论文部分内容阅读
华盛顿州东北部Flodelle Creek汇水盆地的北支流赋存着美国第1个已开采的表生铀矿床。铀从花岗质基岩中淋滤出来,并吸附于富有机质的水池沉积物中。这些水池沉积物和铀的分布,均受冰川残留地形、坡度和海狸活动等的强烈影响。Flodelle Creek汇水盆地的北支流在Fraser(晚威斯康星冰期)冰川作用时被科迪勒拉冰席覆盖。冰碛物和冰水沉积物由于冰川的后退而堆积在谷坡和谷底上。
The northern tributaries of the Flodelle Creek catchment basin in northeastern Washington state host the first mined epigenic uranium deposit in the United States. Uranium is leached from the granite bedrock and adsorbed to organic-rich pool sediments. The distribution of these pool sediments and uranium are strongly influenced by residual glacier topography, slope and beaver activities. The northern tributaries of the Flodelle Creek catchment basin are covered by Cordillera ice sheets during the Fraser Glacier (Late Wisconsin Ice Age). Moraine and ice deposits accumulate on the valley slopes and valleys due to glacial retreat.