Spatial Distribution of Mordenite in Crowley Lake Columns

The Crowley Lake Columns formed after a rhyolitic explosion that occurred 760,000 years ago and produced the Bishop Tuff. These columns formed out of the Bishop Tuff hydrothermally which led to the precipitation of the mineral mordenite, (Na2,Ca,K2) Al2Si10O24 · 7H2O, which is a low-temperature zeolite. A previous study found mordenite in the columns but the distribution of the mineral within the columns was never analyzed. The goal of this study is to research the spatial distribution of mordenite and determine how the abundance changes within the columns. Fibrous mordenite crystals were found using SEM which confirmed its presence. Four samples, r, r/3, r/2, 0, were taken from a column that had a diameter of about 46 centimeters. The four samples were taken from 23 centimeters away from the center point (r), and then another sample from 7.6 centimeters away (r/3), another from 11.5 centimeters away (r/2), and then lastly exactly at the center (0). Those four samples that transected the column were made into a fine powder and were run in XRD and found that mordenite peaks were more prominent in the center of the column compared to the outer layer of the column. Albite was also found in the outer layer of the column but seemed to disappear in the center layer samples. This suggests that column flow may have varied with radius or that different thermodynamic conditions exist at the edge of the column than at the center