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Going to fetch water. It's a quarter mile down and a quarter mile back up and it's pretty scenic actually. You are walking through lava rock and then you have wildflowers along the way as well. Upper photo has expiring Glacier Lilys.
PURCELL LAVA. Soon after the youngest layers of Siyeh limestone had accumulated on the floor of the sea and while they were still under water, a mass of molten rock was squeezed up from far below and extruded in the form of a submarine lava flow over the recently accumulated sediments. Several times this lava poured out forming a total thickness varying between 50 and 275 feet. One of the best exposures is on the west side of Swiftcurrent Pass and in Granite Park just west and northwest of the chalet.
In fact it is this lava flow which gives the name, albeit wrongly, to Granite Park. The material of the flow is very fine-grained and dark (basic), in contrast to the light color and coarse grain of granite. Nonetheless, many prospectors are wont to call every igneous rock, regardless of its composition, a granite. A number of ellipsoidal structures ("pillows") up to two feet in diameter within this lava indicate that it was extruded under water. The Purcell is thickest in the vicinity of Boulder Pass, where the trail traverses its ropy and stringy surface for a distance of several hundred yards.
Later, after the Shepard and part of the Kintla formation were laid down on top of the Purcell, another similar flow spread over the sea floor. https://www.nps.gov/parkhistory/online_ ... 3/sec4.htm
PURCELL LAVA. Soon after the youngest layers of Siyeh limestone had accumulated on the floor of the sea and while they were still under water, a mass of molten rock was squeezed up from far below and extruded in the form of a submarine lava flow over the recently accumulated sediments. Several times this lava poured out forming a total thickness varying between 50 and 275 feet. One of the best exposures is on the west side of Swiftcurrent Pass and in Granite Park just west and northwest of the chalet.
In fact it is this lava flow which gives the name, albeit wrongly, to Granite Park. The material of the flow is very fine-grained and dark (basic), in contrast to the light color and coarse grain of granite. Nonetheless, many prospectors are wont to call every igneous rock, regardless of its composition, a granite. A number of ellipsoidal structures ("pillows") up to two feet in diameter within this lava indicate that it was extruded under water. The Purcell is thickest in the vicinity of Boulder Pass, where the trail traverses its ropy and stringy surface for a distance of several hundred yards.
Later, after the Shepard and part of the Kintla formation were laid down on top of the Purcell, another similar flow spread over the sea floor. https://www.nps.gov/parkhistory/online_ ... 3/sec4.htm
Jul 31 2018