DEPOSITIONAL ANALYSIS OF A BOULDER-RICH DIAMICTITE, WITMARSUM, PARANÁ STATE, BRAZIL
Grain size analysis of the matrix’s composition, roundness, and sphericity was conducted on the one phi grain size fraction. These analyses have also been conducted at a similar correlative outcrop approximately 4 meters away to compare conclusions. Adobe Illustrator was used to trace clasts and a clast size ratio of 3:2 was used for apparent orientation analysis. Apparent orientation and sediment analysis will help determine the depositional environment of the diamictites of Witmarsum.
Matrix samples were quartz dominated indicating that the Furnas Formation was incorporated into much of the diamictite. Roundness and sphericity were similar indicating no changes in provenance. A near-horizontal clast orientation is apparent, suggesting that the diamictite was deposited as a debris flow in a subaqueous environment.
Research for this study was funded by a grant from the N.S.F.-R.E.U. Program (NSF-EAR-1262945).