The role of geology in prospecting for lead and zinc in the Tri-state district

The present generation has seen many changes in all phases of human endeavor, and the changes which have been made in the extraction of metals from the earth are not the least or these. The application of science to our industries has revolutionized many of them. Today quantity production in our factories is an accepted thing, and in the mines, application of the same principles has made possible the working of the low-grade copper deposits of Utah, Arizona, Chile and Belgian Congo. The mining industry has made use of almost all of the sciences in one form or another to aid it in economically extracting the ore from the earth, but this paper will deal with but one of these; the science or geology and its application to the search for lead and zinc in the Tri-State District of Missouri, Kansas and Oklahoma. In the early days of mining around Joplin, Missouri, shallow shafts were sunk wherever surface indications were favorable. If ore were struck in the first shaft, drifting would immediately be started, and a \u27gouge\u27 would be in operation. If ore were not struck in the first shaft, another would be sunk some distance from the first. When the faces were worked far enough from the shaft that a long tram was necessary, the shaft would be abandoned and another sunk in the direction of the orebody. The mills in those days consisted of one or more hand-jigs, so that it was no trouble to move the mill with the shaft. Most of the early mining was done from grass-roots down to the water-level, which was usually about fifty feet from the surface. Lead ore only was taken; the zinc ore then had no value. As the price of lead ore advanced and uses for zinc were found, it became profitable to go below the water table and mine the larger ore deposits found there. This necessitated pumping the water and made the original investment too large for the individual or small group of miners. With the advent of capital, the hand-jig method of recovering the ore gave way to mechanically operated jigs and tables. The large amount of capital put into the mills required that an orebody be blocked out with a reasonable degree of accuracy, before the mill was built and money spent for pumping equipment. This state of affairs heralded the advent of the churn drill as a means of proving the existence of an orebody before a shaft was sunk. In the Joplin district three or four holes on a forty-acre tract was considered amply sufficient to prove or disprove the existence of a mineable deposit of ore. Many of the methods in use in the old Joplin district were changed with the discovery of the unusually rich deposits of ore found in the vicinity of Picher, Oklahoma. The author is especially familiar with the deposits of this camp, and it is with the geology and methods of prospecting in this camp that the present paper will deal. The methods of prospecting are now the same in all parts of the district, but the geology, especially the type of ore deposits, is different in the several camps of the district. With the coming of the churn drill, prospecting was put on a more exact basis, but it was not until the last few years that the operators have felt the need of more scientific prospecting. The application of geology to prospecting by the larger companies engaged in mining is only in its infancy, and it really has not had a chance to show what it can do, and how it can save the operator thousands of dollars by locating the barren areas and limiting the intensive prospecting to areas that have the best possibilities --Introduction, pages 1, 3

The transmission of pressure in the dry pressing of typical building brick and fire brick mixes as affected by the degree of pressure, physical character of mix ingredient, and the moisture content of the mix

In February, 1929, the Dry Press Committee of the National Brick Manufacturers Association, in cooperation with the department of Ceramics of the Missouri School of Mines and Metallurgy, began several investigations relating to dry press ware. This Committee suggested a great number of possible investigations, and are now systematically proceeding along these lines. This investigation has for its object: (1) The transmission of pressure in the dry pressing of typical building brick and fire brick mixes as affected by the degree of pressure; and (2) As affected by the moisture content of the mix. this thesis contains a description of equipment and raw materials used, and a detail of the testing methods --Introduction, page 1

The Levantine Basin - crustal structure and origin

The origin of the Levantine Basin in the Southeastern Mediterranean Sea is related to the opening of the Neo-Tethys. The nature of its crust has been debated for decades. Therefore, we conducted a geophysical experiment in the Levantine Basin. We recorded two refraction seismic lines with 19 and 20 ocean bottom hydrophones, respectively, and developed velocity models. Additional seismic reflection data yield structural information about the upper layers in the first few kilometers. The crystalline basement in the Levantine Basin consists of two layers with a P-wave velocity of 6.06.4 km/s in the upper and 6.56.9 km/s in the lower crust. Towards the center of the basin, the Moho depth decreases from 27 to 22 km. Local variations of the velocity gradient can be attributed to previously postulated shear zones like the Pelusium Line, the DamiettaLatakia Line and the BaltimHecateus Line. Both layers of the crystalline crust are continuous and no indication for a transition from continental to oceanic crust is observed. These results are confirmed by gravity data. Comparison with other seismic refraction studies in prolongation of our profiles under Israel and Jordan and in the Mediterranean Sea near Greece and Sardinia reveal similarities between the crust in the Levantine Basin and thinned continental crust, which is found in that region. The presence of thinned continental crust under the Levantine Basin is therefore suggested. A β-factor of 2.33 is estimated. Based on these findings, we conclude that sea-floor spreading in the Eastern Mediterranean Sea only occurred north of the Eratosthenes Seamount, and the oceanic crust was later subducted at the Cyprus Arc

Investigations to determine a possible source of the Carboniferous sandstone of the Ozark region

In preparing this thesis the object has been to determine, by comparisons, a possible source of the Carboniferous sandstones. It is perfectly obvious that the material came from some older formation. Considering all the possible sources from which the Carboniferous sandstone could have originated, we, have the Pre-Cambrian igneous rocks of the St. Francois Mountains, the basal Cambrian sandstone or the La Motte formation, the Roubidoux formation (chiefly sandstone), and the St. Peter formation (essentially sandstone) --Introduction, page 4

Episodic methane concentrations at seep sites on the upper slope Opouawe Bank, southern Hikurangi Margin, New Zealand

Along many active and some passive margins cold seeps are abundant and play an important role in the mechanisms of methane supply from the subsurface into seawater and atmosphere. With numerous cold seeps already known, the convergent Hikurangi Margin east of North Island, New Zealand, was selected as a target area for further detailed, multidisciplinary investigation of cold seeps within the New Vents and associated projects. Methane and temperature sensors (METS) were deployed at selected seep sites on the Opouawe Bank off the southeastern tip of North Island and near the southern end of the imbricate-thrust Hikurangi Margin, together with seismic ocean bottom stations. They remained in place for about 48 h while seismic data were collected. The seeps were associated with seep-related seismic structures. Methane concentrations were differing by an order of magnitude between neighbouring stations. The large differences at sites only 300 m apart, demonstrate that the seeps were small scale structures, and that plumes of discharged methane were very localised within the bottom water. High methane concentrations recorded at active seep sites at anticlinal structures indicate focused fluid flow. Methane discharge from the seafloor was episodic, which may result from enhanced fluid flow facilitated by reduced hydrostatic load at low tides. The strong semi-diurnal tidal currents also contribute to the fast dilution and mixing of the discharged methane in the seawater. Despite dispersal by currents, fluid flow through fissures, fractures, and faults close to the METS positions and tidal fluctuations are believed to explain most of the elevated methane concentrations registered by the METS. Small earthquakes do not appear to be correlated with seawater methane anomalies

a seismic investigation of the crustal structure and the evolution of the Messinian evaporites

The Levantine Basin - a seismic investigation of the crustal structure and the evolution of the Messinian evaporites ABSTRACT This work presents an analysis of the crustal structure of the Levantine Basin, based on refraction seismic and gravity data, and an analysis of the evolution of the Messinian evaporites, based on reflection seismic data. Forward and inverse modelling of refraction seismic traveltimes along two profiles yielded 2-D velocity-depth-profiles. Gravity modelling along these profiles provided further information on the crustal structure. A great number of reflection seismic profiles was used for the analysis of the Messinian evaporites, which allowed an exhaustive investigation of the geometry of the evaporite layers, depositional phases of the evaporites and of their structural evolution. The Levantine Basin is located in the Southeastern Mediterranean Sea. The basin and its margin are key areas for the understanding of the geodynamic evolution of the Eastern Mediterranean. The opening of the Levantine Basin is closely related to the opening of the Neo-Tethys. Many geodynamic reconstructions of this area have been developed, but the key question, the origin of the crust, remained open. The Levantine Basin is also a world class site for studying the initial stages of salt tectonics driven by differential sediment load. The Messinian evaporites are comparatively young (deposited during the Messinian Salinity Crisis 5.9 - 5.3 Ma ago), the sediment load varies along the basin margin, they are hardly tectonically overprinted, and the geometry of the basin and the overburden is well-defined...thesi

The structures beneath submarine methane seeps : seismic evidence from Opouawe Bank, Hikurangi Margin, New Zealand

The role of methane in the global bio-geo-system is one of the most important issues of present-day research. Cold seeps, where methane leaves the seafloor and enters the water column, provide valuable evidence of subsurface methane paths. Within the New Vents project we investigate cold seeps and seep structures at the Hikurangi Margin, east of New Zealand. In the area of Opouawe Bank, offshore the southern tip of the North Island, numerous extremely active seeps have been discovered. High-resolution seismic sections show a variety of seep structures. We see seismic chimneys either characterised by high-amplitude reflections or by acoustic turbidity and faults presumably acting as fluid pathways. The bathymetric expression of the seeps also varies: There are seeps exhibiting a flat seafloor as well as a seep located in a depression and small mounds. The images of the 3.5 kHz Parasound system reveal the ear-surface structure of the vent sites. While highamplitude spots within the uppermost 50 m below the seafloor (bsf) are observed at the majority of the seep structures, indicating gas hydrate and/or authigenic carbonate formations with an accumulation of free gas underneath, a few seep structures are characterised by the complete absence of reflections, indicating a high gas content without the formation of a gas trap by hydrates or carbonates. The factors controlling seep formation have been analysed with respect to seep location, seep structure, water depth, seafloor morphology, faults and gas hydrate distribution. The results indicate that the revailing structural control for seep formation at Opouawe Bank is the presence of numerous minor faults piercing the base of the gas hydrate stability zone

Integrated side-scan, sub-bottom profiler and seismic signatures of methane seepage from Omakere Ridge on New Zealand’s Hikurangi margin

Omakere Ridge is one of a series of prominent northeast-southwest orientated anticlinal ridges associated with major thrust faults on New Zealand’s Hikurangi margin. The Hikurangi margin is an extensive gas hydrate province and recent marine surveys have confirmed that the mid-slope Omakere Ridge is a zone of methane-rich seabed seepage. Acoustic flares initially observed in the area by fishermen, were imaged in the water column at Omakere Ridge during a 2006 RV Tangaroa survey (TAN06-07). Anomalous methane concentrations (up to 165 nM) were detected by a methane sensor (METS) attached to a conductivity-temperature-depth-optical backscatter device (CTD) on TAN06-07 and a 2007 RV Sonne survey (SO-191). Six seep sites have been identified at the southern end of Omakere Ridge, where it bifurcates into two parallel ridgelines. All sites are located towards the crests of the two ridgelines in approximately 1150 m water depth. The seabed seeps were identified acoustically with an EdgeTech Deep-Tow side-scan operating at 75 kHz, and are shown as high backscatter intensity areas on processed side-scan data, which are interpreted to be methane derived authigenic carbonate hardgrounds. Acoustic shadows behind hardgrounds in the side-scan far range suggest the seabed features have moderate relief. Sub-bottom profiles acquired with an EdgeTech Deep-Tow chirper system, operating at 2-10 kHz, identified numerous signatures of shallow gas in the near subsurface. These signatures include zones of acoustic turbidity and gas blanking, interpreted to mark shallow gas fronts. The evidence for shallow gas in the subsurface from the sub-bottom profiler displays a marked spatial correlation with seabed expressions of seepage. The seepage sites also correspond to potential gas indicators in multi-channel seismic data, such as interpreted amplitude anomalies. Enigmatic subsurface features in the subbottom profiler data, such as potential amplitude anomalies and gas blanking, which are below the depression that bifurcates the ridge and are not associated with surface expressions of seepage, may represent lithological and topographic features or may be a component of the gas migration pathway which feeds the seeps on the ridge crest. Underwater video and still camera images show seabed seepage sites of high backscatter intensity represent widespread authigenic carbonate concretions and chemoherms associated with biological assemblages including siboglinid tube worms, vesicomyid clams, bathymodiolin mussels, and bacterial mats. A high backscatter intensity site of similar acoustic character to, and directly adjacent to, seep sites on the southern part of the ridge does not contain seep fauna and is interpreted to be a cold-water reef. While this feature may represent a relict seep, this finding highlights the fact that present day seepage cannot be identified with acoustic techniques alone

Acoustic and visual characterisation of methane-rich seabed seeps at Omakere Ridge on the Hikurangi Margin, New Zealand

Six active methane seeps and one cold-water reef that may represent a relict seep were mapped at Omakere Ridge on New Zealand's Hikurangi Margin during cruises SO191 and TAN0616. Hydroacoustic flares, interpreted to be bubbles of methane rising through the water column were identified in the area. The seep sites and the cold-water reef were characterised by regions of high backscatter intensity on sidescan sonar records, or moderate backscatter intensity where the seep was located directly below the path of the sidescan towfish. The majority of sites appear as elevated features (2–4 m) in multibeam swath data. Gas blanking and acoustic turbidity were observed in sub-bottom profiles through the sites. A seismic section across two of the sites (Bear's Paw and LM-9) shows a BSR suggesting the presence of gas hydrate as well as spots of high amplitudes underneath and above the BSR indicating free gas. All sites were ground truthed with underwater video observations, which showed the acoustic features to represent authigenic carbonate rock structures. Live chemosynthetic biotic assemblages, including siboglinid tube worms, vesicomyid clams, bathymodiolin mussels, and bacterial mats, were observed at the seeps. Cold-water corals were the most conspicuous biota of the cold-water reef but widespread vesicomyid clam shells indicated past seep activity at all sites. The correlation between strong backscatter features in sidescan sonar images and seep-related seabed features is a powerful tool for seep exploration, but differentiating the acoustic features as either modern or relict seeps requires judicial analysis and is most effective when supported by visual observations