GEOLOGICAL SOCIETY News:
Wheeler Geologic Area near Creede, Colo. Courtsy/LAGS
Dr. Paul G. Drakos, Senior Geologist and Vice President of Glorieta Geoscience, Inc. in Santa Fe is the featured speaker for the Los Alamos Geological Society meeting, set for 7:30 p.m., Tuesday July 17 at the Christian Church, 92 East Road, Los Alamos.
Drakos’ talk is entitled, “Soil-stratigraphic framework, timing of recent eolian events, and preservation of archaeological sites on the Pajarito Plateau.”
Stratigraphic relationships and soil characteristics provide a geomorphic framework for Coalition Period to Classic Period Ancestral Puebloan, Archaic, and Paleoindian sites on the Pajarito Plateau near Los Alamos.
The record of eolian and colluvial deposition on mesa tops and within canyons indicates periods of widespread deposition during the late Pleistocene to latest Holocene (generally < 1 ka deposits).
Ancestral Puebloan sites are partially buried, and are generally in good archaeological context. In many cases Coalition and Classic Period sites can be differentiated based on soil stratigraphic relationships.
Mesa top sites are underlain by 0-1.5 m of Pleistocene and Holocene deposits recording a sequence of discontinuous soils that represent episodic eolian deposition and soil formation followed by erosion.
In canyon settings, deposits are less extensively preserved recording net erosion during the Holocene across most of the landscape. Archaic and Paleoindian sites are typically buried in mesa top settings but several sites have been exposed in excavations in good archaeological context.
Early to middle Holocene colluvial deposits locally preserve Archaic sites in canyons. The archaeological context of artifacts at Archaic sites can be affected by colluvial transport and extensive bioturbation.
The relative paucityof pre-1 ka Holocene deposits likely skews the archaeological record against preservation of Archaic sites.
Although few sites have been recorded, the presence of late Pleistocene to early Holocene deposits in many geomorphic settings indicates that the proper conditions exist for preservation of Paleoindian sites on the Pajarito Plateau.
July Field Trip
The July field trip is to the Wheeler Geologic Area near Creede, Colo. Meet at 7 a.m., Saturday July 21 in Creede. Plan on bringing rock breaking equipment, storage items to protect small specimens, a hand lens, eye protection, camera, sunscreen, extra clothing, water, lunch and snacks for this trip.
Contact Paul Bradley at Ppbradpp@aol.com for more details and to confirm attendance.