Monitoring of Sierra Nevada Caves Reveals the Potential for Stalagmites to Archive Seasonal Variability

In the southwestern United States, California (CA) is one of the most climatically sensitive regions given its low (≤250 mm/year) seasonal precipitation and its inherently variable hydroclimate, subject to large magnitude modulation. To reconstruct past climate change in CA, cave calcite deposits (stalagmites) have been utilized as an archive for environmentally sensitive proxies, such as stable isotope compositions (δ18O, δ13C) and trace element concentrations (e.g., Mg, Ba, Sr). Monitoring the cave and associated surface environments, the chemical evolution of cave drip-water, the calcite precipitated from the drip-water, and the response of these systems to seasonal variability in precipitation and temperature is imperative for interpreting stalagmite proxies. Here we present monitored drip-water and physical parameters at Lilburn Cave, Sequoia Kings Canyon National Park (Southern Sierra Nevada), CA, and measured trace element concentrations (Mg, Sr, Ba, Cu, Fe, Mn) and stable isotopic compositions (δ18O, δ2H) of drip-water and for calcite (δ18O) precipitated on glass substrates over a two-year period (November 2018 to February 2021) to better understand how chemical variability at this site is influenced by local and regional precipitation and temperature variability. Despite large variability in surface temperatures and precipitation amount and source region (North Pacific vs. subtropical Pacific), Lilburn Cave exhibits a constant cave environment year-round. At two of the three sites within the cave, drip-water δ18O and δ2H are influenced seasonally by evaporative enrichment. At a third collection site in the cave, the drip-water δ18O responds solely to precipitation δ18O variability. The Mg/Ca, Ba/Ca, and Sr/Ca ratios are seasonally responsive to prior calcite precipitation at all sites but minimally to water-rock interaction. Lastly, we examine the potential of trace metals (e.g., Mn2+ and Cu2+as a geochemical proxy of recharge and find that variability in their concentrations has high potential to denote the onset of the rainy season in the study region. The drip-water composition is recorded in the calcite, demonstrating that stalagmites from Lilburn Cave, and potentially more regionally, could record seasonal variability in weather even during periods of substantially reduced rainfall.

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Identifying short-term and seasonal trends in cave drip water trace element concentrations based on a daily-scale automatically collected drip water dataset

Chemical Geology ◽

10.1016/j.chemgeo.2012.08.009 ◽

2012 ◽

Vol 330-331 ◽

pp. 1-16 ◽

Cited By ~ 14

Author(s):

James U.L. Baldini ◽

Frank McDermott ◽

Lisa M. Baldini ◽

Chris J. Ottley ◽

Kathryn L. Linge ◽

...

Keyword(s):

Trace Element ◽

Short Term ◽

Drip Water ◽

Seasonal Trends ◽

Element Concentrations ◽

Cave Drip Water ◽

Daily Scale

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ENSO–cave drip water hydrochemical relationship: a 7-year dataset from south-eastern Australia

Hydrology and Earth System Sciences ◽

10.5194/hess-20-4625-2016 ◽

2016 ◽

Vol 20 (11) ◽

pp. 4625-4640 ◽

Cited By ~ 16

Author(s):

Carol V. Tadros ◽

Pauline C. Treble ◽

Andy Baker ◽

Ian Fairchild ◽

Stuart Hankin ◽

...

Keyword(s):

Trace Element ◽

El Niño ◽

El Nino ◽

Flow Path ◽

Geochemical Composition ◽

Drip Water ◽

South Eastern ◽

Cave Drip Water ◽

Eastern Australia ◽

Water Signal

Abstract. Speleothems (cave deposits), used for palaeoenvironmental reconstructions, are deposited from cave drip water. Differentiating climate and karst processes within a drip-water signal is fundamental for the correct identification of palaeoenvironmental proxies and ultimately their interpretation within speleothem records. We investigate the potential use of trace element and stable oxygen-isotope (δ18O) variations in cave drip water as palaeorainfall proxies in an Australian alpine karst site. This paper presents the first extensive hydrochemical and δ18O dataset from Harrie Wood Cave, in the Snowy Mountains, south-eastern (SE) Australia. Using a 7-year long rainfall δ18O and drip-water Ca, Cl, Mg / Ca, Sr / Ca and δ18O datasets from three drip sites, we determined that the processes of mixing, dilution, flow path change, carbonate mineral dissolution and prior calcite precipitation (PCP) accounted for the observed variations in the drip-water geochemical composition. We identify that the three monitored drip sites are fed by fracture flow from a well-mixed epikarst storage reservoir, supplied by variable concentrations of dissolved ions from soil and bedrock dissolution. We constrained the influence of multiple processes and controls on drip-water composition in a region dominated by El Niño–Southern Oscillation (ENSO). During the El Niño and dry periods, enhanced PCP, a flow path change and dissolution due to increased soil CO2 production occurred in response to warmer than average temperatures in contrast to the La Niña phase, where dilution dominated and reduced PCP were observed. We present a conceptual model, illustrating the key processes impacting the drip-water chemistry. We identified a robust relationship between ENSO and drip-water trace element concentrations and propose that variations in speleothem Mg / Ca and Sr / Ca ratios may be interpreted to reflect palaeorainfall conditions. These findings inform palaeorainfall reconstruction from speleothems regionally and provide a basis for palaeoclimate studies globally, in regions where there is intermittent recharge variability.

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Seasonal variability of oxygen and hydrogen stable isotopes in precipitation and cave drip water at Guilin, southwest China

Environmental Earth Sciences ◽

10.1007/s12665-014-3224-7 ◽

2014 ◽

Vol 72 (8) ◽

pp. 3183-3191 ◽

Cited By ~ 15

Author(s):

Xia Wu ◽

Xiaoyan Zhu ◽

Moucheng Pan ◽

Meiliang Zhang

Keyword(s):

Stable Isotopes ◽

Seasonal Variability ◽

Southwest China ◽

Drip Water ◽

Cave Drip Water

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Geochemical maps showing distributions of anomalous element concentrations and of anomalous drainage basins, Mokelumne Wilderness and contiguous roadless areas, central Sierra Nevada, California

10.3133/mf1201c ◽

1983 ◽

Keyword(s):

Sierra Nevada ◽

Drainage Basins ◽

Element Concentrations ◽

Roadless Areas

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Trace Element Concentrations in the Mediterranean Mussel Mytilus galloprovincialis Lamarck, 1819 Caught from Sinop Coast of the Black Sea, Turkey

The Open Marine Biology Journal ◽

10.2174/1874450801206010001 ◽

2012 ◽

Vol 6 (1) ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Levent Bat

Keyword(s):

Trace Element ◽

Black Sea ◽

Mytilus Galloprovincialis ◽

The Black Sea ◽

Element Concentrations ◽

Mediterranean Mussel ◽

The Mediterranean

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ASSESSMENT OF TRACE ELEMENT CONCENTRATIONS IN THE FARMINGTON RIVER, HARTFORD COUNTY, CT

10.1130/abs/2016ne-272210 ◽

2016 ◽

Author(s):

Matthew Costa ◽

◽

Carley M. Cavanaugh ◽

Oluyinka Oyewumi

Keyword(s):

Trace Element ◽

Element Concentrations

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MAGMA-WALL ROCK INTERACTION IN THE ST FRANCOIS MOUNTAINS, MISSOURI: UNRAVELLING MAGMATIC ARCHITECTURE USING MICROSTRUCTURES AND TRACE ELEMENT GEOCHEMISTRY

10.1130/abs/2020sc-343245 ◽

2020 ◽

Author(s):

Gary S. Michelfelder ◽

◽

Kimberly LaRue

Keyword(s):

Trace Element ◽

Wall Rock ◽

Trace Element Geochemistry ◽

Element Geochemistry ◽

Rock Interaction

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Magnetite texture and trace-element geochemistry fingerprint of pulsed mineralization in the Xinqiao Cu-Fe-Au deposit, Eastern China

American Mineralogist ◽

10.2138/am-2020-7414 ◽

2020 ◽

Vol 105 (11) ◽

pp. 1712-1723

Author(s):

Yu Zhang ◽

Pete Hollings ◽

Yongjun Shao ◽

Dengfeng Li ◽

Huayong Chen ◽

...

Keyword(s):

Trace Element ◽

Triple Junction ◽

Eastern China ◽

Black Shales ◽

Hydrothermal Fluids ◽

Oscillatory Zoning ◽

Trace Element Geochemistry ◽

Element Geochemistry ◽

Rock Interaction ◽

Multiple Pulses

Abstract The origin of stratabound deposits in the Middle-Lower Yangtze River Valley Metallogenic Belt (MLYRB), Eastern China, is the subject of considerable debate. The Xinqiao Cu-Fe-Au deposit in the Tongling ore district is a typical stratabound ore body characterized by multi-stage magnetite. A total of six generations of magnetite have been identified. Mt1 is commonly replaced by porous Mt2, and both are commonly trapped in the core of Mt3, which is characterized by both core-rim textures and oscillatory zoning. Porous Mt4 commonly truncates the oscillatory zoning of Mt3, and Mt5 is characterized by 120° triple junction texture. Mt1 to Mt5 are commonly replaced by pyrite that coexists with quartz, whereas Mt6, with a fine-grained foliated and needle-like texture, commonly cuts the early pyrite as veins and is replaced by pyrite that coexists with calcite. The geochemistry of the magnetite suggests that they are hydrothermal in origin. The microporosity of Mt2 and Mt4 magnetite, their sharp contacts with Mt1 and Mt3, and lower trace-element contents (e.g., Si, Ca, Mg, and Ti) than Mt1 and Mt3 suggest that they formed via coupled dissolution and reprecipitation of the precursor Mt1 and Mt3 magnetite, respectively. This was likely caused by high-salinity fluids derived from intensive water-rock interaction between the magmatic-hydrothermal fluids associated with the Jitou stock and Late Permian metalliferous black shales. The 120° triple junction texture of Mt5 suggests it is the result of fluid-assisted recrystallization, whereas Mt6 formed by replacement of hematite as a result of fracturing. The geochemistry of the magnetite suggests that the temperature increased from Mt2 to Mt3 and implies that there were multiple pulses of fluids from a magmatic-hydrothermal system. Therefore, we propose that the Xinqiao stratiform mineralization was genetically associated with multiple influxes of magmatic hydrothermal fluids derived from the Early Cretaceous Jitou stock. This study demonstrates that detailed texture examination and in situ trace-elements analysis under robust geological and petrographic frameworks can effectively constrain the mineralization processes and ore genesis.

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