Valerie A Hall
Biographic Data
| ID | 5598451 |
|---|---|
| NAME | Valerie A Hall |
| GIVEN NAMES | Valerie A |
| FAMILY NAME | Hall |
| SIGNATURE | HALL V A |
| AFFILIATIONS | Queen's University Belfast |
| VERIFIED | No |
| TOTAL WORKS | 20 |
| TOTAL CITATIONS | 178 |
| WORKS AS AUTHOR | 20 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1992 |
| LATEST PUBLICATION YEAR | 2016 |
| H-INDEX | 8 |
Tephrostratigraphical investigation of lake sediments and a peat bog in Northeastern China since 20,000 years
This is a detailed tephrostratigraphical investigation of late Quaternary deposits in the Longgang and Changbaishan Volcanic Fields of northeastern China. A total of 45 reference samples which were collected from either side of the Chinese/Korean border showed very similar geochemical characteristics to the Millennium eruption of Tianchi Volcano. Through comparing the published data of the glass shards detected in Gushantun with these reference s…
Assessing the potential for cryptotephra studies in Northeastern China
Quaternary tephrochronology and tephrostratigraphy are employed globally for chronological control and site correlation, but the potential for these approaches in Northeastern China has not been fully explored, in spite of this being a volcanically active region. Microscopic and precise electron microprobe geochemical analyses were performed on crypto- or macrotephra layers in maar lake sediments from Sihailongwan, and peat from Gushantun, from t…
A multi-proxy palaeoenvironmental investigation of the findspot of an Iron Age bog body from Oldcroghan, Co. Offaly, Ireland
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
Tephra-dated climate-and human-impact studies during the last 1500 years from a raised bog in central Ireland
Historic Icelandic tephrochronology constrains the time frame of a plant macrofossil and palynological study of ombrotrophic peat to evaluate the effects of climatic and human impact over the last 1500 years on the landscape at a large monastic site in the Irish Midlands. The plant macrofossil climate proxy record indicates maximum wetness during the sixth century AD. Decreasing wetness occurred from the late ninth century to the late thirteenth …
The vegetation history of monastic and secular sites in the midlands of Ireland over the last two millennia
New dates for first millennium BC tephra isochrones in Ireland
Three distinct, first millennium BC tephras (BMR-190, OMH-185, GB4-150) have been recognized in Irish peat deposits, including a previously undated ash (BMR-190). We present the results of a programme of high-precision 14 C wiggle-matching on a peat profile containing all three tephras from Glen West, County Fermanagh, Northern Ireland. The wiggle-match provides highly refined dates of 705-585cal. BC for BMR-190, 755-680cal. BC for OMH-185 and 80…
Assessing the impact of Icelandic volcanism on vegetation systems in the north of Ireland in the fifth and sixth millennia BC
The ‘Lairg tephras’ comprise two of the three most abundantly represented tephra layers in Irish Holocene peat sequences. The impact of these tephras on the vegetation at two lowland raised bogs in Northern Ireland is investigated through high-resolution pollen percentage and concentration studies. The palynological response of mire and dryland taxa to the tephra falls is assessed. No significant palynological response to either tephra event is r…
Rhyolitic tephra horizons in northwestern Europe and Iceland from the AD 700s–800s
The distribution and geochemistry of four rhyolitic tephra horizons from Iceland dated to the ad 700s–800s is assessed. These include the rhyolitic phase of the Landnám tephra (ad 870s), the ad 860 layer, a previously unrecorded tephra called the GA4–85 layer (c. ad 700–800) and the Tjïrnuvík tephra (c. ad 800s). The ad 860 and GA4–85 layers were first found in peat bogs in north Ireland. They are here correlated with equivalent horizons on Icela…
Vegetation history of mid- to western Ireland in the 2nd millennium a.d.; fresh evidence from tephra-dated palynological investigations
Late-Quaternary Icelandic tephras in Ireland and Great Britain
Microscopic studies of late-Quaternary tephras from Iceland yield a detailed tephrochronology in deposits of the British Isles, where the quantities of volcanic glass employed are much less than those used to construct almost any other late-Quatemary tephrochronology. We summarize improved methods of isolating extremely sparse glass shards for light microscope and electron microprobe analysis and provide major element geochemistry for 20 volcanic…
Late-Quaternary Icelandic tephras in Ireland and Great Britain
Radiocarbon dating of a recent high latitude peat profile
The value of both high-precision (HP) and AMS 14 C determinations in the fine-resolution dating of recent peat at Stor Åmyrân, near Umeå, northern Sweden has been explored. A detailed chronology of accumu lation, based on 14 C, an occurrence of the Askja AD 1875 tephra and 241 Am measurements has been derived for the last 700 years. This shows significant changes in the mass balance of the peat profile, with minimum rates of net carbon sequestrat…
Mid- and late-Holocene vegetation history and tephra studies at Fenton Cottage, Lancashire, U.K
Tephrochronological studies in northern England
Tephrostratigraphic investigations of two upland blanket bogs in northern England show that micro scopic layers of tephra are present. Their geochemistry shows that they are identical to two Icelandic tephra layers of known age found at sites in Scotland and the north of Ireland. The work extends the regional tephro chronology of the mid-Holocene for the British Isles
Hekla-4 ash, the pine decline in Northern Ireland and the effective use of tephra isochrones
Dates of Holocene Icelandic volcanic eruptions from tephra layers in Irish peats
Tephra from historic and prehistoric eruptions of Oraefajøkull and Hekla, Iceland, have been found in Irish peats. Using a series of stratigraphically related high-precision radiocarbon measure ments, the date of a known-age eruption has been satisfactorily estimated. Based on the same techniques, the calendrical date of the Hekla 4 eruption has been estimated as 2310 ± 20 BC
Icelandic volcanic ash and the mid-Holocene Scots pine (Pinus sylvestris) decline in the north of Ireland
Tephra-linked pollen and dendrochronological studies were performed on mid-Holocene subfossil peats and pines and two lowland raised bogs in the north of Ireland. The results demonstrated that at these sites, contrary to recent findings in the north of Scotland, there was no temporal link between the decline in pine pollen and tephra from the eruption of the Icelandic volcano Hekla (H4)
Pollen Concentrate Preparation from Highly Organic Holocene Peat and Lake Deposits for AMS Dating
Many of the problems inherent with conventional 14 C dating of lake and peat deposits are eliminated by AMS dating of pollen concentrates. Published work describes production of pollen concentrates through expulsion of most of the deposit matrix by repeated deflocculation, selective sieving and final retention of the largest subfossil pollen taxa. Less suited to pollen concentrate production are the highly organic peats and lake muds from the Bri…
Towards a tephrochronology for the Holocene of the north of Ireland
Discrete layers of tephra have been found in both raised and blanket bogs in the north of Ireland. Some of the layers have been identified to an Icelandic source and, in two cases, specific eruptions of known radiocarbon age are suggested. Nine layers spanning the Holocene are replicated in three lowland raised bogs. One of the major layers has also been identified at a number of sites in two separate upland blanket peat systems and in a lake sed…
Dates of Holocene Icelandic volcanic eruptions from tephra layers in Irish peats
Tephra from historic and prehistoric eruptions of Oraefajøkull and Hekla, Iceland, have been found in Irish peats. Using a series of stratigraphically related high-precision radiocarbon measure ments, the date of a known-age eruption has been satisfactorily estimated. Based on the same techniques, the calendrical date of the Hekla 4 eruption has been estimated as 2310 ± 20 BC
Towards a tephrochronology for the Holocene of the north of Ireland
Discrete layers of tephra have been found in both raised and blanket bogs in the north of Ireland. Some of the layers have been identified to an Icelandic source and, in two cases, specific eruptions of known radiocarbon age are suggested. Nine layers spanning the Holocene are replicated in three lowland raised bogs. One of the major layers has also been identified at a number of sites in two separate upland blanket peat systems and in a lake sed…
Radiocarbon dating of a recent high latitude peat profile
The value of both high-precision (HP) and AMS 14 C determinations in the fine-resolution dating of recent peat at Stor Åmyrân, near Umeå, northern Sweden has been explored. A detailed chronology of accumu lation, based on 14 C, an occurrence of the Askja AD 1875 tephra and 241 Am measurements has been derived for the last 700 years. This shows significant changes in the mass balance of the peat profile, with minimum rates of net carbon sequestrat…
Late-Quaternary Icelandic tephras in Ireland and Great Britain
Microscopic studies of late-Quaternary tephras from Iceland yield a detailed tephrochronology in deposits of the British Isles, where the quantities of volcanic glass employed are much less than those used to construct almost any other late-Quatemary tephrochronology. We summarize improved methods of isolating extremely sparse glass shards for light microscope and electron microprobe analysis and provide major element geochemistry for 20 volcanic…
Icelandic volcanic ash and the mid-Holocene Scots pine (Pinus sylvestris) decline in the north of Ireland
Tephra-linked pollen and dendrochronological studies were performed on mid-Holocene subfossil peats and pines and two lowland raised bogs in the north of Ireland. The results demonstrated that at these sites, contrary to recent findings in the north of Scotland, there was no temporal link between the decline in pine pollen and tephra from the eruption of the Icelandic volcano Hekla (H4)
Pollen Concentrate Preparation from Highly Organic Holocene Peat and Lake Deposits for AMS Dating
Many of the problems inherent with conventional 14 C dating of lake and peat deposits are eliminated by AMS dating of pollen concentrates. Published work describes production of pollen concentrates through expulsion of most of the deposit matrix by repeated deflocculation, selective sieving and final retention of the largest subfossil pollen taxa. Less suited to pollen concentrate production are the highly organic peats and lake muds from the Bri…
Mid- and late-Holocene vegetation history and tephra studies at Fenton Cottage, Lancashire, U.K
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
The vegetation history of monastic and secular sites in the midlands of Ireland over the last two millennia
New dates for first millennium BC tephra isochrones in Ireland
Three distinct, first millennium BC tephras (BMR-190, OMH-185, GB4-150) have been recognized in Irish peat deposits, including a previously undated ash (BMR-190). We present the results of a programme of high-precision 14 C wiggle-matching on a peat profile containing all three tephras from Glen West, County Fermanagh, Northern Ireland. The wiggle-match provides highly refined dates of 705-585cal. BC for BMR-190, 755-680cal. BC for OMH-185 and 80…
Tephrochronological studies in northern England
Tephrostratigraphic investigations of two upland blanket bogs in northern England show that micro scopic layers of tephra are present. Their geochemistry shows that they are identical to two Icelandic tephra layers of known age found at sites in Scotland and the north of Ireland. The work extends the regional tephro chronology of the mid-Holocene for the British Isles
A multi-proxy palaeoenvironmental investigation of the findspot of an Iron Age bog body from Oldcroghan, Co. Offaly, Ireland
Rhyolitic tephra horizons in northwestern Europe and Iceland from the AD 700s–800s
The distribution and geochemistry of four rhyolitic tephra horizons from Iceland dated to the ad 700s–800s is assessed. These include the rhyolitic phase of the Landnám tephra (ad 870s), the ad 860 layer, a previously unrecorded tephra called the GA4–85 layer (c. ad 700–800) and the Tjïrnuvík tephra (c. ad 800s). The ad 860 and GA4–85 layers were first found in peat bogs in north Ireland. They are here correlated with equivalent horizons on Icela…
Vegetation history of mid- to western Ireland in the 2nd millennium a.d.; fresh evidence from tephra-dated palynological investigations
Hekla-4 ash, the pine decline in Northern Ireland and the effective use of tephra isochrones
Tephra-dated climate-and human-impact studies during the last 1500 years from a raised bog in central Ireland
Historic Icelandic tephrochronology constrains the time frame of a plant macrofossil and palynological study of ombrotrophic peat to evaluate the effects of climatic and human impact over the last 1500 years on the landscape at a large monastic site in the Irish Midlands. The plant macrofossil climate proxy record indicates maximum wetness during the sixth century AD. Decreasing wetness occurred from the late ninth century to the late thirteenth …
Assessing the potential for cryptotephra studies in Northeastern China
Quaternary tephrochronology and tephrostratigraphy are employed globally for chronological control and site correlation, but the potential for these approaches in Northeastern China has not been fully explored, in spite of this being a volcanically active region. Microscopic and precise electron microprobe geochemical analyses were performed on crypto- or macrotephra layers in maar lake sediments from Sihailongwan, and peat from Gushantun, from t…
Assessing the impact of Icelandic volcanism on vegetation systems in the north of Ireland in the fifth and sixth millennia BC
The ‘Lairg tephras’ comprise two of the three most abundantly represented tephra layers in Irish Holocene peat sequences. The impact of these tephras on the vegetation at two lowland raised bogs in Northern Ireland is investigated through high-resolution pollen percentage and concentration studies. The palynological response of mire and dryland taxa to the tephra falls is assessed. No significant palynological response to either tephra event is r…
Towards a tephrochronology for the Holocene of the north of Ireland
Discrete layers of tephra have been found in both raised and blanket bogs in the north of Ireland. Some of the layers have been identified to an Icelandic source and, in two cases, specific eruptions of known radiocarbon age are suggested. Nine layers spanning the Holocene are replicated in three lowland raised bogs. One of the major layers has also been identified at a number of sites in two separate upland blanket peat systems and in a lake sed…
Icelandic volcanic ash and the mid-Holocene Scots pine (Pinus sylvestris) decline in the north of Ireland
Tephra-linked pollen and dendrochronological studies were performed on mid-Holocene subfossil peats and pines and two lowland raised bogs in the north of Ireland. The results demonstrated that at these sites, contrary to recent findings in the north of Scotland, there was no temporal link between the decline in pine pollen and tephra from the eruption of the Icelandic volcano Hekla (H4)
Pollen Concentrate Preparation from Highly Organic Holocene Peat and Lake Deposits for AMS Dating
Many of the problems inherent with conventional 14 C dating of lake and peat deposits are eliminated by AMS dating of pollen concentrates. Published work describes production of pollen concentrates through expulsion of most of the deposit matrix by repeated deflocculation, selective sieving and final retention of the largest subfossil pollen taxa. Less suited to pollen concentrate production are the highly organic peats and lake muds from the Bri…
Dates of Holocene Icelandic volcanic eruptions from tephra layers in Irish peats
Tephra from historic and prehistoric eruptions of Oraefajøkull and Hekla, Iceland, have been found in Irish peats. Using a series of stratigraphically related high-precision radiocarbon measure ments, the date of a known-age eruption has been satisfactorily estimated. Based on the same techniques, the calendrical date of the Hekla 4 eruption has been estimated as 2310 ± 20 BC
Tephrochronological studies in northern England
Tephrostratigraphic investigations of two upland blanket bogs in northern England show that micro scopic layers of tephra are present. Their geochemistry shows that they are identical to two Icelandic tephra layers of known age found at sites in Scotland and the north of Ireland. The work extends the regional tephro chronology of the mid-Holocene for the British Isles
Hekla-4 ash, the pine decline in Northern Ireland and the effective use of tephra isochrones
Radiocarbon dating of a recent high latitude peat profile
The value of both high-precision (HP) and AMS 14 C determinations in the fine-resolution dating of recent peat at Stor Åmyrân, near Umeå, northern Sweden has been explored. A detailed chronology of accumu lation, based on 14 C, an occurrence of the Askja AD 1875 tephra and 241 Am measurements has been derived for the last 700 years. This shows significant changes in the mass balance of the peat profile, with minimum rates of net carbon sequestrat…
Mid- and late-Holocene vegetation history and tephra studies at Fenton Cottage, Lancashire, U.K
Late-Quaternary Icelandic tephras in Ireland and Great Britain
Microscopic studies of late-Quaternary tephras from Iceland yield a detailed tephrochronology in deposits of the British Isles, where the quantities of volcanic glass employed are much less than those used to construct almost any other late-Quatemary tephrochronology. We summarize improved methods of isolating extremely sparse glass shards for light microscope and electron microprobe analysis and provide major element geochemistry for 20 volcanic…
Late-Quaternary Icelandic tephras in Ireland and Great Britain
Assessing the impact of Icelandic volcanism on vegetation systems in the north of Ireland in the fifth and sixth millennia BC
The ‘Lairg tephras’ comprise two of the three most abundantly represented tephra layers in Irish Holocene peat sequences. The impact of these tephras on the vegetation at two lowland raised bogs in Northern Ireland is investigated through high-resolution pollen percentage and concentration studies. The palynological response of mire and dryland taxa to the tephra falls is assessed. No significant palynological response to either tephra event is r…
Rhyolitic tephra horizons in northwestern Europe and Iceland from the AD 700s–800s
The distribution and geochemistry of four rhyolitic tephra horizons from Iceland dated to the ad 700s–800s is assessed. These include the rhyolitic phase of the Landnám tephra (ad 870s), the ad 860 layer, a previously unrecorded tephra called the GA4–85 layer (c. ad 700–800) and the Tjïrnuvík tephra (c. ad 800s). The ad 860 and GA4–85 layers were first found in peat bogs in north Ireland. They are here correlated with equivalent horizons on Icela…
Vegetation history of mid- to western Ireland in the 2nd millennium a.d.; fresh evidence from tephra-dated palynological investigations
New dates for first millennium BC tephra isochrones in Ireland
Three distinct, first millennium BC tephras (BMR-190, OMH-185, GB4-150) have been recognized in Irish peat deposits, including a previously undated ash (BMR-190). We present the results of a programme of high-precision 14 C wiggle-matching on a peat profile containing all three tephras from Glen West, County Fermanagh, Northern Ireland. The wiggle-match provides highly refined dates of 705-585cal. BC for BMR-190, 755-680cal. BC for OMH-185 and 80…
Tephra-dated climate-and human-impact studies during the last 1500 years from a raised bog in central Ireland
Historic Icelandic tephrochronology constrains the time frame of a plant macrofossil and palynological study of ombrotrophic peat to evaluate the effects of climatic and human impact over the last 1500 years on the landscape at a large monastic site in the Irish Midlands. The plant macrofossil climate proxy record indicates maximum wetness during the sixth century AD. Decreasing wetness occurred from the late ninth century to the late thirteenth …
The vegetation history of monastic and secular sites in the midlands of Ireland over the last two millennia
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
A multi-proxy palaeoenvironmental investigation of the findspot of an Iron Age bog body from Oldcroghan, Co. Offaly, Ireland
Assessing the potential for cryptotephra studies in Northeastern China
Quaternary tephrochronology and tephrostratigraphy are employed globally for chronological control and site correlation, but the potential for these approaches in Northeastern China has not been fully explored, in spite of this being a volcanically active region. Microscopic and precise electron microprobe geochemical analyses were performed on crypto- or macrotephra layers in maar lake sediments from Sihailongwan, and peat from Gushantun, from t…
Tephrostratigraphical investigation of lake sediments and a peat bog in Northeastern China since 20,000 years
This is a detailed tephrostratigraphical investigation of late Quaternary deposits in the Longgang and Changbaishan Volcanic Fields of northeastern China. A total of 45 reference samples which were collected from either side of the Chinese/Korean border showed very similar geochemical characteristics to the Millennium eruption of Tianchi Volcano. Through comparing the published data of the glass shards detected in Gushantun with these reference s…
Geology (20 works) · Archaeology (19 works) · Geology and Paleoclimatology Research (19 works) · Paleontology (18 works) · Volcano (18 works) · Geography (17 works) · Tephra (17 works) · Peat (14 works) · Physical geography (14 works) · Holocene (13 works)