https://theses.otagogeology.org.nz/files/original/9d35ce56d9e030408b577e2c62f7f3a6.pdf 5b1fcef94b00f41d957b6cf3461b44a2 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 Location WKT (WGS84) The location stored in WKT (WGS84) format POLYGON ((169.843932088292917 -44.865329939080048,169.8506967159542 -44.750475080303403,169.9595647268508 -44.749140835097755,169.956916995764857 -44.866255759474939,169.843932088292917 -44.865329939080048)) Author last name Last name of the Author Hughes Project type Is it an MSc, PhD, BSc(Hons) or PGDipSci? BSc(Hons) Advisers Who supervised/advised this student Koons, P. Abstract The Abstract for this thesis Gravity models provide evidence for extensive thrusts on two fault systems in the Hawkdun Basin. Central Otago. These sets of faults trend northwest and northeast and are referred to as the Hawkdun and Manuherikia Fault Systems respectively. The gravity profiles also reveal significant basement topography which is related to these faults. The orientation of the basin margins departs from northeast and northwest trends where the Hawkdun and Manuhenkia faults do not control the range-fronts. Gravity profiles indicate low-angle sediment/ basement transition in these areas which may be original sedimentological contacts. Truncation of the northeasterly trending faults by those which trend northwest, an observation which is supported by 1:1M and 1:250 000 Bouguer anomaly maps, implies that the northwesterly trending faults were generated earlier and/or are deeper seated. Problems in removing the regional variation from the observed gravity wavelength of the values are complicated by the structures controlling the basin and structures which influence the regional gravity field. The bulk density of the sediment infilling the basin compared to the basement rock is the critical parameter tor gravity interpretation. This density contrast ranges from 0.86 to 0.6Mg/m3 based on electric drill logs. Despite constraints from these logs on density and depth to basement under the sediment, the models presented do not always fit the observed residuals. It is concluded that the problem with regional removal is compounded by three-dimensional effects from complex lateral density changes in the Hawkdun Basin. The Hawkdun and Manuherilda thrusting fault systems revealed by this study are the expression of the continuing compressional tectonic regime in New Zealand caused by the collision of the Indian and Pacific plates. Strain measurements from other regions in the South Island suggest that both sets of faults are currently active. Department The department where the student is studying primarily. Geology Named locality Named locality describing the field area location. Hawkdun Basin Thesis description Number of pages, maps, CDs, etc. 64 leaves : ill. (some col.), 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 1984Hughes Creator An entity primarily responsible for making the resource Hughes, S. L. M. Date A point or period of time associated with an event in the lifecycle of the resource 1984 Title A name given to the resource Gravity survey of the Hawkdun basin. Subject The topic of the resource Coal geology Geophysics Tectonics basin evaluation gravity survey neotectonics thrust faulting