Giudicárie line
Encyclopedia
The Giudicárie line is a major geologic fault
zone in the Italian
Alps
, named for the Giudicarie
valleys area. It runs from Meran in the northeast as a more or less straight line along the lower part of the Val di Sole
, along the Val Rendena
(upper Sarca
valley) and then along the Chiese
valley to the Lago d'Idro (Idro Lake).
The northern part of the line is part of the Periadriatic Seam
that separates the Southern Alps
from the nappe stacks of the Central Alps and runs from west to east along the Alpine mountain chain. The Periadriatic Seam branches of to the west at the upper Val di Sole, where it is called Tonale line. In fact the northeast orientated Giudicárie line off-sets the (east-west) Periadriatic Seam by 100 kilometers.
The fault zone contains older (Tertiary
) mylonite
s, showing it was a ductile shearzone in that period. These mylonites have been overprinted by brittle
thrusting
still active today. The northwest dipping
fault plane serves as a dextral transform fault
as well as a compressive thrust fault
.
Geologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...
zone in the Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
, named for the Giudicarie
Giudicarie
Giudicarie is an area of eastern Trentino, northern Italy, which includes the upper courses of the rivers Sarca and Chiese....
valleys area. It runs from Meran in the northeast as a more or less straight line along the lower part of the Val di Sole
Val di Sole
The Sole Valley is a valley in Trentino, northern Italy.Sole Valley applies to the Vermiglio Valley, the east-west aligned valley of the river Noce and its sidevalleys, among which the Peio Valley that heads to the Ortler...
, along the Val Rendena
Val Rendena
Val Rendena is the valley of the Sarca river in Trentino, northern Italy.Main towns include Spiazzo Rendena and Pinzolo....
(upper Sarca
Sarca
The Sarca is a river springing from the Adamello-Presanella mountains in the Italian Alps and flowing into Lake Garda in Northern Italy. As an emissary of the lake it becomes known as the Mincio....
valley) and then along the Chiese
Chiese
The Chiese, also known in the Province of Brescia as the Clisi, is a 160 km Italian river which is the principal immisary and sole emissary of the sub-alpine lake Lago d’Idro, and is a left tributary of the Oglio....
valley to the Lago d'Idro (Idro Lake).
The northern part of the line is part of the Periadriatic Seam
Periadriatic Seam
The Periadriatic Seam is a distinct geologic fault in Southern Europe, running S-shaped about 1000 km from the Tyrrhenian Sea through the whole Southern Alps as far as Hungary. It forms the division between the Adriatic plate and the European plate...
that separates the Southern Alps
Southern Alps (geology)
The Southern Alps are a geological subdivision of the European Alps. The Southern Alps are the part of the Alps that are found south of the Periadriatic Seam, a major geological faultzone across the Alps...
from the nappe stacks of the Central Alps and runs from west to east along the Alpine mountain chain. The Periadriatic Seam branches of to the west at the upper Val di Sole, where it is called Tonale line. In fact the northeast orientated Giudicárie line off-sets the (east-west) Periadriatic Seam by 100 kilometers.
The fault zone contains older (Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
) mylonite
Mylonite
Mylonite is a fine-grained, compact rock produced by dynamic recrystallization of the constituent minerals resulting in a reduction of the grain size of the rock. It is classified as a metamorphic rock...
s, showing it was a ductile shearzone in that period. These mylonites have been overprinted by brittle
Brittle
A material is brittle if, when subjected to stress, it breaks without significant deformation . Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound. Brittle materials include most ceramics and glasses ...
thrusting
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
still active today. The northwest dipping
Strike and dip
Strike and dip refer to the orientation or attitude of a geologic feature. The strike line of a bed, fault, or other planar feature is a line representing the intersection of that feature with a horizontal plane. On a geologic map, this is represented with a short straight line segment oriented...
fault plane serves as a dextral transform fault
Transform fault
A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere, is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction. Furthermore, transform faults end abruptly...
as well as a compressive thrust fault
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
.