Abstract by Ryan Chadburn
TESTING THE HYPOTHESIS OF A MEGA-SCALE LANDSLIDE ORIGIN FOR THE EAST TRAVERSE MOUNTAINS, UTAH - EVIDENCE FROM MINERALS
The East Traverse Mountains (ETM) form a topographic salient on Utah’s Wasatch fault zone. We propose the ETM is a mega-scale landslide block, 57 km2 in size, that slid 16 km westward from the upper reaches of the Oligocene Little Cottonwood stock (LCS) to its current location. One avenue of testing this hypothesis is to examine the alteration and unique accessory minerals of pebble dikes from the top (ETM) and bottom (LCS) of this porphyry Mo-W mineralized magmatic system.
The Little Cottonwood stock contains a younger central phase, the White Pine (WP), which is slightly less mafic than normal LCS. It hosts a sub-economic, broadly-distributed porphyry molybdenum deposit. This phase was intruded, fractured, and altered roughly with quartz, sericite, and pyrite (QSP). Within the mineralized system, a small intrusion is exposed, the Red Pine Porphyry. Heavy mineral separates from the WP contain pyrite, molybdenite, uranothorite, green Fe-poor titanite as well as yellow Fe-rich titanite, and zircon.This unique assemble of minerals give petrographic evidence that the East Traverse Mountain block was once stratigraphically above the White Pine of the LCS.