Biografie

since 2009

Ph.D. candidate; Spatio-temporal interactions among tectonics, climate, erosion and sedimentation in the intermontane basins and Andean foreland areas of NW Argentina (advisor: Manfred R. Strecker)

2009

Diploma in Geology “Neotectonic and Landscape Evolution in the Eastern Cordillera of NW Argentina, Quebrada de Humahuaca (23°-24°S)”

Forschung

Spatio-temporal interactions among tectonics, climate, erosion and sedimentation in the intermontane basins and foreland areas of NW Argentina

The Andes today present a major orographic barrier to atmospheric circulation on a hemispheric scale. Moisture-bearing air masses, drawn into a seasonal low-pressure system in the Chaco lowland to the east of the orogen, rise progressively along the eastern flanks of the orogen and are adiabatically cooled during their ascent, resulting in summer thunderstorms and heavy rainfall. The eastern flanks receive rainfall of between 3,000 and 6,000 mm/a, whereas the intermontane basins in the Eastern Cordillera and the NW Sierras Pampeanas receive only 200 mm/a or less (Fig.1). The Puna Plateau receives even less precipitation. Focused precipitation along the eastern flanks and leeward aridification are characteristic of the entire length of the South Central Andes, and are manifested by an across-strike decrease in vegetative cover and fluvial transport efficiency. This present-day climatic gradient is also mirrored by the stable oxygen (O) and hydrogen (H) isotope composition of rainfall across the eastern plateau margin. By analogy with this present-day situation and other similar settings with strong precipitation gradients, stable isotope compositions preserved in the sedimentary archives of intermontane basins may therefore reflect past topographic and environmental changes associated with the development of orographic barriers.

Figure 1 – (A) Shaded relief DEM and principal morphotectonic domains of the South Central Andes (after Jordan et al., 1983). (B) Mean annual rainfall map showing steep precipitation gradients along the eastern flanks of the Eastern Cordillera (EC), the Santa Barbará System (SBS), and the Sierras Pampeanas (SP). (C) Swath-profile compilation of topography, rainfall, and 3km-relief using the area and precipitation data shown in B).

Hydrogen-isotope geochemistry of hydrated volcanic glass

Volcanoes located within the volcanic arc and on the Puna Plateau of the Central Andes have been repeatedly active since the late Miocene, resulting in vast ash-fall deposits (>10⁵ km²) in the eastern Andes and foreland regions, providing unique, dateable event horizons. An important factor is that rhyolitic glass incorporates large amounts of meteoric water (3-5 wt%) into its structure. This hydration process occurs in parallel with a change in the D/H-ratio of the glass (δD_glass), thus representing a unique fingerprint of the H-isotope composition of the meteoric water present during hydration. This allows the reconstruction of the isotopic composition of paleo-precipitation (δD_ppt), which is an important indicator of long-term changes in precipitation patterns and continental moisture transport. One of the advantage of these volcanic glasses over authigenic and biogenic minerals, however, lies in their widespread occurrence and their potential for  high precision geochronology (e.g., U/Pb zircon, ⁴⁰Ar/³⁹Ar sanidine). Hydrated glass, therefore, provides a very useful isotopic record that can be linked to paleoclimatic conditions if the original isotopic composition of the studied material is preserved over geologic time because (a) deposition and hydration are relatively rapid on geologic time scales, (b) the chemical composition of the proxy material is constant over large areas, and (c) interpretation of spatial variations in the H-isotope composition of time-equivalent ashes only requires knowledge of relative changes in δD_glass. This reduces additional uncertainties, compared with those studies that need to account for absolute changes in isotopic compositions.

Lehre

MScP02 Seminar/Kolloquium Geowissenschaften

Publikationen

Journal contributions:

Pingel, H., Strecker, M.R., Hilley, G.E., Alonso, R., Schmitt, A.K. (submitted to Basin Research). Neotectonic basin and landscape evolution in the Eastern Cordillera of NW Argentina, southern Humahuaca Basin (~24°S).

Hain, M., Strecker, M.R., Bookhagen, B., Alonso, R.N., Pingel, H.,  Schmitt, A.K. (2011). Neogene to Quaternary broken-foreland formation and sedimentation dynamics in the Andes of NW Argentina (25°S). Tectonics, 30, TC2006, doi:10.1029/2010TC002703.

Conference Abstracts:

Pingel, H., Strecker, M.R., Hilley, G.E., Alonso, R., Schmitt, A.K. (2011). Sedimentary and Tectonic Evolution of the Intermontane Humahuaca Basin in the Eastern Cordillera of NW Argentina (~23.5°S): Possible Feedbacks between Sedimentary and Tectonic Processes. AGU Fall Meeting Abstracts, T24C-07, 2011, San Francisco, USA.

Pingel, H., Strecker, M.R., Hilley, G.E., Alonso, R., Schmitt, A.K. (2011). Intermontane Basin and Landscape Evolution in the Eastern Cordillera of NW Argentina – S Humahuaca Basin (23°S). Geophysical Research Abstracts, 13, EGU2011-11654, EGU General Assembly 2011, Vienna, Austria.

Pingel, H., Strecker, M.R., Hilley, G.E., Alonso, R., Schmitt, A.K. (2009). Neotectonic Basin and Landscape Evolution in the Eastern Cordillera of NW Argentina - Humahuaca Basin (23-24° S). AGU Fall Meeting Abstracts, T43B-2060, 2009, San Francisco, USA, (Poster)

Pingel, H. and Strecker, M.R. (2009). Neotectonic evolution of the southern intermontane Humahuaca basin, E Cordillera, Argentina (23°S lat): insights into Neogene to Quaternary foreland basin and landscape evolution in the southern central Andes. TECTSED 2009, Bonn, Germany, (Poster)