| Text Description: |
Present at Site A and Site B of Chester Bluff. Slaven's Roadhouse (SR) tephra, in contrast to Site B, is present 2m above the reworked PrH/MC tephra beds at Site A whereas SR tephra is below PrH/MC tephra at Site B. SR is heavily faulted, reworked and dipping steeply at Site A. Loess associated with the reworked SR is strongly mottled, Fe-stained, and includes small organic horizons that are reworked and overturned. Solifluction may have caused the mottling and overturning of the tephra beds or, alternatively, a faulted block of silt may have obscured the true stratigraphic position of the tephra beds. At Site B, SR is 2m above BP and is the lowest of six tephra beds, Tom King (TK), MC, PrH, Ben Creek (BC) and Yukon Tanana (YT), found within 2m of one another. SR, TK, MC and PrH are deposited within greyish brown loess 0.5 to 1m below a major organic unit that contains BC and YT. At the downstream end of the 6m lateral section the tephra beds are reworked and faulted downward. At the upstream end, the major organic unit above SR, TK, MC and PrH is deformed along its base, causing the tephra beds to be overturned and partially reworked into the base of the unit. A 6m wide trench was excavated to fully delineate the tephrostratigraphic relations of the six tephra beds. SR is distinctly white, forming wispy pods up to 2mm thick and 3 cm long that are continuous across the trench. Glass morphology that contains bubble-walled and tri-cuspate shards, but also frothy inflated pumice. Contaminated with detrital material, making it difficult to determine phenocryst populations. The composition reported was calculated from analyses of six samples: UA1058, UA1073, UA1074, UA1215, UA1220, and UA1225. |