Victor J Polyak
Datos Biográficos
| ID | 4129227 |
|---|---|
| NOMBRE | Victor J Polyak |
| NOMBRES | Victor J |
| APELLIDO | Polyak |
| FIRMA | POLYAK V J |
| AFILIACIONES | University of New Mexico |
| ORCID | 0000-0002-2010-1066 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 10 |
| TOTAL DE CITAS | 45 |
| TOTAL COMO AUTOR | 10 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 2007 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2024 |
| ÍNDICE H | 2 |
Characterization of phreatic overgrowths on speleothems precipitated in the northern Adriatic during a sea-level stillstand at ca. 2.8 ka
We examined a Late Holocene sea-level stillstand using phreatic overgrowths on speleothems (POS) recovered from Medvjeđa Špilja [Bear Cave] (northern Adriatic Sea) from −1.28 ± 0.15 m below present mean sea level. Different mineralogical analyses were performed to characterize the POS and better understand the mechanisms of their formation. Results reveal that the fibrous overgrowth is formed of calcite and that both the supporting soda straw and…
Hydroclimate variability from western Iberia (Portugal) during the Holocene
Iberia is predicted under future warming scenarios to be increasingly impacted by drought. While it is known that this region has experienced multiple intervals of enhanced aridity over the Holocene, additional hydroclimate-sensitive records from Iberia are necessary to place current and future drying into a broader perspective. Toward that end, we present a multi-proxy composite record from six well-dated and overlapping speleothems from Buraca …
A speleothem-based mid-Holocene precipitation reconstruction for West-Central Florida
The mid-Holocene was the warmest segment of the current interglacial and possessed a weak latitudinal temperature gradient, which impacted climate teleconnections and thus precipitation variability. Our window into the mid-Holocene climate is a high-resolution (near annual) stalagmite stable isotope-based paleoprecipitation record from Brown’s Cave in West-Central Florida. The oxygen isotopic (δ 18 O) time series is tied to a uranium-series (U-se…
Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans
American Beauty Modern Native American ancestry traces back to an East Asian migration across Beringia. However, some Native American skeletons from the late Pleistocene show phenotypic characteristics more similar to other, more geographically distant, human populations. Chatters et al. (p. 750 ) describe a skeleton with a Paleoamerican phenotype from the eastern Yucatan, dating to approximately 12 to 13 thousand years ago, with a relatively com…
Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry
Development and Disintegration of Maya Political Systems in Response to Climate Change
Maya and Climate Climate has affected the vitality of many different societies in the past, as shown by numerous records across the globe and throughout human history. One of the most obvious and spectacular examples of this is from the Classic Maya civilization, whose advanced culture left highly detailed records of all aspects of their existence between 300 and 1000 C.E. Kennett et al. (p. 788 ; see the cover) present a detailed climate record …
High resolution stalagmite climate record from the Yucatán Peninsula spanning the Maya terminal classic period
Episodes of late Holocene aridity recorded by stalagmites from Devil's icebox Cave, Central Missouri, USA
Two stalagmites from Devil's Icebox Cave, central Missouri, display similar δ 13 C and δ 18 O values and trends during the late Holocene. Positive δ 13 C excursions at 3.5–2.6 ka and 1.2–0.9 ka are interpreted to reflect drier conditions. These elevated stalagmite δ 13 C values could have plausibly been driven by increasing C 4 plant abundances over the cave or an increased contribution of bedrock carbon, both of which could reflect decreased eff…
Younger Dryas to mid-Holocene environmental history of the lowlands of NW Transylvania, Romania
Pollen, micro-charcoal and total carbon analyses on sediments from the Turbuta palaeolake, in the Transylvanian Basin of NW Romania, reveal Younger Dryas to mid-Holocene environmental changes. The chronostratigraphy relies on AMS 14 C measurements on organic matter and U/Th TIMS datings of snail shells. Results indicate the presence of Pinus and Betula open woodlands with small populations of Picea , Ulmus , Alnus and Salix before 12,000 cal yr B…
New age constraints on the Middle Stone Age occupations of Kharga Oasis, Western Desert, Egypt
New age constraints on the Middle Stone Age occupations of Kharga Oasis, Western Desert, Egypt
Hydroclimate variability from western Iberia (Portugal) during the Holocene
Iberia is predicted under future warming scenarios to be increasingly impacted by drought. While it is known that this region has experienced multiple intervals of enhanced aridity over the Holocene, additional hydroclimate-sensitive records from Iberia are necessary to place current and future drying into a broader perspective. Toward that end, we present a multi-proxy composite record from six well-dated and overlapping speleothems from Buraca …
Episodes of late Holocene aridity recorded by stalagmites from Devil's icebox Cave, Central Missouri, USA
Two stalagmites from Devil's Icebox Cave, central Missouri, display similar δ 13 C and δ 18 O values and trends during the late Holocene. Positive δ 13 C excursions at 3.5–2.6 ka and 1.2–0.9 ka are interpreted to reflect drier conditions. These elevated stalagmite δ 13 C values could have plausibly been driven by increasing C 4 plant abundances over the cave or an increased contribution of bedrock carbon, both of which could reflect decreased eff…
Younger Dryas to mid-Holocene environmental history of the lowlands of NW Transylvania, Romania
Pollen, micro-charcoal and total carbon analyses on sediments from the Turbuta palaeolake, in the Transylvanian Basin of NW Romania, reveal Younger Dryas to mid-Holocene environmental changes. The chronostratigraphy relies on AMS 14 C measurements on organic matter and U/Th TIMS datings of snail shells. Results indicate the presence of Pinus and Betula open woodlands with small populations of Picea , Ulmus , Alnus and Salix before 12,000 cal yr B…
New age constraints on the Middle Stone Age occupations of Kharga Oasis, Western Desert, Egypt
High resolution stalagmite climate record from the Yucatán Peninsula spanning the Maya terminal classic period
Development and Disintegration of Maya Political Systems in Response to Climate Change
Maya and Climate Climate has affected the vitality of many different societies in the past, as shown by numerous records across the globe and throughout human history. One of the most obvious and spectacular examples of this is from the Classic Maya civilization, whose advanced culture left highly detailed records of all aspects of their existence between 300 and 1000 C.E. Kennett et al. (p. 788 ; see the cover) present a detailed climate record …
Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry
Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans
American Beauty Modern Native American ancestry traces back to an East Asian migration across Beringia. However, some Native American skeletons from the late Pleistocene show phenotypic characteristics more similar to other, more geographically distant, human populations. Chatters et al. (p. 750 ) describe a skeleton with a Paleoamerican phenotype from the eastern Yucatan, dating to approximately 12 to 13 thousand years ago, with a relatively com…
A speleothem-based mid-Holocene precipitation reconstruction for West-Central Florida
The mid-Holocene was the warmest segment of the current interglacial and possessed a weak latitudinal temperature gradient, which impacted climate teleconnections and thus precipitation variability. Our window into the mid-Holocene climate is a high-resolution (near annual) stalagmite stable isotope-based paleoprecipitation record from Brown’s Cave in West-Central Florida. The oxygen isotopic (δ 18 O) time series is tied to a uranium-series (U-se…
Hydroclimate variability from western Iberia (Portugal) during the Holocene
Iberia is predicted under future warming scenarios to be increasingly impacted by drought. While it is known that this region has experienced multiple intervals of enhanced aridity over the Holocene, additional hydroclimate-sensitive records from Iberia are necessary to place current and future drying into a broader perspective. Toward that end, we present a multi-proxy composite record from six well-dated and overlapping speleothems from Buraca …
Characterization of phreatic overgrowths on speleothems precipitated in the northern Adriatic during a sea-level stillstand at ca. 2.8 ka
We examined a Late Holocene sea-level stillstand using phreatic overgrowths on speleothems (POS) recovered from Medvjeđa Špilja [Bear Cave] (northern Adriatic Sea) from −1.28 ± 0.15 m below present mean sea level. Different mineralogical analyses were performed to characterize the POS and better understand the mechanisms of their formation. Results reveal that the fibrous overgrowth is formed of calcite and that both the supporting soda straw and…
Geology and Paleoclimatology Research (9 obras) · Archaeology (7 obras) · Geography (7 obras) · Cave (6 obras) · Geology (6 obras) · Paleontology (6 obras) · Climate change (5 obras) · Holocene (5 obras) · Physical geography (5 obras) · Speleothem (5 obras)