NEXT MEETING: Wednesday, May 18, 2022, 6PM: the GCAS is thrilled to announce this year's first general meeting IN PERSON at the Roundup Lodge in San Lorenzo (Mimbres Valley) near the junction of Highways 152 and 35! Start at 6PM with your own plates/utensils/beverage & a dish for yourself or to share. Brief general meeting at 6:45 PM. Skip social time if you like but our Featured Speaker, the WNMU Museum's new Director and archaeologist, Danielle Romero, makes her presentation on Elk Ridge Ceramics at 7PM sharp. Danielle, a ceramics specialist with years of investigating Mimbres and other sites, will make her topic most engaging. Read more about Danielle here. In order to offer our members a safe and comfortable experience the GCAS follows CDC and New Mexico Department of Health guidelines for indoor gatherings including masking, distancing, and vaccinations. We recommend all attendees follow the same.

NEXT FIELD TRIP: Sunday, June 5, 2022 - Park Service-guided visit to TJ Ruin at the Gila Cliff Dwellings National Monument. Meet at the Cliff Dwellings Visitor Center parking lot no later than 10:50 am, tour to begin at 11:00 am. Drive north on Highway 15/Pinos Altos Rd for about 45 miles from US 180 in Silver City. Drive can take as much as 2 hours! Site is reached via a short hike to the top of a 100 ft bluff. Site is not shaded! Dogs are not allowed on the site and cannot be left in vehicles or tied up in the parking lot. NOTE: the area is currently experiencing heavy smoke impacts from the Black Fire. Check this website and the Park Service website at (Alerts) the day before/morning of the field trip to see current status of the field trip and area conditions. Remember, to protect vulnerable resources we offer our field trips to members only. Members’ invited guests are welcome, as long as they ride in that member’s vehicle.

Navajo Culture On Mars!
MAREC Progress Report - Phase III

Meet D-Stretch: the Archaeologist's Friend

Picto 3 - natural Picto 3 - StretchSome avocational archaeologists have already learned of the fascinating technology of D-Stretch, aka decorrelation stretch, a digital imaging tool that was originally developed to enhance (i.e., "stretch") the color differences in aerial photographs. Today, this technology has become more widely used and user-friendly to boot. It is now an essential tool to analyze rock art images, especially ones too faint for the naked eye to see.

Picto 4- Stretch Picto 4- naturalThe two pairs of images you see on this page were taken by the GCAS's own Marglyph, alias Margaret Berrier. She has kindly given us permission to post them here so that we can all see how significant the D-Stretch enhancement can be. The left-most photos are her examples of natural, "naked eye" photos of rock art; and the brightly colored photos next to them reveal the same image in D-Stretch.

For many more images of rock art in D-Stretch as well as technical data, start at the D-Stretch home page itself.

In its most professional format, D-Stretch is a plugin to the Javascript program, ImageJ, that must be installed before D-Stretch can be used. Some of our more tech-savvy readers may be inclined to select this alternative. However, for the more casual of us avocational archaeologists who do not necessarily need high functionality, there's an app for that. Our GCAS President, the straightforward Kyle Meredith, opted for the straightforward app and reports: "...I looked up the app on Google Play for my android phone and ordered it. I think the price was $19.99. SO EASY!" Kyle adds that use of the D-Stretch app has a bit of a learning curve but it promises to be big fun for anyone interested in photographing and enhancing rock art in the field. Like all of us GCAS members who've spent a year itching for resumption of field trips.

If Joe Bob Briggs were into rock art, he'd say check it out.

/s/ webmaster


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