Syncline
In structural geology, a syncline is a fold with younger layers closer to the center of the structure. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed smaller folds. Synclines are typically a downward fold, termed a synformal syncline (i.e. a trough); but synclines that point upwards, or perched, can be found when strata have been overturned and folded (an antiformal syncline).
Characteristics
On a geologic map, synclines are recognized by a sequence of rock layers that grow progressively younger, followed by the youngest layer at the fold's center or hinge, and by a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate circular the structure is a basin. Folds typically form during crustal deformation as the result of compression that accompanies orogenic mountain building.
Notable examples
Podcasts:
Swingline
by: Adrian BelewSwingline throughout the backyards of the midwest
lean back, baby, in your seat on the train
look through the window pane
Look at that kid over there with no underwear
and a silly dog who doesn't care
his mother stretches to reach the clothes line
while a mean neighbor leans on the population sign
Non-stop through the backyards of the midwest
eavesdrop, baby, from your seat on the train
look through the window pane
Some kinda Buick left in a stream
it used to be somebody's' dream
a town stares at the summer heat waves
past a smooth afternoon,