Detrital Thermochron Alaska (Detrital Insight Alaskan Ranges (Detrital…
Detrital Thermochron Alaska
Alaska - glaciated terrane mystery
Little known about what goes on beneath ice i.e. bedrock
Alaska Ranges = tectonically complex w lotsa faults beneath ice
Bedrock age distribution
Inland = older
Toward margin = younger (near fault)
Theory: Subglacial flow of material ?
Around Malaspina Glacier
v young ages
(> 40% grain age distribution)
Where are they coming from ?
Seaward throat of ice funnels material from fault inland
which Malaspina Glacier cuts across ?
What's happening beneath ice field?
Crosses highest peak elevations & indenter corner orogen
Cuts through Central part of fold & thrust belt & Wranger Range
Young ages coincide with topographic lows
Bedrock msmts apatite & zircon thermochronometry
How well does detrital record represent bedrock erosion?
Detrital Insight Alaskan Ranges
Detrital material ages sheds light on
Fault structure activity
Erosion in subglacial envmt --> erosion is signif
(interconnectivity of subglacial drainage)