Höchegg-Brekzie
Back to Molasse alluvial fansRepresentation and status
- Color CMYK
- (0%,10%,24%,2%)
- Color RGB
- R: 250 G: 225 B: 190
- Rank
- lithostratigraphic Bed
- Validity
- Unit is in Use
- Status
- informal term
Nomenclature
- Deutsch
- Höchegg-Brekzie
- Français
- Brèche de la Höchegg
- Italiano
- Breccia della Höchegg
- English
- Höchegg Breccia
- Origin of the Name
-
Höchegg (ZH), Turbenthal, auf der Südostseite des Schauenbergs
- Historical Variants
-
Hörnli-Brekzie (Tanner 1944), Höchegg-breccia = Hörnli-breccia = Hörnli-Höchegg-massflow (Bolliger 1998a), Hörnli breccia = Hörnli-Höchegg breccia (Kälin & Kempf 2009)
Description
- Description
-
Kälin & Kempf 2009: Tanner (1944) described an isolated breccia similar to the Hüllistein conglomerate in the steep western flank of the eastern Swiss Hörnli summit, however, considerably thinner and stratigraphically much higher. In the Schauenberg area, Bolliger (1998) identified a second outcrop of the same characteristic debris flow deposit and interpreted it as a more distal equivalent of Tanner's Hörnli breccia. The so called Hörnli-Höchegg breccia contributes further valuable information for the correlation of the Hörnli and Schauenberg sections, despite the fact that it resembles only a small erosional remnant due to its high lithostratigraphic position.
- Thickness
- 0.5 – 2 m (Bolliger 1998a)
Age
- Age at top
-
- Serravallian
- Age at base
-
- Serravallian
- Dating Method
-
Sarmatian: Säugerstufe MN8 (Bolliger 1998).
Geography
- Geographical extent
- Am Hörnli und an der Höchegg (Schauenberg) im Töss-Bergland.
- Reference profiles
-
-
Bärtobel (ZH)
Site particularities- Obergrenze
- Untergrenze
- typische Fazies
- Bachprofil
- (2713340 / 1247810)
- Chlihörnli (Tanner 1944 S.34, Bolliger 1998)
-
Bärtobel (ZH)
Palaenography and tectonic
-
- OSM-II
- Kind of protolith
-
- sedimentary
- Metamorphism
- non metamorphic
References
- Definition
-
(1944) :
Beitrag zur Geologie der Molasse zwischen Ricken und Hörnli. Mitt. thurg. natf. Ges. 33, 6-108
S.41: Die [Hörnlugubel-]Mergelzone von 970m zeigt in der Westwand folgendes
Profil (von oben nach unten):
(...)
2 m sandiger Mergel mit feinkörniger brekziöser Einlagerung von dunkeln Kalken. Von oben nach unten nimmt die Menge der ungeordnet durcheinanderliegenden eckigen Kalksplitter zu.
(...)
- Definition
-
(1998) :
Age and geographic distribution of the youngest Upper Freshwater Molasse (OSM). Eclogae geol. Helv. 91/3, 321-332
p.325: Lithostratigraphic correlation received a new impulse with the discovery of a sandy, fine grained and matrix supported microbreccia horizon in the profile at Höchegg [770'860/255'750/825m], Figures 3 and 4. It is very likely, that this peculiar layer correlates with the breccia horizon from Chlihörnli [713'300/247'800/990m], which was first discovered by Tanner (1944) and later interpreted as massflow event by Bolliger
(1992a). The base of this massflow seems not to be erosive, although in its more proximal part at Hörnli. reworked marly components have been found (Bolliger 1992a).