Vedretta of Pisgana (Adamello Group). Geomorphology and Holocene front variations. The Vedretta of Pisgana is located in the upper Narcanello Valley and it terminates with three distinct fronts. The western tongue is the best developed and it deposited several moraines which document Holocene front variations. Late Glacial and Holocene moraines of the Narcanello Valley have been differentiated on the basis of morphological, stratigraphical, textural observations, 14C dates and of the weathering degree of the glacial deposits as well as lichenization and soil development. From the left side of Narcanello Valley comes the oldest 14C date so far obtained in the Adamello Group. A buried soil found at 2545 m a.s.l. between two lateral moraines, Late Glacial and Holocene respectively, yielded an age of 6600 ± 100 14C yr BP (GX-14711). In the same area two dates bracket a Neoglacial advance of the western portion of the Vedretta of Pisgana. The maximum- limiting age is 3015 ± 75 14C 1/ BP (GX-14712), while the minimum- limiting age for the Pisgana glacier advance is 2345 ± 125 4C yr BP (GX-14710). The western portion of the Vedretta of Pisgana retreated about 1000 m since the first years of the XX Century. Three small advances also occurred, the widest between 1939 and 1941 (about 40 m). A geomorphological map of the upper Narcanello Valley completes this note.
Vedretta di Pisgana (Gruppo dell'Adamello). Geomorfologia e variazioni oloceniche della fronte. Con allegata carta geomorfologica alla scala 1:15.000. Vedretta of Pisgana (Adamello Group). Geomorphology and Holocene front variations.
BARONI, CARLO;
1991-01-01
Abstract
Vedretta of Pisgana (Adamello Group). Geomorphology and Holocene front variations. The Vedretta of Pisgana is located in the upper Narcanello Valley and it terminates with three distinct fronts. The western tongue is the best developed and it deposited several moraines which document Holocene front variations. Late Glacial and Holocene moraines of the Narcanello Valley have been differentiated on the basis of morphological, stratigraphical, textural observations, 14C dates and of the weathering degree of the glacial deposits as well as lichenization and soil development. From the left side of Narcanello Valley comes the oldest 14C date so far obtained in the Adamello Group. A buried soil found at 2545 m a.s.l. between two lateral moraines, Late Glacial and Holocene respectively, yielded an age of 6600 ± 100 14C yr BP (GX-14711). In the same area two dates bracket a Neoglacial advance of the western portion of the Vedretta of Pisgana. The maximum- limiting age is 3015 ± 75 14C 1/ BP (GX-14712), while the minimum- limiting age for the Pisgana glacier advance is 2345 ± 125 4C yr BP (GX-14710). The western portion of the Vedretta of Pisgana retreated about 1000 m since the first years of the XX Century. Three small advances also occurred, the widest between 1939 and 1941 (about 40 m). A geomorphological map of the upper Narcanello Valley completes this note.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
