Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Paleomagnetic analysis was conducted on over 1100 specimens from 91 sites collected from a transect of Paleozoic carbonates in Illinois, Kentucky and Tennessee and from mineralization in the central Tennessee Mississippi Valley-type (MVT) zinc-lead ore district. Three characteristic remanence components (ChRMs), termed A, B and C, were observed. The oldest, A, was found in 24 sites of early Paleozoic, fine-grained dolostones from Tennessee and Kentucky. It means pole, after reversal to its antipodal positions, of 126.9{dollar}\sp\circ{dollar}E, 46.1{dollar}\sp\circ{dollar}N, ({dollar}\delta p\ =\ 1.5\sp\circ ,\ \delta m\ =\ 3.0\sp\circ{dollar}) is concordant to the "Kiaman" reserved superchron portion of the Permian apparent polar wander (APW) path for North America. The A ChRM is probably related to the pervasive regional dolomitization that completely surrounds the central Tennessee MVT ore district. The B ChRM, found in 14 sites of MVT ore-stage mineralization, is also dominantly reversed, and gives a pole position of 111.9{dollar}\sp\circ{dollar}E, 50.5{dollar}\sp\circ{dollar}N, ({dollar}\delta p\ =\ 1.7\sp\circ ,\ \delta m\ =\ 3.5\sp\circ{dollar}). It falls on the Permian-Triassic boundary of the North American APW path and is both statistically different from, and younger than, A. Therefore, B is primary and dates the genesis of the mineralization in the central Tennessee ore district. The C ChRM was found at 19 sites in the northwestern part of the transect. Its pole position of 102.7{dollar}\sp\circ{dollar}W, 80.8{dollar}\sp\circ{dollar}N, ({dollar}\delta p\ =\ 5.1\sp\circ ,\ \delta m\ =\ 6.4\sp\circ{dollar}) falls on the present Earth's magnetic pole position and hence it is probably less than 10,000 years old. Successfully defining these three ChRMs, both geographically and temporally, shows that paleomagnetism can be used to date and map fluid-flow events in sedimentary basins.;Bingham statistics were applied to the data for the A and B ChRM directions to examine the process of MVT mineralization. The azimuth and amount of bias of the A and B ChRMs show that host rock remagnetization (and probably pervasive dolomitization) predated mineralization by about 20 Ma and that the ore deposit formed in about 10 Ma. Bingham analysis for five other North American MVT ore districts also shows that the remagnetization of the host rocks was a precursor to the mineralization and that mineralization required {dollar}\sim{dollar}25 Ma on average.



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