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SummaryThe Kangerdlugssuaq late dike swarm, which strikes at a high angle to the well-known East Greenland coastal swarm, is described and chemical analyses presented. The basic members are characterized by a high potassium content. A variety of kaersutite-bearing gabbroic inclusions in one member of this swarm is described in detail and microprobe analyses of clinopyroxenes, amphiboles, plagioclases, sheet silicates, and spinel minerals are presented. On the basis of this evidence it is deduced that these inclusions derive from a cumulate sequence formed at depths of between 5 and 10 km beneath the Lower Tertiary land surface. It is likely that fractionation of such assemblages causes a transition, at relatively low pressure, from undersaturated to oversaturated compositions, but the products appear to be quantitatively minor.

Mycorrhizal fungi were associated with citrus roots or soils in 78 of 79 orchards and nurseries in California and in 64 of 66 citrus orchards and nurseries in Florida. Glomus fasciculatus, G. macrocarpus, G. etunicatus, G. constrictus, and Sclerocystis sinuosa were present in both states. In addition, G. microcarpus and G. monosporus were found in California. Gigaspora margarita and G. mosseae were associated with citrus in Florida but not in California. Glomus fasciculatus was consistently associated with young trees (0-30 yr), whereas G. constrictus was consistently associated with older trees (30-70 yr). Total numbers of mycorrhizal chlamydospores associated with citrus in California were negatively correlated with soil P and organic matter, but were positively correlated with soil Na and pH. Glomus macrocarpus was more frequently found in California citrus soils of high P content than was G. microcarpus, and G. monosporus appeared to inhabit soils of higher B, Ca + Mg, or salinity than several other mycorrhizal fungi. In California, chlamydospores of both G. fasciculatus and G. constrictus were most numerous from November to May and least numerous from June to September.

Five rare earth-bearing minerals found in rocks of the Chilwa Alkaline Province, Malawi, are described. Zirconolite, occurring in nepheline syenite, is unusual in being optically zoned, and microprobe analyses indicate a correlation of this zoning with variations in Si, Ca, Sr, Th, U, Fe, Nb and probably water; it is argued that this zoning is a hydration effect. A second compositional zoning pattern, neither detectable optically nor affected by the hydration, is indicated by variations in Th, Ce and Y such that, although total REE abundances are similar throughout, there appears to have been REE fractionation during zirconolite growth from relatively heavy-REE and Th-enrichment in crystal cores to light-REE enrichment in crystal rims.Chevkinite is an abundant mineral in the large granite quartz syenite complexes of Zomba and Mulanje, and analyses are given of chevkinites from these localities. There is little variation in composition within each complex, and only slight differences between them; they are all typically light-REE-enriched. The Mulanje material was shown by X-ray diffraction to be chevkinite and not the dimorph perrierite, but chemical arguments are used in considering the Zomba material to be the same species. Other rare earth minerals identified are monazite, fluocerite and bastnäsite. These are briefly described and microprobe analyses presented.

SUMMARY Six citrus cultivars were grown with and without the mycorrhizal fungus Glomus fasciculatus under three fertilizer regimes all without phosphorus. The average mycorrhizal dependency (Gerdemann 1975) of Rough lemon and Brazilian sour orange were greater than the mycorrhizal dependecies of Alemow, Troyer citrange, Bessie sweet orange and Trifoliate orange. The mycorrhizal dependency of each cultivar, except Bessie sweet and Trifoliate orange, was substantially altered by at least one of the fertilizer regimes, and therefore the order of mycorrhizal dependency was different at all three fertilizer regimes. On the average, citrus rootstocks exhibited the greatest mycorrhizal dependency with the least fertilization. The average percentage phosphorus in non-mycorrhizal leaf tissues was inversely correlated with the mycorrhizal dependency of citrus cultivars at the medium fertilizer regime. An inverse correlation was observed between the dry weights of non-mycorrhizal roots of the citrus cultivars and the mycorrhizal dependency of the citrus cultivars.

Ussingite is unstable at 1 kb total pressure in the system $$ussingite-H_{2}O$$. Instead, the natural ussingite has an albite liquidus slightly in excess of 775°C. This liquid can dissolve 5.6 wt% $$H_{2}O$$ before becoming saturated. At subliquidus temperatures, two isobaric invariant assemblages occur: (1) nepheline (ne) + albite (ab) + analcite (anl) + vapor (v) + liquid (1) at 525 ± 5°C and (2) ne + ab + anl + sodium disilicate ($$ns_{2} + 1 at 462 \pm 12°C$$. These are most likely the expressions of the univariant reactions $$anl + v \rightarrow ab + ne + 1, and anl + ns_{2} \rightarrow ab + ne + 1$$. Assemblages involving analcite and a persodic liquid in the system $$Na_{2}O-Al_{2}O_{3}-SiO_{2}-H_{2}O$$ are found to occur at lower temperatures for a constant pressure, and at lower pressures for a constant temperature. The high potential water contents of persodic-rich liquids produces a prolonged negative slope to the vapor-saturation boundary at subliquidus temperatures. This will increase by one ...

The pseudoternary system nepheline-diopside-sanidine represents a plane within the six-component system CaO-MgO-Al₂O₃Na₂O-K₂O-SiO₂ as well as a plane through the tetrahedron nepheline-kalsilite-silica-diopside. Liquidus phase relations show primary phase fields of olivine, nepheliness, leucitess, and diopsidess and the presence of piercing points at $$Ne_{51}Di_{21}San_{28}$$ (1,1158° ± 10° C) and $$Ne_{44,5}Di_{12}San_{43,5}$$ (1,120° ± 5° C). Subliquidus phase relations for silica-poor portions of the system exhibit the crystallization of melilite and the disappearance of both melilite and olivine by reaction. The appearance of melilite is attributed to the desilication of pyroxene while its disappearance is probably caused by the desilication of alkali feldspar. The crystallization of melilites in alkali-rich silica-undersaturated rocks is believed to be controlled by the amounts of alkali feldspar in their parental liquids. In the complex CaO-MgO-Al₂O₃-Na₂O-K₂O-SiO₂ system, two planes are designated t...

Yield of young lemon trees increased with either soil application of K2SO4 or foliage application of KNO3 in an orchard where leaf K was low. Leaf Zn was low but one annual foliage spray of ZnSO4 (control in this study) supplied adequate Zn and there was no response to additional Zn sprays. Peel thickness decreased, and percent juice and percent acid in the juice increased with added K.