TY - JOUR A1 - Gomez, Andreas A. A1 - Jaramillo, Carlos A. A1 - Parra, Mauricio A1 - Mora, Andres T1 - Huesser Horizon : a lake and a marine incursion in northwestern South America during the early Miocene N2 - The Cenozoic stratigraphic sequence in the foothills of the Eastern Cordillera of Colombia is mostly fluvial in nature and very thick (similar to 8000 m), but it contains very few mollusk-bearing horizons. Recent fieldwork discovered a well-preserved molluscan assemblage that occurs near the top of the Carbonera Formation (lower Miocene) in the central foothills of the Eastern Cordillera. This level, named the Huesser horizon, is laterally extensive and can be followed for tens of kilometers. The horizon is 10 m thick and was divided into eight levels, five of them highly fossiliferous. Most of the levels are dominated by the freshwater gastropod Sheppardiconcha, with lower abundances of the bivalves Anodondiles and Mytilopsis. The top level is dominated by specimens from the bivalve family Arcidae. The taxonomic composition of the assemblage is similar to that of the Magdalena and Amazonas Basins during the early-to- middle Miocene. Paleoecologic, taphonomic, and palynological analyses indicate that the Huesser accumulated in a freshwater lake system, capped by a marine incursion. The development of a large lake and the subsequent marine event could be related to increasing subsidence coincident with eustatic sea-level rise that has been identified for the basin during the early Miocene. Y1 - 2009 UR - http://palaios.geoscienceworld.org/ U6 - https://doi.org/10.2110/palo.2007.p07-074r SN - 0883-1351 ER - TY - JOUR A1 - Rodil, Iván F. A1 - Jaramillo, Eduardo A1 - Hubbard, David M. A1 - Dugan, Jenifer E. A1 - Melnick, Daniel A1 - Velasquez, Carlos T1 - Responses of Dune Plant Communities to Continental Uplift from a Major Earthquake: Sudden Releases from Coastal Squeeze JF - PLoS one N2 - Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5 degrees S) caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco) over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the effects of natural and human induced disturbances, and promotes the development of dune vegetation as natural barriers can provide societal and conservation benefits in coastal ecosystems. Y1 - 2015 U6 - https://doi.org/10.1371/journal.pone.0124334 SN - 1932-6203 VL - 10 IS - 5 PB - PLoS CY - San Fransisco ER - TY - GEN A1 - Rodil, Iván F. A1 - Jaramillo, Eduardo A1 - Hubbard, David M. A1 - Dugan, Jenifer E. A1 - Melnick, Daniel A1 - Velasquez, Carlos T1 - Responses of dune plant communities to continental uplift from a major earthquake BT - sudden releases from coastal squeeze T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5 degrees S) caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco) over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the effects of natural and human induced disturbances, and promotes the development of dune vegetation as natural barriers can provide societal and conservation benefits in coastal ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 516 KW - Chile earthquake KW - sandy-beach KW - New-Zealand KW - salt spray KW - vegetation KW - conservation KW - disturbance KW - protection KW - habitats KW - zonation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409629 SN - 1866-8372 IS - 516 ER - TY - JOUR A1 - Parra, Mauricio A1 - Mora, Andrés A1 - Jaramillo, Carlos A1 - Strecker, Manfred A1 - Sobel, Edward A1 - Quiroz, Luis A1 - Rueda, Milton A1 - Torres, Vladimir T1 - Orogenic wedge advance in the northern Andes : evidence from the Oligocene-Miocene sedimentary record of the Medina Basin, Eastern Cordillera, Colombia N2 - Foreland basin development in the Andes of central Colombia has been suggested to have started in the Late Cretaceous through tectonic loading of the Central Cordillera. Eastward migration of the Cenozoic orogenic front has also been inferred from the foreland basin record west of the Eastern Cordillera. However, farther east, limited data provided by foreland basin strata and the adjacent Eastern Cordillera complicate any correlation among mountain building, exhumation, and foreland basin sedimentation. In this study, we present new data from the Medina Basin in the eastern foothills of the Eastern Cordillera of Colombia. We report sedimentological data and palynological ages that link an eastward-thinning early Oligocene to early Miocene syntectonic wedge containing rapid facies changes with an episode of fast tectonic subsidence starting at ca. 31 Ma. This record may represent the first evidence of topographic loading generated by slip along the principal basement-bounding thrusts in the Eastern Cordillera to the southwest of the basin. Zircon fission-track ages and paleo-current analysis reveal the location of these thrust loads and illustrate a time lag between the sedimentary signal of topographic loading and the timing of exhumation (ca. 18 Ma). This lag may reflect the period between the onset of range uplift and significant removal of overburden. Vitrinite reflectance data document northward along-strike propagation of the deformation front and folding of the Oligocene syntectonic wedge. This deformation was coupled with a nonuniform incorporation of the basin into the wedge-top depozone. Thus, our data set constitutes unique evidence for the early growth and propagation of the deformation front in the Eastern Cordillera, which may also improve our understanding of spatiotemporal patterns of foreland evolution in other mountain belts. Y1 - 2009 UR - http://gsabulletin.gsapubs.org/ U6 - https://doi.org/10.1130/B26257.1 SN - 0016-7606 ER -