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Paleozoic rocks of the Pelly Mountains, central Yukon, preserve greater than 150 m.y. of sedimentation, magmatism and base-metal mineralization. To identify secular trends in regional tectonics and metallogeny, a multi-year project on the stratigraphy of the Pelly Mountains in the Quiet Lake (105F) and Finlayson Lake (105G) map areas was initiated. Field studies during summer 2015 focused on two stratigraphic intervals: (1) mafic volcanic, volcaniclastic and clastic rock successions assigned to the Cambrian-Ordovician Cloutier and Groundhog formations (Kechika group); and (2) felsic volcanic, volcaniclastic and clastic rock successions assigned to the Devonian-Mississippian Black Slate and Felsic Volcanic formations (Seagull group). Cambrian-Ordovician strata were deposited in a marine environment characterized by episodic mafic volcanism and extensional tectonism. Devonian-Mississippian strata record the transition from an extensional turbidite basin to a metalliferous volcanic rift basin, and resemble key rock assemblages of the Selwyn basin (Earn Group) and Yukon-Tanana terrane (Grass Lakes and Wolverine Lake groups).

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

The Permian Yessabah Limestone, a thick crinoidal limestone unit, appears abruptly in the stratigraphic succession over a large area of the Hastings Block in northeastern New South Wales, disconformably overlying clastic rocks with sharply contrasting facies associations. The formation is part of a thick depositional sequence that began with a major sea-level fall at the end of the Carboniferous. The sea-level fall produced a major basinward shift in facies causing rejuvenation of streams and the deposition of braided-stream gravels in the onshore areas while a mass-movement association, the Parrabel Beds, was deposited offshore in the deep basin (the lowstand systems tract). The Yessabah Limestone was deposited as part of the transgressive systems tract in a shallow-marine high-energy environment as sea level again began to rise. The highstand systems tract then prograded over the Yessabah Limestone in the form of a distal turbidite association , the Warbro Formation and associated units, as sea level reached its maximum. The growth of both crinoids and bryozoa was prolific; their two distinctive faunal assemblages alternately dominated the sea floor, producing thick units of well-washed crinoid-rich limestone followed by a bryozoan-rich unit. As sea level rose, conditions became unsuitable for carbonate deposition and the area was again invaded by clastic sediments, forming a distal turbidite association that prograded across the limestones as part of the highstand systems tract.

Continued investigations of sedimentary units in the Tatonduk and Coal Creek inliers of the western Ogilvie Mountains have resulted in a refinement of the regional Neoproterozoic and early Paleozoic stratigraphy. The proposed correlations simplify Yukon stratigraphic nomenclature and promote synthesis of geological data. Strata of the Fifteenmile, Rapitan and Hay Creek groups, as well as the upper WindermereSupergroup are present in both inliers. Prominent unconformities within the Fifteenmile Group, and between the Windermere Supergroup and the variable overlying Paleozoic stratigraphy, represent at least three distinct tectonic events and basin-forming episodes. We propose redefinition of the Fifteenmile Group, abandonment of the Tindir Group, and recognition of strata equivalent to the Coates Lake Group and Mackenzie Mountains supergroup. This refined nomenclature across the Ogilvie, Wernecke and Mackenzie mountains is a step toward enhanced regional correlation of exposures in the northern Cordillera and Proterozoic inliers of the western Arctic.

Lime Peak is an Upper Triassic carbonate complex approximately 40 km northeast of Whitehorse. It is one of many carbonate buildups in the Whitehorse Trough which occur as isolated lenses surrounded by Triassic greywacke and volcanic-clast conglomerates derived from an arc to the southwest. The carbonates at Lime Peak are particularly well-exposed and have been shown to be a series of organic reefs which shed debris into surrounding inter-reef areas. Fieldwork at Lime Peak in 1980 established the existence of massive reefal limestones occurring in 3 distinct forms. The variability of both the geometry and the lithology of the massive limestones was observed in 1980 but was not studied in detail. Considerable effort was spent in 1981 mapping lithology in order to establish the nature and extent of organic framework in the reefal bodies and to develop an explanation for the three distinct growth forms.