Geology 15                                                                                          West Valley College

Geology of California                                                                                  Robert Lopez


Study Questions 12: Rodinia, TCM, Sierra Nevada Metamorphic Rocks, Sierra Nevada Uplift


1)      Be sure that you can sketch a cross-section of the continental margin of California during the late Mesozoic and identify the Sierra Nevada batholith (arc), Great Valley sequence (arc-trench gap), Franciscan Complex (subduction zone), Melones Fault zone, Coast Range Ophiolite, and the Farallon Plate.


2)      Sketch in cross-section, the asymmetry of the Sierra Nevada (Fig. 8-4). 


3)      Why is the Sierra asymmetrical?


4)      Approximately when was the Sierra Nevada uplifted?


5)      What is the evidence that the Sierra Nevada uplift is young?


6)      What are inverted valleys?


7)      What are Table Mountains?


8)      What are the two divisions of rocks in the Sierra Nevada? Give at least two examples of each.


9)      What kinds of rocks form the Minarets and the Ritter Range, and when did the form?


10)  What is the name of the geological structure the Minarets and Ritter Range form?


11)  What evidence do we have that Rodinia existed and formed 1.0 to 1.2 Ga (pp. 485-486)?


12)  What group of rocks now found in Death Valley and in the Mojave show evidence that Rodinia rifted about 700 Ma (p. 488)?


13)  The Trailing Continental Margin sediments found in Death Valley (Noonday/Ibex Dolomite, Jonnie/Sterline Quartzite) are analogous to which Paleozoic rock group in the high Sierra (roof pendant now).


14)  What are the four Paleozoic and Early Mesozoic metamorphic units of the Western Metamorphic Belt (Fig. 8-25, p.183)?


15)  What is the name of the first mountain-forming event (orogeny) in the Sierra Nevada?


16)  What rocks collided with ancestral California during this first orogeny?


17)  What marine sedimentary complex and island arc rocks collided with ancestral California during the Sonoma Orogeny?


18)  What marine complex and island arc rocks collide with ancestral California during the Nevadan Orogeny?


19)  What is Nevadan Cleavage and when did it form? Where are the Tombstone Slates exposed and what type of metamorphism gave them their unusual structure?


20)  What are the Shoo Fly Complex, Northern Sierra Terrane, Calaveras Complex (and Sonoma Arcs), Foothills Metamorphic Belt (marine rocks and Nevadan Arcs)?


21)  Know the ages, type of rocks, and terranes involved in the three orogenies (Antler, Sonoma, Nevadan) that formed mountain ranges prior to the present Sierra Nevada?


22)  When did Foothills subduction occur?  What caused this Paleozoic, Early Mesozoic subduction to set westward to form the Franciscan Subduction?


23)  What fault zone represents the Late Paleozoic to Early Mesozoic ancient subduction zone in the Foothills terrane?