strati.ch - Lexique lithostratigraphique de la Suisse

Représentation et statut

Origine du nom: Höchegg (ZH), Turbenthal, auf der Südostseite des Schauenbergs

Variantes historiques: Hörnli-Brekzie (Tanner 1944), Höchegg-breccia = Hörnli-breccia = Hörnli-Höchegg-massflow (Bolliger 1998a), Hörnli breccia = Hörnli-Höchegg breccia (Kälin & Kempf 2009)

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.

Âge au sommet

Âge à la base

Extension géographique: Am Hörnli und an der Höchegg (Schauenberg) im Töss-Bergland.

Coupes de référence

Type de protolithe

Définition: Tanner Hans (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.

(...)

Révision: Bolliger T. (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).