960 D. Submarine Geology and Geophysics OLR (1987) 34 (11) "

Triassic deposits, distinguished by the presence of large, exotic limestone blocks formed by subaqueous slumping are described for occurrences in the Koryak Mountains, the Canadian Cordillera, and elsewhere. Analysis of available data shows that the exotic bodies accumulated in basins with an oceanic crust fairly remote from continental source areas. The exotic material must have been derived from inner-basin carbonate rises with a volcanic base- ment. The presence of Paleozoic and Triassic elastic chert beds in these sections shows that tectonic movements were active throughout the region. It is concluded that the formation of the exotic bodies should be attributed to destructive processes of a new type in regions with an oceanic crust. Geolog. Inst., Acad. of Sei., Moscow, USSR.

87:6307 Tiwari, R.K., 1987. Higher-order eccentricity cycles

of the Middle and Late Miocene climatic varia- tions. Nature, Lond., 327(6119):219-221.

Recent spectral analyses of non-glacial climatic records of the Mid-Cretaceous and Early Mesozoic exhibit the dominance of 100- and 400-kyr eccen- tricity cycles and exclude the possibility that the above periodicities originate from the internal variability of ice sheets. Walsh spectrum analyses of 10 Myr oxygen (6z80) and carbonate (813C) isotope variations (Mid and Late Miocene) reveal statis- tically significant periodicities of ca. 2.0 and 1.25 Myr, 800, 400, 115 and 93 kyr and harmonies of the higher-order terms with remarkable resolution. Higher-order periodicities, hitherto unexplained in the spectrum of deep-sea records, match quite well with predicted large eccentricity cycles in the Earth's orbital variations, indicating that eccentricity forcing (induced by orbital variations) exerts a major influence on the Earth's climate. Inst. fur Geophysik, Olshausenstr 40-60, Christian Albrechts Univ., 23 Kiel, FRG.

D I S 0 . P a l e o n t o l o g y (see also E-BIOLOGICAL OCEANOGRAPHY)

87:6308 Amieux, Pascal, 1987. Petrographic description of

Foraminifera by combination of natural light and cathodoluminescent pictures. C. r. Acad. Sci., Paris, (S6r. II)304(13):741-744. (In French, English abstract.)

A new petrographic method is described for the analysis of mierofauna in thin section. Study of natural light and cathodolumineseent pictures of Ophthalmidium sp. shows that the levels of obser-

vation are at different depths of the same thin section. Comparison of these pictures yields data valuable for determination of partially reerystallized microfauna. Univ. de Geneve, Dept. de Geol. et de Paleontol., 13, rue des Maraichers, 1211 Geneva 4, Switzerland.

87:6309 Belford, D.J., 1983. Note on costellate planktonic

Foraminifera, and the generic designation of Late Cretaceous forms from Western Australia. BMR Bull., Australia, 217:1-10.

87:6310 Chaproniere, G.C.H., 1983. Tertiary larger forami-

niferids from the northwestern margin of the Queensland Plateau, Australia. BMR Bull, Aus- tralia, 217:31-57.

Sixteen species of larger foraminiferids (those with complicated internal structures) have been recorded from four localities. The assemblages are from Tertiary a 3 (early Middle Eocene), Tertiary lower e, and Tertiary upper e (Late Oligocene to Early Miocene). This represents the first record of Tertiary a3 from Australia. The Tertiary upper e assemblage is a new one for this region; one species, Sherbornina carteri, is described as new.

87:6311 Cronin, T.M., 1987. Evolution, biogeography, and

systematic, of Pm'/ana: evolution and spociation in Ostracoda, III. Mere. paleont. Soc, 21:71pp.

A study of Puriana specimens from the eastern Pacific, western Atlantic, Gulf of Mexico. and Caribbean, using original measurements, statistical analyses, and scanning electron photomicrographs from an earlier study, demonstrates that distinct evolutionary responses to the introduction of land and deep water barriers and climate change occurred within Neogene and Quaternary species. Although the isolation of large populations by the elevation of the Isthmus of Panama did not result in lineage splitting, the isolation of small populations on Caribbean islands did in many cases lead to the evolution of new species or subspecies. The study provides specific examples of speciation by clado- genesis and supports a model of evolution driven by abiotic factors in the environment. USGS, 970 Natl. Center, Reston, VA 22092, USA. (hbf)

87:6312 Mateu, Guillermo and Magdalena Gaza, 1986.

Foraminifera and coceolithophores associated with Corallium rubmm (L.). Systematics, ecology and paleoceanographie evolution. Boln Inst. esp. Oceanogr., 3(4):13-52. (In Spanish, English ab-