03091nas a2200193 4500008004100000245009100041210006900132260001200201300001200213490000700225520246400232100002502696700002202721700002102743700001902764700001902783700002402802856007102826 2019 eng d00aRose Road Localities: Town of Pitcairn, St. Lawrence County, New York Part 2—Geology0 aRose Road Localities Town of Pitcairn St Lawrence County New Yor c10/2019 a540-5520 v943 a

IN PART I OF THIS SERIES we gave a brief introduction to the two localities at Rose Road in the Town of Pitcairn, St. Lawrence County, New York (fig. 2), and presented their detailed history (Chamberlain et al. 2018 Chamberlain, S. C., G. W. Robinson, S. Robinson, M. R. Walter, D. G. Bailey, J. R. Chiarenzelli, and M. Lupulescu. 2018. The Rose Road localities, Town of Pitcairn, St. Lawrence County, New York: Part 1–History. Rocks & Minerals 93: 44230.[Taylor & Francis Online] [Google Scholar]). In Part 2 we provide information about the geology and probable geological origin of both the Wollastonite Skarn and the Purple Diopside Mound

1 aChiarenzelli, J., R.1 aLupulescu, M., V.1 aRobinson, G., W.1 aBailey, D., G.1 aWalter, M., R.1 aChamberlain, S., C. uhttps://www.tandfonline.com/doi/full/10.1080/00357529.2019.164102402516nas a2200181 4500008004100000245014700041210006900188300001400257490000800271520180300279100002502082700001602107700002202123700002102145700001502166700001802181856013502199 2017 eng d00aLyon Mountain ferroan leucogranite suite: Magmatic response to extensional thinning of overthickened crust in the core of the Grenville orogen0 aLyon Mountain ferroan leucogranite suite Magmatic response to ex a1472-14880 v1293 a

Evidence is presented for the crystallization age (ca. 1066−1033 Ma) and origin of the Lyon Mountain Granite (formerly Lyon Mountain Gneiss), a widespread magnetite-bearing leucogranitic igneous suite in the Adirondack Highlands. Recent reinterpretations of U-Pb zircon results have led some to propose that the Lyon Mountain Granite was intruded synchronously with the Shawinigan anorthosite-mangerite-charnockite-granite (AMCG) suite at ca. 1165−1145 Ma. However, this interpretation conflicts with the recognized chronology of the region based on field and analytical studies, which have established a late to postkinematic Ottawan crystallization age (ca. 1050 Ma). Herein, we show that the older ages reported are a consequence of zircon inheritance; we summarize existing and provide new U-Pb zircon data expanding the recognized extent of the Lyon Mountain Granite; and we review long-recognized field relationships and temporal associations among structures within the region and southern Grenville Province. Field relations include a spatial, and likely temporal, link with iron oxide−apatite deposits, gabbroic and amphibolite bodies, and association with late extensional faults and hydrothermal alteration. The variable fabric of the Lyon Mountain Granite is a consequence of magmatic/intrusive processes, proximity to synintrusive structures, and timing of intrusion relative to deformation during an ∼30 m.y. period. The Lyon Mountain Granite formed during late Ottawan anatexis related to gravitational collapse of overthickened crust. Its anhydrous ferroan nature, zircon xenocryst population, and association with magnetite-apatite deposits can be explained by partial melting of Shawinigan-aged, AMCG-dominated lower crust.

1 aChiarenzelli, J., R.1 aSelleck, B.1 aLupulescu, M., V.1 aBickford, M., E.1 aValley, P.1 aMcLelland, L. uhttps://pubs.geoscienceworld.org/gsabulletin/article/doi/10.1130/B31697.1/208117/lyon-mountain-ferroan-leucogranite-suite-magmatic02104nas a2200277 4500008004100000020001800041245017100059210006900230260003700299300001400336520113000350653002401480653002001504653002101524653002301545653002501568653001501593653002901608100002501637700001801662700001601680700001901696700002201715700002001737856006901757 2017 eng d a978012803386900aSediment Provenance Utility of Detrital Zircon Grains From Upper Amphibolite Facies Rocks of the Grenville Supergroup, Adirondack Lowlands, Northeastern United States0 aSediment Provenance Utility of Detrital Zircon Grains From Upper aAmsterdam, NetherlandsbElsevier a371 - 4013 a

Detrital zircons in quartz-rich lithologies from the deformed and metamorphosed Mesoproterozoic Adirondack Lowlands in northern New York, part of the Grenville Province, have been used to document sediment provenance and basin evolution, and provide initial temporal constraints on sedimentation. Despite the effects of Shawinigan (c. 1200–1150 Ma) and Elzevirian (c. 1240–1225 Ma) orogenesis, zircon grains recovered from quartz-rich lithologies from the Grenville Supergroup largely retain detrital morphology and isotopic systematics, while displaying minimal metamorphic effects. The ages obtained constrain deposition of the entire sequence between c. 1276 and 1255 Ma. Changes in provenance track the evolution of the basin from the initial rift-drift phase, foredeep development, and transition to final basin fill and response to initial pre-Elzevirian compression. The relative lack of zircons derived from the Superior Province and predominance of those from south-central Laurentia during deposition of the sequences indicates the influence of an intervening oceanic basin to the north.

10aAdirondack Lowlands10aBasin evolution10aDetrital zircons10aGrenville Province10aGrenville Supergroup10aProvenance10aUpper amphibolite facies1 aChiarenzelli, J., R.1 aKratzmann, D.1 aSelleck, B.1 aDeLorraine, W.1 aLupulescu, M., V.1 aMazumder, Rajat uhttp://linkinghub.elsevier.com/retrieve/pii/B978012803386900014900560nas a2200157 4500008004100000022002200041245007200063210006900135260005000204100002500254700002200279700001400301700003100315700001500346856004100361 2016 eng d a978-1-55557-343-000aBedrock Geology of the Witherbee Quadrangle, Essex County, New York0 aBedrock Geology of the Witherbee Quadrangle Essex County New Yor aAlbany, New YorkbNew York State Museumc20161 aChiarenzelli, J., R.1 aLupulescu, M., V.1 aGrohn, L.1 aNascimento, de, Santana do1 aWalton, M. uhttp://www.nysm.nysed.gov/file/2875/00565nas a2200169 4500008004100000245005000041210004900091260004200140300001200182653001200194100002500206700002200231700001500253700002500268700001800293856008400311 2014 eng d00aUltramafic/Mafic Rocks of the Pyrites Complex0 aUltramaficMafic Rocks of the Pyrites Complex bNew York State Geological Association a133-16110ageology1 aChiarenzelli, J., R.1 aLupulescu, M., V.1 aBailey, D.1 aChiarenzelli, J., R.1 aValentino, D. uhttps://nysm.nysed.gov/staff-publications/ultramaficmafic-rocks-pyrites-complex00525nas a2200169 4500008004100000245008100041210006900122300000900191490000600200653001200206100002500218700001800243700002200261700001400283700001700297856004100314 2011 eng d00aDifferentiating Shawinigan and Ottawan Orogenesis in the Central Adirondacks0 aDifferentiating Shawinigan and Ottawan Orogenesis in the Central a2-220 v710ageology1 aChiarenzelli, J., R.1 aValentino, D.1 aLupulescu, M., V.1 aThern, J.1 aJohnston, S. uhttp://dx.doi.org/10.1130/GES00583.100530nas a2200157 4500008004100000245011400041210006900155300001200224490000600236653001200242100002500254700002200279700001400301700001600315856004100331 2011 eng d00aTectonic Implications of the Discovery of a Shawinigan Ophiolite (Pyrites Complex) in the Adirondack Lowlands0 aTectonic Implications of the Discovery of a Shawinigan Ophiolite a333-3560 v710ageology1 aChiarenzelli, J., R.1 aLupulescu, M., V.1 aThern, E.1 aCousens, B. uhttp://dx.doi.org/10.1130/GES00608.101810nas a2200229 4500008004100000245010500041210006900146300001200215490000700227520110000234653002401334653001701358653001801375653002401393100002501417700002201442700001601464700001401480700001501494700001401509856005701523 2010 eng d00aEnriched Grenvillian Lithospheric Mantle as a Consequence of Long-lived Subduction Beneath Laurentia0 aEnriched Grenvillian Lithospheric Mantle as a Consequence of Lon a151-1540 v383 a

Geochemical and Nd isotopic data from mafic and newly discovered ultramafic rocks in the Adirondack Lowlands suggest widespread enrichment of the lithospheric mantle under the Grenville Province. Incompatible element abundances and previously published Hf TDM (zircon) (depleted mantle model age) and Nd TDM ages from rocks of the anorthosite-mangerite-charnockite-granite suite in the Adirondack Highlands document similar enrichment in the lower crust and its strong influence on subsequent magmatic events throughout the Ontario-Quebec-Adirondack segment of the Grenville Province. Likely the consequence of long-lived (ca. 1.4–1.2 Ga) northwest-directed subduction along the southeast edge of Laurentia (previously proposed Andean margin), this enrichment is similar to that associated with the vast (>240,000 km2) ultrapotassic province of the western Churchill Province. Enrichment of the lithospheric mantle beneath orogenic belts is a predictable and important differentiation process that has operated on Earth for at least the past 3 b.y.

10aAdirondack Lowlands10aGeochemistry10ageochronology10alithospheric mantle1 aChiarenzelli, J., R.1 aLupulescu, M., V.1 aCousens, B.1 aThern, E.1 aCoffin, L.1 aRegan, S. uhttp://geology.gsapubs.org/content/38/2/151.abstract