Geology Reference
In-Depth Information
a
b
Figure 1.7
Los-Angeles Basin. Oil and gas field location map.
a
. Regional faults,
b
. Oil
and gas fields. Fields:
1
. Beverly Hills,
2
. Cheviot Hills,
3
. Salt Lake,
4
. Los-Angeles,
5
. Englewood,
6
. Playa del Rey,
7
. El Segundo,
8
. Bowdini,
9
. Montebello,
10
. Santa Fe
Springs,
11
. Rosecrans,
12
. Dominguez,
13
. Torrance,
14
. Wilmington,
15
. Long Beach,
16
. Seal Beach,
17
. Hantington beach,
18
. Brea Olinda,
19
. West Coyote,
20
. East Coyote,
21
. Yorba Linda,
22
. Kramer,
23
. Richfield,
24
. Olive,
25
. San Clemente.
thick. he Pliocene deposits, up to 2,100 m thick, comprise alternating
sands, silty clays, silts and clayey rocks. The Quaternary interval is gen-
erally represented by coarse-grained material dominated by sands and
pebble-stones; the thickness is up to 800 m. The major lithofacies pat-
tern in the basin is increase in the clay content toward the center of the
depression.
Structurally, the depression is a complex combination of individual
blocks and steps subsiding toward the center along the lengthwise regional
faults. The major lineaments are normal faults Newport-Englewood,
Wittier and Norwalk. Local highs in the area usually group within the
band of these faults; they are quite elongated and substantially faulted
by smaller faults. Three types of local highs are identified. In the areas
of a shallow crystalline basement (the western part of the depression -
Torrance-Wilmington zone) prevail structures draping basement highs. In
the areas of a deeper basement most typical are the highs formed by the
tangential forces. Within the band of Newport-Englewood fault system are
developed the folds formed due to vertical motions of the basement blocks.
Typical for the region is a substantial neotectonic activity associated with
