Microstructural characterization of natural fractures and faults in the Opalinus Clay: insights from a deep drilling campaign across central northern Switzerland

Swiss Journal of Geosciences

Table 2 Structural measurements of the selected samples

Borehole	Depth [m]	Structure	Fault plane Dip direction [°]	Fault plane Dip [°]	Lineation Azimuth [°]	Lineation Plunge [°]	Shear sense	Interpreted Deformation phase
BOZ1_1	619.65	Strike-slip fault	237	56	155	25	Up/dextral	N-S shortening
BOZ2_1	482.70	Thrust fault	154	30	180	25		NNW-SSE shortening
BOZ2_1	507.70	Thrust fault	305	34	20	20	Up
BOZ2_1	527.87	Thrust fault	171	12	142	8		NNW-SSE shortening
BOZ2_1	531.77	Thrust fault	155	17	155	15	Up	NNW-SSE shortening
BOZ2_1	541.82	Tension gash—vertical wiggly	236	83	–	–	–	E-W extension
BOZ2_1	546.69	Tension gash—vertical wiggly	207	75	–	–	–	NW–SE extension
STA2_1	793.15	Normal fault	356	15	–	–	–	NW–SE extension
STA3_1	830.87	Tension gash—Inclined straight	77	25	–	–	–	N-S shortening
STA3_1	851.27	Thrust fault	136	5	182	2	Up	NNW-SSE shortening
MAR1_1	668.85	Normal fault	186	31	181	29	Down	–
MAR1_1	676.56	Tension gash	102	7	–	–	–	SSW-NNE or SSE-NNW shortening
MAR1_1	676.56	Normal fault	230	33	–	–	Down	E-W extension
TRU1_1	846.70	Normal fault	96	59	10	15	Sin	–
TRU1_1	849.70B	Normal fault	–	–	–	–	–	–