Archive for April 12th, 2015

Geomorphology at Fern Valley and along the Little Killbuck

April 12th, 2015

group_fernThe group at Fern Valley. Gaging Wilkin Run and measuring water levels in wells. We are fortunate to be able to monitor the streamflow, climate and geomorphic changes along Wilkin Run. Thanks again to Betty and David Wilkin for donating Fern Valley to the College.

leo_icsdLeo examining the Ice Contact stratified drift of the terminal moraine that in part lies across Fern Valley. This deposit records the Laurentide’s ice sheet advance into the proglacial Odell Lake (note the gray lacustrine clays and silts to Leo’s left). The exposure is capped with loess – the parent material of the soils here.

wellA well installed in the middle of the Run indicates whether the stream is gaining or losing. It is confusing at first.

gagingThe Archaeology team measures the velocity profile at Fern Valley. Note the terrace in the background, most of this sediment is eroded soils – likely introduced over the past few hundred years – so-called Legacy sediments.

deltaDescribing the stratigraphy along the Little Killbuck Valley – this is a delta – topsets (note the channel fills at the top) and foresets (The students are standing on the foreset beds, the foresets are muddy and weathered because the local bedrock is weathered shale and there was some rain falling that day) – the bottomsets are shown below.

lacustrineThe bottomset beds Рgray silts to the right.  Jim navigates a modern mudflow fan on his way to the colluvium that  lies above the bedrock contact.