May 12 Geology talk at East Jefferson Rotary Club

On Thursday May 12, I'll be giving a 30-minute powerpoint presentation on the Geology of Port Hadlock, Chimacum and Irondale to the East Jefferson Rotary Club held at the Tri-Area Community Center.

This part of East Jefferson County is home to excellent beach exposures of glacial deposits, roadcuts showcasing Crescent basalt, limonite bog iron ore deposits, a monolith and more.

The local Crescent basalts have excellent vuggy yellow calcite crystals. (Photo courtesy WashingtonMinerals.com, see link for more Beaver Valley basalt quarry minerals: http://www.washingtonminerals.com/bvq.htm)

Irondale is named for the historic Irondale iron smelter, which produced iron between 1881-1919. The first iron produced at the smelter was pig iron, made from limonite iron ore (bog ore) deposits in Chimacum Valley.

The Chimacum Valley is an active organic farming community, with many exposures of Crescent Basalt visible from Highway 19 (Beaver Valley Road). There are two operating basalt quarries in the Port Ludlow and Shine areas where basalt is mined and crushed, to produce local road aggregate and landscaping rocks.

Local drinking water is supplied by municipal wells that tap into groundwater in the Sparling aquifer, a glacial deposit of coarse-grained Vashon Advance outwash. A talk dedicated to groundwater resources will be held by the local PUD on Wednesday May 25, 2011 at 6 pm, at the Tri-Area Community Center.

Tamanowas Rock - also called Chimacum Rock or Anderson Rock - is a monolith that stands 400 feet above sea level adjacent to Anderson Lake State Park. This rock is composed of adakite lava, which is a rare sort of andesite lava that is made by subducting and melting of an ocean spreading ridge. http://nwgeology.wordpress.com/the-fieldtrips/tamanowas-rock-chimacum-olympic-peninsula/

You can hear a presentation on the volcanic deposits of Tamanowas Rock by Dr. Jeff Tepper from the University of Puget Sound, Saturday June 11, 2011 from 1-2 pm at the Tri-Area Community Center. The talk is sponsored by the Jefferson Land Trust. http://www.saveland.org/Events/Event_Detail.aspx?processID=81