Zeolite deposits of possible economic significance on the northern Alaska Peninsula

Clinoptilolite, mordenite, haulandite and laumontite have been identified in possible economic concentrations on the Alaska Peninsula. Most important are 1) a haulandite bearing water-laid tuff on Agate Island, 2) a thick sequence of terrestrial volcanics containing mordenite and clinoptilolite located between Squirrel Point and Tommy Creek, 3) water-laid tuffs containing high concentrations of clinoptilolite near Dennis Creek and 4) a haulandite bearing siltstone at Chinitna Bay. Zeolite formation in the Iliamna Lake area was produced in "open" systems of fresh water lakes and ground water systems which have transformed vitric volcanic material into zeolites. Burial diagenesis is responsible for alteration of early formed, low temperature-pressure zeolites into high temperature-pressure varieties. The formation of laumontite in a tuffaceous sandstone at Chinitna Bay was the result of low grade burial metamorphism. The mode of formation of haulandite in a welded tuff and siltstone unit, also located at Chinitna Bay, appears to have resulted from diagensis alteration of terrestrial sediments. Transportation of zeolite ore from Iliamna Lake would be by lake to Pile Bay Village then by road to Iliamna Bay and, finally, by ship to the consumer. In the Chinitna Bay area ore can be loaded directly onto ships for transportation to the consumer

Rank 4 vector bundles on the quintic threefold

By the results of the author and Chiantini in Math.AG/0110102, on a general quintic threefold $X \subset {\mathbf P}^4$ the minimum integer $p$ for which there exists a positive dimensional family of irreducible rank $p$ vector bundles on $X$ without intermediate cohomology is at least three. In this paper we show that $p \leq 4$, by constructing series of positive dimensional families of rank 4 vector bundles on $X$ without intermediate cohomology. The general member of such family is an indecomposable bundle from the extension class $Ext^1(E,F)$, for a suitable choice of the rank 2 ACM bundles $E$ and $F$ on $X$. The existence of such bundles of rank $p = 3$ remains under question.Comment: v2: 8 pages. Title changed. One wrong example is removed. More explicit examples are given - v3: typos corrected according to referees suggestions - v.4 final version, to appear on Central European Journal of Mathematic

Book Review: The Bairagi Madonna: Leaves from a Calcutta Notebook

A review of The Bairagi Madonna: Leaves from a Calcutta Notebook by A.F. Thompson

An Iconographical Analysis of the Madonna and Child with Saints in the Enclosed Garden

The Madonna and Child with Saints in the Enclosed Garden, created approximately between the 1440s and 1460s, is a perfect representation of the highly iconographical images produced during the Renaissance. Although it continues to remain unknown as to who the specific artist responsible for this painting is, it has been attributed to either Robert Campin or one of his many followers. Nevertheless, the depiction of the Virgin Mary holding baby Christ on her lap is heightened as the scene takes place within an enclosed garden, otherwise known as hortus conclusus. Throughout the image itself, one is able to understand how the Madonna and the enclosed garden promote one another in the artist’s goal of creating a holy and otherworldly space