For stratigraphic relationships are defined geometric and temporal relationships that characterize the vertical and lateral limits of two lithological units in contact with each other. Thursday, September 23, 2010
Congratulations Last Month Before Baby Is Born
Researchers' Night Emilia - Romagna
For stratigraphic relationships are defined geometric and temporal relationships that characterize the vertical and lateral limits of two lithological units in contact with each other.
For stratigraphic relationships are defined geometric and temporal relationships that characterize the vertical and lateral limits of two lithological units in contact with each other. lithological limits: the limit between two units in contact with each other. This limit may be: Gradual
when the limit is comparable to a surface and the transition from one unit to another is abrupt;
erosion if the surface is erosive type of way;
erosion if the surface is erosive type of way;
Succession concordant and discordant : along the boundary surfaces, two stratigraphic units can enter into mutual relations of geometric consistency or inconsistency. Concordant : succession Vertical stratigraphic layers parallel to each other, they are horizontal or inclined;
discordant stratigraphic sequence of layers is not parallel to each other, but with different inclinations and angles more or less pronounced. 
Onlap : termination of horizontal layers directly on an inclined surface.
Downlap : Termination of layers originally inclined to rest on a horizontal or slightly inclined surface limit.
Toplap : Termination of layering, accompanied by a modest erosion of layers originally inclined surface with respect to a horizontal limit of non-deposition.
Parting erosive : termination of the strata unit smaller than a surface character limit erosion, sub-horizontal and often irregular.
Succession
continuous and discontinuous, in relation to sedimentation processes you can define the temporal relationships between two stratigraphic units in continuity or discontinuity of sedimentation.
express gradual lithological contacts, as is intuitive, a continuity of sedimentation, the clear, however, may reflect both continuity situations, albeit through an abrupt change in type of sedimentation, and disruption more o meno lunghe nella deposizione. Un contatto di tipo erosivo implica una discontinuità temporale, dal momento che una parte dell’unità è stata rimossa per erosione.
Una discontinuità temporale acquista il significato di discontinuità stratigrafica quando rappresenta un intervallo di tempo significativo alla scala geologica. Il tempo geologico non rappresentato da sedimento lungo una superficie di discontinuità è definito come lacuna stratigrafica.
Unconformity:
(discordanza, discontinuità) è una superficie di separazione between two lithological units, which represents a significant break in sedimentation. You define a stratigraphic discontinuity in general. Disconformity: (disconformità) prodottesi stratigraphic discontinuities across the subaerial erosion of rocks emerged due to the lowering of sea level and is not accompanied by tectonic deformation.
Angular Unconformity (angular divergence) when the interruption of sedimentation is accompanied by subaerial erosion and tectonic deformation. Paraconformity:
(paraconcordanza) sedimentary successions geometrically consistent but discontinuous. Nonconormity
(Discrepancy baseline) in which the sedimentary sequence covering the crystalline basement.
B
ibliografia: BOSELLINI A., Mutti E., Ricci Lucchi F. (1997), and sedimentary rocks. Earth Sciences. UTET Ed.
B. SIMPSON (1996); Read geological maps. DARIO FLACOVIO Ed.
( read the article in PDF )
Subscribe to:
Post Comments (Atom)
0 comments:
Post a Comment