TY - JOUR
T1 - Proximal to distal grain-size distribution of basin-floor lobes
T2 - A study from the Battfjellet Formation, Central Tertiary Basin, Svalbard
AU - Spychala, Yvonne T.
AU - Ramaaker, Thymen A.B.
AU - Eggenhuisen, Joris T.
AU - Grundvåg, Sten Andreas
AU - Pohl, Florian
AU - Wróblewska, Sara
N1 - Funding Information:
This project was funded by NWO (grant # NWO‐ALW‐Vidi‐864.13.006), ExxonMobil, Shell Exxon Mobil Corporation, and Equinor for which we are thankful. Sten‐Andreas Grundvåg received funding from the ARCEx project (Research Centre for Arctic Petroleum Exploration), which is funded by the Research Council of Norway (grant number 228107). Furthermore, we would like to thank Captain Stig Henningsen of the MS Farm. We would also like to thank Elisabeth Steel and Zane Jobe for their helpful and constructive reviews which have enabled us to clarify and improve the manuscript.
Publisher Copyright:
© 2021 The Authors. The Depositional Record published by John Wiley & Sons Ltd on behalf of International Association of Sedimentologists.
PY - 2022/6
Y1 - 2022/6
N2 - The grain-size distribution of sediment particles is an important aspect of the architecture of submarine fans and lobes. It governs depositional sand quality and reflects distribution of particulate organic carbon and pollutants. Documenting the grain-size distribution of these deep-marine sedimentary bodies can also offer us an insight into the flows that deposited them. Submarine lobes are commonly assumed to linearly fine from an apex, meaning there should be a proportional relationship between grain size and distance from the lobe apex. However, not much detailed quantitative work has been done to test this hypothesis. Exposure of a 5 km long dip-section of basin-floor lobes in Clinoform 12, Battfjellet Formation, Spitsbergen, enable the study of basinward grain-size evolution in lobe deposits. Furthermore, the dataset allows testing if there are any documentable grain-size differences between lobe sub-environments. For this purpose, the palaeogeography of Clinoform 12 was reconstructed and the youngest lobe, which was exposed in all collected logs, chosen to be evaluated for its grain-size trends. Photographed thin sections of 66 rock samples were analysed to obtain quantitative grain-size distributions. The results show that fining of lobe deposits occurs predominantly in the most proximal and most distal parts of the lobe, while the intermediate lobe, which is dominated by lobe off-axis deposits, is characterised by a relatively consistent grain-size range. Lobe sub-environments show statistically distinct grain-size distributions from lobe axis to lobe fringe. An explanation for these trends is the interplay of capacity and competence-driven deposition with the grain-size stratification of the flows. The outcomes of this study help to better understand the proximal to distal evolution of turbidity currents and their depositional patterns. They also provide important insights in reservoir potential of basin-floor fans at lobe scale.
AB - The grain-size distribution of sediment particles is an important aspect of the architecture of submarine fans and lobes. It governs depositional sand quality and reflects distribution of particulate organic carbon and pollutants. Documenting the grain-size distribution of these deep-marine sedimentary bodies can also offer us an insight into the flows that deposited them. Submarine lobes are commonly assumed to linearly fine from an apex, meaning there should be a proportional relationship between grain size and distance from the lobe apex. However, not much detailed quantitative work has been done to test this hypothesis. Exposure of a 5 km long dip-section of basin-floor lobes in Clinoform 12, Battfjellet Formation, Spitsbergen, enable the study of basinward grain-size evolution in lobe deposits. Furthermore, the dataset allows testing if there are any documentable grain-size differences between lobe sub-environments. For this purpose, the palaeogeography of Clinoform 12 was reconstructed and the youngest lobe, which was exposed in all collected logs, chosen to be evaluated for its grain-size trends. Photographed thin sections of 66 rock samples were analysed to obtain quantitative grain-size distributions. The results show that fining of lobe deposits occurs predominantly in the most proximal and most distal parts of the lobe, while the intermediate lobe, which is dominated by lobe off-axis deposits, is characterised by a relatively consistent grain-size range. Lobe sub-environments show statistically distinct grain-size distributions from lobe axis to lobe fringe. An explanation for these trends is the interplay of capacity and competence-driven deposition with the grain-size stratification of the flows. The outcomes of this study help to better understand the proximal to distal evolution of turbidity currents and their depositional patterns. They also provide important insights in reservoir potential of basin-floor fans at lobe scale.
KW - flow processes
KW - grain-size counting
KW - palaeo-reconstruction
KW - thin sections
KW - turbidites
UR - http://www.scopus.com/inward/record.url?scp=85115956912&partnerID=8YFLogxK
U2 - 10.1002/dep2.167
DO - 10.1002/dep2.167
M3 - Article
AN - SCOPUS:85115956912
SN - 2055-4877
VL - 8
SP - 436
EP - 456
JO - Depositional Record
JF - Depositional Record
IS - 2
ER -