Note that while thrust faults are a type of reverse fault, they are not shown in pure yellow, but in pale yellow. Blind or buried faults are noted with dotted lines. If there is some uncertainty in the sense of slip for a fault, the color of that fault is tinted grey. The more uncertainty there is, the more grey the color -- pure grey means that the sense of slip of that fault is unknown.
When studying this map, keep in mind that this figure is meant for basic qualitative study only, and that the resolution of this map is generally quite low. This means that a slight change in the sense of slip of a fault zone might not be well marked.
Despite these deficiencies, some obvious trends in regional fault activity can still be seen. The dominance of the San Andreas fault zone -- the tectonic plate boundary here in southern California -- can be seen in both the number and orientation of right-lateral strike-slip (red in color) faults, which tend to reflect the trend of the plate boundary.
Counter to this trend is the Garlock fault zone, the largest left-lateral strike-slip (green) fault on this map, and several other major left-lateral faults, primarily concentrated around the margins of the Transverse Ranges. Also associated with the Transverse Ranges and the Los Angeles Basin are numerous reverse faults (including thrust and blind thrust faults). These typically result from the widescale compression generated by the Big Bend of the San Andreas fault.
North of the Garlock fault, we see a different sort of regional "theme" -- extension. Note the predominance of normal and right-normal slip in this area, which is part of the Basin and Range tectonic province. Large normal faults are extremely rare south of this area. The best example is the Crafton Hills fault zone, which looks out of place just south of the east-central Transverse Ranges. This zone of normal faulting exists here because of the intersection of two major right-lateral strike-slip fault zones (the San Andreas and San Jacinto fault zones).