9o6 



W. L[NDGREN~W. H. KNOWLTON 



date the question. Stratigraphic, floral and faunal evidence 

 should as much as possible be considered together to obtain 

 correct results. 



SUMMARY OF POST-JURASSIC GEOLOGICAL HISTORY. 



Basic eruptions along foothill volcanoes, continued from the 

 Jurassic period. 



Folding of the Mariposa beds. 



Intrusion of granitic and dioritic batholites. 



Pre-Chico erosion, continued to approximate peneplain. 



Pre-Chico uplift and break along eastern edge. First differ- 

 entiation of the Sierra Nevada. 



Sinking of the Tahoe-Sierraville moat. 



Dissection of the uplifted peneplain. 



Chico transgression. 



Cretaceous < 



Eocene 



Miocene 



Miocene? 



Pliocene? 



Pliocene 



Retreat of Shore line ; Tejon erosion along valley border and 

 gradual degradation of the Cretaceous peneplain. 



Miocene (Eocene?) deep gravels. 



Heavy Bench gravels. lone transgression along valley border. 



f Rhyolitic eruptions and continued accumulation of gravels. 



i Late Neocene uplift and faulting along the eastern edge of the 



I range. 



(^ Retreat of shore line ; short but acti ve period of erosion. 



Principal andesitic eruptions ; lakes in the Tahoe-Sierraville 

 depression and along the eastern slope. 



Early Pleistocene lake in the Great Valley and ver}' active 



dissection of the uplifted Miocene surface. 

 Basaltic eruptions. 

 Pleistocene <* Glaciation and lakes along the eastern slope. 

 Gradual retreat of the glaciers and lakes. 

 Recent breaks along eastern fault-line. Fluviatile deposits 

 in the Great Valley. 



Waldemar Lindgren. 



