The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
G J Huftile - One of the best experts on this subject based on the ideXlab platform.
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Thin Skinned Tectonics of the upper ojai valley and sulphur mountain area ventura basin california
AAPG Bulletin, 1991Co-Authors: G J HuftileAbstract:By integrating surface mapping with subsurface well data and drawing cross sections and subsurface maps, the geometry of shallow structures and their geologic history of the Upper Ojai Valley of California can be reconstructed. The geometry of shallow structures, the geologic history, and the location of earthquake foci then offer constraints on the deep structure of this complex area. The Upper Ojai Valley is a tectonic depression between opposing reverse faults. Its northern border is formed by the active, north-dipping San Cayetano fault, which has 6.0 km of stratigraphic separation in the Silverthread area of the Ojai oil field and 2.6 km of stratigraphic separation west of Sisar Creek. The fault dies out farther west in Ojai Valley, where the south-vergent shortening is transferred to a blind thrust. The southern border of the Upper Ojai Valley is formed by the Quaternary Lion fault set (Sisar, Big Canyon, and Lion faults), which dips south and merges into the Sisar decollement wiThin the south-dipping, ductile, lower Miocene Rincon formation. Folds with north-dipping axial planes, including the Lion Mountain anticline and Reeves syncline, are middle Pleistocen or older and are related to movement on an unnamed fault in the footwall block of the San Cayetano fault and on the San Cayetano fault, respectively. By the middle Pleistocene, the Sulphur Mountain anticlinorium and the Big Canyon syncline began forming as a fault-propagation fold; the fault-propagation fold is rooted in the Sisar decollement, a passive backthrust rising from a blind thrust at depth. The formation of the Sulphur Mountain anticlinorium was followed closely by the ramping of the south-dipping Lion fault set to the surface over the nonmarine upper Pleistocene Saugus Formation. To the east, the San Cayetano fault overrides and folds the Lion fault set near the surface. Area-balancing of the deformation shows shortening of 15.5 km, and suggests a 17 km depth to the brittle-d ctile transition.
David Salzberg - One of the best experts on this subject based on the ideXlab platform.
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taiwan orogeny Thin Skinned or lithospheric collision
Tectonophysics, 1997Co-Authors: Francis T Wu, David SalzbergAbstract:Abstract The Taiwan orogeny is young and presently very active. It provides an excellent environment for studying ongoing orogenic processes, especially since the region is monitored intensively with dense seismological and geodetic networks, and new studies aiming at deciphering shallow and deep structures in and around Taiwan have been recently conducted or are being planned. The available data can be used continually to test critically hypotheses of the Taiwan orogeny. Hypotheses dealing with the mechanics of mountain building are basic to the understanding of Taiwan orogeny and are particularly amenable to testing. The widely cited ‘Thin-Skinned Tectonics’ hypothesis was formulated to explain mainly the geologic and relatively shallow (
Felipe Bastida - One of the best experts on this subject based on the ideXlab platform.
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crustal thickening and deformation sequence in the footwall to the suture of the variscan belt of northwest spain
Tectonophysics, 1991Co-Authors: A Perezestaun, J R Martinezcatalan, Felipe BastidaAbstract:Abstract The sequence of formation and propagation of structures, as well as the evolution of crustal thickening, in the Variscan belt of northwest Spain are proposed in this paper. The foreland of this mountain belt shows Thin-Skinned Tectonics. A polyphase deformation with associated regional metamorphism is recognized in the hinterland zones. Two important culminations, the Narcea and Lugo antiforms, are present in an E-W cross-section through the footwall to the suture of this orogen. Such culminations are derived from the stacking of several thrust systems generated during two successive periods. The sequence of thrust emplacement helps to clarify the formation of different types of structures at the same time in different places in the orogen.
R A Glen - One of the best experts on this subject based on the ideXlab platform.
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thrust extensional and strike slip Tectonics in an evolving palaeozoic orogen a structural synthesis of the lachlan orogen of southeastern australia
Tectonophysics, 1992Co-Authors: R A GlenAbstract:Abstract The Lachlan Orogen preserves the best and most accessible evidence of the Palaeozoic development of the eastern margin of Gondwanaland. Its history is marked by a raising of freeboard from generally deep marine (Cambrian to Early Silurian), through mixed deep and shallow marine, volcanics and granite-emplacement (mid-Silurian to mid-Devonian), to fluviatile in the mid-Devonian to Early Carboniferous. A long deformation history from latest Ordovician to mid-Carboniferous is marked by formation of: (1) (near-)meridional structures—folds, cleavage and faults—in response to latitudinal shortening, and (2) (near-)latitudinal structures—folds, cleavage and faults—together with strike-slip movement on (near-)meridional faults in response to N-S and NE-SW shortening. Formation of these two sets of structures reflects a long history of oblique compression wiThin the developing orogen. Partitioning of these deformation effects across the Lachlan Orogen leads to recognition of four meridional structural belts, each characterised by different structural histories. The common feature linking all four belts is the Thin-Skinned nature of deformation: steep surface contractional faults flatten with depth, to become parts of linked thrust systems soling into detachments lying at different levels in the upper and middle crust. The Lachlan Orogen is thus characterised by Thin-Skinned Tectonics. The Southwestern Belt is allochthonous and preserves an Early to Middle Devonian east-vergent fold/thrust system which soles into the base of the Ordovician and also into the base of underlying Cambrian greenstones. Together with later strike-slip movement on major faults, this deformation records transpressional insertion of a terrane from the southeast. The Central Belt is characterised by N-S shortening, latitudinal folds and thrusts together with strike-slip movement on NNW-trending faults, and en echelon granites. Southward translation as a separate terrane occurred in the Early Silurian and mid-Devonian. Deep thrusting in the southern part of the belt has exhumed a metamorphic layer from depths of ⩾ 10 km. The Eastern Belt is a Thin-Skinned (near-)meridional thrust belt which has also experienced some strike-slip movement and N-S shortening. Thrusts detach in several major horizons: in the Late Ordovician/earliest Silurian (at a depth of ca. 4 km), wiThin or at the base of the Ordovician, which is internally thickened with inferred duplexing and imbrication, and wiThin a mid-crustal metamorphic layer at ca. ⩾ 10 km. Vergence reversals both parallel and perpendicular to the orogen indicate the presence of tear faults and tectonic wedges. Extensional faults and orogen-parallel extension are also features of the Lachlan Orogen, with the former able to account for the some of the “compressional” Silurian “orogenies” in the Eastern Belt. At deeper crustal levels, upper and mid-crustal shortening was balanced by over/underthrusting wiThin and along boundaries of Precambrian continental basement terranes.
Francis T Wu - One of the best experts on this subject based on the ideXlab platform.
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taiwan orogeny Thin Skinned or lithospheric collision
Tectonophysics, 1997Co-Authors: Francis T Wu, David SalzbergAbstract:Abstract The Taiwan orogeny is young and presently very active. It provides an excellent environment for studying ongoing orogenic processes, especially since the region is monitored intensively with dense seismological and geodetic networks, and new studies aiming at deciphering shallow and deep structures in and around Taiwan have been recently conducted or are being planned. The available data can be used continually to test critically hypotheses of the Taiwan orogeny. Hypotheses dealing with the mechanics of mountain building are basic to the understanding of Taiwan orogeny and are particularly amenable to testing. The widely cited ‘Thin-Skinned Tectonics’ hypothesis was formulated to explain mainly the geologic and relatively shallow (