www.cochisecountyrock.org
“Finding and Grinding Rocks in Cochise County, Arizona since 1962”
March 2007
This issue edited by Don Hammer
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We Value Your Membership
Our records indicate you have not paid your dues. If you have decided to drop your membership in the Club please reconsider. If you have just overlooked paying your dues, please pay immediately. We do not want to drop you from the membership list. This will be your last newsletter unless your dues are paid by March 15.
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Veteran geologist Bill Burton will talk on mineral exploration in Arizona at the March Sunsites Gem and Mineral Club meeting. Mr. Burton earned his Bachelors at the University of Washington and his Masters at UCLA. He did mineral exploration for 35 years with Cypress Minerals much of which was targeting deposits of copper and gold in Arizona. He will give an overview of how a geologist looks at a potential mine from several different levels, examining the geology of the region and district as well as the specific property and its mineralization. He will relate some of his adventures in Arizona as well as describe some of the geological features and mines of Cochise County.
February Field Trip
On Saturday February 17 nine members and three guests assembled in the Community Center parking lot, loaded into three vehicles and caravaned to the Bisbee Mining and History Museum. The new Smithsonian exhibit featured more different kinds of copper minerals than any of us had imagined and many one of a kind specimens collected by the owners of the Bisbee copper mines and donated to the Smithsonian Institution. Some of the specimens were apparently new to science since they were named after the mine owners, i.e. Douglasite, Shattuckite, etc. None of us questioned the attendant’s statement that the collection was worth over a million dollars. A really amazing collection for a small town museum. If you haven’t seen it, it is well worth the trip.
We will go to Dry Canyon in the Whetstones for fossils. Meet in the truck parking lot of Gas City (I-10, Exit 302) on Highway 90 in Benson at 9:00 am on Sunday March 18 and plan to leave promptly at 9:15 so we can arrive at the site by about 10. Turn left into the parking lot at the stoplight and then right into the truck parking area. A high clearance but not 4WD vehicle is needed unless it rains when 4WD is needed. Some of the turns are tight so if you have a choice of a short versus long wheel-base vehicle use the shorter one. We will be collecting grey shale rocks with attached or embedded fossils of corals, crinoids and bivalves. Most are just lying on the surface. Bring light digging tools, bags or pails, lunch, water and lawn chairs.
Gem and Mineral Club Meeting Minutes
February 12, 2007
Vice President Jack Weller called the meeting to order. Paul McKnight was out of the country at this time. We welcomed guests and new members to the club.
There were no questions, corrections, or changes for the minutes printed in the newsletter. Larry made a motion to accept the minutes. Dick Yeager seconded the motion, motion carried.
Walter gave the treasurer’s report. A Certificate of Deposit for $3000.00 was purchased for a period of 180 days at 3.75 percent interest. That leaves us with a balance of $2,092.57.
Irvin gave the Lapidary report. They are meeting on Thursday afternoons at 1 p.m. No one has had any luck finding a used saw. Don told us all lapidary equipment was up in price at the show in Tucson.
Jack told us that the Federation had kept their word on sending us info on other clubs in the area. We also have rock-hounding booklets on sale. Joan Hammer is in charge of the rock raffle tonight. All of this will be available during the intermission.
The Field Trip this month will be to the Bisbee Museum. They have a Smithsonian exhibit that may be of interest. Jack reminded us that the club would pay the $6 entry fee for this trip. A sign-up sheet will be passed around. Also a sign-up for refreshments will be passed around. Hanni Sigel volunteered to be our Hospitality Chairperson. Many thanks to Hanni!
A video of “The making of a continent” will be available after refreshments. With no further business, Don made a motion to adjourn. Jack seconded the motion, motion carried. Meeting adjourned at 7:40 p.m. We enjoyed refreshments from Cynthia Weller and Carol Pontious.
Respectfully,
Carol Pontious. Secretary
Wanted: Rocks. Bring one or more of your favorite rocks to the meeting to be included in the rock raffle. We thank the Fenners, Blandins and Henri vandenBos for donating rocks for our highly successful raffles.
Anyone with suggestions for speakers or program topics or field trip sites please contact one of the officers.
Interested in lapidary? We have a 1 pm Thursday and a Saturday afternoon session – call Irvin Pontious – 824-0110. Silver soldering meets at 2 pm Tuesday – call Larry Strout 826-3991. Silver smithing meets at 3 pm Monday – call Don Hammer 384-3105.
Our President Paul McKnight has returned from 3 weeks in the Philippines. While there he hiked to a marble quarry and visited a marble lapidary operation where he purchased a small slab of black/yellow "snakeskin" patterned marble for the Club's rock raffle.
March
8 Board Meeting
12 Regular Meeting – William Burton, mining geologist. Host: Karen Grassell
18 Field Trip – Dry Canyon in the Whetstones for fossils
April
5 Board Meeting
9 Regular Meeting – Host – Rosita Pontious
14 Field Trip – Swisshelms for jasper and ?
May
10 Board Meeting
14 Regular Meeting
20 Field Trip
June
7 Board Meeting
Picnic
July
Field Trip
August
Field Trip
September
6 Board Meeting
10 Regular Meeting – Host Ilse-Rose Edgett
15 Field Trip
October
4 Board Meeting
8 Regular Meeting
14 Field Trip
November
8 Board Meeting
12 Regular Meeting
17 Field Trip
December
6 Board Meeting
17 Christmas Party
Upcoming Regional Events
March 8 – 11, 2007 Deming Gem & Mineral Society Inc. 42nd Annual Rocks,Gems, Minerals, Geode Cutting, Auctions, Daily Door Prizes, Guided Field Trips, Breakfast & Lunch & More. Phone (505) 544-8643. dgms.bravehost.com
March 10, 2007 Minerals of Arizona, 15th Annual Symposium, Arizona Mining and Mineral Museum, 15th and Washington, Phoenix 602.255.3795
March 16-18, 2007, Albuquerque, NM. 38th Annual ABQ Gem & Mineral Club’s show. Contact Paul Hlava 505.255.5478 www.agmc.info
April 21-22, 2007 Patagonia Gem & Mineral Show, Stage Stop Inn, 303 W. McKeown Ave. 520.394.0125 or dek1934@msn.com
June 7-10, 2007. Rocky Mountain Federation Annual Convention & Show. Roswell, NM. Hosts: Chaparral Rockhounds. Chairman: Frank Whitney 505.623.3236 Fdw@direcway.com This is a joint convention with the American Federation of Mineralogical Societies and being this close, a real opportunity for us to see what these organizations are all about.
President Paul McKnight 520 824-4054
Vice-President Jack Weller 520-826-0625
Secretary Carol Pontious 520 824-0110
Treasurer Walt Sigel 520-826-1009
Delegate at Large Jack Light 520-384-4774
Hospitality Coordinator Hanni Sigel 520-826-1009
Dues are due. $10 for individual and $20 for family. Please mail your check to Sunsites Gem & Mineral Club, PO Box 87, Pearce, AZ 85625. Members with dues unpaid by March 15 will be dropped from the membership rolls.
Fossils
Crinoids are neither abundant or familiar organisms today. However, they dominated the Paleozoic fossil record of echinoderms and shallow marine habitats until the Permo-Triassic extinction, when they suffered a near complete extinction: many Paleozoic limestones are made up largely of crinoid skeletal fragments.
Stalked crinoids, or "sea lilies", lived attached to the bottom, and filtered food particles from the currents flowing past them. The living stalked crinoids mostly inhabit deep water and are therefore difficult for the average underwater enthusiast to observe.
Corals are the skeletons of some marine animals belonging to the Phylum Cnidaria (NÎ-dÂ'-ri-a), a medium-sized phylum that contains a large variety of solitary and colonial invertebrates including sea anemones, hydroids, sea pens, jellyfish, siphonophores, and millepores, in addition to corals. Two body forms, polyp and medusa, are characteristic of the phylum and commonly occur as alternating stages in the development of individuals of the Classes Hydrozoa and Scyphozoa. A third class, Anthozoa, has only the polyp form and includes the true corals. Current molecular studies suggest that Anthozoa is the most primitive of the three classes. Cnidarians are relatively simple; they differ from other multi-celled animals in having only two body layers, in appearing to have a radial symmetry, and in the possession of stinging cells. They may have no skeleton, an organic skeleton, or a mineralized one. Only those with mineralized skeletons, principally the stony corals, are common as fossils. Stony corals belong to the anthozoan Subclass Zoantharia. Their skeletons are external, secreted by the outer tissue layer, and calcareous (composed of CaCO3), but may be formed of either calcite or aragonite.
The oldest known fossil zoantharian corals are from the Lower Cambrian; they are common fossils in rocks of every subsequent geologic period because of their easily preserved skeletons. They were limited to the marine environment and are most common in limestones and calcareous shales, representing relatively clear and moderately shallow water conditions. Coral skeletons are major components of many living and fossil coral reefs such as the Great Barrier Reef that extends for 1200 miles along the northeast coast of Australia. Among the most notable fossil reefs are those in the Triassic of the Alps and the Devonian of western Canada. The latter is an important petroleum source because of the porosity that resulted from reef building.
There are many orders of Paleozoic corals, but the overall complexity and adaptive success of the Mesozoic-Cenozoic Order Scleractinia far exceeds that of the Paleozoic groups. The principal Paleozoic corals, Tabulata and Rugosa, built their skeletons of calcite, whereas the Mesozoic-Cenozoic Scleractinia built their of aragonite. This compositional difference, plus morphologic similarities and differences, is the basis for dividing the Zoantharia into Groups 1 and 2.
Corals are very sensitive to environment, and their mobility is limited to a floating larval stage that may live for a very brief period of time. For these general reasons, most individual species are not widespread and are useful for correlation in only limited areas or special situations. Most species, however, lived for only a short period of geologic time, and many are used as index fossils within their areas of distribution.
The radiating plates seen in many corals, and the honeycomb pattern of coral colonies, are intrinsically appealing and serve many decorative and artistic functions. The esthetic appeal of living coral reefs is evident from the popularity of the numerous coral reef nature parks and preserves that have been established in many parts of the world.
Bivalves are molluscs with a shell made of two interlocking pieces (valves) made of calcium carbonate. They can be found in many different freshwater and marine environments, such as lakes, tide pools, reefs, and hydrothermal vents. Some bivalves attach themselves to hard surfaces (oysters, mussels), a few species can swim (scallops), but most bury or anchor themselves into soft sediment. Partly because they have a hard shell, and partly because they are so numerous, the fossil record of bivalves is fairly good and extends back to the Cambrian.
First known fossil occurrence: Cambrian.
Last known fossil occurrence: Quaternary. This group has living relatives.