by Rachel Armstrong

SOCORRO, N.M., Aug. 24, 2004 — Two new issues of New Mexico Geology have been recently released. One focuses on earthquakes in New Mexico and the other on assemblages of Late Pennsylvanian marine invertebrates in the Holder Formation along Dry Canyon in the Sacramento Mountains of south-central New Mexico.

The February issue of New Mexico Geology features an article on the seismic ground shaking that could possibly occur within the Albuquerque– Belen– Santa Fe corridor from future earthquakes. The authors have developed a series of nine color foldout earthquake hazard maps that portray potential ground shaking in the Albuquerque area. Ground motions were calculated for a postulated M 7.0 scenario earthquake along the north-south-trending Sandia–Rincon faults along the base of the Sandia Mountains.

Compared to other regions in the western U.S., the article states, the hazard in the central Rio Grande rift is viewed as moderate. However, the occurrence of a large earthquake near the Albuquerque metropolitan area could be very damaging due to its location in the Albuquerque Basin where amplification of ground shaking is likely and because of the presence of traditional adobe construction.

The May issue explains that the Holder marine invertebrates have been studied very little, and this article discusses two very different groups. The first group, which lies in mudstone, consists primarily of gastropods and bivalves. The second group, which is embedded in shale and limestone 49 to 66 feet above the first group, consists of more than 100 different marine species.

According to the article, the absence of certain organisms that are only able to live in specific concentrations of saltwater suggests that there were abnormal marine conditions. It also states that the different species in these groups are unique in New Mexico’s Pennsylvanian period.

Another article informs readers that the New Mexico Museum of Natural History and Science’s paleontological database, which includes over 35,902 New Mexico fossils, is now online and available to the public. The website,, does not include sensitive geographic locations, but does include a vast array of data on fossils from over 5,630 locations.

The periodical also includes a report on the New Mexico Science and Engineering Fair, a memorial article about J. Paul Fitzsimmons, and abstracts from talks given at the New Mexico Geological Society’s annual meeting held this April.

New Mexico Geology is published quarterly by New Mexico Bureau of Geology and Mineral Resources (NMBGMR), a service division of New Mexico Tech. A subscription to the award-winning journal costs $12 per year, or $22 for two years. Individual issues may be purchased for $3.50 each. For more information about New Mexico Geology, or any other NMBGMR publication, write to the Bureau Publication Office, New Mexico Tech, 801 Leroy Place, Socorro, NM 87801, call 505.835.5410, or visit the Bureau’s website at http://geoinfo.nmt.edu.