... they may be restricted to the lower part of that zone. Most of them 1088 E. P. KAISER TACONIC THRUST SHEET IN VERMONT are less than 6 inches thick and composed of quartz grains with limonite-calcite matrix. They are full of narrow veinlets of quartz which weather in relief. The weathered rock is coated...

...Ed Landing; Georgia Pe-Piper; William S.F. Kidd; Karem Azmy Abstract The only pillow basalt in synorogenic sedimentary rocks at the exterior margin of the Taconic orogen in eastern North America is at Stark’s Knob in eastern New York. Earlier reported as extrusive into allochthonous Ordovician...

... horizon with iron-oxide staining and mud partings. For locations, see Fig.  2 . ( a ) From northwest part of pit, 1 m below the unconformity in Fig.  4 c , showing limonite-rich horizon parallel to the unconformity and the unconformable bedding above it. ( b ) Two thin red mudstone partings...

..., and that occurrence has been cited by Lotze ( 1958 , 1961 ) and Sdzuy ( 1961 , 1962 ). Herein, we describe several cranidia and fragments that enable positive assignment to Atops . Pseudatops Lake, 1940 is described for the first time in the Iberian Peninsula, with recognition of the Taconic North American...

... Ordovician Taconic and Middle Devonian Acadian ages with two discrete modes at 463 and 369 Ma, and the latter dominated by Late Ordovician Taconic, Middle Devonian Acadian, and Late Devonian Neoacadian ages with discrete modes at 445, 397, 360, and 351 Ma. The new data suggest that early Pennsylvanian...

... evidence indicates that both Taconic and Acadian orogenic episodes are represented in northeastern Alaska and northern Yukon. 1 Manuscript received, April 26, 1971; revised and accepted, September 10, 1971. Publication authorized by the Director, U.S. Geological Survey. 2 U.S. Geological...

... subsidence of these crustal blocks. 1 Manuscript received, August 6, 1982; accepted, June 6, 1983. At all three localities, the evidence suggests extensive fluid migration along the joints. Limonite and goethite have been precipitated within these zones. On fracture surfaces within...

... concentrated on post-Taconic events, in part because of the renewed hydrocarbon exploration activity in the area ( Cooper et al. 2001 ), but also because in both western and central Newfoundland the importance of Silurian orogenesis (the Salinic or Salinian orogeny) has become increasingly recognised ( Dunning...

... The Caledonian–Appalachian orogen provides a rare window through the mid- to lower-crustal levels of an evolving orogenic belt. Early Palaeozoic closure of the Iapetus Ocean resulted in extensive arc-ophiolite accretion to the Laurentian margin (= Grampian–Taconic orogeny) prior to continent–continent collision...

... grain with hematite cement (PPL). Note that cement is present within fractures. M , Nodular hematite cement in reflected light. N , Hematite cement weathered to yellow limonite in reflected light. Porosity types present include interparticle, partial and complete moldic, intraparticle...

... for the most part of angular clasts of sugary dolomite and of shaly clasts accompanied by limonitic clots; the residues from sample 2 also contained grains of pyrite. The residues retained on the 250 µm sieve were whole rock fragments much larger than individual conodont elements and were not examined...

... erosional [his italics] unconformity between the Maquoketa and the underlying rocks in the upper Mississippi valley.” However, he believed that an unconformity does exist on the basis of (1) a basal phosphate zone containing worn and pitted pebbles and limonite, (2) a “knife-edge” lithologic change, (3...

... burrow networks. Pyritic Estill Shale in the Llandovery of Kentucky yields scattered tiny, enrolled trilobites, primarily calymenids and dalmanitids. These enrolled trilobites are infilled with pyrite and typically weathered to limonite (C. Mason, personal communication, 2008). TABLE 1...

... glauconite globules, sometimes with syneresis cracks filled with ferruginous material. Some grains have a thin concentric chamosite rim, and some are variably chloritized. There are also limonite–goethite and chamosite grains (up to 10%). The clasts are of fine- to medium-sandy size, amount to few percent...

..., chlorite, zeolite, and iron and manganese oxides with slickenlines locally developed in a variety of orientations, mainly dip-slip or oblique slip. In thin section, the effects of brittle deformation are limited, with small fractures filled mainly with epidote, white mica, chlorite and limonite...

... area and Har ‘Amram (southern Negev, Israel) Israel J Earth Sci 1971 20 179 205 Rasetti F. Revision of the North American trilobites of the family Eodiscidae J Paleont 1952 26 434 51 Rasetti F. New Lower Cambrian faunule from the Taconic sequence of New York Smithson...

...-V, limonitic stromatolites. Limonite oncoids with basalt granule–pebble cores are abundant in the upper two limestones. Similar condensed limestones characterize proximal (peritidal or intertidal) facies in the Avalonian Lower Cambrian, where upward successions from nodular mudstone to high-energy...

..., chalcopyrite and chalcocite), which is variably oxidized to red–brown hematite or limonite on exposed surfaces ( Figs 11a–d ). Calcite veins up to several centimetres thick and several metres long are widely developed along many minor NE–SW fractures and more northerly striking carbonate veins that occur...

... block (25 cm × 30 cm × 40+ cm) was found in the lower fanglomerate. Slab and thin sections show that the red color is limited to a 5 cm thick, weakly limonite impregnated rind of the boulder, and that the block is a light grey, intraclast-fossil fragment (brachiopod and echinoderm hash dominated...