Some outstanding assumpti

Three examples of incorrect or incomplete assumptions are considered. (1) The oceanic geothermal gradient was originally established using an assumed temperature at the boundary between the rigid lithospheric tectonic plate and the underlying plastically deforming asthenospheric mantle. Revising this invalid temperature assumption has major implications for the concentration of radio-active elements within the mantle, convective patterns and the rate of cooling of the Earth, etc. (2) The earliest 19th century spectral observations of the surface of the Sun identified meteoritic components. This was plausible as Sunspots were thought to be meteoritic impacts, but are now known to be of internal origin. The Sun has no meteoritic materials and its age and origin require major revision. (3) Astronomical changes in the position of objects in the solar system provide causative mechanisms for periodicities in many Earth processes – climate, sea-level, sea-floor spreading, volcanism, etc. Unexplained spectral features probably originate from effects due to the same bodies influencing the solar processes that then affect the magnitude and nature of solar radiation, solar wind, electromagnetic storms, etc., reaching the Earth’s upper atmosphere

Ultra-fine magnetostratigraphy of Cretaceous shallow water carbonates, Monte Raggeto, southern Italy

From Morris, A. & Tarling D.H. (eds) 1996, Paleomagnetic and Tectonics of the Mediterranean Region, Geological Society Special Publicatio

Paleomagnetic evidence of block rotations in the Matese Mountains, Southern Apennines, Italy.

From Morris, A. & Tarling D.H. (eds), 1996, Paleomagnetism and Tectonics of the Mediterranean region, Geological Society Special Publicatio

Archaeomagnetic secular variation in the UK during the past 4000 years and its application to archaeomagnetic dating

International audienceThis paper examines the limitations and deficiencies of the current British archaeomagnetic calibration curve and applies several mathematical approaches in an attempt to produce an improved secular variation curve for the UK for use in archaeomagnetic dating. The dataset compiled is the most complete available in the UK, incorporating published results, PhD theses and unpublished laboratory reports. It comprises 620 archaeomagnetic (directional) data and 238 direct observations of the geomagnetic field, and includes all relevant information available about the site, the archaeomagnetic direction and the archaeological age. A thorough examination of the data was performed to assess their quality and reliability. Various techniques were employed in order to use the data to construct a secular variation (SV) record: moving window with averaging and median, as well as Bayesian statistical modelling. The SV reference curve obtained for the past 4000 years is very similar to that from France, most differences occurring during the early medieval period (or Dark Ages). Two examples of dating of archaeological structures, medieval and pre-Roman, are presented based on the new SV curve for the UK and the implications for archaeomagnetic dating are discussed

Archaeomagnetic Secular Variation in the UK During the Past 4000 Years and its Application to Archaeomagnetic Dating

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Archaeomagnetic Applications for the Rescue of Cultural Heritage.

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