Abstract
Understanding the flow of carbon through hyperalkaline lakes is a key means of
understanding their biogeochemistry, sedimentology and their palaeoenvironmental and palaeoclimatic records. Furthermore, understanding how mineral precipitation is regulated in these lakes can provide insights into how their carbon sequestration behaviour can be managed. We report geophysical surveys of Mono Lake, California, USA, which show unanticipated geomorphological control on the recent /contemporary formation of lacustrine carbonate formations (“tufa”). Acquired shallow penetration seismic data shows a fault zone below the lake floor, but despite the regional evidence for geothermal waters rising up these fractures, we find no evidence for tufa precipitation at the surface exposure of this structure, either in the seismic data or in the swath bathymetry. However, we do find sub-lacustrine tufa columns in this data elsewhere, which is the first time these have been reported directly. We find
and report on a strong link between column location and meteoric Ca supply to the lake, with the latter sourced either through surface runoff or groundwater. For example, a region close to a creek inlet has more frequent and larger tufa bodies, which grow at a wider depth range, than another region far from an inlet but close to the fault. This demonstrates the importance of meteoric water ingress in regulating carbonate mineral formation in these basins, and raises the possibility that management of water within the catchment could be a means to enhance carbon capture within natural and artificial hyperalkaline lakes.
understanding their biogeochemistry, sedimentology and their palaeoenvironmental and palaeoclimatic records. Furthermore, understanding how mineral precipitation is regulated in these lakes can provide insights into how their carbon sequestration behaviour can be managed. We report geophysical surveys of Mono Lake, California, USA, which show unanticipated geomorphological control on the recent /contemporary formation of lacustrine carbonate formations (“tufa”). Acquired shallow penetration seismic data shows a fault zone below the lake floor, but despite the regional evidence for geothermal waters rising up these fractures, we find no evidence for tufa precipitation at the surface exposure of this structure, either in the seismic data or in the swath bathymetry. However, we do find sub-lacustrine tufa columns in this data elsewhere, which is the first time these have been reported directly. We find
and report on a strong link between column location and meteoric Ca supply to the lake, with the latter sourced either through surface runoff or groundwater. For example, a region close to a creek inlet has more frequent and larger tufa bodies, which grow at a wider depth range, than another region far from an inlet but close to the fault. This demonstrates the importance of meteoric water ingress in regulating carbonate mineral formation in these basins, and raises the possibility that management of water within the catchment could be a means to enhance carbon capture within natural and artificial hyperalkaline lakes.
| Original language | English |
|---|---|
| Pages (from-to) | 530-545 |
| Number of pages | 16 |
| Journal | Journal of Sedimentary Research |
| Volume | 92 |
| Issue number | 6 |
| Early online date | 21 Jun 2022 |
| DOIs | |
| Publication status | Published - Jun 2022 |
Bibliographical note
AcknowledgmentsThis work was supported by funding from BP Group. We thank the Mono Lake
Committee for supporting fieldwork and for helping our vessel onto and most of all off the lake, and the State of California for permitting access to the lake and its environs. Dave Marquart is thanked for his support and knowledge of the lake environment. Cody and Phillip are thanked for their help on the lake, and Vern for vital logistical support. Ian Billing is thanked for his instrumental involvement in this project, and his role in shaping our thoughts. We hope he would be pleased with this paper. Dr. Chelsea Pederson, Dr. W. Fischer are heartily thanked for their excellent efforts as reviewers improving this manuscript, and Dr. Juan Carlos Laya is thanked for his careful handling of the manuscript as Associate Editor.