Report on the Geology and Topography of a Portion of the Lake Superior Land District in the State of Michigan: Copper landsHouse of Reps, 1850 |
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Página 20
... bearings , from the most reliable information , are , from Manitou island , at the head of Keweenaw Point , SE . E. 27 miles ; from Point Abbaye , E. by N. N. It lies in the direct route between Grand Island and Keweenaw Point , so that ...
... bearings , from the most reliable information , are , from Manitou island , at the head of Keweenaw Point , SE . E. 27 miles ; from Point Abbaye , E. by N. N. It lies in the direct route between Grand Island and Keweenaw Point , so that ...
Página 29
... bearing north 72 ° east , attains an elevation of one hundred and fifty feet , whose summit is composed of granite , but the flanks consist of horn- blende and mica slate , folded over it like a mantle . The banks of the stream are ...
... bearing north 72 ° east , attains an elevation of one hundred and fifty feet , whose summit is composed of granite , but the flanks consist of horn- blende and mica slate , folded over it like a mantle . The banks of the stream are ...
Página 60
... bearing a close resemblance to certain modern volcanic products . These vesicles are , for the most part , filled with carbonate of lime , chlorite , agates , carnelians , and amethysts , and minerals of the zeolite family . As we ...
... bearing a close resemblance to certain modern volcanic products . These vesicles are , for the most part , filled with carbonate of lime , chlorite , agates , carnelians , and amethysts , and minerals of the zeolite family . As we ...
Página 61
... bearing and inclination , so that the inexperienced observer is inclined to refer the whole to a common origin . This deception is still further increased by observing lines of pseudo stratification in the trap conforming to those of ...
... bearing and inclination , so that the inexperienced observer is inclined to refer the whole to a common origin . This deception is still further increased by observing lines of pseudo stratification in the trap conforming to those of ...
Página 62
... bearing N. 70 ° W. , and dipping NE . 16 ° . The underlying trap differs from that which overlies the detrital rocks , being more amyg- daloidal , and offering less adhesion between the particles . This is sup- posed to be a ...
... bearing N. 70 ° W. , and dipping NE . 16 ° . The underlying trap differs from that which overlies the detrital rocks , being more amyg- daloidal , and offering less adhesion between the particles . This is sup- posed to be a ...
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Términos y frases comunes
adit afford amygdaloid appearance bands bearing north bedded trap belt bluffs boulders calc-spar Carp river chlorite clay cliffs coast compact trap Company composed conglomerate consists containing Copper Harbor crystalline depth distance drift deposites east elevation epidote excavated explorations extended fissures gangue geological granite greenstone Harbor height hills hornblende hundred feet igneous rocks inches intersect iron island Isle Royale Keweenaw Point lake shore Lake Superior limestone lode mass metal Michigan miles mineral mines Montreal river mountains native copper nearly northern northwest numerous observed occur Ontonagon river pebbles places Porcupine mountains porphyry Portage lake portion prehnite quarter of section quartz range 34 region ridge rises sand sandstone Saut seam seen shaft silver slope southeast southern southwest spar strata stratification stream striæ summit surface thickness tons township 58 traced trap range trappean rocks traversed vein veinstone vicinity width
Pasajes populares
Página 9 - The groves were God's first temples. Ere man learned To hew the shaft, and lay the architrave, And spread the roof above them — ere he framed The lofty vault, to gather and roll back The sound of anthems ; in the darkling wood, Amid the cool and silence, he knelt down, And offered to the Mightiest solemn thanks And supplication.
Página 149 - The rubbish taken from the mine is piled up in mounds, which can readily be distinguished from the former contour of the ground.
Página 209 - Fault, in the language of miners, is the sudden interruption of the continuity of strata in the same plane, accompanied by a crack or fissure varying in width from a mere line to several feet, which is generally filled with broken stone, clay, &c.
Página 7 - I have seen several such pieces in the hands of savages; and since they are very superstitious, they esteem them as divinities, or as presents given to them to promote their happiness by the gods who dwell beneath the water. For this reason they preserve these pieces of copper wrapped with their most precious articles.
Página 54 - The temperature of the water of Lake Superior, during the summer, a fathom or two below the surface, is but a few degrees above the freezing point. In the western portion the water is much colder than in the eastern — the surface flow becoming warmer as it advances toward the outlet.
Página 149 - He saw numerous evidences to convince him that this was an artificial excavation, and at a subsequent day, with the assistance of two or three men, proceeded to explore it. In clearing out the rubbish they found numerous stone hammers, showing plainly that they were the mining implements of a rude race. At the bottom of the excavation they found a vein with ragged projections of copper, which the ancient miners had not detached.
Página 119 - It is on the rivers, and the boatman may repose on his oars ; it is in highways, and begins to exert itself along the courses of land conveyance ; it is at the bottom of mines, -a thousand feet below the earth's surface ; it is in the mill, and in the workshops of the trades. It rows, it pumps, it excavates, it carries, it draws, it lifts, it hammers, it spins, it weaves, it prints.
Página 149 - The earth was so packed around the copper as to give it a firm support. The ancient miners had evidently raised it about five feet and then abandoned the work as too laborous. They had taken off every projecting point which was accessible, so that the exposed surface was smooth.
Página 120 - ... fortunate circumstance, not only to the company, but to the whole mining interest on Lake Superior. It gave encouragement to those engaged in these pursuits, and induced them to persevere. It also demonstrated the true source from which the loose masses occasionally found on the lake shore had been derived. It demolished the fanciful theory advanced by at least one geologist as to the transport of the...
Página 149 - When he had penetrated to the depth of eighteen feet, he came to a mass of native copper ten feet long, three feet wide, and nearly two feet thick, and weighing over six tons. On digging around it the mass was found to rest on billets of oak, supported by sleepers of the same material. This wood...