CGnevadanNEVADAN ROCKSI. Granitic Rocksa. Sierra Nevada BatholithBatholith: igneous Pluton (intrusion) that has a surface area of greater 40 sq miles (100 sq km)Formed and cooled deep in the LithosphereExtent--Sierra Nevada Mts, around southern end of Great valley, across Transverse Range into Peninular Rangescountry (host) rockb. Formation (A la Plate Tectanics)(1) Batholith--has roots about 30 miles deep (50km)(2) Paleozoic Strata dip from both east and west towards center (axis of mountain Range)Huge Synclinorium > 100 miles acrossSyncline has been intruded by Granite batholithCGnevadanc. History(1) 150 My ago ocean crust was thrusted under American Continent (Lava flowand volcanism along an island arc system)(2) 140 my pressures great between colliding plates(a) older rock formed were folded and thrust faulted and elevated during Nevadan Orogeny (most intense in Sierra Nevada)(b) Initial thrusting on Great Coast Range Thrust (dips eastward along East flank of Coast Range)(3) Sierra Nevada Block result of 140 my of uplift, westward tilting and erosion(4) Coast Range Thrust inactive surface expression of subduction zone (observed on west side of Great Valley)II. Franciscan Rocks and Building of Coast Ranges and Continental Margina. Franciscan--Eugeosynclinal Sedimentary and Volcanic Rocks massive bedded graywacke within interbedded dark shale, minor chert and Limestone and altered Volcanic Rock (greenstone) and Metamorphic rocks--green Chlorite Actinolite schists and blue glaucophane schistsRocks intruded by masses of peridotite (mostly serpentinized)--origin from upper mantleb. 50,000 ft thickc. glaucophane, Lawsonite, jadeite(1) Low temperature (<300degrees C) (2) high pressure (5,000 to 9,000 Atm)(3) reached depth of >70,000 ft(4) rapid upliftIII. Granite Rocks--contemporaneous with Sierra Nevada GraniteIV. Coast Rangesa. 30,000 ft of unmetamorphosed shelf facies to deep sea fan sandstone, shale, siltstone and minor conglomerate and LimestoneLate Jurassic.-Late Cretaceousb. Thrust faulted over Franciscan and Granite rocksc. Most continuous section lies on eastern flanks of Diable and Mendocino Range above the coast RangesCGnevadanTransition to the Cenozoic PeriodV. Mountain Building and Westward Extension of Continental platforma. Profound faulting--in subduction zone--Great Valley series in the Continental block were thrust many miles westward over oceanic plate rocks of the Franciscan in mid Jurassic.--early Cenozoicb. Subsequent folding uplift and erosion--left only remnants of Coast Range Thrust (except along east side of Coast Ranges)c. Mid Eocene to Oligocene-regime profoundly changes subduction and thrusting ceased and great right lateral strike slip San Andreas fault system began to developd. Opinions differ but displacement totals 160-310 miles since middle Eocene timee. along with stike slip-intermittent uplifting has occurred culminating in major coast range orogeny in late Pliocene-Pleistocene