Bergalite

Bergalite: "A local name for an ultramafic lamprophyre similar to alnöite except that the matrix contains essential feldspathoids as well as melilite. The rock could be described as a haüyne melilitite". (Le Maitre, 2005).

Bergalite was defined by Soellner (1913) from only six dikes in the area around Oberbergen; systematic surveying over the last 15 years has increased the number of know dikes. The petrographic composition of bergalite is hauyne, melilite, perovskite, nepheline, calcite, mica, magnetite and apatite. Pyroxene is characteristically absent from most bergalites, but some pyroxene-bearing examples exist. Bergalites are considered transitional between carbonatites and silicate magmas.

Bibliography

• Ulianov, A., Müntener, O., Ulmer, P., & Pettke, T. (2007). Entrained macrocryst minerals as a key to the source region of olivine nephelinites: Humberg, Kaiserstuhl, Germany. Journal of Petrology, 48(6), 1079-1118.
• Walter, B. F., Marks, M. A. W., & Markl, G. (2016). The Kaiserstuhl natural laboratory-an introduction and first results. Abstract Malawi Expert Council.
• Weisenberger, T. B., Spürgin, S., & Lahaye, Y. (2014). Hydrothermal alteration and zeolitization of the Fohberg phonolite, Kaiserstuhl Volcanic Complex, Germany. International Journal of Earth Sciences, 103(8), 2273-2300.
• Weisenberger, T., & Spuergin, S. (2009). Zeolites in alkaline rocks of the Kaiserstuhl Volcanic Complex, SW Germany–new microprobe investigation and the relationship of zeolite mineralogy to the host rock. Geologica Belgica

Photo
Small, needle like, melilite crystals and rounded apatite (colorless) crystal in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals, and big rectangular apatite crystal in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals, and rounded apatite (colorless) crystals in a bergalite. PPL image, 2x (Field of view = 7mm)
Small, needle like, melilite crystals, pyroxene (green) and colorless hauyne in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals, pyroxene (high birefringence) and hauyne (isotropic) in a bergalite. XPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals and calcite aggregate in a bergalite. PPL image, 2x (Field of view = 7mm)
Small, needle like, melilite crystals and colorless and hexagonal basal section of apatite in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals and colorless and hexagonal basal section of apatite in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals and colorless and big apatite crystals in a bergalite. PPL image, 2x (Field of view = 7mm)
Small, needle like, melilite crystals and colorless and hexagonal basal section of apatite in a bergalite. PPL image, 2x (Field of view = 7mm)	Small, needle like, melilite crystals and colorless and hexagonal basal section of apatite in a bergalite. XPL image, 2x (Field of view = 7mm)