birds, like Osprey(Wiki Evol Birds)

Summitpost/org

Chipmunk

Golden-Mantled Ground SquirrelCallospermophilus lateralisGround squirrel, western North AmericaWide variety of ranges, rocky to meadow to sage.Chipmunk-like stripes not on faceBigger than chipmunk (8” vs 9-12”, 2 oz. vs. 4-14 oz)HibernatorCheek pouches to carry food back

to den at high speedShallow burrows up to 30 m in lengthFood: Seeds, nuts, berries insects and underground fungi.Prey of: Hawks, Jays, weasel, bobcat, coyote.

(Wiki GMGS)

En.wikipedia.org

Evolution of Golden-Mantled Ground SquirrelRodentia:Includes mice, rats, squirrels, prairie dog, porcupine, beaver, guinea pig, hamster and marmots but not rabbits.Paleocene: in LaurasiaSpread all over except Antarctica, and was the

only placental mammal to reach AustraliaAdaptations of rodents:Front incisors keep growing, the softer dentine on the

back wears off, leaving the sharp front enamelacting like a chisel.

Diastema: gap behind incisors, so can close off mouth and throat to wood chips, etc.

Sciuridae: Squirrels, stand upright for long periods.(Wiki Ground Squirrel)

Ecologyedu.com

(Wiki rodentia)

South West Corner of Fallen Leaf LakePale Blue:Sandstone and siltstone

Green:Metavolcanic

PinkEcho lakes granodiorite

F West Tahoe Fault ZoneL Lateral MoraineT Terminal MoraineR Recessional moraines(Loomis, 1983)

L

L

RT

F

F

Nps.gov

Granodiorite

GranodioriteLarge, interlocking, visible crystals:

Igneous Intrusive rockDark crystals of amphibole or biotite.Whitish crystals of Na FeldsparPinkish crystals of K feldspar.Between Granite and Diorite in composition.Specifically called Echo Lake granodiorite

(Loomis, 1983)

Granite: Intrusive, phaneretic , Felsic with composition like rhyolite

Quartz, muscovite, biotite and K feldspar.

Diorite: Intrusive, phaneretic, Intermediate with composition like andesite.Amphibole, biotite, Na feldspar.

Granite

Geology.about.com

Diorite

Granodiorite Boulder with Lichens

Siltstone

SiltstoneMud rock in the region of Glen Alpine FallsCharacteristics:Non interlocking, Lithified fragments, small, uniform clasts, well sorted, rounded, far distance from shore. Some oxidized. Detrital, Layered, Fissile.

Typically deep ocean or lake bottomDeposited in passive continental margin during Paleozoic. Uplift of Plutons, erosion, tilted.Locally, thinly bedded sandstone and siltstone. (Loomis, 1983)

Siltstone

Siltstone Metamorphic rock just below and left of A

A

Scienceforkids.kidiepede.com

Quartz

Milky white, irregular surface, some suggestion of crystal structure. Found as part of Glacial till.

Non ferromagnesian silicate, SiO2In a three dimensional network.

Deposited in hydrothermal regions which penetrate cracks to form veins, which then cool and solidify.

Banded hornfels from contact metamorphism

Banded hornfelCharacteristics:Non- fissile. Fine grained. no foliation. Layers of light alternate with dark.

Parent rock: MudrockMetamorphic, low grade.Layered sandstone and shale metamorphosed by intruding granite pluton.Layers of dark biotite hornfel alternating with

calcite silicate hornfel with lighter color from limestone.(Wiki Hornfels)

Allaboutgenstones.com

Yosemite.ca.us

Glacial TillNo sorting by particle size.Angular clasts of varying sizes.No stratification.

Deposited by glacier in a ridge, in this case a lateral moraine.

References

Berendse, F. & Scheffer, M. (2009). The angiosperm radiation revisited, an ecological explanation for Darwin’s “abominable mystery”.

Ecological Letter 12(9): 865-872. Retrieved from ttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2777257/ on May 24, 2015

Fraley, J. (2013). Golden-mantled Ground Squirrel. Retrieved from

http://fwp.mt.gov/mtoutdoors/HTML/articles/portraits/gmgroundsquirrel.htm on May 23, 2015.

Keeley, J.E. (2012) Ecology and evolution of pine life histories. Retrieved from

http://www.werc.usgs.gov/ProductDetails.aspx?ID=4756 on May 23, 2015.

Konigsmark, T. (2011). Geologic Trips Sierra Nevada. Mendocino, CA:Geo Press.

Loomis, A.A. (1983). Geology of Fallen leaf lake 15’ quadrangle, El Dorado county, CA. Retrieved from

http://ngmdb.usgs.gov/Prodesc/proddesc_370.htm on May 24, 2015.

NHPTV. (2015). Golden-mantled Ground Squirrel. Retrieved from http://www.nhptv.org/natureworks/goldensquirrel.htm on May 23, 2015.

Pines. (2015). Pines, General characteristics, evolution and classification. Retrieved from http://science.jrank.org/pages/5241/Pines.html

on May 23, 2015.

Tulane. (no date). Lab 9, Gymnosperms and Angiosperms. Retrieved from

http://www.tulane.edu/~bfleury/diversity/labguide/gymangio.html on May 23, 2015.

References (continued)

Wiki Evolution. (2015). Evolution of Birds. Retrieved from http://en.wikipedia.org/wiki/Evolution_of_birds on May 23, 2015.

Wiki Ground Squirrel. (2015). Ground Squirrel. Retrieved from http://en.wikipedia.org/wiki/Ground_squirrel on May 25, 2015.

Wiki Hornfels. (2015). Hornfels. Retrieved from http://en.wikipedia.org/wiki/Hornfels on May 25, 2015.

Wiki Jeffrey. (2015). Jeffrey Pine. Retrieved from http://en.wikipedia.org/wiki/Jeffrey_pine on May 23, 2015.

Wiki Osprey. (2015). Osprey. Retrieved from http://en.wikipedia.org/wiki/Osprey on May 23, 2015.

Wiki Pinophyta. (2015). Pinophyta. Retrieved from http://en.wikipedia.org/wiki/Pinophyta on May 23, 2015.