High-precision 238U–234U–230Th disequilibrium dating of the recent past: a review

Zhao, Jian‐xin; Yu, Kefu; Feng, Yuexing

doi:10.1016/j.quageo.2009.01.012

Cited by 99 publications

(58 citation statements)

References 74 publications

(172 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Detailed sample selection and physical pretreatment protocols for such samples are described in Zhao et al (2009), St Pierre et al (2012 and Price et al (2013), for flowstones, straw stalactites, and teeth, respectively. Sample measurement was conducted on a Nu Plasma multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) at the Radiogenic Isotope Facility, The University of Queensland, following procedures described in Zhou et al (2011) andClark et al (2014).…”

Section: U-th Datingmentioning

confidence: 99%

Differential preservation of vertebrates in Southeast Asian caves

Louys¹,

Kealy²,

O’Connor³

et al. 2017

IJS

View full text Add to dashboard Cite

Abstract:Caves have been an important source of vertebrate fossils for much of Southeast Asia, particularly for the Quaternary. Despite this importance, the mechanisms by which vertebrate remains accumulate and preserve in Southeast Asian caves has never been systematically reviewed or examined. Here, we present the results of three years of cave surveys in Indonesia and Timor-Leste, describing cave systems and their attendant vertebrate accumulations in diverse geological, biogeographical, and environmental settings. While each cave system is unique, we find that the accumulation and preservation of vertebrate remains are highly dependent on local geology and environment. These factors notwithstanding, we find the dominant factor responsible for faunal deposition is the presence or absence of biological accumulating agents, a factor directly dictated by biogeographical history. In small, isolated, volcanic islands, the only significant accumulation occurs in archaeological settings, thereby limiting our understanding of the palaeontology of those islands prior to human arrival. In karstic landscapes on both oceanic and continental islands, our understanding of the longterm preservation of vertebrates is still in its infancy. The formation processes of vertebratebearing breccias, their taphonomic histories, and the criteria used to determine whether these represent syngenetic or multiple deposits remain critically understudied. The latter in particular has important implications for arguments on how breccia deposits from the region should be analysed and interpreted when reconstructing palaeoenvironments.

show abstract

Section: U-th Datingmentioning

confidence: 99%

Differential preservation of vertebrates in Southeast Asian caves

Louys¹,

Kealy²,

O’Connor³

et al. 2017

IJS

View full text Add to dashboard Cite

show abstract

“…To examine temporal changes in coral assemblages, we compared the community structure of life assemblages (living scleractinian corals) and death assemblages (dead coral fragments directly adjacent to modern corals), an approach commonly used to identify signals of anthropogenic disturbance and shifts in benthic community structure in the absence of historical baselines [28,29]. We obtained high-precision U-series dates [30] from dead coral samples within death assemblages to estimate the timing of mortality and to explore the age structure of the death assemblages. Finally, we extracted core samples from the reef matrix and quantified long-term (centennial to millennial) trajectories in coral community structure to determine historical baselines of coral assemblages.…”

Section: Introductionmentioning

confidence: 99%

Palaeoecological evidence of a historical collapse of corals at Pelorus Island, inshore Great Barrier Reef, following European settlement

et al. 2013

Self Cite

View full text Add to dashboard Cite

The inshore reefs of the Great Barrier Reef (GBR) have undergone significant declines in water quality following European settlement (approx. 1870 AD). However, direct evidence of impacts on coral assemblages is limited by a lack of historical baselines prior to the onset of modern monitoring programmes in the early 1980s. Through palaeoecological reconstructions, we report a previously undocumented historical collapse of Acropora assemblages at Pelorus Island (central GBR). High-precision U-series dating of dead Acropora fragments indicates that this collapse occurred between 1920 and 1955, with few dates obtained after 1980. Prior to this event, our results indicate remarkable long-term stability in coral community structure over centennial scales. We suggest that chronic increases in sediment flux and nutrient loading following European settlement acted as the ultimate cause for the lack of recovery of Acropora assemblages following a series of acute disturbance events (SST anomalies, cyclones and flood events). Evidence for major degradation in reef condition owing to human impacts prior to modern ecological surveys indicates that current monitoring of inshore reefs on the GBR may be predicated on a significantly shifted baseline.

show abstract

“…Although this assumption was proven to be acceptable for most coral samples from inshore settings 76 (Clark et al 2012; Shen et al 2008), the large associated uncertainty makes the age uncertainty of 77 the corrected 230 Th age for young corals too large to be meaningful (see Zhao et al 2009). 78…”

mentioning

confidence: 99%