- Denny Mountain is one of the better known mineral collecting localities in Washington state, containing a wide variety of attractive skarn minerals. It is the site of the original Denny Claims which followed the contact mineralization. Originally located by Artur Denny (one of the founders of Seattle) in 1869, it was the first recorded lode in the Snoqualmie Pass area. Most of the early work there was in search of economic quantities of Iron. The grade found was fairly high in places, but the impurities in the magnetite and hematite made it useless. Some chalcopyrite was also found but the quantity was insignificant for mining.
- Tonga Plate (Wikipedia)
The Tonga Plate is a small southwest Pacific tectonic plate or microplate. It is centered at approximately 19° S. latitude and 173° E. longitude. The plate is an elongated plate oriented NNE - SSW and is a northward continuation of the Kermadec linear zone north of New Zealand. The plate is bounded on the east and north by the Pacific Plate, on the northwest by the Niuafo’ou Microplate, on the west and south by the Indo-Australian Plate. The Tonga plate is subducting the Pacific plate along the Tonga Trench. This subduction turns into a transform fault boundary north of Tonga. An active rift or spreading center separates the Tonga Plate from the Australian Plate and the Niuafo’ou microplate to the west. The Tonga Plate is seismically very active and is rotating clockwise.