July 2012 CFMS Field Trip

CFMS FIELD TRIPS–SOUTH PALOS VERDES, CA  July 28, 2012 – Saturday 8:00 am - 4:30 pm

This field trip will be a day trip near the ocean at Palos Verdes, CA. There will be 3 sites to collect at. You can go to all the sites or just a few. I have each site time where we will be at if you meet us later in the day. I have detailed maps of all the sites and I would recommend contacting me or go to the CFMS web site for the maps. There will be CFMS signs on my truck, white Ford F-250 crew cab. At each site there will be a brief information meeting about the site and I will bring samples of what to find. We will meet at the first site at Bluff Cove 8:00 am.                                                                                                                                                                                                                                               SITE 1: Glaucophane and Agate location. 8:00-10:30am (Bluff Cove, about 300 yards long switch back to bottom, Medium hike) We will be looking for Glaucophane and agate amongst the beach rocks.

SITE 2: Barite locations for well-formed crystals. 11:00am-1:30pm (about 100 yards switch back to bottom, Medium hike) Once down on the beach we will walk about 200 yards to the dig site. You can collect along the beach, the best stuff you will need to climb up the hill about 100 feet.

SITE 3: Livingstone Quarry for Dog-Tooth Dolomite, Selenite. 2:00-4:30pm. We will go to two collecting sites: first for selenite, walking along on paths about 100 yards from where we parked. For the best selenite you will climb about 100 feet up a hill. After about an hour we will walk on paths about 100 yards to the dog-tooth dolomite. There is surface material or you can use rock pick, chisels to dig.                                                                               

WHAT TO BRING: Sunscreen, large brim hat, shovel, rock hammer or pick, gad or chisel, sledges, collecting bags, buckets, day pack, eye protection, sturdy shoes, drinking water, lunch, newspaper to wrap your rocks.

DIRECTIONS TO SPECIFIC SITES:

SITE 1 - GLAUCOPHANE and AGATE: Head SOUTH on the 405 Freeway, EXIT at the Hawthorne Blvd. Turn right, south on Hawthorne Blvd travel about 7 miles. Turn right, west to Palos Verdes Drive North travel about 2.2 miles make a slight left west to Palos Verdes Drive West travel about 1 mile. Turn right, west to Paseo Del Mar, travel about 1/8 mile. There will be a parking area on the west side of the road, toward the ocean, park there.

SITE 2 - BARITE and SELENITE: From site 1 Paseo Del Mar turn right, south to Palos Verdes Drive West turning into Palos Verdes Drive South travel about 4.9 miles. There will be a large parking lot on the south side of the road, toward the ocean, park there.

SITE 3 - DOG-TOOTH DOLOMITE and SELENITE: From site 2 Palos Verdes Drive South turn right, east travel about 3.5 miles Turn left, north to Forrestal Dr. Travel about 1/4 mile. Park on the side of the road before the gate, they close the gate and you might get locked in.

*Please let me know if you are going to go on the field trip, weather changes. If I don't know you're going on the field trip, I won’t be able to contact you if the field trip is canceled. Even if you might not go, still contact me for the information and maps. Don't wait until the day before.

CONTACTS: For maps, more info & sign up: Robert Sankovich; rmsorca@adelphia.net, (805) 494-7734 or Adam Dean; theagatehunter@verizon.net, (909) 489-4899

                                                                                                                 

July 2012 Rock of the Month

Sandstone

Sandstone (sometimes known as arenite) is a sedimentary rock composed mainly of sand-sized minerals and rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, gray, pink, white and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions.

Rock formations that are primarily composed of sandstone usually allow percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are more apt to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity.

Sandstone is mined by quarrying. It is sometimes found where there used to be small seas. It is usually formed in dry places like the Sahara Desert in Africa, the Arabian Desert in the Middle East and the Australian Desert including Sydney. In the western United States and in central Australia, most sandstone is red.    

     Sandstone is converted into quartzite through heating and pressure related to tectonic compression.

June 2012 Rock of the Month

Shale 

 Shale is a fine-grained sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny silt-sized particles of other minerals, especially quartz and calcite. The typical color is gray. The process in the rock cycle which forms shale is called compaction. The fine particles that compose shale can remain suspended in water long after the larger and denser particles of sand have deposited. Shales are typically deposited in very slow moving water and are often found in lakes, in river deltas, on floodplains and offshore. They can also be deposited on the continental shelf, in relatively deep, quiet water. This process would have taken millions of years to complete. Fossils, animal tracks and even raindrop impact craters are sometimes preserved on shale bedding surfaces. Shales that are subject to the heat and pressure of metamorphism alter first into slate. With the continued increase in metamorphic grade, the slate then becomes schist and finally it will become gneiss.

June 2012 General Meeting Program

Come step outside your comfort zone! Learn something new in the world of lapidary. See how to make a gemstone box. Learn how to make a cabochon. Learn how to create an illuminated mosaic gemstone table. Try your hand at wire wrapping and more. Select club members will be demonstrating and teaching some of their favorite tips and techniques so you too can create a gemstone masterpiece.

 Our next general meeting will be on Thursday June 07, 2012

The Meeting Begins At 7:30 PM In Our Regular Meeting Room At:

Northridge United Methodist Church

9650 Reseda Blvd, Northridge, CA 91324

Guests Are Always Welcome At Our Meetings & Events.

                                                  

May 2012 Rock of the Month

Meteorites & Tektites

 

A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. A meteorite's size can range from small to extremely large. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids. When a meteoroid enters the atmosphere frictional, pressure and chemical interactions with the atmospheric gasses cause the body to heat up and emit light thus forming a fireball, also known as a meteor or shooting star. The term bolide refers to either an extraterrestrial body that collides with the Earth, or to an exceptionally bright, fireball-like meteor regardless of whether it ultimately impacts the surface. As of February 2010, there are approximately 1,086 witnessed falls having specimens in the world's collections. In contrast, there are over 38,660 well-documented meteorite finds. Meteorites have 

traditionally been divided into three broad categories: stony meteorites are rocks, mainly composed of silicate minerals; iron meteorites are largely composed of metallic iron-nickel; and, stony-iron meteorites contain large amounts of both metallic and rocky material.

Tektites are natural glass rocks up to a few centimeters in size, which most scientists argue were formed by the impact of large meteorites on Earth's surface. Tektites are typically black or olive-green, and their shape varies from rounded to irregular. Tektites are among the "driest" rocks, with an average water content of 0.005%. This is very unusual, as most, if not all, of the craters where tektites may have formed were underwater before impact. Also, partially melted zircons have been discovered inside a handful of tektites. This, along with the water content suggests that the tektites were formed under phenomenal temperature and pressure not normally found on the surface of the Earth.