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Title: Site U1556
Site U1556 (30°56.5244′S, 26°41.9472′W; proposed Site SATL-53B) is in the central South Atlantic Ocean at a water depth of 5002 meters below sea level (mbsl) ~1250 km west of the Mid-Atlantic Ridge (see Figure F1 and Tables T1, T2, all in the Expedition 390/393 summary chapter [Coggon et al., 2024d]) on crust that formed at a slow half spreading rate of ~13.5 mm/y, which is the slowest spreading rate in the study region (Kardell et al., 2019; Christeson et al., 2020) (see Figure F7 in the Expedition 390/393 summary chapter [Coggon et al., 2024d]). With an estimated age of 61.2 Ma, Site U1556 is the oldest location of the South Atlantic Transect (SAT) campaign (International Ocean Discovery Program [IODP] Expeditions 390C, 395E, 390, and 393). Site U1556 is less heavily sedimented than Site U1557, which is located 6.5 km east of Site U1556 on 60.7 Ma ocean crust. Together, both sites allow for investigation of the effect of sediment thickness on crustal evolution.  more » « less
Award ID(s):
1326927
NSF-PAR ID:
10487299
Author(s) / Creator(s):
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Publisher / Repository:
International Ocean Discovery Program
Date Published:
Journal Name:
Proceedings of the International Ocean Discovery Program Expedition reports
Volume:
390/393
Issue:
103
ISSN:
2377-3189
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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  1. Site U1557 (30°56.4651′S, 26°37.7892′W, proposed Site SATL-56A) is in the central South Atlantic Ocean at a water depth of ~5011 meters below sea level (mbsl) ~1243 km west of the Mid-Atlantic Ridge (see Figure F1 and Tables T1, T2, all in the Expedition 390/393 summary chapter [Coggon et al., 2024d]) on crust that formed at a slow half spreading rate of ~13.5 mm/y, which is the slowest spreading rate in the study region (Kardell et al., 2019; Christeson et al., 2020) (see Figure F7 in the Expedition 390/393 summary chapter [Coggon et al., 2024d]; Reece et al., 2016; Reece and Estep, 2019). With an estimated age of 60.7 Ma, Site U1557 is just about the oldest location of the South Atlantic Transect (SAT) campaign (International Ocean Discovery Program [IODP] Expeditions 390C, 395E, 390, and 393). Site U1557 is more heavily sedimented than Site U1556, which is located 6.5 km west of Site U1557 on 61.2 Ma ocean crust. Together, both sites allow for investigation of the effect of sediment thickness on crustal evolution. 
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  2. Site U1561 (30˚43.2902′S, 26˚41.7162′W; proposed Site SATL-55A) is in the central South Atlantic Ocean at a water depth of 4910 meters below sea level (mbsl) ~1250 km west of the Mid-Atlantic Ridge (see Figure F1 and Tables T1, T2, all in the Expedition 390/393 summary chapter [Coggon et al., 2024d]) on crust that formed at a slow half spreading rate of ~13.5 mm/y, which is the slowest spreading rate in the study region (Kardell et al., 2019; Christeson et al., 2020; see Figure F7 in the Expedition 390/393 summary chapter [Coggon et al., 2024d]). With an estimated age of 61.2 Ma, Site U1561 is the oldest location of the South Atlantic Transect (SAT) campaign (International Ocean Discovery Program [IODP] Expeditions 390C, 395E, 390, and 393). Site U1561 sits on a basement ridge and is therefore less heavily sedimented than Sites U1556 and U1557, which are located ~25 km south of Site U1561 on 61.2 and 60.7 Ma ocean crust, respectively. Together, all sites in this region allow for investigation of the effect of sediment thickness on crustal evolution. 
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