Cinder cone distribution described using cluster analysis and two-dimensional Fourier analysis in the central transMexican Volcanic Belt, Mexico, and in SE Guatemala and NW El Salvador

Cinder cone distributions in the central TransMexican Volcanic Belt (TMVB) and in SE Guatemala - W El Salvador are analyzed using two techniques new to volcano distribution studies: cluster analysis and two-dimensional Fourier analysis. These methods prove to be effective in identifying structures in cinder cone distributions within the two study areas. The observed structures are related to the distribution of shield and stratovolcanoes, the distribution of topographic lineaments and their orientations, cinder cone petrology, and plate tectonic setting.;Regional cinder cone alignments are recognized for the first time within two large modal clusters using 2-d Fourier analysis. These cinder cone clusters are located in the southwestern central TMVB, approximately 220 km from the trench. It is inferred that these regional cinder cone alignments are related to fracture zones, which ease the migration of magma through the crust. Regional cinder cone alignments are not found within clusters at greater trench - field distances, although topographic lineaments and local cinder cone alignments are more common.;In SE Guatemala - W El Salvador, 263 cinder cones and maars are identified on 52 gradrangles. In this area, 84% of the cinder cones are found within four modal clusters. Regional cinder cone alignments are identified in the Ipala cinder cone field. These regional alignments are oriented N50-60E, parallel to and colinear with regional shear zones, such as the Rio Paz shear zone. Regional cinder cone alignments are not oriented N-S, parallel to the Ipala Graben, although local cinder cone alignments are frequently oriented N-S.;It is speculated that cinder cone magmas rise diapirically in the lower lithosphere because: (a) cinder cones tend to be emplaced in clusters, (b) geobarometers do not indicate rapid transport from depths of greater than 30 km, although the crust in both areas is thought to be 40 km thick, (c) no mantle xenoliths have been reported from the lavas of either area, (d) cinder cone clusters tend to be spaced uniformly and form trigonal patterns. These magmas are dispersed by regional and finally local structures as they reach depths of 25-30 kn in the crust. (Abstract shortened with permission of author.).;A total of 1016 cinder cones and maars are identified on 119 quadrangle maps in the central TMVB.