Abstract ........................................................ 1
Introduction .................................................... 1
Late Eocene to late early Miocene strata—southeast sector ....... 4
Late Eocene to late early Miocene strata—northwest sector ....... 4
South of the Malibu Coast Fault .............................. 7
Limit of marine facies and upper boundary of lower Miocene
strata eastward in the Santa Monica Mountains ............. 8
Northern part of the northwest sector ........................ 8
Clast provenance and transport directions of Sespe
Formation conglomerates ................................... 8
Clast provenance and transport directions in Trancas and
Lower Topanga Canyon Formations ........................... 8
Summary ...................................................... 9
Ages of latest Oligocene and early Miocene marine strata-
southeast and northwest sectors ........................... 9
Paleomagnetic declinations and transrotation—northwest
sector ................................................... 10
Preliminary palinspastic reconstruction ........................ 10
Introduction and constraints ................................ 10
Back-slip of fault separations .............................. 12
Restoration of rotation ..................................... 16
Discussion .................................................. 16
Uncertainties and future challenges ............................ 17
Limits of paleomagnetic declination data .................... 17
Early extensional tectonism along the Malibu Coast-Santa
Monica Fault Zone ........................................ 17
Central trough of the Los Angeles Basin ..................... 18
Junction of the Inglewood and Santa Monica Fault Zones ...... 18
Conclusion ..................................................... 18
Acknowledgments ................................................ 19
References ..................................................... 19
Appendix 1. Petroleum exploration drill holes that provide
control on the total thickness of Vaqueros and
Sespe Formations (differentiated and
undifferentiated) or equivalents ................... 26
Appendix 2. Petroleum exploration drill holes deep enough to
indicate the presence of Vaqueros and/or Sespe
Formations (differentiated and undifferentiated)
but failing to provide thickness control ........... 30
Appendix 3. Petroleum exploration drill holes that provide
critical insights about the regional extent and
history of Vaqueros and/or Sespe strata without
encountering either formation ...................... 32
FIGURES
1. Map of the greater Los Angeles Basin showing major
structural elements, faults, and geographic features ......... 2
2. Chronostratigraphic diagram of time and facies
relationships and formation nomenclature for Post-
Cretaceous and pre-Pliocene rock units in the principal
parts of the Los Angeles Basin region ........................ 3
3. Map showing outcrops and present (plus restored) surface
and subsurface thickness and major facies of the Sespe
plus Vaqueros Formations in the southeast sector ............. 5
4. Map showing outcrops and present (plus restored) surface
and subsurface thickness and major facies of the Sespe plus
Vaqueros and Trancas Formations in the northwest sector ...... 6
5. Map of paleomagnetic declinations for the northwest sector,
with major faults and selected geographic features .......... 12
6. Diagram of major fault separation estimates, noteworthy
regionally developed unconformities (or depositional
interruptions), and important igneous episodes of the
greater Los Angeles region .................................. 13
7. Preliminary palinspastic reconstruction of the greater
Los Angeles Basin region .................................... 14
TABLES
1. Age, paleomagnetic declinations, basis, and published
sources for well documented localities in the northwest
sector of the greater Los Angeles Basin region .............. 11
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