Crustal Structure of the Salton Trough: Incorporation of Receiver Function, Gravity and Magnetic Data

Musa Hussein, Aaron Velasco, Laura Serpa

.

DOI: 10.4236/ijg.2011.24053                

Abstract

The Salton Trough of southwestern California is inferred to be an incipient ocean basin, and is a polyphase basin with significant extension in addition to dextral shear. To further explore the origin and evolution of this basin, we have incorporated receiver function, gravity, and aeromagnetic data to construct new subsurface crustal scale models. Receiver function analysis suggests the Moho is 20 km deep to the southwest of the Salton Sea and deepens to 32 km in the region east of the Salton Trough and dome in shape. Crustal modeling shows that the density of the lower crust is 2950 kg/m3, which is an indication for gabbroic com- position, while the density of the upper crust varies from 2500 kg/m3 to 2600 kg/m3 and the depth of sedi- mentary and meta-sedimentary rocks appears to be 8 - 10 km. Most magnetic anomalies show shallow relief and are low amplitude with some exceptions in the marginal areas, suggesting the absence of shallow buried mafic intrusions and deep basement. Our models show a magmatic body to the southwest of the Salton Sea at depth of about 18 km and extend in SW-NE direction for about 90 km, We expect this magmatic body (mix- ture of lower crust and upper mantle material) is responsible for crustal thinning, stretching and rifting, ac- cording to the crustal models this body doesn’t exist in the north region of Salton Trough, thus, no further propagate of the rift is expected in the north.

Keywords

Data Incorporation, Crustal Models, Magmatic Body, Salton Trough

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	S. Larsen and R. Reilinger, “Age Constraints for the Pre- Sent Fault Configuration in the Imperial Valley, California: Evidence for Northwestward Propagation of the Gulf of California Rift System,” Journal of Geophysical Research, Vol. 96, No. 5624, 1991, pp. 10339-10446. doi:10.1029/91JB00618
[2]	G. Fuis, W. Mooney, J. Healey, G. McMechan and W. Lutter, “A Seismic Refraction Survey of the Imperial Valley Region, California,” Journal of Geophysical Research, Vol. 89, No. 2, 1984, pp. 1165-1189. doi:10.1029/JB089iB02p01165
[3]	V. Bankey, A. Cuevas, D. Daniels, C. Finn, I. Hernandez, P. Hill, R. Kucks,W. Miles, M. Pilkington, C. Roberts, W. Roest, V. Rystrom, S. Shearer, S. nyder, R. Sweeney, J. Velez, J. Phillips and D. Ravat, “Digital Data Grids for the Magnetic Anomaly187 Map of North America,” US Geological Survey Open-File Report, Denver, 2002.
[4]	R. Larson, H. Menard and S. Smith, “Gulf of California: A Result of Ocean Floor Spreading and Transform Faulting,” Science, Vol. 161, No. 3843, 1968, pp. 781-784. doi:10.1126/science.161.3843.781
[5]	D. Moore and E. Buffington, “Transform Faulting and Growth of Gulf of California Since the Late Pliocene,” Science, Vol. 161, No. 3847, 1968, pp. 1238-1241. doi:10.1126/science.161.3847.1238
[6]	W. Elders, R. Rex, T. Mediva, P. Robimson and S. Biehler, “Crustal Spreading in Southern California,” Sci- ence, Vol. 178, No. 4056, 1972, pp. 15-24. doi:10.1126/science.178.4056.15
[7]	J. Crowell, “Sedimentation and Tectonics along the San Andreas Transform Belt,” In: A. G. Sylvester and J. C. Crowell, Eds., Field Trips for the 28th International Geological Congress Sedimentation and Tectonics of North America Belt, American Geophysical Union, Washington DC, 1989, pp. 32-35.
[8]	P. Lonsdale, “Geological and Tectonic History of the Gulf of California,” In D. Wintere, M. Husson and R. Decker, Eds., The Eastern Pacific Ocean and Hawaii, Geological Society of America, New York, 1989, pp. 499-521.
[9]	J. Stock, and K. Hodges, “Transfer of Baja California to the Pacific Plate,” Tectonics, Vol. 8, No. 1, 1989, pp. 99- 115. doi:10.1029/TC008i001p00099
[10]	G. Axen, M. Grove, D. Stockli, O. Lovera, D. Rothstein, J. Fletcher, K. Farley and P. Abbott, “Thermal Evolution of Monte Blanco Dome: Low Angle Normal Faulting during Gulf of California Rifting and Eocene Denudation of the Eastern Peninsular Ranges,” Tectonics, Vol. 19, No. 2, 2000. pp. 197-212. doi:10.1029/1999TC001123
[11]	D. Karig and W. Jensky, “The Protogulf of California,” Earth and Planetary Science Letters, Vol. 17, No. 1, 1972, pp. 169-174. doi:10.1016/0012-821X(72)90272-5
[12]	D. Moore, “Plate Edge Deformation and Crustal Growth, Gulf of California Structural Province,” Geological Society of America Bulletin, Vol. 84, No. 6, 1973, pp. 883-1906. doi:10.1130/0016-7606(1973)84<1883:PDACGG>2.0.CO;2
[13]	J. Curry and D. Moore, “Geological History of the Mouth of the Gulf of California,” In: J. K. Crouch and S. B. Bachmna, Eds., Tectonics and Sedimentary along the California Margin, Pacific Section, Society of Economic Paleontologists and Mineralogists, Bakersfield, 1984, pp. 17-36.
[14]	R. Gastile, “Proceeding of Conference of Geologic Prob- lems of the San Andreas Fault System,” Stanford Univer- sity Publication Geological Sciences, Vol. 11, 1968, pp. 283-286.
[15]	R. Dokka and R. Merriam, “Late Cenozoic Extension of Northeastern Baja California,” Geological Society of America Bulletin, Vol. 93, No. 5, 1982, pp. 371-378. doi:10.1130/0016-7606(1982)93<371:LCEONB>2.0.CO;2
[16]	T. Parsons, J. McCarthy and G. Thompson, “Very Differ- ent Crustal Response to Extreme Extension in the Southern Basin and Range and Colorado Plateau Transition,” In: M. C. Erskine, J. E. Faulds, J. M. Bartley and P. D. Rowley, Eds., American Association of Petroleum Geolo- gists Pacific Section Guidebook, Vol. 78, 2001, pp. 291- 304.
[17]	A. Gonzalez-Fernandez, J. Danobeitia, L. Delgado-Ar- gote, F. Michaud, D. Ccrdoba and R. Bartolome, “Mode of Extension and Rifting History of Upper Tiburón and Upper Delfín Basins, Northern Gulf of California,” Journal of Geophysical Research, Vol. 110, 2005, B01313.
[18]	D. Lizarralde, G. Axen, H. Brown, J. Fletcher, A. Gon- zalez-Fernandez, A. Harding, W. Holbrook, G. Kent, P. Paramo, F. Sutherland and P. Umhoefer, “Variation in Styles of Rifting in the Gulf of California,” Nature, Vol. 448, 2007, pp. 466-469. doi:10.1038/nature06035
[19]	R. Bialas and W. Buck, “How Sediment Promotes Narrow Rifting: Application to the Gulf of California,” Tectonics, Vol. 28, 2009, TC4014. doi:10.1029/2008TC002394
[20]	R. Dorsey, “Sedimentation and Crustal Recycling along an Active Oblique-Rift Margin: Salton Trough and Northern Gulf of California,” Geological Society of America, Vol. 38, 2010, pp. 443-446.
[21]	C. Ammon, G. Randall and G. Zandt, “On the Nonuni- queness of Receiver Function Inversions,” Journal of Geophysical Research, Vol. 95, 1990, pp.15303-15318.
[22]	L. Zhu and H. Kanamori, “Moho Depth Variation in Southern California from Teleseimic Receiver Function,” Journal of Geophysical Research, Vol. 105, No. B2, 2000, pp. 2969-2980. doi:10.1029/1999JB900322
[23]	J. Ligorria and G. Ammon, “Iterative Deconvolution and Receiver Functions Estimation,” Bulletin of Seismological Society of America, Vol. 89, 1999, pp. 1395-1400.
[24]	L. Zhu, “Estimation of Crustal Thickness and Vp/Vs Ratio beneath the Tibetan Plateau from Teleseismic Converted Waves (Abstract),” Eos Transactions American Geophysical Union, Vol. 74, No. 16, 1993, p. 202.
[25]	G. Zandt, S. Myers and T. Wallace, “Crust and Mantle Structure across the Basin and Range Colorado Plateau Boundary at 37?N Latitude and Implication for Cenozoic Extensional Mechanism,” Journal of Geophysical Re- search, Vol. 100, No. B6, 1995, pp. 10529-10548. doi:10.1029/94JB03063
[26]	G. Zandt and C. Ammon, “Continental Crust Composition Constrained by Measurements of Crustal Poisson Ratio,” Nature, Vol. 374, No. 6518, 1995, pp. 152-154. doi:10.1038/374152a0
[27]	D. Eaton, S. Dineva and R. Mereu, “Crustal Thickness and Vp/Vs Variations in the Grenville Orogen (Ontario, Canada) from Analysis of Teleismic Receiver Function,” Tectonophysics, Vol. 420, No. 1-2, 2006, pp. 223-238. doi:10.1016/j.tecto.2006.01.023
[28]	T. Nakajima, T. Matsuzawa, A. Hasegawa and D. Zaho, “Three Dimensional Structure of Vp, Vs, and Vp/Vs beneath Northeastern Japan: Implications for Arc Magmatism and Fluids,” Journal of Geophysical Research, Vol. 106, No. B10, 2001, pp. 21843-21857. doi:10.1029/2000JB000008
[29]	M. Webring, “MINC, a Gridding Program Based on Minimum Curvature,” US Geological Survey Open-File Report 81-1224, 1982, p. 43.
[30]	D. Plouff, “Preliminary Documentation for a Fortran Program to Compute Gravity Terrain Corrections Based on Topography Digitized on a Geographic Grid,” US Geological Survey Open File Report 77-535, 1977, p. 45.
[31]	B. Baranov and H. Naudy, “Numerical Calculation of the Formula of Reduction to the Magnetic Pole,” Geophysics, Vol. 29, No. 1, 1964. pp. 67-79. doi:10.1190/1.1439334
[32]	R. Blakely, “Potential Theory in Gravity and Magnetic Applications,” Cambridge University Press, New York, 1995. doi:10.1017/CBO9780511549816
[33]	M. Talwani, J. Worzel and M. Landisman, “Rapid Gravity Computations for Two-Dimensional Bodies with Application to the Mendocino Submarine Fracture Zone,” Journal of Geophysical Research, Vol. 64, No. 1, 1959, pp. 49-59. doi:10.1029/JZ064i001p00049
[34]	L. Pedersen, “Interpretation of Potential Field Data, a Generalized Inverse Approach,” Geophysical Prospecting, Vol. 25, No. 2, 1977. pp. 199-230. doi:10.1111/j.1365-2478.1977.tb01164.x
[35]	J. Cady, “Calculation of Gravity and Magnetic Anomalies of Finite-Length Right Polygonal Prisms,” Geophysics, Vol. 45, No. 10, 1980, pp. 1507-1512. doi:10.1190/1.1441045
[36]	C. Jennings, “Geologic Map of California. Scale 1: 750,000, California,” Department of Mines and Geology, 1997.
[37]	S. Reynolds, “Geological Map of Arizona. Scale 1: 1,000,000,” Arizona Geological Survey, 1988.
[38]	T. Parsons and T. McCarthy, “Crustal and Upper Mantle Velocity Structure of the Salton Trough Southeast California,” Tectonics, Vol. 15, No. 2, 1996, pp. 456-471. doi:10.1029/95TC02616
[39]	V. Langenheim, R. Jachen, J. Matti, E. Hauksson, D. Morton and A. Christensen, “Geophysical Evidence for Wedging in the San Gergonio Pass Structural Knot, Southern San Andreas Fault Zone, Southern California,” GSA Bulletin, Vol. 117, No. 110, 2005. pp. 1554-1572. doi:10.1130/B25760.1
[40]	J. Lewis, S. Day, H. Magistrale, J. Ealins and F. Vernon, “Regional Crustal Variations off the Peninsular Ranges, Southern California,” Geology, Vol. 28, No. 4, 2000, pp. 303-306. doi:10.1130/0091-7613(2000)28<303:RCTVOT>2.0.CO;2
[41]	M. Hussein, “Integrated and Comparative Geophysical Studies of Crustal Structure of Pull-Apart Basins: The Salton Trough and Death Valley, California Regions,” Ph.D. Dissertation, University of Texas at El Paso, El Paso, 2007.
[42]	R. Dorsey, “Stratigraphic Record of Pleistocene Initiation and Slip on the Coyote Creek Fault, Lower Southern California,” In: A. Bath, Ed., Contributions to Crustal evolution of the southwest United States, Geological Society of America, 2002, pp. 251-269.