Glen Snyder 2014-11-04 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/72e6d378488670471e477a79d73c10d2 https://mcm.lternet.edu/content/mineralogic-composition-cryogenic-evaporites-determined-low-temperature-x-ray-diffactometry As part of a collaborative investigation between researchers at Rice University, Arkansas State University, University of Rochester, and Ohio State University, lakes of the McMurdo Dry Valleys were sampled at discreet depth intervals during the 2005-2006 field season.  Sample splits were subsequently analyzed for chemical and isotopic composition of both gases and dissolved  ions, as well as dissolved organic carbon. In addition, cryogenic salts were sampled in the surrounding lake shores in order to determine the salt sources. Gravity cores were also obtained and in the case of Lake Vanda, a white precipitate was recovered from the lake bottom.            Presented  in this file is the mineralogic composition of salt crusts that were collected on the surface of sediment and rocks surrounding the lakes, as well as the lake-bottom precipitate from Lake Vanda.  The results are based on low-temperature XRD determinations, and Rietveld refinement of whole peaks.             This material is based upon work supported by the National Science Foundation under Grant No.0440686 2005-12-21 2005-12-27 ground condition Metadata completed in 2016This dataset was created Oct 1, 2008 by MCM-LTER information manager (Chris Gardner) after email discussion with PI Glen Snyder. As needed LTER Core Areas inorganic nutrients None <cntorg>McMurdo Dry Valleys LTER</cntorg> <onlink>http://mcmlter.org/</onlink> <span property="dc:title" content="McMurdo Dry Valleys LTER" class="rdf-meta element-hidden"></span> Name: Chris Gardner Role: data manager Name: Inigo San Gil Role: data manager Not Applicable Not Applicable Field and/or Lab Methods  Salts were collected in the areas surrounding the Dry Valley lakes. The samples were bagged and then placed either in boxes or in plastic containers in order to avoid crushing them. The samples were stored in a freezer at -40 C, prior to shipping, due to the instability of Antarcticite at room temperatures. The samples were then shipped under dry ice to Rice University in Houston, then shipped to the Steacie Institute for Molecular Sciences  in Ottawa, which is a division of the Canadian Research Council.            Hailong Lu, a research scientist in the Institute whose specialty is on the structure of marine gas hydrates, placed each sample in a mortar with liquid nitrogen and then ground it into a powder. The powders were then analyzed with a low-temperature XRD. Temperatures were first dropped to -140 C, then gradually  ramped up to room temperature to look at phase changes that occurred on warming. Minerals were identified JADE 8.5 data processing software, and the ICDD PDF-2 Data Base. The relative abundance of each crygenic mineral was dertermined by the Rietveld method of whole-peak fitting.    Salts were collected in the areas surrounding the Dry Valley lakes. The samples were bagged and then placed either in boxes or in plastic containers in order to avoid crushing them. The samples were stored in a freezer at -40 C, prior to shipping, due to the instability of Antarcticite at room temperatures. The samples were then shipped under dry ice to Rice University in Houston, then shipped to the Steacie Institute for Molecular Sciences  in Ottawa, which is a division of the Canadian Research Council.          Hailong Lu, a research scientist in the Institute whose specialty is on the structure of marine gas hydrates, placed each sample in a mortar with liquid nitrogen and then ground it into a powder. The powders were then analyzed with a low-temperature XRD. Temperatures were first dropped to -140 C, then gradually  ramped up to room temperature to look at phase changes that occurred on warming. Minerals were identified JADE 8.5 data processing software, and the ICDD PDF-2 Data Base. The relative abundance of each crygenic mineral was dertermined by the Rietveld method of whole-peak fitting.  unknown ANCILLARY_SNYDER_SALTS DATASET_CODE Table Identifier The data provider Table Identifier Location Name Name of lake where measurement was made The data provider Name of lake where measurement was made Location_Type Sample type description and/or location The data provider Sample type description and/or location Sample_ID Sample identification code The data provider Sample identification code Latitude Sample Latitude The data provider degree Longitude Sample Longitude The data provider degree Date_time Date sample was collected The data provider calendar date/time mm/dd/yyyy gregorian calendar Halite Percent composition of halite The data provider 0 100 dimensionless Antarcticite Percent composition of Antarcticite The data provider 0 100 dimensionless Thenardite Percent composition of Thenardite The data provider 0 100 dimensionless Mirabilite Percent composition of Mirabilite The data provider 0 100 dimensionless Gypsum Percent composition of Gypsum The data provider 0 100 dimensionless Calcite Percent composition of Calcite The data provider 0 100 dimensionless Aragonite Percent composition of Aragonite The data provider 0 100 dimensionless Quartz Percent composition of Quartz The data provider 0 100 dimensionless Albite Percent composition of Albite The data provider 0 100 dimensionless McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 27 column , https://mcm.lternet.edu/sites/default/files/ANCILLARY_SNYDER_SALTS.csv None 2014-11-04 2014-11-04 McMurdo Dry Valleys LTER http://mcmlter.org/ Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee. 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