TY - JOUR
T1 - Varieties of Schmelzelithologien in the impactites of the Steinheim Basin (SW-Germany) | Varietäten von schmelzelithologien in den impaktiten des steinheimer beckens (SW-Deutschland)
AU - Anders, D.
AU - Buchner, E.
AU - Schmieder, Martin
AU - Kegler, P.
PY - 2013
Y1 - 2013
N2 - The 3.8 km diameter wide Steinheim Basin, located in SW Germany, was formed 14.8 Ma ago, most likely simultaneously with the Ries crater, and is one of the best preserved terrestrial impact craters. It lies within a sequence of flat-lying sediments composed of continental Middle Triassic and marine Jurassic formations, topped by Palaeogene and Neogene units. The impact breccias formed during this event occur in a thickness of almost 50 m and mainly consist of Middle to Upper Jurassic limestones and sandstones. In the present study we investigated monomineralic calcite globules as inclusions within silicate melt particles as well as carbonate crack fillings detected in the crater floor limestone. Carbonate-silicate liquid immiscibility provides evidence of a melt origin for the examined calcite globules. The carbonate crack fillings show a dolomitic composition with MgO up to 19.7 wt.-% and are characterised by relics of fluidal textures, "schlieren", and indicators of partial melting of enclosed clasts and the melt-surrounding crater floor limestone. Based on these observations, the observed carbonate crack fillings can be interpreted as dolomite melt assemblages. © 2013 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.
AB - The 3.8 km diameter wide Steinheim Basin, located in SW Germany, was formed 14.8 Ma ago, most likely simultaneously with the Ries crater, and is one of the best preserved terrestrial impact craters. It lies within a sequence of flat-lying sediments composed of continental Middle Triassic and marine Jurassic formations, topped by Palaeogene and Neogene units. The impact breccias formed during this event occur in a thickness of almost 50 m and mainly consist of Middle to Upper Jurassic limestones and sandstones. In the present study we investigated monomineralic calcite globules as inclusions within silicate melt particles as well as carbonate crack fillings detected in the crater floor limestone. Carbonate-silicate liquid immiscibility provides evidence of a melt origin for the examined calcite globules. The carbonate crack fillings show a dolomitic composition with MgO up to 19.7 wt.-% and are characterised by relics of fluidal textures, "schlieren", and indicators of partial melting of enclosed clasts and the melt-surrounding crater floor limestone. Based on these observations, the observed carbonate crack fillings can be interpreted as dolomite melt assemblages. © 2013 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.
U2 - 10.1127/1860-1804/2013/0029
DO - 10.1127/1860-1804/2013/0029
M3 - Article
VL - 164
SP - 491
EP - 501
JO - Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften
JF - Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften
SN - 1860-1804
IS - 3
ER -