During authigenic mineral formation, ash assimilated some elements from the surrounding environment, whereas the set of assimilated elements has been considerably different in the Kinnekulle and BII bentonites.
between 40% and 60%), indicating the dissolution and removal of silica during the transformation of volcanic ash to authigenic minerals.
3e), although truncation and mechanical reworking can also separate stages of authigenic mineral formation.
The present study deals with sepiolite in pan deposits of the south-western Kalahari, as part of a wider investigation of distribution patterns of authigenic minerals in lake basins of the Aminuis region in eastern Namibia.
The clastic matrix is composed mainly of silt-size quartz and illite, the minor clastic minerals are feldspars and chlorite, pyrite is a rather common authigenic mineral
However, the complicated geological conditions and resultant authigenic mineral
structures described in these publications resemble, but do not equal those determined and described in the present study.
Zeolites may occur naturally as authigenic minerals
formed from volcanic glass and various rock-forming minerals by interaction with aqueous solution or fluid in many geochemical environments (Breck, 1974; Mumpton, 1977; Gottardi and Galli, 1985; Hay, 1986; Boles, 1988).
In Authigenic Minerals
of Baltic Terrigenous Sediments (Pin-us, E.
According to the present study, the carriers of the remanent magnetization are (i) allogenic and synsedimentary and/or early diagenetic authigenic ironbearing minerals of the primary sedimentary siliciclastic and carbonate rocks and (u) alteration products of primary minerals or new authigenic minerals
formed during latediagenetic, hydrothermal, or weathering processes.
2005) described the paragenetic sequence of mineralization and characterized the thermal conditions of the formation of different authigenic minerals
in the crater interior.
2%) and the content of light authigenic minerals
(calcite, rare grains of glauconite) increases to 16% of the light minerals.
This is valid for two groups of elements: Rb, Y, and Th that are mainly related to feldspars and other clastic allothigenic minerals, and Mn, Ni, Zn, As, Sr, Pb, and U, which could be carried also by clay minerals and most fine-grained, unspecified authigenic minerals