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Map showing thermal-alteration indicies in roadless areas and the Santa Lucia Wilderness in the Los Padres National Forest, Southwestern California

Miscellaneous Field Studies Map 1655-F

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Abstract

This map shows thermal-alteration indices (TAI's), based on colors of pollen grains, of 115 outcrop and 20 conventional core samples from Mesozoic and lower Tertiary rocks in the southern Coast and western Transverse Ranges, Southwestern California. The TAI's have been calibrated against previously determined vitrinite reflectance values from some of the same sample localities.

South of the Santa Ynez fault, the TAI's of exposed rocks near the fault are mainly between 2+ and 3– (2+/3–) to 3 and are generally in the early stage of thermal maturity with respect to the possible generation of oil. North of the Santa Ynez fault, the exposed rocks have TAI's mostly of 2 to 2+ and are mainly immature or transitional from immature to mature. However, Jurassic(?) and Lower Cretaceous samples from the central San Rafael Mountains have distinctly higher TAI's, similar to those of rocks south of the Santa Ynez fault.

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Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Map showing thermal-alteration indicies in roadless areas and the Santa Lucia Wilderness in the Los Padres National Forest, Southwestern California
Series title:
Miscellaneous Field Studies Map
Series number:
1655
Chapter:
F
Year Published:
1985
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Description:
1 Plate: 46.33 x 35.62 inches
Country:
United States
State:
California
Other Geospatial:
Santa Lucia Wilderness
Scale:
0
Online Only (Y/N):
N
Additional Online Files (Y/N):
N