Conference mulls ocean chemistry problems

1987 ◽  
Vol 65 (41) ◽  
pp. 5-6
Keyword(s):  
Ocean Chemistry

IDENTIFYING LONG-TERM SEAWATER CIRCULATION IN COASTAL AQUIFERS AND ITS POTENTIAL ROLE IN OCEAN CHEMISTRY

2017 ◽  
Author(s):  
Yael Kiro ◽  
◽  
Holly A. Michael ◽  
Carlos Duque ◽  
Yoseph Yechieli
Keyword(s):  
Coastal Aquifers ◽  
Potential Role ◽  
Ocean Chemistry

Paleo-ocean chemistry records in marine opal: Implications for fluxes of trace elements, cosmogenic nuclides (10Be and 26Al), and biological productivity

2006 ◽  
Vol 70 (13) ◽  
pp. 3275-3289 ◽  
Author(s):  
D. Lal ◽  
C. Charles ◽  
L. Vacher ◽  
J.N. Goswami ◽  
A.J.T. Jull ◽  
...  
Keyword(s):  
Trace Elements ◽  
Cosmogenic Nuclides ◽  
Biological Productivity ◽  
Ocean Chemistry

scholarly journals Hydrothermal Flux and Global Ocean Chemistry.

1995 ◽  
Vol 104 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Naotatsu SHIKAZONO
Keyword(s):  
Global Ocean ◽  
Ocean Chemistry

scholarly journals Ocean Acidification 2.0: Managing our Changing Coastal Ocean Chemistry

BioScience ◽  
2014 ◽  
Vol 64 (7) ◽  
pp. 581-592 ◽  
Author(s):  
Aaron L. Strong ◽  
Kristy J. Kroeker ◽  
Lida T. Teneva ◽  
Lindley A. Mease ◽  
Ryan P. Kelly
Keyword(s):  
Ocean Acidification ◽  
Coastal Ocean ◽  
Ocean Chemistry

Ocean chemistry and deep-sea sediments

1993 ◽  
Vol 110 (1-2) ◽  
pp. 177-178
Author(s):  
R. Chester
Keyword(s):  
Deep Sea ◽  
Deep Sea Sediments ◽  
Ocean Chemistry

scholarly journals Even more interdisciplinary future lies ahead for ocean chemistry

Eos ◽  
1999 ◽  
Vol 80 (18) ◽  
pp. 207 ◽  
Author(s):  
Larry Mayer ◽  
Ellen Druffel ◽  
Mike Bender ◽  
Ed Boyle ◽  
Rick Jahnke ◽  
...  
Keyword(s):  
Ocean Chemistry

scholarly journals Isotopically “heavy” pyrite in marine sediments due to high sedimentation rates and non-steady-state deposition

Geology ◽  
2021 ◽  
Author(s):  
Jiarui Liu ◽  
Gilad Antler ◽  
André Pellerin ◽  
Gareth Izon ◽  
Ingrid Dohrmann ◽  
...  
Keyword(s):  
Critical Role ◽  
Global Ocean ◽  
Sedimentation Rates ◽  
Geological Time ◽  
Near Surface ◽  
Reactive Iron ◽  
Depositional Processes ◽  
Pyrite Formation ◽  
Ocean Chemistry ◽  
Sedimentary Pyrite

Sedimentary pyrite formation links the global biogeochemical cycles of carbon, sulfur, and iron, which, in turn, modulate the redox state of the planet’s surficial environment over geological time scales. Accordingly, the sulfur isotopic composition (δ34S) of pyrite has been widely employed as a geochemical tool to probe the evolution of ocean chemistry. Characteristics of the depositional environment and post-depositional processes, however, can modify the δ34S signal that is captured in sedimentary pyrite and ultimately preserved in the geological record. Exploring sulfur and iron diagenesis within the Bornholm Basin, Baltic Sea, we find that higher sedimentation rates limit the near-surface sulfidization of reactive iron, facilitating its burial and hence the subsurface availability of reactive iron for continued and progressively more 34S-enriched sediment-hosted pyrite formation (δ34S ≈ –5‰). Using a diagenetic model, we show that the amount of pyrite formed at the sediment-water interface has increased over the past few centuries in response to expansion of water-column hypoxia, which also impacts the sulfur isotopic signature of pyrite at depth. This contribution highlights the critical role of reactive iron in pyrite formation and questions to what degree pyrite δ34S values truly reflect past global ocean chemistry and biogeochemical processes. This work strengthens our ability to extract local paleoenvironmental information from pyrite δ34S signatures.

scholarly journals Middle Ordovician Upwelling-Related Ironstone of North Wales: Coated Grains, Ocean Chemistry, and Biological Evolution

2021 ◽  
Vol 9 ◽  
Author(s):  
Sarah K. Dunn ◽  
Peir K. Pufahl ◽  
J. Brendan Murphy ◽  
Stephen W. Lokier
Keyword(s):  
Coastal Upwelling ◽  
High Surface ◽  
Biological Evolution ◽  
Deep Ocean ◽  
Middle Ordovician ◽  
Rheic Ocean ◽  
Carbonate Fluorapatite ◽  
Surface Marking ◽  
Ocean Chemistry ◽  
Upwelling Intensity

Middle Ordovician phosphatic ironstone of the Welsh Basin provides new insight into the paleoenvironmental significance of ironstone and Ordovician ocean chemistry. Deposition occurred in a back-arc basin along the southern margin of Avalonia as the Rheic Ocean opened to the south. Ironstone is interpreted to have accumulated as part of an aggradational parasequence on a storm-dominated shelf with coastal upwelling. This parasequence has a laminated pyritic mudstone base that grades upward into variably bioturbated mudstone and coated grain-rich, intraclastic ironstone, which is overlain in turn by cross-stratified grainstone composed entirely of coated Fe grains. A coarser clastic parasequence composed of more proximal lithofacies rests conformably above and suggests the contact between the two parasequences is a maximum flooding surface marking the onset of highstand conditions. Lithofacies associations suggest that sustained coastal upwelling created a wedge of nutrient-rich, ferruginous seawater on the middle shelf that stimulated high surface ocean productivities. Large, coated Fe grains (granule size) composed of discontinuous and concentric carbonate fluorapatite, hematite, and chamosite cortical layers record fluctuations in pore water Eh that are interpreted to have been related to changes in upwelling intensity and intermittent storm reworking of the seafloor. Results support an emerging model for Ordovician ironstone underpinned by the development of ferruginous bottom water that was periodically tapped by coastal upwelling. Expanding, semi-restricted seaways such as the Rheic Ocean were ideal locations for the ponding of this anoxic, hydrothermally enriched seawater, especially during the early Paleozoic when the deep ocean was variably and inconsistently oxygenated. The coincidence of ironstone depositional episodes with graptolite diversification events suggests that, in addition to Fe, the sustained supply of upwelling-related P may have driven the radiation of some planktonic ecosystems during the Great Ordovician Biodiversification Event. Concomitant minor extinctions of benthic trilobites occurred as these ferruginous waters impinged on the shelf.

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