Implications of Thermal Events on Thrust Emplacement Sequence in the Appalachian Fold and Thrust Belt: Some New Vitrinite Reflectance Data

Sharon E. Lewis; James C. Hower

doi:10.1086/629462

Thermal and structural modeling of the Scillato wedge-top basin source-to-sink system: Insights into the Sicilian fold-and-thrust belt evolution (Italy)

Geological Society of America Bulletin ◽

10.1130/b35078.1 ◽

2019 ◽

Vol 131 (11-12) ◽

pp. 1763-1782 ◽

Cited By ~ 8

Author(s):

Martina Balestra ◽

Sveva Corrado ◽

Luca Aldega ◽

Maurizio Gasparo Morticelli ◽

Attilio Sulli ◽

...

Keyword(s):

Short Range ◽

Vitrinite Reflectance ◽

Sediment Provenance ◽

Hydrocarbon Generation ◽

Thermal Maturity ◽

Thrust Belt ◽

Ordered Structures ◽

Source To Sink ◽

Fold And Thrust Belt ◽

Basin Fill

Abstract Temperature-dependent clay mineral assemblages, vitrinite reflectance, and one-dimensional (1-D) thermal and three-dimensional (3-D) geological modeling of a Neogene wedge-top basin in the Sicilian fold-and-thrust belt and its pre-orogenic substratum allowed us to: (1) define the burial history of the sedimentary succession filling the wedge-top basin and its substratum, (2) reconstruct the wedge-top basin geometry, depocenter migration, and sediment provenance through time in the framework of a source-to-sink system, and (3) shed new light into the kinematic evolution of the Apennine-Maghrebian fold-and-thrust belt. The pre-orogenic substratum of the Scillato basin shows an increase in levels of thermal maturity as a function of stratigraphic age that is consistent with maximum burial to 3.5 km in deep diagenetic conditions. In detail, Ro% values range from 0.40% to 0.94%, and random ordered illite-smectite (I-S) first converts to short-range ordered structures and then evolves to long-range ordered structures at the base of the Imerese unit. The wedge-top basin fill experienced shallow burial (∼2 km) and levels of thermal maturity in the immature stage of hydrocarbon generation and early diagenesis. Vitrinite reflectance and mixed-layer I-S values show two populations of authigenic and inherited phases. The indigenous population corresponds to macerals with Ro% values of 0.33%–0.45% and I-S with no preferred sequence in stacking of layers, whereas the reworked group corresponds to macerals with Ro% values of 0.42%–0.47% and short-range ordered I-S with no correlation as a function of depth. Authigenic and reworked components of the Scillato basin fill allowed us to unravel sediment provenance during the Neogene, identifying two main source areas feeding the wedge-top basin (crystalline units of the European domain and sedimentary units of the African domain), and to detect an early phase of exhumation driven by low-angle extensional faults that predated Neogene compression.

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Palaeomagnetic, rock-magnetic and mineralogical investigations of the Lower Triassic Vardebukta Formation from the southern part of the West Spitsbergen Fold and Thrust Belt

Geological Magazine ◽

10.1017/s0016756817001145 ◽

2018 ◽

Vol 156 (4) ◽

pp. 620-638 ◽

Cited By ~ 2

Author(s):

KATARZYNA DUDZISZ ◽

KRZYSZTOF MICHALSKI ◽

RAFAŁ SZANIAWSKI ◽

KRZYSZTOF NEJBERT ◽

GEOFFREY MANBY

Keyword(s):

Remanent Magnetization ◽

Vitrinite Reflectance ◽

Lower Triassic ◽

Natural Remanent Magnetization ◽

The Other ◽

Thrust Belt ◽

The West ◽

Fold And Thrust Belt ◽

Oriented Samples ◽

West Spitsbergen

AbstractMagnetic, petrological and mineralogical data from 13 sites (99 independently oriented samples) of the Lower Triassic rocks located in the SW segment of the West Spitsbergen Fold and Thrust Belt (WSFTB) are presented in order to identify the ferrimagnetic carriers and establish the origin of the natural remanent magnetization (NRM). Volcanic lithoclasts and other detrital resistive grains in which the primary magnetization might endure are present in some samples. On the other hand, petrological studies indicate that sulphide remineralization could have had an important influence on the remagnetization of these rocks. The dominant ferrimagnetic carriers are titanomagnetite and magnetite. While the titanomagnetite may preserve the primary magnetization, the magnetite is a more likely potential carrier of secondary overprints. The complex NRM patterns found in most of the samples may be explained by the coexistence and partial overlapping of components representing different stages of magnetization. Components of both polarities were identified in the investigated material. The reversal test performed on the most stable components that demagnetized above 300°C proved to be negative at the 95% confidence level at any stage of unfolding. They are better grouped, however, after 100% tectonic corrections and the most stable components are clustered in high inclinations (c. 70–80°). This suggests that at least part of the measured palaeomagnetic vectors represent a secondary prefolding magnetic overprint that originated in post-Jurassic time before the WSFTB event. Vitrinite reflectance studies show these rocks have not been subjected to any strong heating (<200°C).

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