Stratigraphy and Sedimentology doi: 10.3390/stratsediment1010005

Authors: Jane L. Alexander Victoria Rivelli Sean T. Thatcher

In the northeastern United States, sediments related to the expansion and contraction of the Laurentide ice sheet have been extensively mapped throughout New England, as well as in New Jersey and on Long Island. However, linking these deposits around New York City is challenging due to the extensive urbanization. Staten Island is less developed than the other boroughs of New York City, however outcrops of rock and surface sediment are limited, making interpretation of its geologic history challenging. When small areas of sediment are temporarily exposed, they can be used to improve our understanding of sediment erosion and deposition over time, helping to link the deposits mapped in New Jersey and Long Island. In this study of two small temporary outcrops, the beds of sediment were measured and described in the field and samples were collected for textural and compositional analyses. The results were interpreted in the context of previous work on similar exposures nearby. The sediments are sands and gravels of fluvioglacial origin containing reworked sediments of both the Pliocene Pensauken Formation and older Triassic rocks of the Newark Basin, interpreted to have been deposited on an outwash plain during the Illinoian glaciation (Marine Isotope Stage 6). They were deposited in a topographic low directly overlying Cretaceous sedimentary rocks, but adjacent to sediments of the Pensauken Formation which had in turn been deposited as an earlier valley fill. Similar sequences of repeated valley fills have been observed in New Jersey but have not been documented on Staten Island. This interpretation solves an apparent disagreement between previous studies by illustrating how both the Pensauken Formation and later fluvioglacial sediments can directly overly Cretaceous sediments across a distance of less than a kilometer.

Stratigraphy and Sedimentology doi: 10.3390/stratsediment1010004

Authors: Pâmela Silveira Costa Edi Mendes Guimarães Alexandre Silva Santos Matheus Denezine Adriana Maria Coimbra Horbe João Gabriel Cavalcante Vieira Sebastião William da Silva Dermeval Aparecido Do Carmo

Thermal maturity assessment in Precambrian sedimentary successions is commonly hindered by the inapplicability of vitrinite reflectance and by the limited calibration of individual proxies. Here, we constrain the thermal maturity of a Mesoproterozoic interval from the L4F3 drill core (Alto Tapajós basin, Amazonian craton) using an integrated approach that combines the Kübler Index (KI), Raman spectroscopy of carbonaceous material measured directly on organic-walled microfossils (RSCM), and the Acritarch Alteration Index (AAI). Illite crystallinity was evaluated from the FWHM of the 10 Å (001) reflection on oriented <2 µm mounts under air-dried and ethylene glycol conditions, with peak decomposition (DecompXR) used for internal quality control. RSCM thermometry was applied to Leiosphaeridia tenuissima wall material, and AAI classes were assigned by standardized transmitted light color comparison. KI proxy values indicate conditions near the late diagenesis-to-incipient anchizone transition, with eight horizons approaching anchizone reference values. RSCM yields peak temperature estimates of 213–263 °C with an uncertainty of approximately ±30 °C, while AAI results are uniform (class 3.0), providing qualitative support consistent with advanced maturation. Together, these indicators place the studied succession broadly within late diagenesis to incipient anchizone conditions and provide constraints relevant to thermal history reconstruction and basin modeling in ancient cratonic settings.

Stratigraphy and Sedimentology doi: 10.3390/stratsediment1010003

Authors: Amanda Z. Calle Brian K. Horton Ryan B. Anderson Raúl García Orlando Quenta Matthew T. Heizler Christina Andry Daniel F. Stockli

Investigation of deposystems, sediment routing, and basin architecture during Gondwana breakup refines understanding of Permian–Cretaceous landscape evolution in the central Andes. New chronostratigraphic and provenance constraints from the Eastern Cordillera and Subandean Zone of Bolivia (19–22°S) are based on U-Pb geochronology of detrital and volcanic zircons and 40Ar/39Ar dating of interbedded basalts. A discontinuous <2 km-thick Permian–Cretaceous succession records deposition in fluvial, lacustrine, alluvial fan, eolian, and shallow marine environments. Stratigraphic correlations indicate alternations between isolated half-graben subbasins and regional, non-compartmentalized basins. Detrital zircon age spectra from 18 sandstones document sediment recycling from western orogenic and magmatic arc sources and eastern cratonic basement. Synextensional successions of Early Triassic, Early Jurassic, and mid-Cretaceous age were sourced mainly from the west, including Carboniferous and Devonian rocks, while post-extensional fluvial and eolian systems were derived chiefly from the eastern craton. Variations in thickness, facies, and mafic magmatism reflect alternating extensional and neutral tectonic regimes, with localized synextensional subsidence potentially linked to extensional collapse, mantle plume activity, and South Atlantic opening. Comparison with Andean regions in Peru and Argentina indicates that episodic extension and post-extensional thermal subsidence accompanied subduction along the western margin of South America during Gondwana-Pangea breakup.

Stratigraphy and Sedimentology doi: 10.3390/stratsediment1010002

Authors: Sandro Galdenzi

This study presents a new 1:10,000 geological map of the Monte Bove area (northern Apennines), produced through an original field survey, which allows a detailed reconstruction of Jurassic tectono-sedimentary evolution. The area is characterized by three wedge-shaped structural highs that emerged from the basin floor due to extensional tectonics, following the demise of the Early Jurassic carbonate platform. Stratigraphic and geometric relationships indicate that these highs were already established by the earliest Pliensbachian, bounded by steep fault escarpments and locally mantled by condensed pelagic deposits. Through the Jurassic, the fault-bounded blocks were progressively buried by predominantly micritic pelagic sediments, with evidence of onlap, unconformities, and reworking. The new geological map allows precise delineation of fault geometries and depositional contacts, highlighting the importance of synsedimentary tectonics in shaping basin architecture and documenting a consistent structural trend.

Stratigraphy and Sedimentology doi: 10.3390/stratsediment1010001

Authors: Brian K. Horton

“No vestige of a beginning, no prospect of an end [...]