Publication Date:
2024-07-01
Description:
High-resolution records of glacial-interglacial variations in biogenic carbonate, opal, and detritus (derived from non-destructive core log measurements of density, P-wave velocity and color; r 〉= 0.9) from 15 sediment sites in the eastern equatorial (sampling resolution is ~1 kyr) clear response to eccentricity and precession forcing. For the Peru Basin, we generate a high-resolution (21 kyr increment) orbitally-based chronology for the last 1.3 Ma. Spectral analysis indicates that the 100 kyr cycle became dominant at roughly 1.2 Ma, 200-300 kyr earlier than reported for other paleoclimatic records. The response to orbital forcing is weaker since the Mid-Brunhes Dissolution Event (at 400 ka). A west-east reconstruction of biogenic sedimentation in the Peru Basin (four cores; 91-85°W) distinguishes equatorial and coastal upwelling systems in the western and eastern sites, respectively. A north-south reconstruction perpendicular to the equatorial upwelling system (11 cores, 11°N-°3S) shows high carbonate contents (〉= 50%) between 6°N and 4°S and highly variable opal contents between 2°N and 4°S. Carbonate cycles B-6, B-8, B-10, B-12, B-14, M-2, and M-6 are well developed with B-10 (430 ka) as the most prominent cycle. Carbonate highs during glacials and glacial-interglacial transitions extended up to 400 km north and south compared to interglacial or interglacial^glacial carbonate lows. Our reconstruction thus favors glacial-interglacial expansion and contraction of the equatorial upwelling system rather than shifting north or south. Elevated accumulation rates are documented near the equator from 6°N to 4°S and from 2°N to 4°S for carbonate and opal, respectively. Accumulation rates are higher during glacials and glacial-interglacial transitions in all cores, whereas increased dissolution is concentrated on Peru Basin sediments close to the carbonate compensation depth and occurred during interglacials or interglacial-glacial transitions.
Keywords:
181KL; 184KL; 189KL; 206KL; 217KL; 222SL; 229KL; 235KL; 243KL; 244KA; 249KL; 251KL; 254KL; 261KA; 268KA; 272KA; 276KL; 278KA; 286KL; ATESEPP; Gravity corer (Kiel type); KAL; Kasten corer; KL; Peru Basin; Piston corer (BGR type); SEDIPERU - TUSCH; SL; SO106/1; SO106/1_181KL; SO106/1_184KL; SO106/1_189KL; SO106/1_206KL; SO106/1_217KL; SO106/1_222SL; SO106/1_229KL; SO106/1_235KL; SO106/2; SO106/2_243KL; SO106/2_244KA; SO106/2_249KL; SO106/2_251KL; SO106/2_254KL; SO106/2_261KA; SO106/2_268KA; SO106/2_272KA; SO106/2_276KL; SO106/2_278KA; SO106/2_286KL; SO79; SO79_108KL; SO79_136KL; SO79_164KL; SO79_169KL; SO79_26KL; SO79_48KL; SO79_53KL; SO79_71KL; SO79_77KL; SO79_82KL; SO79_85KL; SO79_9KL; Sonne
Type:
Dataset
Format:
application/zip, 37 datasets
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