Matches in SemOpenAlex for { <https://semopenalex.org/work/W2041351437> ?p ?o ?g. }
- W2041351437 endingPage "355" @default.
- W2041351437 startingPage "339" @default.
- W2041351437 abstract "Sediments in lakes in the Andean volcanic setting are often made up of diatomaceous ooze together with volcaniclastics and small amounts of carbonates. Despite their scarcity, carbonates along with organic matter provide significant paleoenvironmental information about lake systems. This study focuses on the carbonates in Lake Chungará, their morphologies, distribution and origin deduced from the isotopic markers. These markers reflected changes in the water and the biomass between the onset of the Holocene and around 9.6 cal kyr BP. These changes are marked by general increases in TOC, TN, and TN-δ15NAIR, and by fluctuating values of TOC-δ13CVPDB in its sediments and are probably related to major shifts in the lake surface/volume associated with rises in lake level. An increase in salinity around 10 cal kyr BP is thought to be linked to a short dry period, giving rise to the onset of carbonate production. The mid-Holocene arid period between 7.3 and 3.5 cal ka BP, with a maximum of aridity around 6.0 cal kyr BP, was deduced from δ18OVPDB values in the endogenic carbonates. These results match the reconstructions in Lake Titicaca based on benthic diatoms and paleoshore levels. Offshore sediments mainly consist of a diatomaceous ooze, laminated in the lower half (Unit 1), and banded-massive with tephra layers in the upper half of the sequence (Unit 2). TOC-δ13CVPDB and the C/N ratio confirm that phytoplankton was the main source of organic matter in these sediments. Shallower sediments (units 3 to 5) developed in platform and littoral settings, providing evidence of subaqueous macrophytes and, to a lesser extent, land plants. Carbonate content ranges between 0.1 and 6 wt.% in offshore settings (30 to 40 m water depth) and reaches the maximum values in the lower part of Unit 2. Carbonate minerals (low magnesium calcite and minor amounts of high magnesium calcite and aragonite) are scarce and are arranged in mm-thick layers, commonly forming cm-thick levels or bioclasts. Carbonate layers are made up of euhedral-to-subhedral spindle-shaped calcite crystals and, to a lesser extent, aragonite needles, all in the μm range. Aragonite spheroids coexist in littoral sediments with other carbonate shapes and charophyte remains, where carbonate reaches locally up to 20 wt.%. CO2 photosynthetic depletions related to seasonal phytoplankton blooms were responsible for the high frequency deposition of mm-thick carbonate layers. The average values for δ13CVPDB in lake water, plankton and sediments of Lake Chungará (as organic matter or as carbonate) are around 15‰ higher than commonly reported values in other lakes. This 13C enrichment is attributed to carbon assimilation from a DIC affected by methanogenesis, in which HCO3− is the dominant species. The δ13CVPDB and δ18OVPDB variations and their covariation in endogenic carbonates suggest that lake water volume and lake level increased along the Holocene." @default.
- W2041351437 created "2016-06-24" @default.
- W2041351437 creator A5001410555 @default.
- W2041351437 creator A5021627283 @default.
- W2041351437 creator A5026939932 @default.
- W2041351437 creator A5034929125 @default.
- W2041351437 creator A5044466897 @default.
- W2041351437 creator A5055813501 @default.
- W2041351437 creator A5061190263 @default.
- W2041351437 creator A5065771788 @default.
- W2041351437 creator A5080202509 @default.
- W2041351437 creator A5084777849 @default.
- W2041351437 date "2011-07-01" @default.
- W2041351437 modified "2023-10-11" @default.
- W2041351437 title "Carbonate and organic matter sedimentation and isotopic signatures in Lake Chungará, Chilean Altiplano, during the last 12.3kyr" @default.
- W2041351437 cites W1630919437 @default.
- W2041351437 cites W1927648166 @default.
- W2041351437 cites W1963655791 @default.
- W2041351437 cites W1964739187 @default.
- W2041351437 cites W1968126362 @default.
- W2041351437 cites W1972070875 @default.
- W2041351437 cites W1974391619 @default.
- W2041351437 cites W1974935716 @default.
- W2041351437 cites W1978340835 @default.
- W2041351437 cites W1979964938 @default.
- W2041351437 cites W1982536001 @default.
- W2041351437 cites W1984966004 @default.
- W2041351437 cites W1986867577 @default.
- W2041351437 cites W1990853891 @default.
- W2041351437 cites W1991263522 @default.
- W2041351437 cites W1994344708 @default.
- W2041351437 cites W1994925117 @default.
- W2041351437 cites W1996467276 @default.
- W2041351437 cites W1996871595 @default.
- W2041351437 cites W2005649253 @default.
- W2041351437 cites W2007506888 @default.
- W2041351437 cites W2007985863 @default.
- W2041351437 cites W2008852195 @default.
- W2041351437 cites W2009578763 @default.
- W2041351437 cites W2009607369 @default.
- W2041351437 cites W2010021578 @default.
- W2041351437 cites W2012935147 @default.
- W2041351437 cites W2013428409 @default.
- W2041351437 cites W2020119617 @default.
- W2041351437 cites W2022486566 @default.
- W2041351437 cites W2031770815 @default.
- W2041351437 cites W2034858067 @default.
- W2041351437 cites W2039666610 @default.
- W2041351437 cites W2041183248 @default.
- W2041351437 cites W2041738962 @default.
- W2041351437 cites W2043398939 @default.
- W2041351437 cites W2044460144 @default.
- W2041351437 cites W2045099531 @default.
- W2041351437 cites W2052133962 @default.
- W2041351437 cites W2058758379 @default.
- W2041351437 cites W2062534390 @default.
- W2041351437 cites W2063065929 @default.
- W2041351437 cites W2064132156 @default.
- W2041351437 cites W2072872798 @default.
- W2041351437 cites W2079655318 @default.
- W2041351437 cites W2085992989 @default.
- W2041351437 cites W2100866593 @default.
- W2041351437 cites W2110261248 @default.
- W2041351437 cites W2111111863 @default.
- W2041351437 cites W2112408076 @default.
- W2041351437 cites W2113427692 @default.
- W2041351437 cites W2121539408 @default.
- W2041351437 cites W2121562238 @default.
- W2041351437 cites W2128123878 @default.
- W2041351437 cites W2131278723 @default.
- W2041351437 cites W2136776507 @default.
- W2041351437 cites W2138812961 @default.
- W2041351437 cites W2141777092 @default.
- W2041351437 cites W2154002562 @default.
- W2041351437 cites W2154276443 @default.
- W2041351437 cites W2154284281 @default.
- W2041351437 cites W2156055143 @default.
- W2041351437 cites W2159858068 @default.
- W2041351437 cites W2162314192 @default.
- W2041351437 cites W2167294513 @default.
- W2041351437 cites W2168234811 @default.
- W2041351437 cites W2176203405 @default.
- W2041351437 cites W2322818437 @default.
- W2041351437 cites W2911528385 @default.
- W2041351437 cites W301116544 @default.
- W2041351437 cites W318880995 @default.
- W2041351437 cites W4206012312 @default.
- W2041351437 cites W4231012959 @default.
- W2041351437 cites W4240143469 @default.
- W2041351437 cites W4255503413 @default.
- W2041351437 cites W75947411 @default.
- W2041351437 doi "https://doi.org/10.1016/j.palaeo.2011.05.036" @default.
- W2041351437 hasPublicationYear "2011" @default.
- W2041351437 type Work @default.
- W2041351437 sameAs 2041351437 @default.
- W2041351437 citedByCount "39" @default.
- W2041351437 countsByYear W20413514372012 @default.
- W2041351437 countsByYear W20413514372013 @default.