Vertical and horizontal watermelon seed movements in strike-slip duplexes: An example from the Lambertville Sill, New Jersey
- Recon Systems, Inc., Raritan, NJ (United States)
- Rutgers, The State Univ. of New Jersey, Newark, NJ (United States). Dept. of Geology
A compressional strike-slip duplex developed in the Jurassic Lambertville Sill, Belle Mead, New Jersey, shows both vertical and horizontal watermelon seed type movements of fault slices. The duplex occurs in a N 25--35 E restraining bend in a N 60--75 E dextral strike-slip fault zone. Deformation within the duplex shows a complex Riedel system reflecting layer parallel shortening and simple shear. R shears are oriented N 70--80 E and were active early. P[prime] shears are oriented N 20--30 E and show rotation of up to 20[degree] at their terminations having either bent slicks or two slick fiber plunge directions. P shears show rotations of 40[degree] around the northeast curve in the fault. Helicoidal reverse faults occur perpendicular to the interpreted principle compression direction forming between the R and P fracturing events. Antithetic movement (clockwise rotated P[prime]) dominates adjacent to the southeast bounding fault. Synthetic movement (counterclockwise rotated P) is developed towards the interior of the system. Deformation between these domains includes an overlap of rotated P and P[prime] fractures. Most of the faults are oblique showing a component of dip-slip movement. Plunges on slick fibers range from horizontal to about 40[degree]. In vertical section, movement can be both normal and reverse on a single curved fault plane and appears opposite on either side of a fault slice. The fault slices therefore appear to be emergent or submergent within the zone. Such watermelon seed type movements are also observed in plan view where fault slices or pods appear to slide past each other. In the domain overlap zone, adjacent pods show opposite alternating movement senses.
- OSTI ID:
- 5640330
- Report Number(s):
- CONF-9303211-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:2; Conference: 28. annual Geological Society of America (GSA) Northeastern Section meeting, Burlington, VT (United States), 22-24 Mar 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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