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gravels, decidedly of less coarse texture and containing clay and silt bands, overlie the wash, but the contact is not well defined. Toward their base they contain many quartz pebbles. They are well exposed at Murphy Hill, a little east of the King Solomon shaft. These gravels, which are at least 180 ft. thick, are derived from the semi-schist and greywackes of the adjacent highlands and are correlated with the Maori Bottom gravels of Otago Central which they in general resemble in texture and consolidation. Like them they contain detrital gold usually in small amount. The wash and rusty gravels are in places tilted and faulted, but the amount of deformation is not great compared with that which the Ototaran beds have suffered. They are considered the deposits of a stream or streams that drained the land after the faulting had taken place ; they accumulated in the fault-angles and the narrow structural depressions where, in spite of the great subsequent erosion, they still occur in thick masses and occupy considerable areas. Silts and clays 50 ft. or more thick, possibly lake-beds, but more probably river deposits, overlie the rusty gravels. These again in places are covered with angular talus from the adjacent hills or by terrace gravels. The gravels of the existing streams and the tailings of the miners bring the geological record to the present day. Faults. A major upthrust fault can be traced along the eastern side of the Whakaea Valley from above the Argyle Station southward to Winding Creek, a distance of seven miles ; this fault probably extends north from Argyle Station, but was not traced owing to the obscuring alluvium on the flood-plain of the Whakaea River. Southward from the Winding Creek junction, this fault apparently dies out, but it mav continue southward as a warp or monoclinal flexure along the east side of the Round Downs. Rusty gravels occur along this upthrust fault, and along their east boundary are involved in the movement; schist forms their western boundary for three miles in the southern part and the contact with the schist is depositional arid not faulted. Geophysical prospecting was recommended in this area, the work revealing a concealed fault which trended sub-parallel to the eastern upthrust. The structure, in this locality is therefore a long narrow depressed area bounded east and west by faults which enclose younger sediments. The major fault on the east is a high angle upthrust, but from the geophysical data the fault on the west appears to be a normal fault with downthrow to the east. The classification of this type of fault structure is difficult, it is not a rift block or graben, and is apparently a hybrid. Rusty gravels identical with those overlying the King Solomon lead occur along this fault-bounded depression ; and the King Solomon lead may be present in this area also, underlying the rusty gravel, and overlying the infaulted pre-deformational white sands and lignite clay, or the fossiliferous marine beds, or the basement rocks. The rusty gravels were traced southward down the Whakaea Valley from Winding Creek ; schist gravels occur in this direction, but rusty gravels are present in the re-entrant along the range where Winding Creek crosses the western block, and small disconnected patches occur on the sides of the low part that leads through the western block into the next valley. They occur in the old Break-em-All claim on Winding Creek, and as already stated overlie the wash worked at King Solomon Mine. A fault was traced south-west from Winding Creek along the eastern side of the Wendon Valley and continues in this direction for twelve miles into Otama Valley. The evidence for this fault is mainly physiographic, but the actual fault-plane can be seen at the mouth of a small creek where the King Solomon pipe-line rises from the tailings ; at this point rusty semi-schist, and greywacke gravel are downthrown to the westward against the basement rock ; the fault-plane here is almost vertical. This fault was not directly observed elsewhere, but a bold scarp continues to the south-west and defines the south-east boundary of the depressed area. The western boundary of this depression or rift is also defined by a fault. At its northern end this western fault was not seen on the surface, but was revealed by geophysical work. Two miles south-west down to the depressed area, beyond the saddle which divides Wendon Creek from Stony Creek, this western-bounding fault is clearly seen ; along this stretch of the depression it shows as a low, conspicuous scarp easily traceable into the Otama Valley. Clays and silts which overlie the rusty gravels at the King Solomon end of the depiession or rift occupy the area between the bounding fault-walls, but minor patches of marine (Ototoran) beds and white sands with lignites outcrop at several places. Observations in the King Solomon Mine workings show that the east-bounding fault dips about 55° eastwards ; it is an upthrust fault, and this attitude probably persists southward. The west-bounding fault for the greater part of its length presents an almost undissected scarp (except where breached by streams consequent on the eastern fault scarp) which dips 50° to 60° to the east, suggesting a normal fault with downthrow to the east. Other minor faults occur in the area. The fault-bounded rift or graben along the east side of the Whakaea Valley is structurally similar to that which extends southward from King Solomon Mine. Pre-Whakaea River. The interpretation from these observations and other data not discussed here is that a pre-Whakaea River flowed southward down a fault-angle depression a little east of the present bed of the Whakaea River. This depression is floored with infaulted pre-deformational sand, lignite, clay, and marine beds. The river swung eastward at the low notch or sag in the ridge now occupied by Winding Creek. It crossed the western fault-block (which has since been uplifted) and flowed southward down the Stony-Wendon depression. The rusty gravel along the east side of the Whakaea Valley, the patches of gold-bearing gravel containing " chinamen " boulders which occur along the notch or sag connecting the Whakaea with the Stony Creek - Wendon Valley, the gold-bearing gravel at the Break-em-All claim and the King Solomon Mine are deposits of this ancient river.

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