Simon E. Engelhart
Stephen J. Culver
Alan R. Nelson
Richard W. Briggs
Peter J. Haeussler
Andrew C. Kemp
2013
<div class="article-section-wrapper js-article-section "><p>We describe the modern distribution of salt-marsh and tidal-flat foraminifera from Sitkinak Island (Trinity Islands) and Simeonof Island (Shumagin Islands), Alaska, to begin development of a dataset for later use in reconstructing relative sea-level changes caused by great earthquakes along the Alaska-Aleutian subduction zone. Dead foraminifera were enumerated from a total of 58 surface-sediment samples collected along three intertidal transects around a coastal lagoon on Sitkinak Island and two intertidal transects on Simeonof Island. Two distinctive assemblages of salt-marsh foraminifera were recognized on Sitkinak Island.<span> </span><i>Miliammina fusca</i><span> </span>dominated low-marsh settings and<span> </span><i>Balticammina pseudomacrescens</i><span> </span>dominated the high marsh. These two species make up >98% of individuals. On Simeonof Island, 93% of individuals in high-marsh settings above mean high water were<span> </span><i>B. pseudomacrescens</i>. The tidal flat on Simeonof Island was dominated by<span> </span><i>Cibicides lobatulus</i><span> </span>(60% of individuals), but the lower limit of this species is subtidal and was not sampled. These results indicate that uplift or subsidence caused by repeated earthquakes along the Alaska-Aleutian subduction zone could be reconstructed in coastal sediments using alternating assemblages of near monospecific<span> </span><i>B. pseudomacrescens</i><span> </span>and low-marsh or tidal-flat foraminifera.</p></div>
application/pdf
10.2113/gsjfr.43.1.88
en
Cushman Foundation for Foraminiferal Research
Modern salt-marsh and tidal-flat foraminifera from Sitkinak and Simeonof Islands, southwestern Alaska
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