Geosphere; December 2005; v. 1; no. 3;
p. 111-118; DOI: 10.1130/GES00014.1
© 2005 Geological Society of America
Strain transfer and partitioning between the Panamint Valley, Searles Valley, and Ash Hill fault zones, California
J. Douglas Walker1,
Eric Kirby2 and
Joseph E. Andrew3
1 Department of Geology, University of Kansas, Lawrence, Kansas 66045, USA
2 Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
3 Department of Geology, Youngstown State University, Youngstown, Ohio 44555, USA
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Figure 1. Location map for the Searles Valley–Panamint Valley study area. Active faults considered in our analysis are shown in red, and main bounding structures (Ash Hill, Manly Pass, Searles Valley, and Panamint Valley fault zones) are shown as bold lines; other regional faults are shown as bold black lines. Fault systems are somewhat simplified. Green arrows point in direction of slip for the various fault zones (as described in text); vector for Ash Hill system is actually determined for an area  30 km north of the figure. The Garlock fault is on the southern boundary of the area, and Death Valley is located to the east of the Panamint Range. The locations of Figures 3 and 5 are indicated by boxes. HC—Hall Canyon; MC—Manly canyon; SCT—Sand Canyon thrust; SVF—Searles Valley fault. Sand Canyon is located where the arrow from SCT crosses the range front. Base map modified from Walker et al. (2002)
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Figure 2. Scatter plot of fault striae for the Manly Pass fault zone in the northern part of the Slate Range. Mean vector plunges 48° toward 292°. Red lines are Kamb 2% contours (maximum = 10%). Blue oval is 95% confidence area for mean vector (radius is 17°)
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Figure 3. Orthophotograph of alluvial fan at the mouth of canyon below Manly Fall (here called Manly canyon). The NE-trending normal faults in the center of photo are the extension of the Manly Pass fault zone. These faults apparently terminate and merge to the east at the strike-slip faults of the Panamint Valley zone. Debris flow levees discussed in the text are at the southern end of a prominent strike-slip fault and location is shown with yellow line and arrow labeled with DL. Normal fault scarp noted in text is just off the photo to the right
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Figure 4. Block diagram showing the interaction of the Searles Valley, Manly Pass, Panamint Valley, and Ash Hill fault systems. Note that north is toward the lower left. The Ash Hill fault transfers to a complex array of faults that end at the Manly Pass fault (details of transfer are not shown here). Bold lines with arrows are the slip vectors for each segment of the fault system. Bold red arrow in lower left shows regional extension direction. Strike and dip symbols show local orientation of the fault zones. Figure inspired by diagram in Caskey et al. (1996)
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Figure 5. ASTER satellite image for the Panamint Valley and northern Slate Range. Left frame is the base image. Right frame overlain by faults shown on Figure 1. In addition, gravity contours (in mgal; green lines) are shown along with gravity observation points (blue points; data from Smith et al. [1968], and National Geophysical Data Center [1999]). P—prominent playa in southern Panamint Valley. Location shown on Figure 1
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Figure 6. Schematic diagrams showing slip directions and fault interactions for the Searles Valley, Manly Pass, Panamint Valley, and Ash Hill fault zones. A: Main faults in system showing slip direction (green arrows) and regional maximum extension direction (red arrow). Blue dot shows the intersection point of the Manly Pass with the Panamint Valley fault zone. Same position is shown in other panels (along with regional direction) for reference. B: Diagram isolating the main normal faults in the system. The Manly Pass and northern Panamint Valley zones form a segmented normal fault. These faults are not perpendicular to extension direction, so some dextral shear must be accommodated by oblique slip and regional strike-slip faults (in gray color). Green triangular region shows area of highest subsidence inferred from slip on intersecting normal faults and proposed relay zone in strike-slip system (see below). C: Diagram isolating the mainly strike-slip faults in the system. The Ash Hill and southern Panamint Valley faults form a left-stepping geometry in the dextral system. Because deformation is transtensional, we hypothesize that the interactions of these faults occur on a connecting zone (schematically shown as dashed strike-slip fault) that is roughly parallel to the extension direction. No single fault connects these structures. See text for discussion of linkage
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Copyright © 2009 by Geological Society of America
