Authigenic K-feldspar in the Bromsgrove Sandstone Formation (Triassic) of ccntral England

Ali, Asim; Tuner, P.

doi:10.1306/212f7f09-2b24-11d7-8648000102c1865d

Cited by 47 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The low potassium values are probably due to the presence of small amounts of albite and anorthite and the substitution of barium for potassium. This explanation is consistent with the findings of Ali and Turner (1982), who reported an inverse relationship between potassium and barium-sodium contents in microprobe traverses across K-feldspar overgrowths. The low totals obtained for authigenic K-feldspar in the dolostones may possibly be due to the presence of organic matter or structural water.…”

Section: Accessory Mineralssupporting

confidence: 93%

Studies in diagenesis

Mumpton¹

1986

View full text Add to dashboard Cite

U.S. GEOLOGICAL SURVEY BULLETIN 1578Cover shows scanning electron micrograph of late-stage smectite (lower left) coating earlier chabazite crystals formed on early-stage smectite, in altered Pliocene vitric tuff, Durkee, Oregon. See article by A.j . Gude 3rd, and R. A. Sheppard, (this volume, PREFACEThe collection of research papers in this volume evolved from a workshop on diagenesis in sedimentary rocks sponsored by the U.S. Geological Survey. The workshop was held March 16--18, 1982, in Golden, Colorado, and was attended by 248 participants from the Survey's Geologic and Water Resources Divisions.The idea for the workshop came to four of us-Walt Dean, Phoebe Hauff, Harry Tourtelot, and me-during a series of informal discussions in late 1980. The complexity and interdisciplinary nature of the broad range of diagenetic processes were clearly recognized, as was their importance in the genesis, transport, emplacement, and mode of occurrence of a wide variety of organic fuels and mineral resources. The advantages of bringing together scientists who were actively engaged in diagenesis studies from several branches in two divisions of the Survey were readily apparent, and so a proposal for such a multidisciplinary and interdivisional workshop was formulated. The proposal was accepted and approved by the Survey in early 1981 .The workshop comprised two days of technical sessions consisting of oral papers and concurrent poster displays. A third day was set aside so that participants could schedule one-on-one conferences with any of the invited guest speakers or arrange small group discussions on topics of mutual interest. Each of the four half-day technical sessions represented a different aspect of diagenesis---<=hemical, carbonate, fine clastic, and coarse clastic-and began with an invited review paper on the theme of that session. The program opened with an overview "keynote" paper by Robert M. Garrels on the role of diagenesis in the geochemical cycle. In the first session, Robert A. Berner reviewed advances in several aspects of sediment-fluid interaction accompanying early diagenesis, and Lynton Land surveyed diagenesis in carbonate rocks to lead off the second session. In the third session John Hower reviewed the advancements in clay mineral diagensis, and in the final session Raymond Siever discussed thermal and burial relationships during the history of sedimentary basins.During these sessions 50 Survey authors presented 22 talks and 9 poster displays on topics ranging from diagenesis in limestones to uranium deposits to zeolitic tuffs. The authors reported findings of field, laboratory, and theoretical investigations dealing with such disparate approaches as organic geochemistry of hydrocarbon maturation, stable isotope fractionation, petrographic analysis, mineral equilibria and dissolution kinetics, mapping and field relations, and trace element geochemistry. The concurrent poster sessions presented results of more intensely focused studies.The workshop's flavor and organization have been retained in this...

show abstract

Section: Accessory Mineralssupporting

confidence: 93%

Studies in diagenesis

Mumpton¹

1986

View full text Add to dashboard Cite

show abstract

“…These characteristics have much in common with those of authigenic K‐feldspar (Kastner & Siever 1979; Ali & Turner 1982; Worden & Rushton 1992). Other features in common are the relationships between optical continuity between the lens and its substrate and the structure and composition of the substrate (Waugh 1978; Ali & Turner 1982). Complex zonal extinction patterns are also characteristic of authigenic K‐feldspar (e.g.…”

Section: Growth Of the K‐feldspar Lensesmentioning

confidence: 92%

Growth and albitization of K‐feldspar in crystalline rocks in the shallow crust: a tracer for fluid circulation during exhumation?

Holness

2003

Geofluids

View full text Add to dashboard Cite

A general feature of medium‐ to coarse‐grained, sheet‐silicate bearing, quartzo‐feldspathic rocks of either metamorphic or igneous affinity is the retrograde development of lenses of pure K‐feldspar at the grain boundaries between sheet silicate (0 0 1) faces and original feldspar grains. The growth of these lenses acts to displace and deform the sheet silicate grain by a force of crystallization, although the substrate feldspar and adjacent quartz are not deformed. Subsequent to the growth of the lenses they are replaced to variable degrees by pure albite, which grows into the lens from the substrate feldspar behind an irregular replacement front. The composition and texture of both K‐feldspar and replacive albite suggest a strong affinity with authigenic feldspars, although it is considered likely that the K‐feldspar of the lenses is derived from low‐temperature biotite‐breakdown reactions. A model is proposed whereby the lenses grow into open pores at dilatant sites in response to infiltration of aqueous fluids as the crystalline rocks are exhumed under brittle conditions. Continued circulation of infiltrating fluids in a temperature gradient results in the replacement of K‐feldspar by albite via an alkali exchange process. The lenses point to a significant grain‐scale permeability in crystalline rock at shallow levels in the crust.

show abstract

“…crystal lattice of the clay or coatings around the framework grains (Besly and Turner, 1983;Tucker, 2001). Grain-coating illite was the first phase to be precipitated when the activity of K + and H 4 SiO 4 was sufficiently high (Ali and Turner, 1982).…”

Section: Authigenesis Of Grain-coating Illite And/or Hematitementioning

confidence: 99%

Diagenetic evolution of the Ansian–Pliensbachian Adigrat Sandstone, Blue Nile Basin, Ethiopia

Wolela¹

2010

Journal of African Earth Sciences

View full text Add to dashboard Cite

Authigenic K-feldspar in the Bromsgrove Sandstone Formation (Triassic) of ccntral England

Cited by 47 publications

References 0 publications

Studies in diagenesis

Studies in diagenesis

Growth and albitization of K‐feldspar in crystalline rocks in the shallow crust: a tracer for fluid circulation during exhumation?

Diagenetic evolution of the Ansian–Pliensbachian Adigrat Sandstone, Blue Nile Basin, Ethiopia

Contact Info

Product

Resources

About