AIPG-TX

NOTICE: FIELD TRIP IS NOW BOOKED UP (FULL) and REGISTRATION IS CLOSED. 

Attention all AIPG Texas Members:

A field trip is to be held to examine the fascinating structural geology, as well as the sedimentology and stratigraphy of the Glen Rose formation, in the Canyon Dam Gorge near New Braunfels.  This will be held in connection with the AIPG National Board Meeting to be held in San Antonio. This field trip offers an opportunity for face-time with your National and local section AIPG Board Members.

We will also visit historic San Pedro Springs, the original site of the settlement of San Antonio

• Date: Sunday, Feb. 3rd, 2019.
• Time: 8.00 am to 4.00 pm.
• Meet: Drury Inn San Antonio Airport:  95 NE Interstate 410 Loop, San Antonio, TX 78216
• Leader: Dr. Tom Ewing, author of “Texas through Time” and others.
• Cost: about $50 per person.
• Clothing: stout walking shoes, a walking stick if needed. Rain gear depending on forecast.
• Tools: hand lens, penknife, dilute HCl, camera, notebook. Also bring water.
• Guidebook: included in  field trip price.

Geology: This spectacular canyon was carved out by the flash flood of July 5th, 2002.  It exposes a fresh section of about 40% of the total thickness of the Glen Rose formation: very fine details of subtidal and intertidal lithofacies can be seen, as well as dinosaur footprints. The gorge also exposes nearly 0.5 miles of the Hidden Valley Fault, which has a displacement of about 61 m and is a member of the Balcones Fault system. The structure of the fault zone is complicated by the presence of many imbricated curved slip planes causing large rotations of early faults by the movement of later ones.

San Pedro Springs issue from the Balcones Fault Zone, which forms the main part of the Edwards Aquifer in San Antonio.  All of San Antonio’s water supply comes from the Edwards Aquifer, which is therefore under some stress: San Antonio is in the process of buying water rights in Paleocene and Eocene rocks some distance NE of the city.  The Edwards Aquifer is one of the most prolific aquifers in the US.

Notes:  The walk through the gorge is about one mile, and there are steep paths at each end. If it is wet, the rocks can be slippery.  Bring water to drink. We will supply lunches from Jason’s Deli, and will ask for food preferences closer to the date of the trip.

Transport will be in vans or a bus, depending on the number of registrants.

All members of the Texas Section of AIPG are invited to take part: please contact John Berry at jlbassoc@gmail.com or 512-452-8068 as soon as you can to secure a reservation.