Hornbuck-Member

Representation and status

Color CMYK

siehe Villigen-Formation

Color RGB

R: 180 G: 190 B: 210

Rank

lithostratigraphic Member (Subformation)

Validity

Unit is in Use

Status

valid formal name

Status discussion

Nomenclature

Deutsch

Hornbuck-Member

Français

Membre du Hornbuck

Italiano

Membro del Hornbuck

English

Hornbuck Member

Origin of the Name

Hügel Hornbuck (Deutschland), E Griessen / Klettgau [non: Hornbuck (AG) wo die Villigen-Fm. jedoch auch auftritt !]

Historical Variants

Hornbuckschichten (Würtenberger & Würtenberger 1866), Hornbuckschichten (Hantke 1967), Hornbuck Member (Gygi 2000c)

Nomenclatorial Remarks

Gygi (2000b: 133) schlägt Typus-Profil vor (Nordhang des Hornbuck, 675.850/276.220).

Description

Description

"Wechsellagerung von mergeligen Kalksteinen mit Mergeln. Die Kalksteine führen Kiesel-Schwämme" (Gygi 2000b: 134)

Thickness

Ca. 10 m (Gygi 2000c)

Components

• ammonites
• sponges

Hierarchy and sequence

Superordinate unit

• Villigen-Formation

Units at roof

• Küssaburg-Member

Units at floor

• Effingen-Member

Upper boundary

Austreten der Schwämme und der mergeligen Zwischenlagen

Lower boundary

Erste Schämme-Vorkommen über den mergeligen Effingen-Mb.

Age

Age at top

• Oxfordian

Note about top

Bimammatum-Zone

Age at base

• Oxfordian

Note about base

Bimammatum-Zone, Berrense-Subzone

Dating Method

Biostratigraphie: Ammoniten der Berrense- bis Bimammatum-Zone (Gygi 2000b/c)

Geography

Geographical extent

Klettgau, Randen-Gebiet.

Type area

Hornbuck, N von Riedern am Sand, Unterklettgau-Tal, Süddeutschland

Type profile

• Hornbuck (Deutschland)
  Site particularities
  • Obergrenze
  • typische Fazies
  Site accessibility
  • Strassenanschnitt / Bahnanschnitt
  Coordinates
  • (2675850 / 1276220)
  Note
  • Waldstrasse am Nordhang auf Kote 500 m (Gygi 1969 Pl.19 Profil RG76, Gygi 2000c S.133)

Palaenography and tectonic

• Malm of the Jura Mountains

Paleogeography

Argovian Basin

Tectonic unit (resp. main category)

• Jura :
  Juragebirge

Kind of protolith

• sedimentary

Metamorphism

non metamorphic

References

Definition

Würtenberger F. J., Würtenberger L. (1866) : Der Weisse Jura im Klettgau und angrenzenden Randengebirg. Verh. natw. Vereins Karlsruhe 2, 11-68

S.25

Definition

Gygi R. A. (2000) : Annotated index of lithostratigraphic units currently used in the Upper Jurassic of northern Switzerland. Eclogae geol. Helv. 93/1, 125-146

p.133: Hornbuck Member (Würtenberger & Würtenberger 1866) ; Member of the Villigen Formation The name Hornbuck Member (Hornbuck-Schichten) was introduced by Würtenberger & Würtenberger (1866. p. 25). It refers to the hill called Hornbuck north of Riedern am Sand that belongs to the township of Erzingen in the Unterklettgau valley, southern Germany. Würtenberger & Würtenberger did not designate a type section, and Gygi (1969. Pl. 19) was not in a position to give a complete section of the member in the Klettgau valley or the Randen hills. The best outcrop of the member is section RG 76 along a forest road on the north slope of Hornbuck hill at coordinates 675.850/276.220 at the elevation of 500 m, LK 1051 Eglisau. This section can be desig-