30 Cape Anguille and Codroy Island: The Snakes Bight Formation at Cape Anguille and on Codroy Island displays spectacular folds at a range of scales (Figs. 5a–d). The folded layers are interlaminated siltstone and mudstone (Fig. 6a). Sharp contacts separate deformed layers above and below from undeformed strata. In some locations, rafts containing folded laminae are surrounded by more layers of homogeneous sediment that themselves show larger scale folds (Fig. 5b); as a result, the internal laminated rafts may show superimposed fold patterns (Fig. 5b). Individual folds are tight to isoclinal and range from <1 to 75 cm in half-wavelength measured perpendicular to regional bedding. As shown by a stereographic projection (Fig. 7), folds predominantly plunge gently to the NNE. Their axial surfaces dip moderately NW (Fig. 7). Viewed down plunge these folds are commonly s-folds, verging WNW. Hyde et al. (1988) describe similar tight to isoclinal folds with shallow plunge in Anguille Group strata in the Deer Lake sub-basin (Fig. 1).

31 At outcrop scale, hinges of the folds appear as approximately similar folds: Class 2 of Ramsay and Huber (1987); both sandstone and mudstone layers are thickened in fold hinges. However, on close examination, many sandstone layers show class 1C geometry (i.e., inner surface more tightly curved than outer surface) while adjacent mudstone shows class 3 (i.e., inner arc is less tightly curved than outer arc), indicating that the sand was stronger than mud during deformation, the normal condition for clastic sedimentary rocks deformed at low temperature. However, in some cases sandstone shows class 3 geometry (Fig. 5e), showing that it was weaker than adjacent mudstone at the time of deformation; Waldron and Gagnon (2011) cited this geometry as a clear indicator of deformation while sand was liquidized.

32 Folded siltstone rafts within the larger mass of folded material are common at this location (Fig. 5b). The rafts thin laterally and show convolute laminae suggesting that they were partially lithified. Disaggregation implies that partially lith-ified layers were incorporated as rafts into a larger system of mobile material. Alsop and Marco (2011) and Alsop et al. (2019) have shown similar structures in Late Pleistocene strata adjacent to the Dead Sea and argued that folded strata truncated by undeformed strata of a similar facies, and rafts of folded strata incorporated into a larger structure, are un-equivocal indicators of deformation prior to complete lith-ification.

33 Boswarlos: At Boswarlos (Fig. 2), an angular unconformity between early Paleozoic Humber Zone strata below and Ship Cove Formation above is exposed. Above the unconformity is dominantly very-fine grained to pebbly limestone dipping sub-horizontally (~05°) to the southwest. A detailed stratigraphic column (Fig. 6b) shows four intervals exhibiting tight to isoclinal folds, here attributed to soft-sediment deformation. Undeformed subhorizontal strata truncate limbs and hinges of folds (Figs. 5g, h). These folds comprise tight to isoclinal class 2 (similar) folds, some of which have curved hinges, resembling sheath folds (Fig. 5g). Fold hinges plunge gently, displaying a girdle distribution when plotted together on a spherical projection (Fig. 7c). Plunges of fold hinges on the sheath fold shown in Figure 7 range from 06° to 53° and the folds close to the north and east. Axial surfaces dominantly dip gently S to SW, and strike E to SE. Shear at base of the soft-sediment folds and thinning of limbs indicate transport to the west.

34 Interpretation: Soft-sediment folds comprise strata that were folded prior to complete lithification, in which inter-granular displacements are the main mechanism of deformation (Rossetti 1999; Kang et al. 2010). Soft-sediment folds are commonly attributed to down-slope gravity sliding, but Waldron and Gagnon (2011) pointed out that this is not necessarily the case: unconsolidated sediments are pres-ent in many tectonically active environments where they may undergo soft-sediment deformation associated with the motion of underlying tectonic faults. Folded beds at Cape Anguille and Codroy Island show preferential fold hinge orientations within the overall plane of bedding (Fig. 7). At Cape Anguille the folds trend NNE, have a gentle plunge, and commonly show s-asymmetry verging WNW when viewed down plunge. These observations show that folds at this location likely formed during movement of mobilized sediment downslope towards the WNW, consistent with the direction of paleocurrent flow in the Snakes Bight and Friars Cove formations (Knight 1983). The geometries of folds in both the Anguille Group and Codroy Group examples clearly indicate that sediments were unlithified at the time of deformation but do not clearly indicate whether tectonism, topographic slope, or some combination of the two provided the necessary differential stress to deform the sediments.

35 At multiple intervals in the Snakes Bight Formation at Cape Anguille (Fig. 6a) are bulbous irregularities that resemble load structures but which crop out on the tops of beds. Cross-bedding and cross-lamination in adjacent sandstone beds clearly indicates that these beds are upright. In plan-view, these structures are approximately 1–5 cm in diameter and appear as rounded siltstone forms within a mudstone matrix (Figs. 8a, b) covering, and protruding from, the tops of siltstone beds. In some locations the exposed bulb structures cover three or more square metres of a single bedding surface.

36 In cross-sectional view, these polygonal structures range described in metamorphic rocks. The extensional structures 1–10 cm in height (Fig. 8c); they are convex-up siltstone bodies surrounded by mudstone. Overlying the structures, laminated finer siltstone and mudstone and siltstone vary in thickness so as to compensate for the greater thickness of coarse siltstone in the convex bulb structures, as shown in thin section (Fig. 8d). These laminae show laterally uniform dip and thickness with the exception of locations immediately above the siltstone bulbs, where they are thinned. The bottom surfaces of the deformed siltstone layers that display the bulbs are undulatory and locally may show conventional (downward protruding) load structures or soft-sediment folds (Fig. 8c). Clastic dykes and sedimentary boudins (described below) cross-cut the structures (Fig. 8e).

37 The structures described above superficially resemble conventional load structures noted, for example, in Turkey by Hempton and Dewey (1983), in Spain by Alfaro et al. (2002) and Ezquerro et al. (2015), in England by Owen (2003) and Collinson (2005), and in a physical simulation by Moretti et al. (1999); the bulb structures differ in being ‘upside-down’. Similar structures have been described with variable names: ‘cycloids’ by Hempton and Dewey (1983) and Scott and Price (1988), ‘mushroom-like silts’ by Rodríguez-Pascua et al. (2000), and ‘bulb-shaped structures’ by Nikolaeva (2009). Closely comparable structures in the Horton Group of the Windsor-Kennetcook sub-basin were described as ‘bulb structures’ by Snyder and Waldron (2016), which is the term used here. In those examples, silt was deposited in layers of uniform thickness and was later deformed, pinching out laterally as a result of sediment flow into the bulbs. The contorted nature of the silt in the bulb structures indicates that sediment was likely liquidized during their formation. Flow of water within the layers and between larger silt grains during liquidization led to density contrasts which enabled the bulbs to rise diapirically into overlying finer-grained muds, accounting for the observed localized variations in grain size and sorting.

38 Ribbed features exposed on bedding top surfaces are commonly observed within interbedded siltstone and mud-stone of the Snakes Bight and Friars Cove formations (Fig. 6a). In plan view these structures are 1–10 mm wide and create a pattern of parallel hatching on bedding surfaces (Figs. 8f, g). They are commonly found on the top of siltstone and sandstone beds; intervening layers of mudstone do not show the ribbed features. The contacts above and below beds with the ribbed features are parallel; there are no erosional features at the bedding surface. At microscopic scale, the spaces between the sandstone strips are filled by mudstone. These structures show preferential orientation, trending dominantly N–S and NE–SW (Fig. 8f), oblique to fold hinges.

39 These structures are likely produced by extension parallel to bedding in sediments that were incompletely cemented, kinematically equivalent to boudins that are more usually resulted from semi-brittle extension of more rigid siltstone and sandstone; the spaces created between boudins were filled by finer-grained, sediment that clearly behaved in a more ductile manner. As there is both a brittle and ductile component to these structures, they likely formed prior to complete lithification. Their preferred orientation reflects stresses originating from slopes or from tectonic deformation of wet sediment. Comparable features were described as “pull-apart structure” by Corbett (1973) in turbidites from Tasmania. Other examples of sedimentary boudins were described by Waldron et al. (2007) and Snyder and Waldron (2016) in correlative rocks in the Windsor-Kennetcook sub-basin in Nova Scotia.

40 Clastic dykes in the Snakes Bight Formation occur in interlaminated siltstone and mudstone layers (Fig. 6a). Dykes are composed of grey siltstone and cross-cut dark grey mud-stone at a high angle to bedding and bedding-parallel fissility. The dykes range from 4–14 cm in height (i.e., perpendicular to bedding), and 5 mm–14 cm in width as measured where they are visible on the top surfaces of beds, but narrow with depth. The dykes are elongate, striking dominantly NE–SW, confirming the observation of Knight (1983). Where multiple dykes occur in one horizon, they are most often aligned parallel to each other, but some sections show perpendicular dykes trending NW–SE (Fig. 8h). We did not observe tightly contorted clastic dykes with the geometries seen in the Horton Group of Nova Scotia, interpreted as the result of compaction of surrounding mud (Martel and Gibling 1996; Snyder and Waldron 2016). However, this may have been because the majority of dykes were observed on bedding surfaces, not in cross-section.

41 The clastic dykes are wider at the top and thin with depth, typically originating in a single coarser bed but terminating at different stratigraphic intervals, indicating that the dyke fills were sourced downward from above. They clearly developed before the sediment was fully lithified. However, the contacts between siltstone and adjacent mudstone are sharp, which suggests brittle deformation of mud at a shallow depth of formation (Parnell and Kelly 2003). Waldron and Gagnon (2011) argued that when mud acts more rigidly than coarser sediment, it indicates that the coarser sediment behaved as a fluid with a lower yield stress than the mud, suggesting that the dyke-filling silt was mobilized by sediment liquidization, while the surrounding mud was sufficiently dewatered to undergo brittle deformation.

42 The clastic dykes at Cape Anguille cross-cut sedimentary boudins and soft-sediment folds (Fig. 8e). The top surface of one sandstone bed shows a bedding-parallel fault (219/23 NW) and clastic dykes on the same surface. The sandstone fill of the clastic dyke appears in positive relief clearly cross-cutting gently WSW-plunging (254-14) slickenlines (Fig. 8a.), which indicates that the dyke formed after the fault moved.

43 Soft-sediment deformation structures are features that form soon after deposition of sediment and before complete lithification. Soft-sediment structures provide information on early deformation of sedimentary rocks in tectonically active environments such as strike-slip systems and sedimentary basins cut by faults (Hempton and Dewey 1983; Plint 1985; Rossetti 1999; Sibson 2003; Berra and Felletti 2011; Waldron and Gagnon 2011; Snyder and Waldron 2016; Tang et al. 2020). Liquidization (liquefaction and/or fluidization) is the most common deformation mechanism (Maltman 1994; Maltman and Bolton 2003; van Loon and Mazumder 2011, Alsop et al. 2019). Liquidization of sediment commonly occurs at or near the sediment–water interface, although if unlithified wet sediments are sealed by an overlying impermeable layer, overpressured conditions may develop, and liquidization can therefore occur deeper in a sediment pile (Maltman and Bolton 2003; van Rensbergen et al. 2003). Overpressure can liquidize a fluid-saturated bed if it is either rapidly buried or horizontally compressed by tectonic processes (Maltman 1994; Jolly and Lonergan 2002; Maltman and Bolton 2003; Taki and Pratt 2012).

44 The soft-sediment deformation structures described above can be broadly classified into those that were exposed at the sediment–water interface and those that formed later in the sediment pile. Alsop et al. (2019) note that structures truncated by undeformed strata are an indication of formation near the sediment surface, before minor erosion. Amongst the structures we observed, soft-sediment folds are in some cases truncated and unconformably overlain by undisturbed strata, suggesting that they formed near the sediment surface.

45 The sedimentary boudins and bulb structures show no evidence of exposure at sediment surfaces; both are best explained as products of liquidization during overpressuring, where overlying impermeable mudstone (or evaporite) provided a seal and prevented the expulsion of interstitial water during burial. The lack of erosional features and presence of overlying mudrock suggest these structures formed within the sediment pile after some amount of burial. Sedimentary boudins were observed to cross-cut the bulb structures, indicating that these structures also probably formed within the sediment pile.

46 Clastic dykes show diverse relationships. In some cases they were truncated at the sediment surface, whereas in other cases they cross cut features such as sedimentary boudins and bulb structures, indicating formation within the sediment pile. A single example of a dyke cutting a fault with subhorizontal slickenlines (Fig. 8a) suggests that strike-slip faulting was active during early stages of diagenesis. Clastic dykes may therefore have formed at intervals throughout deposition and early stages of diagenesis.

47 A range of triggering mechanisms are recognized to have the potential to create soft-sediment deformation structures of the types identified in the BSGSB. These include meteorite impact, tsunami, permafrost thawing, groundwater fluctuations, paleoslope, wave and tide action, seismicity, rapid sediment loading, and overpressured conditions (Moretti et al. 1999; Alfaro et al. 2002; Moretti and Sabato 2007; Owen and Moretti 2011; Hermanrud et al. 2013; Alsop et al. 2019; Tang et al. 2020). Many of these can be excluded as the trigger for deformation in the BSGSB. Soft-sediment deformation structures are present on multiple, closely spaced stratigraphic surfaces; explanations that invoke large, rare events, such as tsunami and meteorite impacts (Long 2004; Tang et al. 2020) are unlikely. Permafrost may be eliminated as a cause because, at the time of deposition, Newfoundland was at a low latitude in a warm climate (Calder 1998). Preferential orientation of many of the structures suggests that vertical fluctuations in the groundwater table are not a likely trigger for deformation.

48 Waldron and Gagnon (2011) show that soft-sediment deformation structures with preferred orientation can be induced by down-slope gravity-driven processes, by movement on underlying tectonic faults, or by combinations of the two (for example, where tectonic activity produces steep topographic slopes). Because soft-sediment folds are observed in three different formations (Snakes Bight, Spout Falls, and Ship Cove), we suggest that the BSGSB was tectonically active throughout deposition of the Anguille Group, and that deformation continued into deposition of the Ship Cove Formation of the Codroy Group. However, at its type locality the Ship Cove Limestone is uniform, with no soft-sediment structures. This distribution suggests that soft-sediment deformation was localized, possibly to the vicinity of active faults. The immediate triggers for soft-sediment deformation may have included causes as diverse as rapid sediment loading, waves, tides, and seismic shaking (Sims 1975; Gatmiri 1990; Rossetti 1999; Owen and Moretti 2011; Moretti et al. 2016). Regardless of the immediate trigger, the presence of soft-sediment structures with tectonically controlled orientations shows that tectonism was active during sedimentation. Our observations suggest that part of the contrast in deformation style between the northern and southern BSGSB may be due to the abundance of soft-sediment deformation structures in the thick, rapidly- deposited strata of the southern sub-basin.

50 Mineral exploration directed at gypsum, potash, and halite in the Codroy Group in the Flat Bay anticline area (Fig. 2) has produced a significant amount of drilling data. Rho-den et al. (1999) examined drill core from Leeson Resources Inc. LR-98-1 and LR-98-2, east of the Flat Bay anticline (Fig. 2) in the northern part of the basin, and interpreted a salt-expulsion minibasin in the area. The two wells penetrated 681 m and 359 m of Carboniferous strata, respectively. Drill core contains sandstone, siltstone, mudstone, conglomerate, and an increasing amount of evaporites (gypsum and halite) with depth; halite is the dominant lithology below ~360 m in LR-98-1 and LR-98-2 (Rhoden et al. 1999). Immediately above the Ship Cove Formation, the Codroy Road Formation is logged as thick foliated intervals of dominant halite and anhydrite with frequent limestone bands. The thick halite package contains bands and/or inclusions of mudstone and siltstone that make up between 2 and 40% of the drilled section (Fig. 4). We infer that stratigraphic sections exposed in outcrop, now devoid of halite, originally contained significantly larger proportions of evaporite, and that sections of siltstone breccia observed in outcrop represent residues, after solution, of originally much thicker successions of interstratified siltstone and evaporite in the subsurface.

51 To supplement outcrop and drill-core information, time-migrated 2-D seismic reflection data were acquired from the Newfoundland and Labrador Department of Natural Resources (Figs. 2, 9). The data are of poor to moderate quality, and we have not attempted any reprocessing. Initial horizon identification and interpretations were made by comparison with maps, drill core, and data from offshore BSGSB. Because we lack logged wells tied to the seismic lines, our horizon interpretations are necessarily tentative. Nonetheless, we identify evaporites based on their lack of coherence and weak internal reflectivity. Evaporites are commonly recognizable on seismic profiles from passive margins as zones of incoherent low reflectivity (Jackson and Hudec 2017) showing major fluctuations in thickness, an interpretation confirmed from our experience in other parts of the Maritimes basin, where thick evaporites (“lower Windsor salt”) commonly occur above a highly reflective basal anhydrite interval (gypsum in outcrop), that in turn rests upon limestone (Macumber Formation and equivalents).

52 Based on the above arguments we identify a consistent deep reflection (horizon BA, possibly representing a basal anhydrite unit of the Codroy Road Formation that represents the boundary between bright but poorly coherent reflections below and a discontinuous convex-up zone of incoherent reflections above, interpreted to represent evaporites.

53 Above both these units is a reflective interval that defines antiform-synform pairs (Fig. 9). The base of this reflective interval can be traced across most lines, here termed horizon TS (Fig. 9) possibly representing a top-salt reflection. In parts of the section where the inferred evaporites are absent, BA and TS join to form a single reflection. Horizons in the moderately reflective package above TS appear to downlap directly on to the merged BA-TS surface. To the southeast, reflections overlying horizon TS, dipping moderately to the southeast, change dip to parallel the subhorizontal horizon BA. We interpret these relationships to suggest that the lenticular interval between BA and TS represents remnants of an originally more continuous evaporite layer that has been expelled from the section into adjacent salt structures.

54 The interval above horizon TS shows significant variations in two-way travel time between reflections across the seismic profile, interpreted to indicate thickness changes. On the line shown in Figure 9, thickness between reflections increases near the hinge of a syncline; thickness between reflections decreases near the hinge of an anticline.

55 The geometries on these seismic lines are similar to salt- related structures on passive continental margins (Hudec et al. 2009) where expulsion of evaporites is caused by younger sediment subsiding into an evaporite-filled layer. Lateral thickness changes in overlying sediment record differential subsidence during sedimentation. The surface where material above and below the evaporite package (horizon TS and horizon BA) are juxtaposed is therefore interpreted as a primary salt weld (Fig. 9).

56 Ship Cove (Fig. 2) was mapped by Knight (1983) and von Bitter and Plint-Geberl (1982) as a continuous conformable succession spanning the Spout Falls, Ship Cove, Codroy Road, and Robinsons River formations. We remapped this area and measured a detailed section from the top of the Ship Cove Formation into the base of the Codroy Road Formation (Fig. 10). In this section, laminated limestone, mud-stone, massive conglomerate, gypsum, and multicoloured weakly foliated siltstone breccia (Figs. 11a, b) alternate. Thin beds of gypsum occur within the siltstone breccia packages. The repetitive character of the succession suggests that the Codroy Road Formation was deposited during cyclic changes in the depositional environment. Giles (1981, 2009) interpreted correlative rocks from the Windsor Group in the Shubenacadie sub-basin in Nova Scotia and noted similar cycles at mesoscopic and macroscopic scale. von Bitter and Plint-Geberl (1982), Utting and Giles (2004, 2008) revisited these sections focusing on conodonts and palynomorphs respectively. These results were incorporated into our sections, resolving questions on younging and dip directions.

57 The new map and cross-section in Figure 12 show uniformly dipping Spout Falls and Ship Cove Formation at the stratigraphic base of the section. Above these units, the cross-section (C–D in Fig. 12), perpendicular to major fold axes, shows alternating folded sections of foliated siltstone breccia, gypsum, and minor carbonates. The gypsum sections have varying texture, but consistently show foliated dark and light bands in which the foliation is broadly parallel to layering. The lithological intervals can be broadly correlated across folds, but map relationships require that the thickness of the lowest Codroy Road Formation gypsum varies dramatically when traced laterally, which suggests extreme ductility due to evaporite flow. In the overlying Codroy Road Formation, a series of anticline–syncline pairs comprise the remainder of the section. Interbedded boundstone, sandstone, siltstone breccia, and gypsum form a large anticline further north. Gypsum outcrops near the core of this anticline are steeply foliated at water-level, but the foliation is itself folded about a near-horizontal secondary axial trace, suggesting the presence of refolded folds.

58 We interpret expulsion of evaporites along the top of the Ship Cove Formation that created the thickened evaporite package shown in the cross-section in Figure 12. The parallel contact between the Ship Cove Formation limestone and an overlying siltstone breccia and gypsum (Fig. 10) likely represents a surface where evaporites were expelled or dissolved forming a primary salt weld.

59 One of the most structurally complex coastal sections in the BSGSB mapped by Knight (1983) extends from Stormy Point to Cape Anguille (Fig. 2), passing through Capelin Cove. For this study, the Capelin Cove section was remapped (Fig. 13). The strata were separated into three mappable siltstone breccia units, two separate gypsum-dominated packages, and two black limestone packages (Fig. 13).

60 To the south of the Capelin Cove section are sandstone, dark shale, siltstone, and rare gypsum beds of the Woody Cape Member. One sandstone bed within the member has quartz pseudomorphs after halite (Fig. 11c) suggesting that parts of the Woody Cape Member were deposited in hyper-saline water. Crossbedding and climbing ripples in the sandstone provide unequivocal way-up indicators. This package of rock has variable dip, ranging from steeply dipping (~75° south) and younging to the south, to near horizontal (~07° north), to overturned (~58° south) and younging to the north (Fig. 13). The pattern of bedding orientations clearly shows that the Woody Cape Member is folded in a downward-facing fold: an antiformal syncline. Such structures typically require two episodes of shortening in their formation, the first to form an upward-facing fold and the second to rotate it so that strata at the hinge are upside-down.

61 The contact between Woody Cape Member and Searston Formation to the south comprises a near-vertical brecciated zone exposed in the cliff. The contact zone is ~5.5 m wide and strikes approximately E–W (250°) (Figs. 11d, e). Within this zone is fine-grained very poorly consolidated breccia and gouge. Broken sandstone layers are present near the edges of the zone, with orientations subparallel to bedding in the adjoining units. Multiple surfaces on the competent rocks display slickenlines and deformation bands of varying orientations.

62 To the south of the brecciated zone are sandstone, siltstone, and coal measures of the Searston Formation that dip 50–60° and young to the southeast. Searston Formation rocks measured inland also young to the south and east forming a synclinal elliptical pattern (Fig. 2).

63 The contact between Woody Cape Member and Searston Formation was interpreted by Knight (1983) as the steeply dipping Stormy Point fault, striking approximately east-west. Traced inland, this structure passes through a poorly exposed valley of the Grand Codroy River, interpreted by Knight (1983) as underlain by a belt of Codroy Group between the Anguille Mountains to the north and a structural basin filled with Searston Formation (Barachois Group) which lies to the south. However, the diametrically opposed younging directions of the formations on either side of the interpreted fault make reconstruction of fault slip very diffi-cult. In contrast, the configuration of two oppositely younging, steeply dipping formations, separated by breccia, closely resembles the geometry of some salt welds observed in seismic profiles of passive continental margins (Jackson and Hudec 2017). Secondary salt welds represent steeply dipping zones where salt migrated into a diapiric salt wall, and tertiary salt welds represent subhorizontal salt canopies; in both cases a weld is formed when salt is expelled from the wall or canopy, and the resulting weld may show divergent younging directions of strata preserved on either side. Secondary and tertiary salt welds are rare in outcrop. However, the structure at Capelin Cove resembles salt welds described by Rowan et al. (2012) in the La Popa Basin in Mexico and by Thomas and Waldron (2017) at Little Judique, Cape Breton Island in rocks of comparable age in the Maritimes basin. It is therefore interpreted that the contact separating Woody Cape Member and Searston Formation is a salt weld, not a fault. The brecciated zone represents the material left after salt expulsion or solution. Bedding measurements from the Searston Formation, to the south and inland (Fig. 2) outline an elliptical structural basin suggesting that the Searston Formation strata occur within a salt-expulsion minibasin. Inland, the expression of the salt weld could route through Grand Codroy River (Fig. 2), which is a low elevation area with poor exposure consistent with the former presence of a diapiric evaporite wall. To the north, the Woody Cape Member probably represents an earlier, late Visean minibasin that also subsided into salt of the Codroy Road Formation. The downward-facing fold in the Woody Cape Member probably represents an originally recumbent, SE-facing fold that formed during late Visean minibasin subsidence and development of a salt canopy as shown schematically in Figure 14a. Expulsion of salt from the canopy allowed deposition of the Searston Formation above. Subsequent tilting associated with the development of the Anguille anticline rotated the fold into its downward-facing orientation (Fig. 14b). We therefore reinterpret the Stormy Point fault of Knight (1983) as a Serpukhovian salt weld.