| |
Records |
Links  |
|
Author |
Smedley, P.L.; Bearcock, J.M.; Ward, R.S.; Crewdson, E.; Bowes, M.J.; Darling, W.G.; Smith, A.C. |
|
| |
Title |
Monitoring of methane in groundwater from the Vale of Pickering, UK: Temporal variability and source discrimination |
Type |
Journal Article |
| |
Year |
2023 |
Publication |
Chemical Geology |
Abbreviated Journal |
|
|
| |
Volume |
636 |
Issue |
|
Pages |
121640 |
|
| |
Keywords |
Aquifer, Biogenic, Ethane, Hydrocarbons, Methane, Shale gas |
|
| |
Abstract |
Groundwater abstracted from aquifers in the Vale of Pickering, North Yorkshire, UK and monitored over the period 2015–2022, shows evidence of variable but commonly high concentrations of dissolved CH4. Sampled groundwater from the Jurassic organic-rich Kimmeridge Clay Formation (boreholes up to 180 m depth) has concentrations up to 57 mg/L, and concentrations up to 59 mg/L are found in groundwater from underlying confined Corallian Group limestone (borehole depths 50–227 m). The high concentrations are mainly from boreholes in the central parts of the vale. Small concentrations of ethane (C2H6, up to 800 μg/L) have been found in the Kimmeridge Clay and confined Corallian groundwaters, and of propane (C3H8, up to 160 μg/L) in deeper boreholes (110–180 m) from these formations. The concentrations are typically higher in groundwater from the deeper boreholes and vary with hydrostatic pressure, reflecting the pressure control on CH4 solubility. The occurrences contrast with groundwater from shallow Quaternary superficial deposits which have low CH4 concentrations (up to 0.39 mg/L), and with the unconfined and semi-confined sections of the Corallian aquifer (up to 0.7 mg/L) around the margins of the vale. Groundwater from the Quaternary, Kimmeridge Clay formations and to a small extent the confined Corallian aquifer, supports local private-water supplies, that from the peripheral unconfined sections of Corallian also supports public supply for towns and villages across the region. Dissolved methane/ethane (C1/C2) ratios and stable-isotopic compositions (δ13C-CH4, δ2H-CH4 and δ13C-CO2) suggest that the high-CH4 groundwater from both the Kimmeridge Clay and confined Corallian formations derives overwhelmingly from biogenic reactions, the methanogenesis pathway by CO2 reduction. A small minority of groundwater samples shows a more enriched δ13C-CH4 composition (−50 to −44 ‰) which has been interpreted as due to anaerobic or aerobic methylotrophic oxidation in situ or post-sampling oxidation, rather than derivation by a thermogenic route. Few of the existing groundwater sites are proximal to abandoned or disused conventional hydrocarbon wells that exist in the region, and little evidence has been found for an influence on groundwater dissolved gases from these sites. The Vale of Pickering has also been under recent consideration for development of an unconventional hydrocarbon (shale-gas) resource. In this context, the monitoring of dissolved gases has been an important step in establishing the high-CH4 baseline of groundwaters from Jurassic deposits in the region and in apportioning their sources and mechanisms of genesis. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0009-2541 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
THL @ christoph.kuells @ smedley_monitoring_2023 |
Serial |
172 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Li, J.; Pang, Z.; Liu, Y.; Hu, S.; Jiang, W.; Tian, L.; Yang, G.; Jiang, Y.; Jiao, X.; Tian, J. |
|
| |
Title |
Changes in groundwater dynamics and geochemical evolution induced by drainage reorganization: Evidence from 81Kr and 36Cl dating of geothermal water in the Weihe Basin of China |
Type |
Journal Article |
| |
Year |
2023 |
Publication |
Earth and Planetary Science Letters |
Abbreviated Journal |
|
|
| |
Volume |
623 |
Issue |
|
Pages |
118425 |
|
| |
Keywords |
Kr dating, Cl dating, Geothermal water, Groundwater dynamics, Weihe basin |
|
| |
Abstract |
81Kr and 36Cl can both be used to date groundwater beyond the dating range of 14C. 81Kr usually provides reliable groundwater ages because it has uniform initial distribution and negligible subsurface generation, while 36Cl is commonly influenced by subsurface sources or “dead” chloride dissolution. Therefore, the combined use of 81Kr and 36Cl could provide clues on the evolution history of groundwater. In the present study, we performed 36Cl and 81Kr dating of geothermal water in Weihe Basin of China and interpreted the possible cause of disagreement. Two distinct water masses were identified with distinctive isotopic signals: groundwater with significant δ18O shifts (up to −2.0‰), dissolved dead Cl and ages < 1.0 Ma (Cluster A), and older water with little δ18O shifts, negligible dissolved Cl and ages >1.0 Ma (Cluster B). The results confirm the eastward flow path of Cluster B to the Ancient Sanmen Lake with an increasing trend of Cl concentration and age. Modern recharge from the mountains flows to the basin center with intense interaction between water and carbonate under respective reservoir temperatures (100 ∼ 130 °C). These waters flow through the saline stratum emerging from the spillover of the Ancient Sanmen Lake, resulting in higher dead Cl dissolution. A significant linear relationship is observed with the older end-member of ∼1.3Ma under the topographically-driven faster circulation effect. 81Kr ages seem to support the hypothesis that the birth of the modern Yellow River was at about 1.0–1.3 Ma. We inferred the drainage reorganization from the Ancient Sanmen Lake to the modern Yellow River since the Mid-Pleistocene Transition induced the change in groundwater dynamics as well as its chemical evolution. The excavation of the Ancient Sanmen Lake and the accentuated incision of the Weihe River induced groundwater gradient, and therefore the recharge from precipitation from both slopes of the Qinling Mountains in the south and the Beishan Mountains in the north. Our results highlight the effects of dead Cl on 36Cl dating and demonstrate the significant impact of catchment reorganization on groundwater dynamics and its chemistry. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0012-821x |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
THL @ christoph.kuells @ Li2023118425 |
Serial |
212 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chase, B.M.; Meadows, M.E. |
|
| |
Title |
Late Quaternary dynamics of southern Africa’s winter rainfall zone |
Type |
Journal Article |
| |
Year |
2007 |
Publication |
Earth-Science Reviews |
Abbreviated Journal |
|
|
| |
Volume |
84 |
Issue |
3 |
Pages |
103-138 |
|
| |
Keywords |
Last Glacial Maximum, palaeoenvironment, Quaternary, southern Africa, westerlies, winter rainfall zone |
|
| |
Abstract |
Variations in the nature and extent of southern Africa’s winter rainfall zone (WRZ) have the potential to provide important information concerning the nature of long-term climate change at both regional and hemispheric scales. Positioned at the interface between tropical and temperate systems, southern Africa’s climate is influenced by shifts in the Intertropical Convergence Zone, the westerlies, and the development and position of continental and oceanic anticyclones. Over the last glacial–interglacial cycle substantial changes in the amount and seasonality of precipitation across the subcontinent have been linked to the relative dominance of these systems. Central to this discussion has been the extent to which the region’s glacial climates would have been affected by expansions of Antarctic sea-ice, equatorward migrations of the westerlies, more frequent/intense winter storms and an expanded WRZ. This paper reviews the developing body of evidence pertaining to shifts in the WRZ, and the evolution of ideas that have been presented to explain the patterns observed. Dividing the region into three separate axes, along the western and southern margins of the continent and across the interior into the Karoo and the Kalahari, a range of evidence from both terrestrial sites and marine cores is considered, and potential expansions of the WRZ expansions are explored. Despite the limitations of many of the region’s proxy records, a coherent pattern has begun to develop of a significantly expanded WRZ during phases of the last glacial period, with the best-documented being between 32–17 ka. While more detailed inferences will require the recovery and analysis of longer and better-dated records, this synthesis provides a new baseline for further research in this key region. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0012-8252 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
THL @ christoph.kuells @ chase_late_2007 |
Serial |
102 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Orloff, K.G.; Mistry, K.; Charp, P.; Metcalf, S.; Marino, R.; Shelly, T.; Melaro, E.; Donohoe, A.M.; Jones, R.L. |
|
| |
Title |
Human exposure to uranium in groundwater |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Environmental Research |
Abbreviated Journal |
|
|
| |
Volume |
94 |
Issue |
3 |
Pages |
319-326 |
|
| |
Keywords |
Groundwater, Human exposure, Uranium, Urine |
|
| |
Abstract |
High concentrations of uranium (mean=620μg/L) were detected in water samples collected from private wells in a residential community. Based on isotopic analyses, the source of the uranium contamination appeared to be from naturally occurring geological deposits. In homes where well water concentrations of uranium exceeded the drinking water standard, the residents were advised to use an alternate water source for potable purposes. Several months after the residents had stopped drinking the water, urine samples were collected and tested for uranium. Elevated concentrations of uranium (mean=0.40μg/g creatinine) were detected in urine samples, and 85 percent of the urine uranium concentrations exceeded the 95th percentile concentration of a national reference population. Urine uranium concentrations were positively correlated with water uranium concentrations, but not with the participants’ ages or how long they had been drinking the water. Six months later, a second urine sample was collected and tested for uranium. Urine uranium concentrations decreased in most (63 percent) of the people. In those people with the highest initial urine uranium concentrations, the urine levels decreased an average of 78 percent. However, urine uranium concentrations remained elevated (mean=0.27μg/g), and 87 percent of the urine uranium concentrations exceeded the 95th percentile concentration of the reference population. The results of this investigation demonstrated that after long-term ingestion of uranium in drinking water, elevated concentrations of uranium in urine could be detected up to 10 months after exposure had stopped. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0013-9351 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
THL @ christoph.kuells @ orloff_human_2004 |
Serial |
136 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Strandmann, P.A.E.P. von; Reynolds, B.C.; Porcelli, D.; James, R.H.; Calsteren, P. van; Baskaran, M.; Burton, K.W. |
|
| |
Title |
Assessing continental weathering rates and actinide transport in the Great Artesian Basin |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Geochimica et Cosmochimica Acta |
Abbreviated Journal |
|
|
| |
Volume |
70 |
Issue |
18, Supplement |
Pages |
497 |
|
| |
Keywords |
|
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0016-7037 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
THL @ christoph.kuells @ strandmann_assessing_2006 |
Serial |
116 |
|
| Permanent link to this record |
