Late Wisconsinan ice-flow reconstruction for the central Great Lakes region

1985 ◽  
Vol 22 (6) ◽  
pp. 935-940 ◽  
Author(s):  
Stephen Irving Dworkin ◽  
Grahame J. Larson ◽  
G. William Monaghan
Keyword(s):  
Lake Michigan ◽  
Source Area ◽  
Heavy Mineral ◽  
Lake Huron ◽  
Georgian Bay ◽  
South Central ◽  
Mineral Assemblages ◽  
Specific Source ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

Late Wisconsinan tills from the lower peninsula of Michigan can be differentiated with respect to the Lake Michigan, Saginaw, and Huron–Erie lobes on the basis of their heavy-mineral assemblages. Using discriminant analysis, the heavy-mineral assemblages can also be associated with specific source areas on the Canadian Shield. These associations suggest that (1) the Lake Michigan Lobe flowed southwestward across a region north of Lake Huron and then into southwestern Michigan; (2) the Saginaw Lobe flowed southwestward across a region northwest of Georgian Bay and then into south-central Michigan; and (3) the Huron–Erie Lobe flowed southwestward across a region north of Georgian Bay and then southward into southeastern Michigan.Comparison of the heavy-mineral assemblages of tills from southeastern Michigan with those from younger tills just south of Lake Huron indicates that a significant westward shift in source area occurred during the retreat of the Huron–Erie Lobe from southeastern Michigan.

Absence of Glaciation in Illinois during Marine Isotope Stages 3 through 5

1996 ◽  
Vol 46 (1) ◽  
pp. 19-26 ◽  
Author(s):  
B. Brandon Curry ◽  
Milan J. Pavich
Keyword(s):  
Oxygen Isotope ◽  
Late Stage ◽  
Lake Michigan ◽  
Early Stage ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Argillic Horizon ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

A10Be inventory and14C ages of material from a core from northernmost Illinois support previous interpretations that this area was ice free from ca. 155,000 to 25,000 yr ago. During much of this period, from about 155,000 to 55,000 yr ago, 10Be accumulated in the argillic horizon of the Sangamon Geosol. Wisconsinan loess, containing inherited 10Be, was deposited above the Sangamon Geosol from ca. 55,000 to 25,000 yr ago and was subsequently buried by late Wisconsinan till deposited by the Lake Michigan Lobe of the Laurentide Ice Sheet. The Sangamonian interglacial stage has been correlated narrowly to marine oxygen isotope substage 5e; our data indicate instead that the Sangamon Geosol developed during late stage 6, all of stages 5 and 4, and early stage 3.

scholarly journals Mexico: Basement framework and pre-Cretaceous stratigraphy

2020 ◽  
Author(s):  
Uwe C. Martens ◽  
Roberto S. Molina Garza
Keyword(s):  
Gulf Of Mexico ◽  
Detrital Zircon ◽  
Source Area ◽  
White Mica ◽  
Late Triassic ◽  
Source Areas ◽  
Local Character ◽  
South Central ◽  
Specific Source ◽  
Maya Mountains

ABSTRACT Provenance determinations of sediment deposited in circum–Gulf of Mexico basins rely on understanding the geologic elements present in the basement provinces located from northeast Mexico to Honduras. Relevant geologic features of these provinces are herein summarized in text and pictorial form, and they include the Huizachal-Peregrina uplift, western Gulf of Mexico, Huayacocotla, Zapoteco, Mixteca, Xolapa, Juchatengo, Cuicateco, Mixtequita, south-central Chiapas, southeast Chiapas, western Guatemala, central Guatemala, Maya Mountains, and the Chortis block. We recognized basement elements of local character that serve as fingerprints for specific source areas. However, many elements are ubiquitous, such as 1.4–0.9 Ga, high-grade metamorphic rocks that occur both as broad exposures and as inliers in otherwise reworked crust. Xenocrystic and detrital zircon of Mesoproterozoic age is very common and hence not diagnostic of provenance. Neoproterozoic rocks are very scarce in Mexican basement provinces. However, Ediacaran–Cambrian detrital zircon grains are found in Mexican Paleozoic strata; these were possibly derived from distant sources in Gondwana and Pangea. Ordovician–Silurian magmatism is present in approximately half the provinces; magmatic detrital zircon of such age is somewhat informative in terms of provenance. More useful populations are detrital zircon grains with Ordovician–Silurian metamorphic overgrowth, which seem to be mainly sourced from the Mixteca region or the southern Chiapas Massif. Devonian basement has only been discovered in the Maya Mountains of Belize, and detrital zir-on of such age seems to be characteristic of that source. A similar case can be made about Carboniferous zircon and the Acatlán Complex, Middle Pennsylvanian zircon and Juchatengo plutons, and Late Triassic zircon and the basement exposed in central Guatemala. In all these cases, the age and geographic extent of the zircon source are restricted and serve as a distinct fingerprint. Plutons of Permian–Early Triassic age are widespread, and detrital zircon grains from them are rather nonspecific indicators of source area. Future dating of detrital white mica using 40Ar-39Ar could help in recognizing Carboniferous–Triassic schist from more restricted schist occurrences such as west Cuicateco (Early Cretaceous) and central Guatemala (Late Cretaceous).

A Proposed Diachronic Revision of Late Quaternary Time-Stratigraphic Classification in the Eastern and Northern Great Lakes Area

2000 ◽  
Vol 54 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Paul F. Karrow ◽  
Aleksis Dreimanis ◽  
Peter J. Barnett
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Late Quaternary ◽  
Great Lakes Region ◽  
Quaternary Deposits ◽  
Late Wisconsinan ◽  
Stratigraphic Nomenclature ◽  
Lake Michigan Lobe

A succession of stratigraphic codes (1933, 1961, 1983) has guided attempts to refine classifications and naming of stratigraphic units for Quaternary deposits of the Great Lakes region. The most recent classifications for the late Quaternary of the Lake Michigan lobe (1968) and the eastern Great Lakes (1972) have been widely used, but later work has created the need for revision. An attempt has been made to integrate the two previous classifications following the diachronic system of the 1983 Code of Stratigraphic Nomenclature. A new nomenclature for the higher, more broadly recognized units was presented in 1997. We here present the diachronic nomenclature for finer subdivisions recognized in the eastern and northern Great Lakes. Following the interglacial Sangamon Episode, the three parts of the Wisconsin Episode are further subdivided as follows: the Ontario Subepisode (former Early Wisconsinan) comprises the Greenwood, Willowvale, and Guildwood phases; the Elgin Subepisode (former Middle Wisconsinan) comprises the Port Talbot, Brimley, and Farmdale phases; and the Michigan Subepisode (former Late Wisconsinan) consists of Nissouri, Erie, Port Bruce, Mackinaw, Port Huron, Two Creeks, Onaway, Gribben, Marquette, Abitibi, and Driftwood phases. Succeeding interglacial time to the present is the Hudson Episode.

scholarly journals Heavy mineral stratigraphy of Palaeozoic and Mesozoic sandstones of southwestern Sinai, Egypt: A reassessment

GeoArabia ◽  
2011 ◽  
Vol 16 (3) ◽  
pp. 31-64 ◽  
Author(s):  
Robert W.O’B. Knox ◽  
Mamdouh F. Soliman ◽  
Mahmoud A. Essa
Keyword(s):  
Source Area ◽  
Climatic Conditions ◽  
Heavy Mineral ◽  
Arabian Shield ◽  
Nubian Shield ◽  
Mineral Assemblages ◽  
History Of ◽  
Southwestern Sinai ◽  
Arabian Nubian Shield ◽  
Improved Methods

ABSTRACT Improved methods of analysis and quantification of heavy mineral assemblages in Cambrian to Early Cretaceous sandstones of southwest Sinai have revealed successive changes in provenance that reflect both rejuvenation of the Arabian Shield and changes in the topographic configuration of the source area. Three mineral units have been identified in the Cambrian succession, at least three in the Carboniferous and three in the Cretaceous. It is predicted that the genetic units defined by these successive changes in mineralogy will be of regional extent and thus assist in elucidating the history of uplift of the Arabian-Nubian Shield and provide a better means of correlating sandstone units into adjacent areas. Variation in the abundance of apatite in the Cambrian succession is independent of provenance signature and is interpreted as reflecting alternating dry and humid climatic conditions.

scholarly journals High (ultrahigh) pressure metamorphic terrane rocks as the source of the detrital garnets from the Middle Jurassic sands and sandstones of the Cracow Region (Cracow-Wieluń Upland, Poland)

2012 ◽  
Vol 62 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Štefan Méres ◽  
Roman Aubrecht ◽  
Michał Gradziński ◽  
Milan Sýkora
Keyword(s):  
Middle Jurassic ◽  
Source Area ◽  
Heavy Mineral ◽  
Ultrahigh Pressure ◽  
Metamorphic Rocks ◽  
Outer Western Carpathians ◽  
Mineral Assemblages ◽  
Pieniny Klippen Belt ◽  
Metamorphic Terrane ◽  
Crystalline Complexes Of

ABSTRACT Aubrecht, R., Meres, Š., Gradziński, M. and Sykora, M. 2012. High (ultrahigh) pressure metamorphic terrane rocks as the source of the detrital garnets from the Middle Jurassic sands and sandstones of the Cracow Region (Cracow- Wieluń Upland, Poland). Acta Geologica Polonica, 62 (2), 231-245. Warszawa. The Middle Jurassic (Upper Bathonian/Lower Callovian) sands and sandstones of the Cracow-Wieluń Upland contain detrital garnets with high contents of the pyrope molecule (30-73 mol %). The predominance of detrital pyrope garnets, and inclusions represented mainly by omphacite and kyanite, show that the garnets were derived from high (ultrahigh) pressure (H/UHP) metamorphic terrane rocks (garnet peridotites, eclogites and granulites). Their source is unknown. The Moldanubian Zone of the Bohemian Massif is closely comparable. However, the terranes between this zone and the Cracow- Wieluń Upland are dominated by almandine garnets. The relatively low proportion of almandine garnets in the examined samples indicates that transport of the detrital material could not have been from a far distant source as the garnet assemblage would otherwise be strongly dominated by almandine. A less distant possible source could have been the Gory Sowie Mts., which incorporate UHP/HP metamorphic rocks, but the exposed areal extent of these rocks is too small. It is possible that larger portions of these metamorphic rocks are buried beneath the Cenozoic cover and might have earlier represented a larger source area. Reworking of the entire heavy mineral spectra from older clastics is improbable because of the low maturity of the heavy mineral assemblages (higher proportion of less stable minerals). The source area therefore remains unknown. Most probably it was formed by primary crystalline complexes of lower crust to mantle origin, outcrops of which were not far distant from the area of deposition. Similar detrital garnet compositions were also recorded in the Outer Western Carpathians (Flysch Zone, Pieniny Klippen Belt), i.e. the crustal segments which formed the Silesian and Magura cordilleras; the Czorsztyn Swell was also formed by similar rocks.

scholarly journals Stratigraphic evolution of heavy-mineral provenance signatures in the sandstones of the Wajid Group (Cambrian to Permian), southwestern Saudi Arabia

GeoArabia ◽  
2007 ◽  
Vol 12 (4) ◽  
pp. 65-96 ◽  
Author(s):  
Robert W.O’B. Knox ◽  
Stephen G. Franks ◽  
Joshua D. Cocker
Keyword(s):  
Saudi Arabia ◽  
Tectonic Setting ◽  
Drainage System ◽  
Source Area ◽  
Major Change ◽  
Heavy Mineral ◽  
Source Rocks ◽  
The South ◽  
Data Set ◽  
Mineral Assemblages

ABSTRACT The Wajid Group of southwestern Saudi Arabia consists of a dominantly sandy succession of Cambrian to Permian age that spans several discrete phases in the tectonic evolution of the Arabian Peninsula. The principal aim of this study was to determine whether successive changes in the tectonic setting are reflected in changes in provenance-related mineralogy. Because of the relatively limited compositional range of the Wajid sandstones, heavy-mineral assemblages have been used as the primary tool for assessing changes in provenance signature. A comparison of heavy-mineral and petrological data has, however, also been carried out. Variation in the relative abundances of zircon, rutile, monazite, tourmaline and apatite has revealed significant changes in provenance signature between the Dibsiyah (Cambrian–Ordovician), Sanamah (Ordovician–Silurian), Khusayyayn (Devonian–Carboniferous) and Juwayl (Carboniferous–Permian) sandstones. Since previous studies have established that northward-flowing rivers deposited the fluvial sandstones of the Wajid Group, it appears that the source area lay to the south. In the absence of data from the region to the south, it is not possible to identify specific source areas. It is clear, however, that the successive changes in provenance signature must reflect exposure of new source rocks through progressive denudation, changes in the pattern of tectonic uplift or changes in the drainage system. It is also possible that some of the observed mineral variation is related to lateral influx of sands through long-shore drift during times of high sea level. Two distinct mineral compositions occur within the Dibsiyah sandstones, indicating that a major change in provenance took place during deposition of the Upper Dibsiyah sands. The boundary between the Dibsiyah and Sanamah formations is sharply defined, although the overall composition of the Sanamah sandstones is in many respects similar to that of the Dibsiyah sandstones. There is a relatively small difference in composition between the Sanamah sandstones and the associated diamictites. A major change in provenance is indicated at the base of the Khusayyayn Formation, with an increase in the proportion of monazite and staurolite. This change in composition persists into the Juwayl Formation although the greater variability displayed by the Juwayl heavy-mineral assemblages indicates contribution from several sources. Heavy-mineral assemblages in the Juwayl sandstones are comparable to those of the Unayzah C and B sandstones of central Saudi Arabia, but differences suggest mixing between a southern (Juwayl) and western (Shield) source for the Unayzah sandstones. Compositionally, Wajid sandstones range from quartz arenite to arkose. Comparison of the petrographic and heavy-mineral data is hampered by the different grain-size ranges studied. However, it would appear that samples with similar heavy-mineral provenance character do not necessarily possess similar feldspar percentages, even when the latter are corrected for in-situ kaolinization. The data set is too small to establish an explanation for this apparent discrepancy.

Detection of spatial and temporal hydro-meteorological trends in Lake Michigan, Lake Huron and Georgian Bay

2019 ◽  
Vol 22 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Aisha Javed ◽  
Vincent Y. S. Cheng ◽  
George B. Arhonditsis
Keyword(s):  
Lake Michigan ◽  
Lake Huron ◽  
Georgian Bay
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