Geologic Maps of the Northeastern Part of the Portola 30' x 60' Quadrangle, Lassen, Plumas and Sierra Counties, California

by
T.L.T. Grose

The California Geological Survey is pleased to announce the release of a new series of Open-File reports that feature geologic mapping of the NE part of the Portola 30' x 60' quadrangle. The area covered by this geologic mapping lies mainly within the Sierra Nevada geomorphic province but includes part of the Basin and Range province of northeastern California. The mapping encompasses approximately 1,150 square miles of southernmost Lassen County, southeastern Plumas County and eastern Sierra County. These maps portray the general geology of the area and provide basic geologic information on the age, distribution, and description of the various rock types, location of faults and other geologic structures. For more detailed information about the geologic setting of this series of Open-File reports, click here (pdf file).

OFR 2000-21
Geologic Map of the Blairsden 15’ Quadrangle, Plumas County, California –
by T.L.T. Grose, 1 plate, map scale 1:62,500.

OFR 2000-22
Geologic Map of the Portola 15’ Quadrangle, Plumas County, California –
by T.L.T. Grose, 1 plate, map scale 1:62,500.

OFR 2000-23
Geologic Map of the Chilcoot 15’ Quadrangle, Lassen and Plumas Counties, California –
by T.L.T. Grose and M. Mergner, 1 plate, map scale 1:62,500.

OFR 2000-24
Geologic Map of the Sierraville 15’ Quadrangle, Sierra and Plumas Counties, California –
by T.L.T. Grose, 1 plate, map scale 1:62,500.

OFR 2000-25
Geologic Map of the Loyalton 15’ Quadrangle, Lassen, Plumas and Sierra Counties, California –
by T.L.T. Grose, 1 plate, map scale 1:62,500.

Availability: The Open-File reports listed above are available for reference at the Sacramento, San Francisco and Los Angeles offices. Click here for CGS office locations. They can be purchased: 1) by phone or fax, using VISA or MasterCard 2) by mail with check or money order enclosed, or 3) over the counter at the Sacramento office. Click here for mail order form.

Prices for the reports are:
$8.00 each folded, or $10.00 each rolled and mailed in tube,
or purchase the entire series of five maps for $30.00 folded, or $40.00 rolled and mailed in tube. Shipping and handling not included.