Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons

Emily E. Zawacki; Matthijs C. van Soest; Kip V. Hodges; Jennifer J. Scott; Mélanie Barboni; Manfred R. Strecker; Craig S. Feibel; Christopher J. Campisano; J. Ramón Arrowsmith

doi:10.1016/j.epsl.2022.117375

Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons

Emily E. Zawacki, Matthijs C. van Soest, Kip V. Hodges, Jennifer J. Scott, Mélanie Barboni, Manfred R. Strecker, Craig S. Feibel, Christopher J. Campisano, J. Ramón Arrowsmith

Continental Scientific Drilling Facility

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Detrital zircons from two major rift basins within the East African Rift System (EARS) provide a means to evaluate not only sediment provenance and landscape dynamics in sedimentary basins, but also the timing of the silicic volcano-tectonic evolution of the rift system. We sampled from drill cores collected by the Hominin Sites and Paleolakes Drilling Project (HSPDP) in Ethiopia and Kenya to study the detrital mineral records of the Northern Awash (NA; 3.3–2.9 Ma) and West Turkana (WTK; 1.9–1.4 Ma) drill cores. We performed (U-Th)/He and U/Pb analyses on detrital zircons using single crystal laser ablation double dating (LADD) techniques. Analyses of four NA samples yielded zircon ²⁰⁶Pb/²³⁸U dates younger than ∼45 Ma, consistent with derivation from silicic volcanic rocks associated with EARS activity. Most of these samples lack zircon ²⁰⁶Pb/²³⁸U dates from ∼22–13 Ma, due to a decrease in silicic volcanism and a watershed configuration limiting delivery of silicic source materials to the sample site. NA zircon ²⁰⁶Pb/²³⁸U dates imply a sedimentary source from the western Afar margin, with a transition to more localized sediment reworking within the Afar Depression after a major regional tectonic reorganization and formation of a disconformity at ∼2.9 Ma. The WTK sample yielded many zircons with Cenozoic ²⁰⁶Pb/²³⁸U dates similar to those from the NA core, but the WTK sample also sources a small population of Neoproterozoic zircons associated with rocks from the Mozambique Belt and reworked sedimentary deposits. Despite being recorders of predominantly silicic activity, the detrital zircon U/Pb dates from both drill sites track the established timing of major volcanic phases in the EARS. A subset of zircons from both sites has concordant ²⁰⁶Pb/²³⁸U and (U-Th)/He dates, indicating a short duration between zircon crystallization and eruption of the host volcanic rock, but the majority of zircon (U-Th)/He dates are significantly younger than the ²⁰⁶Pb/²³⁸U dates for the same zircon. Some (U-Th)/He dates are even younger than the depositional age of the sedimentary sample from which it was collected. The observed spread in zircon (U-Th)/He dates likely reflects partial resetting associated with late mafic volcanism and/or hydrothermal activity within this dynamic rift environment.

Original language	English (US)
Article number	117375
Journal	Earth and Planetary Science Letters
Volume	580
DOIs	https://doi.org/10.1016/j.epsl.2022.117375
State	Published - Feb 15 2022

Bibliographical note

Funding Information:
We thank Mark Shapley, Emma Burnett, Pawel Kuczaj, and Tara Berglund for their contributions to the identification and interpretation of sedimentary injectites and other sedimentary indicators of hydrothermal activity. We thank the Ledi-Geraru Research Project team for helpful discussions. We thank Samuel Boone, Cynthia Ebinger, and Chris Morley for their helpful and constructive comments on this manuscript. Initial core processing and sampling were conducted at the US National Lacustrine Core Facility (LacCore) at the University of Minnesota. We thank HSPDP PI Andy Cohen and the numerous members of the NA and WTK initial core sampling team and field team, including the people of the Nariokotome and Mille regions. Funding for the HSPDP NA and WTK sites was provided by the International Continental Drilling Program (ICDP), and the NSF (Grants EAR-1123942 , BCS-1241859 , and EAR-1338553 ). This is publication number 49 of the Hominin Sites and Paleolakes Drilling Project.

Publisher Copyright:
© 2022 Elsevier B.V.

Keywords

detrital zircon
East African Rift
hydrothermal alteration
laser ablation double dating

Continental Scientific Drilling Facility tags

HSPDP-WTK
HSPDP-NAW

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Publisher link

10.1016/j.epsl.2022.117375

Find It

Find It at U of M Libraries

Cite this

Zawacki, E. E., van Soest, M. C., Hodges, K. V., Scott, J. J., Barboni, M., Strecker, M. R., Feibel, C. S., Campisano, C. J., & Arrowsmith, J. R. (2022). Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons. Earth and Planetary Science Letters, 580, Article 117375. https://doi.org/10.1016/j.epsl.2022.117375

Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons. / Zawacki, Emily E.; van Soest, Matthijs C.; Hodges, Kip V. et al.
In: Earth and Planetary Science Letters, Vol. 580, 117375, 15.02.2022.

Research output: Contribution to journal › Article › peer-review

Zawacki, EE, van Soest, MC, Hodges, KV, Scott, JJ, Barboni, M, Strecker, MR, Feibel, CS, Campisano, CJ & Arrowsmith, JR 2022, 'Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons', Earth and Planetary Science Letters, vol. 580, 117375. https://doi.org/10.1016/j.epsl.2022.117375

@article{c9439c393bb940a79d3d3056da26014a,

title = "Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons",

abstract = "Detrital zircons from two major rift basins within the East African Rift System (EARS) provide a means to evaluate not only sediment provenance and landscape dynamics in sedimentary basins, but also the timing of the silicic volcano-tectonic evolution of the rift system. We sampled from drill cores collected by the Hominin Sites and Paleolakes Drilling Project (HSPDP) in Ethiopia and Kenya to study the detrital mineral records of the Northern Awash (NA; 3.3–2.9 Ma) and West Turkana (WTK; 1.9–1.4 Ma) drill cores. We performed (U-Th)/He and U/Pb analyses on detrital zircons using single crystal laser ablation double dating (LADD) techniques. Analyses of four NA samples yielded zircon 206Pb/238U dates younger than ∼45 Ma, consistent with derivation from silicic volcanic rocks associated with EARS activity. Most of these samples lack zircon 206Pb/238U dates from ∼22–13 Ma, due to a decrease in silicic volcanism and a watershed configuration limiting delivery of silicic source materials to the sample site. NA zircon 206Pb/238U dates imply a sedimentary source from the western Afar margin, with a transition to more localized sediment reworking within the Afar Depression after a major regional tectonic reorganization and formation of a disconformity at ∼2.9 Ma. The WTK sample yielded many zircons with Cenozoic 206Pb/238U dates similar to those from the NA core, but the WTK sample also sources a small population of Neoproterozoic zircons associated with rocks from the Mozambique Belt and reworked sedimentary deposits. Despite being recorders of predominantly silicic activity, the detrital zircon U/Pb dates from both drill sites track the established timing of major volcanic phases in the EARS. A subset of zircons from both sites has concordant 206Pb/238U and (U-Th)/He dates, indicating a short duration between zircon crystallization and eruption of the host volcanic rock, but the majority of zircon (U-Th)/He dates are significantly younger than the 206Pb/238U dates for the same zircon. Some (U-Th)/He dates are even younger than the depositional age of the sedimentary sample from which it was collected. The observed spread in zircon (U-Th)/He dates likely reflects partial resetting associated with late mafic volcanism and/or hydrothermal activity within this dynamic rift environment.",

keywords = "detrital zircon, East African Rift, hydrothermal alteration, laser ablation double dating",

author = "Zawacki, {Emily E.} and {van Soest}, {Matthijs C.} and Hodges, {Kip V.} and Scott, {Jennifer J.} and M{\'e}lanie Barboni and Strecker, {Manfred R.} and Feibel, {Craig S.} and Campisano, {Christopher J.} and Arrowsmith, {J. Ram{\'o}n}",

note = "Funding Information: We thank Mark Shapley, Emma Burnett, Pawel Kuczaj, and Tara Berglund for their contributions to the identification and interpretation of sedimentary injectites and other sedimentary indicators of hydrothermal activity. We thank the Ledi-Geraru Research Project team for helpful discussions. We thank Samuel Boone, Cynthia Ebinger, and Chris Morley for their helpful and constructive comments on this manuscript. Initial core processing and sampling were conducted at the US National Lacustrine Core Facility (LacCore) at the University of Minnesota. We thank HSPDP PI Andy Cohen and the numerous members of the NA and WTK initial core sampling team and field team, including the people of the Nariokotome and Mille regions. Funding for the HSPDP NA and WTK sites was provided by the International Continental Drilling Program (ICDP), and the NSF (Grants EAR-1123942 , BCS-1241859 , and EAR-1338553 ). This is publication number 49 of the Hominin Sites and Paleolakes Drilling Project. Publisher Copyright: {\textcopyright} 2022 Elsevier B.V.",

year = "2022",

month = feb,

day = "15",

doi = "10.1016/j.epsl.2022.117375",

language = "English (US)",

volume = "580",

journal = "Earth and Planetary Science Letters",

issn = "0012-821X",

publisher = "Elsevier",

}

TY - JOUR

T1 - Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons

AU - Zawacki, Emily E.

AU - van Soest, Matthijs C.

AU - Hodges, Kip V.

AU - Scott, Jennifer J.

AU - Barboni, Mélanie

AU - Strecker, Manfred R.

AU - Feibel, Craig S.

AU - Campisano, Christopher J.

AU - Arrowsmith, J. Ramón

N1 - Funding Information: We thank Mark Shapley, Emma Burnett, Pawel Kuczaj, and Tara Berglund for their contributions to the identification and interpretation of sedimentary injectites and other sedimentary indicators of hydrothermal activity. We thank the Ledi-Geraru Research Project team for helpful discussions. We thank Samuel Boone, Cynthia Ebinger, and Chris Morley for their helpful and constructive comments on this manuscript. Initial core processing and sampling were conducted at the US National Lacustrine Core Facility (LacCore) at the University of Minnesota. We thank HSPDP PI Andy Cohen and the numerous members of the NA and WTK initial core sampling team and field team, including the people of the Nariokotome and Mille regions. Funding for the HSPDP NA and WTK sites was provided by the International Continental Drilling Program (ICDP), and the NSF (Grants EAR-1123942 , BCS-1241859 , and EAR-1338553 ). This is publication number 49 of the Hominin Sites and Paleolakes Drilling Project. Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/2/15

Y1 - 2022/2/15

N2 - Detrital zircons from two major rift basins within the East African Rift System (EARS) provide a means to evaluate not only sediment provenance and landscape dynamics in sedimentary basins, but also the timing of the silicic volcano-tectonic evolution of the rift system. We sampled from drill cores collected by the Hominin Sites and Paleolakes Drilling Project (HSPDP) in Ethiopia and Kenya to study the detrital mineral records of the Northern Awash (NA; 3.3–2.9 Ma) and West Turkana (WTK; 1.9–1.4 Ma) drill cores. We performed (U-Th)/He and U/Pb analyses on detrital zircons using single crystal laser ablation double dating (LADD) techniques. Analyses of four NA samples yielded zircon 206Pb/238U dates younger than ∼45 Ma, consistent with derivation from silicic volcanic rocks associated with EARS activity. Most of these samples lack zircon 206Pb/238U dates from ∼22–13 Ma, due to a decrease in silicic volcanism and a watershed configuration limiting delivery of silicic source materials to the sample site. NA zircon 206Pb/238U dates imply a sedimentary source from the western Afar margin, with a transition to more localized sediment reworking within the Afar Depression after a major regional tectonic reorganization and formation of a disconformity at ∼2.9 Ma. The WTK sample yielded many zircons with Cenozoic 206Pb/238U dates similar to those from the NA core, but the WTK sample also sources a small population of Neoproterozoic zircons associated with rocks from the Mozambique Belt and reworked sedimentary deposits. Despite being recorders of predominantly silicic activity, the detrital zircon U/Pb dates from both drill sites track the established timing of major volcanic phases in the EARS. A subset of zircons from both sites has concordant 206Pb/238U and (U-Th)/He dates, indicating a short duration between zircon crystallization and eruption of the host volcanic rock, but the majority of zircon (U-Th)/He dates are significantly younger than the 206Pb/238U dates for the same zircon. Some (U-Th)/He dates are even younger than the depositional age of the sedimentary sample from which it was collected. The observed spread in zircon (U-Th)/He dates likely reflects partial resetting associated with late mafic volcanism and/or hydrothermal activity within this dynamic rift environment.

AB - Detrital zircons from two major rift basins within the East African Rift System (EARS) provide a means to evaluate not only sediment provenance and landscape dynamics in sedimentary basins, but also the timing of the silicic volcano-tectonic evolution of the rift system. We sampled from drill cores collected by the Hominin Sites and Paleolakes Drilling Project (HSPDP) in Ethiopia and Kenya to study the detrital mineral records of the Northern Awash (NA; 3.3–2.9 Ma) and West Turkana (WTK; 1.9–1.4 Ma) drill cores. We performed (U-Th)/He and U/Pb analyses on detrital zircons using single crystal laser ablation double dating (LADD) techniques. Analyses of four NA samples yielded zircon 206Pb/238U dates younger than ∼45 Ma, consistent with derivation from silicic volcanic rocks associated with EARS activity. Most of these samples lack zircon 206Pb/238U dates from ∼22–13 Ma, due to a decrease in silicic volcanism and a watershed configuration limiting delivery of silicic source materials to the sample site. NA zircon 206Pb/238U dates imply a sedimentary source from the western Afar margin, with a transition to more localized sediment reworking within the Afar Depression after a major regional tectonic reorganization and formation of a disconformity at ∼2.9 Ma. The WTK sample yielded many zircons with Cenozoic 206Pb/238U dates similar to those from the NA core, but the WTK sample also sources a small population of Neoproterozoic zircons associated with rocks from the Mozambique Belt and reworked sedimentary deposits. Despite being recorders of predominantly silicic activity, the detrital zircon U/Pb dates from both drill sites track the established timing of major volcanic phases in the EARS. A subset of zircons from both sites has concordant 206Pb/238U and (U-Th)/He dates, indicating a short duration between zircon crystallization and eruption of the host volcanic rock, but the majority of zircon (U-Th)/He dates are significantly younger than the 206Pb/238U dates for the same zircon. Some (U-Th)/He dates are even younger than the depositional age of the sedimentary sample from which it was collected. The observed spread in zircon (U-Th)/He dates likely reflects partial resetting associated with late mafic volcanism and/or hydrothermal activity within this dynamic rift environment.

KW - detrital zircon

KW - East African Rift

KW - hydrothermal alteration

KW - laser ablation double dating

UR - http://www.scopus.com/inward/record.url?scp=85123289646&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85123289646&partnerID=8YFLogxK

U2 - 10.1016/j.epsl.2022.117375

DO - 10.1016/j.epsl.2022.117375

M3 - Article

AN - SCOPUS:85123289646

SN - 0012-821X

VL - 580

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

M1 - 117375

ER -

Sediment provenance and silicic volcano-tectonic evolution of the northern East African Rift System from U/Pb and (U-Th)/He laser ablation double dating of detrital zircons

Abstract

Bibliographical note

Keywords

Continental Scientific Drilling Facility tags

UN SDGs

Publisher link

Find It

Other files and links

Fingerprint

Cite this