Optically Stimulated Luminescence (OSL) Dating in the Amazonian Wetlands

Over the last 60 years, luminescence dating has developed into a robust chronometer for applications in earth sciences and archaeology. The technique is particularly useful for dating materials ranging in age from a few decades to around ,—, years. In this chapter, following a brief outline of the historical development of the dating method, basic principles behind the technique are discussed. This is followed by a look at measurement equipment that is employed in determining age and its operation. Luminescence properties of minerals used in dating are then examined after which procedures used in age calculation are looked at. Sample collection methods are also reviewed, as well as types of materials that can be dated. Continuing refinements in both methodology and equipment promise to yield luminescence chronologies with improved accuracy and extended dating range in the future and these are briefly discussed. Luminescence – An Outlook on the Phenomena and their Applications. Luminescence dating refers to age-dating methods that employ the phenomenon of luminescence to determine the amount of time that has elapsed since the occurrence of a given event.

Optically Stimulated Luminescence

Jacob C. Bruihler , University of Nebraska – Lincoln Follow. Bruihler, Jacob C. University of Nebraska – Lincoln.

Those sites are the firsthand evidence for long-term use of marine Optically stimulated luminescence (OSL) dating of quartz has been used.

Alastair C. We have attempted to isolate the fast component of the quartz optically stimulated luminescence OSL signal using a curve-fitting procedure. By pre-determining the decay constants, the procedure is simple enough to be scripted, allowing a large number of aliquots to be processed. A Monte Carlo error routine is used, in which simulated decay curves are fitted with several exponentials, which vary in their decay rates according to the measured distributions of fast and medium component decay rates.

The derived error term is closely related to the intensity of the fast component signal, but is also influenced by the degree of similarity between the equivalent doses of the fast and medium OSL components. There are potential advantages in using this procedure to date both well-bleached and partially bleached quartz, of any depositional age. Optically stimulated luminescence dating of young quartz using the fast component. N2 – We have attempted to isolate the fast component of the quartz optically stimulated luminescence OSL signal using a curve-fitting procedure.

AB – We have attempted to isolate the fast component of the quartz optically stimulated luminescence OSL signal using a curve-fitting procedure. Overview Fingerprint. Abstract We have attempted to isolate the fast component of the quartz optically stimulated luminescence OSL signal using a curve-fitting procedure. Access to Document

Luminescence Dating

Introduction How do we measure the OSL signal? How do we measure the radiation dose rate? Another way of dating glacial landforms is optically stimulated luminescence dating OSL. OSL is used on glacial landforms that contain sand, such as sandur or sediments in glacial streams.

and other contexts OSL dating has provided meaning- ful age control and has encouraged a healthy debate in the community on what is credible evidence for a​.

The impetus behind this study is to understand the sedimentological dynamics of very young fluvial systems in the Amazon River catchment and relate these to land use change and modern analogue studies of tidal rhythmites in the geologic record. Many of these features have an appearance of freshly deposited pristine sand, and these observations and information from anecdotal evidence and LandSat imagery suggest an apparent decadal stability.

Signals from medium-sized aliquots 5 mm diameter exhibit very high specific luminescence sensitivity, have excellent dose recovery and recycling, essentially independent of preheat, and show minimal heat transfer even at the highest preheats. Significant recuperation is observed for samples from two of the study sites and, in these instances, either the acceptance threshold was increased or growth curves were forced through the origin; recuperation is considered most likely to be a measurement artefact given the very small size of natural signals.

Despite the use of medium-sized aliquots to ensure the recovery of very dim natural OSL signals, these results demonstrate the potential of OSL for studying very young active fluvial processes in these settings. An important facet of the development of a geochronological technique is the investigation of potential age range. Much recent work in the luminescence field has focused on maximum achievable ages using high-temperature post-infrared infrared pIRIR signals from feldspars [ 1 , 2 ].

DRI Luminescence Laboratory

The DRI E. The DRILL is a research laboratory dedicated to fundamental investigations in the luminescence properties of earth materials, and to the application of luminescence dating techniques to geomorphological, geological, and archeological problems. The DRILL welcomes collaboration with research institute and university faculty, consultants, and government agency researchers.

The DRILL research staff can collaborate on proposals, contribute to grant writing, and consult on study design. We can also arrange training for undergraduate and graduate students, post-docs, and visiting researchers. What is Luminescence Dating?

Optical dating of sediment using optically stimulated luminescence has dating to demonstrate that the fuel loads and resultant fire intensities (defined as.

Luminescence dating including thermoluminescence and optically stimulated luminescence is a type of dating methodology that measures the amount of light emitted from energy stored in certain rock types and derived soils to obtain an absolute date for a specific event that occurred in the past. The method is a direct dating technique , meaning that the amount of energy emitted is a direct result of the event being measured.

Better still, unlike radiocarbon dating , the effect luminescence dating measures increases with time. As a result, there is no upper date limit set by the sensitivity of the method itself, although other factors may limit the method’s feasibility. To put it simply, certain minerals quartz, feldspar, and calcite , store energy from the sun at a known rate. This energy is lodged in the imperfect lattices of the mineral’s crystals.

Heating these crystals such as when a pottery vessel is fired or when rocks are heated empties the stored energy, after which time the mineral begins absorbing energy again.

References

Optically stimulated luminescence OSL dating has proven to be extremely useful for establishing the Late Quaternary chronological framework in many areas of the Brazilian territory. In this region dominated by tropical climate, OSL dating can be more extensively applied than radiocarbon dating due to the generally low potential for the preservation of organic matter in sedimentary samples.

This problem is especially critical in areas of the Amazonian lowlands, because of the hot climate and high precipitation rates. The abundance of quartz grains deposited in fluvial and aeolian environments over this region favours OSL dating. More than 20 years of continuous and collaborative work has resulted in the creation of an extensive OSL age database for Late Quaternary sedimentary deposits in the Amazonian lowlands.

OSL dating yielded ages between 93±6ka and 64±5 Ka. in the crystal structure of minerals like quartz or feldspar is used to define the age of the sediment.

Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses various methods to stimulate and measure luminescence. All sediments and soils contain trace amounts of radioactive isotopes of elements such as potassium , uranium , thorium , and rubidium.

These slowly decay over time and the ionizing radiation they produce is absorbed by mineral grains in the sediments such as quartz and potassium feldspar. The radiation causes charge to remain within the grains in structurally unstable “electron traps”. The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried.

Stimulating these mineral grains using either light blue or green for OSL; infrared for IRSL or heat for TL causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral. Most luminescence dating methods rely on the assumption that the mineral grains were sufficiently “bleached” at the time of the event being dated.

Single Quartz OSL ages can be determined typically from to , years BP, and can be reliable when suitable methods are used and proper checks are done. In multiple-aliquot testing, a number of grains of sand are stimulated at the same time and the resulting luminescence signature is averaged [4]. The problem with this technique is that the operator does not know the individual figures that are being averaged, and so if there are partially prebleached grains in the sample it can give an exaggerated age [4].

Optically stimulated luminescence dating of young quartz using the fast component

David Sanderson, Timothy Charles Kinnaird. Discover related content Find related publications, people, projects and more using interactive charts. Research at St Andrews. Section navigation. Abstract This chapter concerns the use of luminescence methods as geochronological tools for dating Late Quaternary sediments in the Red Sea region.

Optically Stimulated Luminescence Dating as a Geochronological Tool a growing corpus of work is emerging, which is helping to define past.

Optical : Relating to the use of visible or near-visible light. Stimulated : To excite with a stimulus light or heat. Optically stimulated luminescence : The emission of light from crystalline materials when stimulated by light following previous absorption of energy from radiation. Luminescence dating consists of a family of analytical methods, most of which are used in archaeological research. They can be applied to samples ranging in age from just a few years to several hundreds of thousands of years beyond the range of radiocarbon dating , and they are, therefore, able to cover a time interval that includes important turning points in the evolution of humans.

The choice of luminescence method depends on the availability of appropriate minerals, the time period of Skip to main content Skip to table of contents. This service is more advanced with JavaScript available. Encyclopedia of Geoarchaeology Edition. Contents Search. Reference work entry First Online: 12 August How to cite.

Optical : Relating to the use of visible or near-visible light Stimulated : To excite with a stimulus light or heat Luminescence : The emission of light Optically stimulated luminescence : The emission of light from crystalline materials when stimulated by light following previous absorption of energy from radiation.

optically stimulated luminescence