Publisher Correction: First experimental evaluation of the alpha efficiency in coarse-grained quartz for ESR dating purposes: implications for dose rate evaluation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

On the geoarchaeology of Limyra (SW Anatolia)-new insights into the famous Lycian city and its environs.

Geoarchives in ancient settlement sites and their environs bear valuable information about Holocene landscape evolution and human-environment interactions. During the last six millennia, sea-level and coastline changes have had a significant impact on coastal settlements, some of which even had to be relocated. This paper reveals new insights into the spatio-temporal development of the Lycian city of Limyra. Selected sediment cores were analyzed using a multiproxy approach, combining sedimentology, geochemistry, micropaleontology, and 14C dating. When the postglacial sea-level rise decelerated, a coastal barrier and a deep lake, presumably a lagoon, evolved after the mid-Holocene. The siltation history of the lake is complex: three coastal peat layers (mid-4th millennium BC, end of 3rd/beginning of 2nd millennium BC, beginning of 1st millennium BC), indicate periods of semiterrestrial conditions. That they are sandwiched by lake sediments is consistent with new expansion phases of the lake, most likely triggered by coseismic subsidence. There is evidence of a former lakeshore, dated to between 1400 and 1100 BC, with an intentionally deposited layer of anthropogenic remains, now at 5.5 m below the surface. In the mid-1st millennium BC, the lake silted up, river channels evolved, and people started to settle the area of the later city of Limyra.

First experimental evaluation of the alpha efficiency in coarse-grained quartz for ESR dating purposes: implications for dose rate evaluation.

We present the first experimental evaluation of the alpha efficiency value for electron spin resonance (ESR) dating of coarse quartz grains, which is used for the evaluation of the internal and external alpha dose rate components. Based on our results, we recommend the use of an a-value of 0.07 ± 0.01 (1σ) for both the Al and Ti centres. Although we acknowledge that quartz ESR alpha efficiency may be sample dependent, and could also be impacted by other sources of uncertainty, this potential variability is presently impossible to evaluate given the absence of other experimental a-values available in the ESR dating literature. Measured radioactivity of quartz grains from the Moulouya catchment (NE Morocco) provides an internal dose rate in the range of 50-70 µGy/a when using an a-value of 0.07. The use of this empirically derived a-value for the evaluation of the internal and external alpha dose rate has a limited overall impact on the final ESR age results: they change by <2% and <3%, respectively, in comparison with those obtained with an assumed a-value. However, the large variability observed among the broader sample dataset for quartz internal radioactivity and hydrofluoric acid (HF) etching rates underscores the potential importance of undertaking experimental evaluations of alpha dose rate parameters for each dated sample.

A prehistoric tsunami induced long-lasting ecosystem changes on a semi-arid tropical island--the case of Boka Bartol (Bonaire, Leeward Antilles).

The Caribbean is highly vulnerable to coastal hazards. Based on their short recurrence intervals over the intra-American seas, high-category tropical cyclones and their associated effects of elevated storm surge, heavy wave impacts, mudslides and floods represent the most serious threat. Given the abundance of historical accounts and trigger mechanisms (strike-slip motion and oblique collision at the northern and southern Caribbean plate boundaries, submarine and coastal landslides, volcanism), tsunamis must be considered as well. This paper presents interdisciplinary multi-proxy investigations of sediment cores (grain size distribution, carbonate content, loss-on-ignition, magnetic susceptibility, microfauna, macrofauna) from Washington-Slagbaai National Park, NW Bonaire (Leeward Antilles). No historical tsunami is recorded for this island. However, an allochthonous marine layer found in all cores at Boka Bartol reveals several sedimentary criteria typically linked with tsunami deposits. Calibrated (14)C data from these cores point to a palaeotsunami with a maximum age of 3,300 years. Alternative explanations for the creation of this layer, such as inland flooding during tropical cyclones, cannot entirely be ruled out, though in recent times even the strongest of these events on Bonaire did not deposit significant amounts of sediment onshore. The setting of Boka Bartol changed from an open mangrove-fringed embayment into a poly- to hyperhaline lagoon due to the establishment or closure of a barrier of coral rubble during or subsequent to the inferred event. The timing of the event is supported by further sedimentary evidence from other lagoonal and alluvial archives on Bonaire.