Publication Date:
2023-08-28
Description:
The Carnegie Ridge is a linear, aseismic, submarine ridge lying between the Galapagos Islands and the coast of South America. Surface ship, near bottom, and grain size studies from the saddle have been used to delineate the present geological environment and history of the ridge. Structurally the Carnegie Ridge is rather simple in profile, being bounded by east-west trending scarps which give the ridge a block-faulted appearance. Acoustic basement over the ridge appears smooth on reflection profiles and is composed of chert. The sedimentary sequence above the chert horizon contains a lower chalk unit overlain by calcareous ooze. Where erosion has exposed the chalk a karst-like micro-topography is present which is characterized by steep walled channels and cliffs and consolidated bed forms undergoing erosion and dissolution. The ridge crest has been stripped of almost its entire sediment cover. Thick sequences of sediment are found only in areas protected from north or south flowing bottom currents. Evidence of erosion is provided by extensive channeling on both the north and south flanks of the ridge. Near bottom observations in one channel on the north flank revealed a large field of sand dunes indicating northward, downslope sediment transport. These dunes are found on manganese-encrusted chalk which floors the channel.
Keywords:
Carnegie Ridge, Pacific Ocean; Comment; Deposit type; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Description; Event label; FFC; File name; Free fall corer; Identification; MG1; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; PC; Photo/Video; Piston corer; Position; PV; Quantity of deposit; Size; Substrate type; Uniform resource locator/link to image; Visual description; Y71-03; Y71-03-20; Y71-03-21C; Y71-03-26PC; Y71-03-30C; Y71-03-32; Y71-03-32C; Y71-03-34C; Yaquina
Type:
Dataset
Format:
text/tab-separated-values, 112 data points
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