Paleoclimatic Variability At Frequencies Ranging From 1 Cycle Per 10000 Years To 1 Cycle Per 1000 Years - Evidence for Nonlinear Behavior of the Climate System

The paleoclimatic variability at frequencies ranging from 10/sup -4/ cycle per year (cpy) to 10/sup -3/ cpy is investigated using a set of three deep-sea cores from the Indian Ocean. Three frequency bands of high paleoclimatic variability are first defined using upper and lower limits of the significant spectral power concentrations: the bands are centered around the spectral maxima located at 10.3, 4.7, and 2.5 kyr. The localization of spectral lines is then refined by high-resolution spectral analysis. Some of the resulting lines have frequencies which are close to those previously detected in other paleoclimatic records, including the precessional peak at 19 kyr. Additional lines are also in good correspondence with the response of a nonlinear climatic oscillator forced by insolation variations, including peaks at 13 kyr, 10.4 kyr and 9.4 kyr. This correspondence suggests orbital forcing. Moreover, for the Indian Ocean which is influenced by the monsoon circulation, it is plausible that the precessional contribution of the forcing interacts strongly with the precipitation-temperature feedback used in the model, thus emphasizing the nonlinearity of the response.Anglai

Distinctive Volcanic Material for the Production of Campana A Ware: The Workshop Area of Neapolis at the Duomo Metro Station in Naples, Italy

Recent transportation infrastructure works in Naples, Italy, provided important discoveries related to the production of pottery in the Hellenistic workshop area of Piazza Nicola Amore. A minero-petrographic investigation was conducted on 35 samples belonging to the widespread Campana A ware and production indicators (clayey raw materials, unfired Graeco-Italic amphorae, kiln wastes, workshop tools). Additional analysis was conducted on black-glaze and common ware samples for comparison. The analyses reveal compositional and technological homogeneity of Campana A ware. Samples are characterized by low CaO content with evidence of both volcanic and sedimentary components, suggesting that different clay sources were properly mixed to prepare a standard recipe. Production indicators, black-glaze and common wares, have a composition well consistent with the calcareous clays from the island of Ischia. Leucite- and garnet-bearing temper from the Somma Volcano were used for the preparation of coarse-grained pastes, unfired Graeco-Italic amphorae, and clayey raw materials, thus suggesting that they represented the clay sources for amphorae production. Our results reveal new technological and socioeconomic aspects of Hellenistic pottery production in the Bay of Naples, in particular for the Campana A ware, now representing a new reference group: Neapolis