کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4689800 1636089 2012 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Seaweed-assisted, benthic gravel transport by tidal currents
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Seaweed-assisted, benthic gravel transport by tidal currents
چکیده انگلیسی

Traction transport of pebbles and cobbles occurs subtidally at current velocities below 0.5 m s− 1 when seaweed attached to clasts provides additional lift and drag to the clast. In the Juan de Fuca Strait, British Columbia, Canada, the seaweed Cymanthere triplicata commonly attaches to pebbles and provides sufficient additional surface area for tidal currents to drag the clast along the seafloor. Using in situ measurements of current velocities at 13 m water depth, the threshold for initiation of motion of a 30 mm pebble with attached seaweed is 0.3 m s− 1. This is approximately one order of magnitude less than the activation velocity for a 30 mm pebble without attached seaweed.In addition to kelp-rafted (floated) gravel, seaweed-assisted, benthic gravel transport is possible in marine settings where unidirectional currents (e.g., tidal currents, storm-induced bottom currents) are sufficient to transport pebbles alongshore, and into and across the offshore (below fairweather wave base). If preserved in the rock record, deposits of algal-enhanced gravel deposited via unidirectional, subtidal currents will likely appear as isolated gravel clasts encased in sandstone, reflecting the similar current velocities required to transport these two clast groups.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sedimentary Geology - Volumes 265–266, 15 July 2012, Pages 121–125
نویسندگان
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