Search

The analysis here of 22 volcanic rock samples indicates a diverse set of volcanic rock types (Table 1, Figures 1 through 2).  The obsidian nodules collected from Turkey Ridge rhyolite on the NW side of Cerro Rubio are most definitely derived from the Cerro Toledo Rhyolite (CTR) event based on comparison with a large body of CTR source standards from Rabbit Mountain and the ash flow tuff to the south including "Obsidian Ridge" (see Shackley 2005; Table 2 and 3 and Figure 2 herein).  Using XRF the composition is well within those standards (see Table 2 and Figures 2 and 3).

The analysis here of 22 volcanic rock samples indicates a diverse set of volcanic rock types (Table 1, Figures 1 through 2).  The obsidian nodules collected from Turkey Ridge rhyolite on the NW side of Cerro Rubio are most definitely derived from the Cerro Toledo Rhyolite (CTR) event based on comparison with a large body of CTR source standards from Rabbit Mountain and the ash flow tuff to the south including "Obsidian Ridge" (see Shackley 2005; Table 2 and 3 and Figure 2 herein).  Using XRF the composition is well within those standards (see Table 2 and Figures 2 and 3).

This dissertation investigated the initial and multi-year effects of a catastrophic wildfire (Las Conchas fire in 2011) on adjacent and downstream aquatic ecosystems in comparison to pre-fire conditions. Specifically, the research looked at 1) multi-year water quality responses along the river continuum using data collected before, immediately after and for multiple years post-fire, 2) differential water quality and whole-stream metabolism responses of paired headwater catchments over multiple years after disturbance, and 3) fish communities at two sites on a larger river downstream of the extensive region impacted by the catastrophic wildfire.Overall, the research in this dissertation highlights the importance of long-term ecological data collection using advanced instrumentation that can be used to evaluate the effects of a changing climate and climate-mediated disturbances on water resources. Secondly, these studies emphasize the need to collect water quality and biological data at temporal and spatial scales that more effectively capture the hydrology and water quality dynamics of landscape-scale disturbances that are becoming more common and more destructive with climate change and growing human impingement on forested lands. Thirdly, this research highlights the importance of evaluating streamflow pathways, geomorphology, physiochemical properties with biogeochemical processes, and watershed-specific hydrologic connections within their landscapes prior to and following landscape-scale disturbance.

This dissertation investigated the initial and multi-year effects of a catastrophic wildfire (Las Conchas fire in 2011) on adjacent and downstream aquatic ecosystems in comparison to pre-fire conditions. Specifically, the research looked at 1) multi-year water quality responses along the river continuum using data collected before, immediately after and for multiple years post-fire, 2) differential water quality and whole-stream metabolism responses of paired headwater catchments over multiple years after disturbance, and 3) fish communities at two sites on a larger river downstream of the extensive region impacted by the catastrophic wildfire.Overall, the research in this dissertation highlights the importance of long-term ecological data collection using advanced instrumentation that can be used to evaluate the effects of a changing climate and climate-mediated disturbances on water resources. Secondly, these studies emphasize the need to collect water quality and biological data at temporal and spatial scales that more effectively capture the hydrology and water quality dynamics of landscape-scale disturbances that are becoming more common and more destructive with climate change and growing human impingement on forested lands. Thirdly, this research highlights the importance of evaluating streamflow pathways, geomorphology, physiochemical properties with biogeochemical processes, and watershed-specific hydrologic connections within their landscapes prior to and following landscape-scale disturbance.

Using dendroecological and archaeological methods and data we investigated the temporal dynamics of forest regeneration and fire history following depopulation of four large Pueblo IV period (1300-1600) villages on the Jemez Plateau, New Mexico. With tree rings we reconstructed the timing of reforestation on village footprints after depopulation–a novel approach to terminus ante quem dating of site occupation. Our tree-ring based forest age structure and fire history chronologies enabled us to reduce by 51 to 70 years the range of previous estimates of village depopulation dates derived primarily from terminal ceramic assemblages. One of the four village sites we investigated was depopulated in 1696, two were depopulated between 1625 and 1700 CE, while the fourth village was depopulated earlier (pre 1500), but the area was likely in continued use for agriculture or other seasonal purposes until the mid-1600s. Our results indicate that the Jemez were highly influential ecological agents. Forest structure and fire regime dynamics changed greatly after the departure of most people from these landscapes after circa 1650 CE. The terminus ante quem methods that we demonstrate in the Jemez Mountains have strong potential to constrain and refine low temporal resolution chronologies of human occupation at archaeological sites within other forested ecosystems of the Southwest and elsewhere.

Using dendroecological and archaeological methods and data we investigated the temporal dynamics of forest regeneration and fire history following depopulation of four large Pueblo IV period (1300-1600) villages on the Jemez Plateau, New Mexico. With tree rings we reconstructed the timing of reforestation on village footprints after depopulation–a novel approach to terminus ante quem dating of site occupation. Our tree-ring based forest age structure and fire history chronologies enabled us to reduce by 51 to 70 years the range of previous estimates of village depopulation dates derived primarily from terminal ceramic assemblages. One of the four village sites we investigated was depopulated in 1696, two were depopulated between 1625 and 1700 CE, while the fourth village was depopulated earlier (pre 1500), but the area was likely in continued use for agriculture or other seasonal purposes until the mid-1600s. Our results indicate that the Jemez were highly influential ecological agents. Forest structure and fire regime dynamics changed greatly after the departure of most people from these landscapes after circa 1650 CE. The terminus ante quem methods that we demonstrate in the Jemez Mountains have strong potential to constrain and refine low temporal resolution chronologies of human occupation at archaeological sites within other forested ecosystems of the Southwest and elsewhere.

Volcanically impacted continental rift basins that experience coeval subsidence and volcanism challenge the conventional sedimentation models for continental rift basins. A field study was undertaken at the eastern margin of Bearhead basin within the southeastern Jemez volcanic field of north central New Mexico and synthesized with previous workers' research. The 7.5 km-wide basin is part of the Rio Grande Rift. A brief episode of rhyolitic volcanism at 6.5-7.1 Ma overfilled the basin with about 550 m of lava and primary pyroclastic deposits and minor fluvial sediments. As a result, little or no coarse-grained epiclastic sediments were shed from adjacent footwall highlands and deposited into the basin along its margins, which is a trait of conventional rift basin models. Additionally, the reworked volcaniclastic sediments, which are mostly observed in the lower stratigraphy, were generally longitudinally transported through the basin, even at the basin margins, as opposed to transverse deposition on the footwall-derived alluvial fans. The prominent sedimentary clast types shift from older andesite to mostly younger rhyolitic volcaniclastic facies and lavas depicting the change in the type and composition of volcanism. This pattern contrasts with unroofing of progressively older rocks to provide sediment into a conventional rift basin. Pyroclastic-flow, surge, fall, and block-and-ash-flow deposits dominate the stratigraphic record with fewer hiatuses as basin filling progressed. In the Bearhead basin, the accumulation rate of mostly volcanic fill sourced from coeval dome complexes, including vents within the basin, exceeded the subsidence of the basin, and thus overfilling the basin. This differs from the conventional models, where subsidence typically exceeds the accumulation rate of sedimentary fill sourced from uplifted highlands along and near the basin margin. Volcanism can, therefore, obscure typical features that are used to recognize coeval tectonism. Careful

Chapters on general aspects of geothermal systems are followed by case histories of systems chosen to represent a range of development round the world. Contents: Geothermal systems, conductive heat flow, geothermal anomalies, by L. Rybach, p.3-36, 112 refs.; Convective heat and mass transfer in hydrothermal systems, by S.K. Garg and D.R. Kassoy, p.37-76, 82 refs.; Prospecting for geothermal resources, by J.T. Lumb, p.77-108, 135 refs.; Application of water geochemistry to geothermal exploration and reservoir engineering, by R.O. Fournier, p.109-143, 71 refs.; Heat extraction from geothermal reservoirs, by I.G. Donaldson and M.A. Grant, p.145-179, 65 refs.; Geothermal resource assessment, by L.J. Patrick Muffler, p.181-198, 48 refs.; Environmental aspects of geothermal development, by Max D. Crittenden, p.199-217, 49 refs.; The low enthalpy geothermal resource of the Pannonian basin, Hungary, by Peter Ottlik and others, p.221-245, 19 refs.; Exploration and development at Takinoue, Japan, by Hisayoshi Nakamura and Kiyoshi Sumi, p.247-272, 8 refs.; The Krafka geothermal field, northeast Iceland, by Valgardur Stefannson, p.273-294, 22 refs.; The geothermal system of the Jemez Mountains, New Mexico and its exploration, by A. William Laughlin, p.293-320, 70 refs.; Extraction-reinjection at Ahuachapan geothermal field, El Salvador, by Gustavo Cuellar, Mario Choussy and David Escobar, p.321-336, 11 refs., Chapters on general aspects of geothermal systems are followed by case histories of systems chosen to represent a range of development round the world. Contents: Geothermal systems, conductive heat flow, geothermal anomalies, by L. Rybach, p.3-36, 112 refs.; Convective heat and mass transfer in hydrothermal systems, by S.K. Garg and D.R. Kassoy, p.37-76, 82 refs.; Prospecting for geothermal resources, by J.T. Lumb, p.77-108, 135 refs.; Application of water geochemistry to geothermal exploration and reservoir engineering, by R.O. Fournier, p.109-143, 71 refs.; Heat extraction from geothermal reservoirs, by I.G. Donaldson and M.A. Grant, p.145-179, 65 refs.; Geothermal resource assessment, by L.J. Patrick Muffler, p.181-198, 48 refs.; Environmental aspects of geothermal development, by Max D. Crittenden, p.199-217, 49 refs.; The low enthalpy geothermal resource of the Pannonian basin, Hungary, by Peter Ottlik and others, p.221-245, 19 refs.; Exploration and development at Takinoue, Japan, by Hisayoshi Nakamura and Kiyoshi Sumi, p.247-272, 8 refs.; The Krafka geothermal field, northeast Iceland, by Valgardur Stefannson, p.273-294, 22 refs.; The geothermal system of the Jemez Mountains, New Mexico and its exploration, by A. William Laughlin, p.293-320, 70 refs.; Extraction-reinjection at Ahuachapan geothermal field, El Salvador, by Gustavo Cuellar, Mario Choussy and David Escobar, p.321-336, 11 refs.