Luminous Efficiency Measurements for Silicon and Aluminum Simulated Micrometeors

Abstract

The microscopic structure of silicified Cedrela vvood, as- signable to the form genus Cedreloxylon SELMEIER, 1987, is described from the northern Alpine Foreland in southern Ger- many and Austria. Two structurally different wood types of Ccdroxylon can be distinguishcd based on cross sections. The wood of Cedreloxylon i s compared to that seen i n extant and other fossil taxa of Cedrela. In adebtion, the ring widths of 45 Cedrela wood fragments are recorded. The results suggest that minute anatomy and growth ring width may vary considerably withm a smgle tree, depending on the topographic position (e.g., stem, branch, root) of the respective fragment. Finally, a few comments are offered on the difficult task of interpreting fossil tree-rings with regard to palaeoclimatology, and some aspects are exemplified based on the material at band.