Fold trap regime
| Exploring for Oil and Gas Traps | |
| |
| Series | Treatise in Petroleum Geology |
|---|---|
| Part | Traps, trap types, and the petroleum system |
| Chapter | Classification of exploration traps |
| Author | Richard R. Vincelette, Edward A. Beaumont, Norman H. Foster |
| Link | Web page |
| Store | AAPG Store |
Classes and definitions
The proposed classes in the fold trap regime are monocline, local dome, regional dome, local nose, regional nose, local anticline, regional anticline, and syncline. The following outline shows the classes, some of the subclasses, style, and their definitions. The Subclasses listed are not inclusive but represent the more common types of fold traps and show how the proposed classification scheme can be developed and defined.
Regime: Fold
A fold trap is formed by syn- or postdepositional processes that deform geological surfaces into a curved or nonplanar arrangement (Biddle and Weilchowsky, 1995).
- Class: Monocline
- A fold that occurs where strata dip or flex from the horizontal in one direction only and are not a part of a anticline or syncline.[1] A monocline can form only part of the trap closure and must combine with other elements for closure.
- Class: Regional nose
- A short plunging anticline without closure. A trap where a nose is a trapping element must combine with other elements to have closure.
- Class: Local nose
- Class: Regional dome
- Circular or elliptical anticline many miles (km) in diameter.
- Class: Local dome
- Circular or elliptical anticline
- Class: Regional anticline
- Elongate convex upward fold.
- Class: Local anticline
- Subclass: Simple
- Subclass: Fault bounded or cross faulted
- Styles: Relief, symmetry, internal faulting, internal geometry
- Class: Syncline
- Elongate concave upward fold.
Families
Based on their genesis, folds can be divided into two superfamily categories: tectonic and nontectonic. The outline below presents the superfamilies, families, and subfamilies and their definitions for anticlinal fold traps. As with fold classes, the fold families listed below are not inclusive but merely represent the more common fold families.
Regime: Fold
- Class: Local anticline
- Superfamily: Tectonic
- Folds resulting from deformation by tectonic processes such as compression or extension.
- Family: Compressional fold
- Formed by compressive tectonic deformation.
- Subfamily: Thrust-belt fold
- Subfamily: Foreland fol
- Subfamily: Cratonic-basin fold
- Variety: Paleostructure
- Variety: Inverted
- Family: Transpressional fold
- Subfamily: Single phase
- Subfamily: Paleostructure
- Subfamily: Inverted structure
- Family: Structural drape fold
- Form over a deeper structural feature such as a fault block.
- Family: Extensional fold
- Form by extensional tectonic deformation.
- Subfamilies: Rollover anticline
- Form as a result of rollover into a listric normal fault.
- Family: Basement uplift
- Superfamily: Nontectonic
- Folds result from deformation by nontectonic processes such as uplift by intrusion or diapirism, differential compaction, salt withdrawal, salt solution, or meteoric impact.
- Family: Intrusive core
- Dome or anticline form as a result of intrusion.
- Subfamilies: Salt dome or anticline
- Form as a result of uplift by salt movement.
- Subfamilies: Shale dome or anticline
- Form as a result of a shale diapir.
- Subfamilies: Igneous dome
- Form as a result of igneous intrusion.
- Family: Differential-compaction (drape) anticline
- Form by the differential compaction of sediments over a buried structure such as a reef or horst.
- Family: Salt-solution anticline
- Form as a result of salt dissolution.
- Family: Salt-withdrawal anticline
- Form as a result of salt movement out of an area.
- Family: Astrobleme
- Form as result of the impact of a meteor.
See also
References
- ↑ Rittenhouse, G., 1972, Stratigraphic-trap classification, in King, R., E., ed., Stratigraphic Oil and Gas Fields: AAPG Memoir 16, p. 14–28.
External links
| find literature about Fold trap regime |
|
|
|
|