Transactions . c h r ^•ol tftE * u. LEGEND CAMBRIAN SHALES ;;; BASAL CONGLOMERATE. ALGONKIAN. SCHISTSjANO RELATED ROCKS. 1 IGNEOUS RCCKJCHIEFLY RHYOLITEAND PHONOLITE. AREAS FROM WHICH WOLFRAMITE HAS BEEN MINED. SCALE OF FEET Geological Map of the Vicinity of Lead City, South Dakota.(Geology by T. A. Jaggar and J. M. Boutwell.) 686 WOLFRAMITE IN THE BLACB HILLS OF SOUTH DAKOTA. slmi in on three sides by later strata, bu1 separated from themain area of schists to the south by only a narrow belt of Cam-brian rocks and their included masses of porphyry. Through-out this northern area,
Transactions . c h r ^•ol tftE * u. LEGEND CAMBRIAN SHALES ;;; BASAL CONGLOMERATE. ALGONKIAN. SCHISTSjANO RELATED ROCKS. 1 IGNEOUS RCCKJCHIEFLY RHYOLITEAND PHONOLITE. AREAS FROM WHICH WOLFRAMITE HAS BEEN MINED. SCALE OF FEET Geological Map of the Vicinity of Lead City, South Dakota.(Geology by T. A. Jaggar and J. M. Boutwell.) 686 WOLFRAMITE IN THE BLACB HILLS OF SOUTH DAKOTA. slmi in on three sides by later strata, bu1 separated from themain area of schists to the south by only a narrow belt of Cam-brian rocks and their included masses of porphyry. Through-out this northern area, erosion lias not cut so deeply into thecrystalline schists as further south ; so t hat, he-ides the rude beltof enclosing Cambrian strata, isolated outliers of that formationcap the higher hills within its confines. Nearly at the centerof this area of crystalline rocks and just south of one of thesedetached remnants is Lead City. The map accompanying thispaper shows this town in the northern portion, and extends southso as to inclu
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
