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Categorical Data Analysis
Published in William M. Mendenhall, Terry L. Sincich, Statistics for Engineering and the Sciences, 2016
William M. Mendenhall, Terry L. Sincich
Study of orocline development. In Tectonics (Oct. 2004), geologists published their research on the formation of oro-clines (curved mountain belts) in the central Appalachian mountains. A comparison was made of two nappes (sheets of rock that have moved over a large horizontal distance), one in Pennsylvania and the other in Maryland. Rock samples at the mountain rim of both locations were collected and the foliation intersection axes (FIA) preserved within large mineral grains was measured for each. The accompanying table shows the number of rock samples in the different FIA measurement categories at the two locations. The geologists tested whether the distribution of FIA trends were the same for the Pennsylvania Nappe and Maryland Nappe using a chi-square test of independence.
Paleomagnetism of the Carboniferous Gresford Block, Tamworth Belt, southern New England Orogen: minor counter-clockwise rotation of a primary arc segment
Published in Australian Journal of Earth Sciences, 2020
The Tasmanides of eastern Australia (Champion, 2016; Champion, Kositcin, Huston, Mathews, & Brown, 2009; Glen, 2005, 2013; Glen, Belousova, & Griffin, 2016; Jessop, Daczko, & Piazolo, 2019; Rosenbaum, 2018) stand out as the widest segment of Terra Australis, the Paleozoic orogen that extended for nearly half an earth’s circumference along the paleoPacific margin of Gondwana (Cawood, 2005) (Figure 1). Its width reflects structural duplications through a remarkable concentration of oroclinal structures, in, from west to east, the Delamerian Orogen (Musgrave, 2015; Shaanan, Rosenbaum, & Sihombing, 2018), Thomson Orogen (Abdullah & Rosenbaum, 2018; Doublier, Purdy, Hegarty, Nicoll, & Zwingmann, 2018; Glen, 2005, 2013; Harrington, 1974), Lachlan Orogen (Cayley, 2012; Cayley & Musgrave, 2015; Dunstan, Rosenbaum, & Babaahmadi, 2016; Moresi, Betts, Miller, & Cayley, 2014), and, in particular, the southern New England Orogen (Cawood, Leitch, Merle, & Nemchin, 2011; Flood & Fergusson, 1982; Glen & Roberts, 2012; Korsch & Harrington, 1987; Phillips, Robinson, Glen, & Roberts, 2016; Rosenbaum, 2012a, 2018). Why did so many oroclinal structures develop in the southern and central Tasmanides? The southernmost Lachlan oroclines have been attributed to a northward indenting VanDieland (Cayley, 2012; Cayley & Musgrave, 2015). Most other oroclines are located near to and mainly to the south of a major orogen-crossing structure in the central Tasmanides (Abdullah & Rosenbaum, 2017, 2018; Burton, 2010; Dunstan et al., 2016; Glen et al., 2013; O’Sullivan, Kohn, & Mitchell, 1998; Rosenbaum, 2018) that includes the Darling Lineament and Cato fracture zone and may extend across eastern Gondwana (Figure 1; Klootwijk, 2013). Orocline formation may be an inherent feature of differential backarc development along the developing Terra Australis Orogen (Moresi et al., 2014; Rosenbaum, 2018), and/or driven by changes in plate motions (Cawood & Buchan, 2007; Klootwijk, 2013). It is an open question as to what extent displacements along this major shear zone, during middle–late Paleozoic in particular, may have contributed to this inordinate development of oroclinal structures in the central and southern Tasmanides.