1 10 2 https://theses.otagogeology.org.nz/files/original/fdf814028f135e4e6272d226dab28647.pdf bcfbde90971418ea5a4b2d48fdf7b0ab Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Geology theses OU Geology thesis Thesis or dissertation completed by University of Otago Geology students Author last name Last name of the Author Todd Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? MSc Advisers Who supervised/advised this student Craw, D. Whigham, P. Abstract The Abstract for this thesis The Wangaloa opencast coal mine was operational from 1945 to 1989. Initial rehabilitation to Pinus radiata was unsuccessful and an alternative programme was adopted in 200 1, which involved the clearing of exotic vegetation, re-contouring of overburden waste piles and the planting of approximately 70,000 native seedlings. The overall aims of this thesis were to investigate the physical hydrogeology of Wangaloa, and to gain an understanding of the factors influencing native plant revegetation at the site. A steady state hydrogeological model was constructed for Wangaloa using Visual MODFLOW. The modelled total flux of 344-351 m3/day and drain outflow of 117m3/day met the calibration criteria. There was a discrepancy of 2% between the modelled inflow and outflow. The shape of the modelled potentiometric surface was similar to contours manually interpreted from piezometer heads. However, the calculated head values poorly matched the observed values with a normalised RMS of 24%. The model was sensitive to small changes in hydraulic conductivities, recharge, evapotranspiration and boundary conditions. Overall, the model did not adequately represent the hydrogeological system at Wangaloa, and manual methods may be more appropriate. To further develop the model additional information is required, especially on the complex geology and hydraulic conductivities at the site. Substrate types at the mine site included soils and overburden with varying amounts of quartz, silt and coal. Organic matter content, moisture content and bulk density were characterised for the site based on 68 sample locations. Substrate pH was measured in December 2003, March, June and September 2004. Average pH ranged from 2.6 to 5.4 over the site. Overburden pH (2.6-5.4) was more variable than pH of the soils (4.8 to 4.7). The relatively high pH values on overburden were attributed to the application of topsoil to some areas, while the low values are due to acid mine drainage. The performance of 470 native plantings in 54 plots was examined by assigning survival ratings and measuring their size in December 2003, March, June and September 2004. Kohiihii, koromiko, manuka and wineberry were investigated to ascertain variances in performance between species. The seedlings were planted in the autumn and spring of 2003, and by September 2004 the mortality rate was 22-29%. Wineberry had a significantly higher death rate than other species, at almost 50%. Dead plants were distributed across the site in all substrate types, although, eastern mine soil plots generally had higher mortality rates. Group 1 (autumn) plantings had an average growth rate of 110% in September 2004, while Group 2 (spring) had 26%. Of the selected species koromiko grew best for both Group 1 (123%) and 2 (85%). Wineberry had the lowest growth rate for Group 1 (29%), while kohiihU had the lowest for Group 2 (8%). Spatial patterns of planting growth were more distinct than planting mortality. Overall, growth on overburden was lower than on mine soils, and eastern mine soil plots had less growth than those on western mine soils. Planting performance data and substrate properties (pH, bulk density, organic matter and moisture content) were compared using a geographical information system (GIS) and geographically weighted regression (GWR) to identify relationships between these variables. Results showed that there were no clear relationships between these substrate properties and planting mortality. In contrast, the substrate data explained on average 80% of the variation in planting growth. Other factors that were identified in this study as likely to have had some effect on planting performance included overburden versus non-overburden substrates, species selection, browsing and time of planting. It was also suggested that the level of land disturbance, distance from remnant native bush, landforms/microclimates, nutrient toxicity and/or deficiency, planting stock genetics and planting technique may have been of influence. From this study, it was apparent that there are limitations in the use of standard soil analysis techniques for mine substrates. This study highlighted the importance of considering environmental variables in combination, rather than individually, when assessing revegetation success. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Wangaloa Otago southeast Thesis description Number of pages, maps, CDs, etc. x, 161, [40] p. : ill., maps ; 30 cm. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Identifier An unambiguous reference to the resource within a given context 2005Todd Creator An entity primarily responsible for making the resource Todd, Andrea Jane. Date A point or period of time associated with an event in the lifecycle of the resource 2005 Title A name given to the resource Hydrogeology and revegetation of the Wangaloa opencast coal mine, South-east Otago, New Zealand Subject The topic of the resource Coal mining Hydrology Map coal mines environmental aspects rehabilitation https://theses.otagogeology.org.nz/files/original/161f3ed18854daecad9872df7ed8339c.pdf 53d569af8d2f58fcc8c287846076ec24 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Geology theses OU Geology thesis Thesis or dissertation completed by University of Otago Geology students Author last name Last name of the Author Hewlett Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Craw, D. Abstract The Abstract for this thesis At Reefton, mesothermal gold deposits occur in the Ordovician Greenland Group basement, and bituminous coal deposits occur in overlying Eocene Brunner Coal Measures. These different resource types occur in close proximity to one another in the '" same topography, vegetation and climate. Both types of resource/have been mined for X many years and as a result historic mining areas discharge water with chemistry reflecting the mineralogy of the deposits. Coal measures release natural acid rock drainage throughout the region due to oxidation of pyrite in coal and associated sediments. The acid generating capacity of the Brunner Coal Measures exceeds the acid neutralising capacity. Levels of acidity are increased in mining areas, and pH near 3 is common. Water discharging from coal mines contain Pb (up to 0.768 ppm), Ni (up to 0.08 ppm), Zn (up to 1.36 ppm) and Cu (up to 0.286 ppm). Gold mines contain pyrite, arsenopyrite and stibnite. Discharge waters from these sites have pH near 7 because of the high acid neutralizing capacity of the basement rocks. Water discharging from gold mines contains elevated As (up to 58.9 ppm), Ni (up to 0.271 ppm), Zn (up to 0.83 ppm), Sb (0.106 ppm), Cu (up to 0.121 ppm), Fe (up to 486 ppm). Both coal and gold mining sites have iron oxyhydroxide precipitates in drainage waters. These precipitates are more abundant at gold mining sites, and one deposit is up to 5m thick. Hydrated Iron Oxides (HFO) occurs in discharge from coal mines but occurs in . smaller quantities and often downstream from the source. Gold mine iron oxyhydroxide contains Zn (up to 353 ppm), Ni (up to 592 ppm), Cr (up to 17 ppm), Cu (up to 72 ppm), Pb (up to 29 ppm), Sb (up to 1180 ppm) and this material is particularly high in As (up to 20 wt%). Most of the material is amorphous but distinctive zones (mm scale) are As rich (up to 30 wt% As oxide). Pharmacosiderite, K2Fe4(As04)3 (OH)5.6.3H20, is a secondary mineral in one deposit. These iron oxyhydroxide deposits are useful indicators for the metals mobilised into the environment by oxidation in the historic workings. Iron oxyhydroxide at coal mine sites contain Zn (up to 89 ppm), Ni (up to 10 ppm), As (up to 163 ppm), Cr (up to 23 ppm), ,)9Jup;-t'\ 16), and Cu (up to 11 ppm). J arosite group minerals, schwertmannite, an~ g~dt~i!~)lave been identified in the coal mine iron '- ----- oxyhydroxide, although much of the material is amorphous. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Reefton Thesis description Number of pages, maps, CDs, etc. xiv, 204 leaves : ill. (some col.), maps (some col.) ; 30 cm. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Identifier An unambiguous reference to the resource within a given context 2003Hewlett Creator An entity primarily responsible for making the resource Hewlett, Lucy (Lucy Hewlett) Date A point or period of time associated with an event in the lifecycle of the resource 2003 Title A name given to the resource Environmental geology of gold and coal mines, Reefton, New Zealand Subject The topic of the resource Metal-ore deposits coal mines gold mines