375 documents found in 149ms
# 371
Demory, Francois • Oberhänsli, Hedi • Nowaczyk, Norbert • Gottschalk, Matthias • Wirth, Richard • (et. al.)
Abstract: Higher abundance of greigite during glacial intervals coincides with small increases of the S content (Fig. 11B). Greigite levels in glacial sediments cannot be correlated between cores (Fig. 12), which suggests that greigite concentrations are driven by local processes. We suggest that faecal pellets could be a suitable microenvironment for sulphate reduction. And while greigite could potentially act as proxy for faecal pellets in glacial sediments, unfortunately, we cannot rely on this possible indicator since the greigite is very sensitive to onshore alterations after sampling (Snowball and Thompson, 1990).
# 372
Demory, Francois • Oberhänsli, Hedi • Nowaczyk, Norbert • Gottschalk, Matthias • Wirth, Richard • (et. al.)
Abstract: Increased presence of greigite (high SIRM/κLF) coincides with maximum sulphur contents observed at the beginning of interglacial stages (Fig. 11A). At similar levels in another sediment core of Lake Baikal, Watanabe et al. (2004) observed pyrite mineralization. They attributed these pyrite-rich levels to mineralization at sediment/water interface under anoxic bottom water conditions. However, we prefer to interpret the greigite as a result of magnetite transformation when sulphate reduction occurs in the interglacial sediments. Peak sulphur contents would therefore be due to sulphur mineralization within the sediment and would not result from an enrichment of the sediment in sulphur at the sediment/water interface.
# 373
Demory, Francois • Oberhänsli, Hedi • Nowaczyk, Norbert • Gottschalk, Matthias • Wirth, Richard • (et. al.)
Abstract: In selected intervals, we measured titanium and iron contents in parallel to rock magnetic parameters (Fig. 9). Titanium content is a good reflection of detrital input since minerals containing titanium are not very sensitive to dissolution. Iron, however, is rather mobile and involved in the redox history of highly porous sediments: the spike of iron observed on top of the sedimentary column (Fig. 9A) marks the redox front. We observed a strong similarity between the titanium and HIRM curves: the detrital input decreases from the late glacial to the Holocene. In ancient sediments, HIRM and titanium display similar variations with high values in glacials and low values in interglacials (Fig. 9B).
# 374
Grünthal, Gottfried • Wahlström, Rutger
Abstract: The EMEC earthquake catalogue is an extension in time and space of the CENEC catalogue (Grünthal et al., 2009, http://doi.org/10.1007/s10950-008-9144-9). It consists of some 45,000 entries in Europe and the Mediterranean area and extends to the west to encompass the North Atlantic Ridge. The criteria are Mw ≥ 3.5 for events with latitude ≥ 44°N and Mw ≥ 4.0 for events with latitude < 44°N, in the time period 1000-2006. Data within the catalogue area can be obtained as ASCII-file through the EMEC Earthquake Catalogue Web Service. This webservice also enables the creation of seismicity maps according to user's specifications. In addition, a list of earthquakes in the time period 300-999 for Mw ≥ 6.0 in the catalogue area with latitude ≤ 40°N and longitude ≥ 10°E is given and a list of fake events in the time period 1000-1799.
# 375
Boesche, Nina K. • Mielke, Christian • Segl, Karl • Chabrillat, Sabine • Rogass, Christian • (et. al.)
Abstract: This data pubilcation includes EnMAP-like imaging spectroscopy data files to be used for mineral mapping with the EnMAP BOX software. It is simulated EnMAP satellite data, which is based on hyperspectral flight campaign data with the AVIRIS-NG and HyMap sensors. In preparation of the EnMAP satellite mission, an EnMAP BOX software package provides tools for visualization and scientific analysis of the data. Among many applications, the EnMAP BOX contains geological mapping tools (EnGeoMAP). Here we apply these tools to several representative test cases (Boesche, 2015; Boesche et al. 2016; Mielke et al., 2016). The test data comprise two study sites. The first scene covers the Mountain Pass open pit mine - a carbonatite deposit in California, USA. It contains calcitic rock units and rare earth element (REE) bearing minerals of the bastnaesite group, also called fluorocarbonates (Olson et al., 1954). The REE concentrations at mountain pass are 9.2% on average, among the highest in the world (Brüning and Böhmer, 2011). The high concentration and the open pit activities make Mountain Pass an ideal test site to investigate the rare earth element distribution in the surface layer. The airborne image data were collected in 2014 by Jet Propulsion Laboratory (JPL), USA, with the AVIRIS-NG sensor and form the basis for EnMAP simulations (Segl et al., 2012; Thompson et al., 2015). The second HyMap spectral image data covers part of the Miocene Cabo de Gata Nίjar volcanic field, in southeast Spain. It comprises a subset of (Chabrillat et al., 2016) covering the Rodalquilar and Lomilla Calderas, which host the economically relevant gold-silver, lead-zinc-silver-gold and alunite deposits. It is a hydrothermal alteration complex, representing the silicic alteration, the advanced argillic alteration zone, which grades into the argillic and propylitic zone (Arribas et al., 1995, 1989). The image data are part of the Cabo de Gata Nίjar HyMap imagery which was collected during the DLR HyEurope airborne campaign 2005 in the frame of the GFZ land degradation program (Chabrillat et al., 2016, 2005). We use these datasets to simulate EnMAP-like images for classification and mapping using spectroscopic remote sensing techniques in the EnGeoMAP tools. The EnMAP end-to-end Simulation (EeteS) tool produced simulated EnMAP like data with a spatial sampling distance of 30 x 30 m and 242 spectral bands (Guanter et al., 2015; Segl et al., 2012). File format for both sites: Band Sequential Image Files (*.bsq) and file header (*.hdr). The full description of the datasets is given in the associated data report by Boesche et al. (2016).
The Environmental Mapping and Analysis Program (EnMAP) is a German hyperspectral satellite mission that aims at monitoring and characterizing the Earth’s environment on a global scale. EnMAP serves to measure and model key dynamic processes of the Earth’s ecosystems by extracting geochemical, biochemical and biophysical parameters, which provide information on the status and evolution of various terrestrial and aquatic ecosystems. In the frame of the EnMAP preparatory phase, pre-flight campaigns including airborne and in-situ measurements in different environments and for several application fields are being conducted. The main purpose of these campaigns is to support the development of scientific applications for EnMAP. In addition, the acquired data are input in the EnMAP end-to-end simulation tool (EeteS) and are employed to test data pre-processing and calibration-validation methods. The campaign data are made freely available to the scientific community under a Creative Commons Attribution-ShareAlike 4.0 International License. An overview of all available data is provided in in the EnMAP Flight Campaigns Metadata Portal http://www.enmap.org/?q=flights.
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