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Changes in lithospheric composition and strength associated with rifting of the Rodinian supercontinent (ca. 780–485 Ma) served to localize Mesozoic tectonic activity in the McCall region of west-central Idaho, USA. Although discrimination diagrams support slab failure melting, ca. 150–121 Ma calcic magmatism in the Hazard Creek complex and chemically similar intrusive rocks of northeastern Oregon, USA (e.g., Cornucopia stock), is best explained by progressive loading of oceanic crust. Westward-directed thrusting across the Laurentian continental margin and adjacent island-arc terranes (Olds Ferry/Wallowa; Blue Mountains province) led to partial melting of metabasaltic source rocks at pressures and depths sufficient for garnet stability (>10 kbar, ∼35 km). Early pluton emplacement during right-oblique arc–continent collision overlapped in time with subduction zone reorganization, which involved a change in dip direction (westward to eastward) under the accreting Blue Mountains block. Ensuing magmatic activity predated and was concurrent with ca. 116 Ma thrust reactivation of the Wallowa/Olds Ferry boundary, which temporally overlapped with contractional deformation along the terrane–continent accretionary boundary. Later synorogenic magmatism was focused along the accretionary boundary, where rising anatectic melts were caught between the eastwar-dimpinging/northward-migrating (obliquely colliding) terrane block and continental margin backstop (Rodinian rift architecture). Middle Cretaceous dextral transpression viewed in this manner precludes the need for an outboard “hit-and-run” collider (Insular superterrane) and thus, a post-accretion shear zone in western Idaho. [ABSTRACT FROM AUTHOR]

New U-Pb zircon geochronology from the Riggins region of west-central Idaho refines the timing of contractional deformation across the Salmon River suture zone (SRSZ), a broad north- to northeast-striking belt (>25 km wide) of high strain recording Jura-Cretaceous island-arc-continent collision. Laser ablation--inductively coupled plasma--mass spectrometry (LA-ICP-MS) yields mid-Cretaceous crystallization ages on formerly undated plutonic rocks sampled from the Salmon River canyon. In the Crevice pluton (~105 Ma), the development of steep to moderate northerly striking gneissic foliation ([S.sub.1]) was followed by tops-to-the-west slip on shallow mylonitic shear zones [S.sub.2] and brittle overprinting via systematic joints ([J.sub.n]) of regional extent. Together, these structures form the pluton's internal architecture. Subvertical gneissic foliation in the adjacent Looking Glass pluton (~92 Ma) indicates ductile deformation was ongoing in the Late Cretaceous. Prior to this investigation, penetrative fabrics in local arc volcanogenic, plutonic, and continental rocks have been unequivocally linked to post-collisional dextral transpression on the narrow ( Une nouvelle geochronologie par U-Pb sur zircon pour la region Riggins du centre-ouest de l'Idaho precise le moment de la deformation par contraction a travers la zone de suture de Salmon River (SRSZ), une large ceinture (>25 km) de direction nord a nord-est de grandes contraintes enregistrant des collisions au Jurassique-Cretace entre des iles d'arcs et le continent. La spectrometrie de masse a source plasma a couplage inductif avec ablation laser (LA-ICP-MS) a donne des ages de cristallisation au Cretace moyen a partir de roches plutoniques prelevees dans le canyon de la riviere Salmon non datees anterieurement. Dans le pluton Crevice (~105 Ma), le developpement de foliation gneissique (Si) a direction nord et a pendage fort a modere a ete suivi par un decrochement <> sur des zones de cisaillement mylonitiques a faible profondeur ([S.sub.2]) et une surimpression cassante par des joints (Jn) systematiques d'etendue regionale. Ensemble, ces structures forment l' architecture interne du pluton. Une foliation subverticale des gneiss dans le pluton adjacent de Looking Glass (~92 Ma) indique qu'une deformation ductile etait en cours au Cretace tardif. Avant cette investigation, les textures dans les roches d'arcs locaux volcanogenes, plutoniques et continentales, avaient ete reliees sans equivoque a une transpression post-collision dextre sur la zone de cisaillement etroite (, Introduction In the North American Cordillera, initial [sup.87]Sr/[sup.86]Sr isotope ratios record the transition from plutons emplaced into oceanic lithosphere on the arc (western) side to those intruded into continental lithosphere [...]

The Salmon River belt is composed of metamorphic tectonites with poorly dated Mesozoic and Paleozoic protoliths that lie between volcanic arc assemblages of northeastern Oregon and the western margin of the North American continent in west-central Idaho. To the west, the Salmon River belt overlies late Paleozoic and Mesozoic volcanic arc rocks of the Wallowa terrane on a shallowly east-dipping fault; to the east the belt is separated from North American rocks by the western Idaho shear zone. The Salmon River belt is divided into western and eastern assemblages composed of greenschist- and amphibolite-facies metamorphic tectonites, respectively, and is deformed in three and locally four generations of penetrative structures. First-generation structures are synmetamorphic, west-vergent, tight to isoclinal folds with a penetrative axial-planar cleavage and downdip stretching lineation. Second- and third-phase structures are postmetamorphic and consist of open to close, upright to slightly overturned folds with north-south and east-west trending penetrative axial-planar cleavages, respectively. Low-angle faults truncate metamorphic structures within the Salmon River belt and juxtapose rocks with different metamorphic grades. The faults formed together with second-generation structures and are deformed by third-generation folds. The age of metamorphic and postmetamorphic structures is constrained by deformed carbonate rocks of Late Triassic age and clastic rocks of late Early Jurassic age and by the ca. 145 Ma emplacement of an undeformed tonalitic pluton. Along the eastern margin of the Salmon River belt, structures are overprinted and transposed by a younger, steeply east-dipping mylonitic shear zone, the mid-Cretaceous western Idaho shear zone. Synmetamorphic structures within the Salmon River belt formed before amalgamation of the Wallowa terrane and the North American fringing-arc complex and developed as part of a regional belt of intra-arc metamorphic tectonites. The pre-Cretaceous docking of the Wallowa terrane is recorded within the Salmon River belt by development of postmetamorphic structures and predates formation of the western Idaho shear zone. The western Idaho shear zone formed after the amalgamation of the arc terranes and records the intraplate deformation associated with the collapse of the fringing-arc and back-arc-basin system. Keywords: structure, tectonics, Wallowa terrane, Salmon River belt, Cordilleran Arc, Mesozoic.

Polyphase structural mapping and mineral age dating across the Salmon River suture zone in west-central Idaho (Riggins region; ~45°30'N, ~117°W-116°W) support a late Mesozoic history of penetrative deformation, dynamothermal metamorphism, and intermittent magmatism in response to right-oblique oceanic-continental plate convergence (Farallon-North America). High-strain linear-planar tectonite fabrics are recorded along an unbroken ~48 km west-to-east transect extending from the Snake River (Wallowa intra-oceanic arc terrane; eastern Blue Mountains Province) over the northern Seven Devils Mountains into the lower Salmon River Canyon (ancestral North America; western Laurentia). Given the temporally overlapping nature (ca. 145-90 Ma) of east-west contraction in the Sevier fold-and-thrust belt (northern Utah-southeast Idaho-southwest Montana segment), we propose that long-term terrane accretion and marginparallel northward translation in the Cordilleran hinterland (~41°N-46°N latitude; modern coordinates) drove mid- to upper-crustal shortening >250 km eastward into the foreland region (~115°W-113°W). During accretion and translation, the progressive transfer of arc assemblages from subducting (Farallon) to structurally overriding (North American) plates was accommodated by displacement along a shallow westward-dipping basal décollement system underlying the Cordilleran orogen. In this context, large-magnitude horizontal shortening of passive continental margin strata was balanced by the addition of buoyant oceanic crust--late Paleozoic to Mesozoic Blue Mountains Province--to the leading edge of western Laurentia. Consistent with orogenic float modeling (mass conservation, balance, and displacement compatibility), diffuse dextral-transpressional deformation across the accretionary boundary (Salmon River suture: Cordilleran hinterland) was kinematically linked to eastward-propagating structures on the continental interior (Sevier thrust belt; Cordilleran foreland). As an alternative to noncollisional convergent margin orogenesis, we propose a collision-related tectonic origin and contractional evolution for central portions of the Sevier belt. Our timing of terrane accretion supports correlation of the Wallowa terrane with Wrangellia (composite arc/plateau assemblage) and implies diachronous south-to-north suturing and basin closure between Idaho and Alaska. [ABSTRACT FROM AUTHOR]

Background. Transcription factor NF-κB has been implicated in numerous human inflammatory diseases. Acute pancreatitis can result in remote tissue injury, but the involved mechanisms are unknown. This study evaluates the role of systemic NF-κB activation in the pathogenesis of lung inflammation in a transgenic pancreatitis model.Materials and methods. Using transgenic mice expressing photinus luciferase controlled by an NF-κB-dependent promoter, luciferase activity was measured in pancreas, liver, and lung tissues as a surrogate marker of NF-κB activity. Luciferase activity was measured by in vivo bioluminescence and correlated to an in vitro luciferase assay of organ homogenates. Following measurement of luciferase activity in uninjured animals, these animals were fed a choline-deficient, ethionine supplemented diet for 48 h to induce pancreatitis, and luciferase activity was then measured at 48, 60, 72, and 96 h. Lung inflammation was determined by total nucleated cell counts in bronchoalveolar lavage (BAL) fluid.Results. Bioluminescence detected increased luciferase activity over the upper abdominal region at 48 and 60 h (P < 0.05), and over the thorax at 60 and 72 h (P < 0.05). Luciferase assays showed significantly increased luciferase activity in both liver and lung tissue at 48 (liver = P < 0.005, lung = P < 0.05) and 60 h (liver = P < 0.05, lung = P < 0.05) compared to activity in uninjured controls. Total nucleated cell counts in BAL fluid were significantly increased at 72 h (P < 0.05) compared with controls.Conclusion. In this model, NF-κB binding activity is increased in the liver and lung. These data suggest that the liver modulates pancreatitis-induced systemic inflammatory response syndrome (SIRS) and suggest strategies to reduce multisystem injury. [Copyright &y& Elsevier]

We have previously reported reduced overall and disease-free survival in black patients from a 10-year retrospective review of 668 patients from tumor registry data. This study of 213 patients reports the analysis of available archived tissue from a city hospital (n=44 patients, 53% black) and from a university medical center (n=169, 10.6% black). Two senior pathologists independently reviewed slides for predetermined histologic criteria reported to correlate with survival: tumor type, stage at diagnosis, character of invasion, vascular or perineural invasion, the presence of residual adenoma, the presence of a Crohn's-like reaction and number of nodes resected. Differences in discrete variables were compared using the Chi-squared test. Differences in continuous variables were analyzed using independent t tests. No statistically significant differences were identified in tumor stage or type by institution or race. In patients treated at the city hospital, there was a higher incidence of infiltrating tumors (85% vs. 61%, p<0.001), vascular invasion (70% vs. 36%, p<0.05) and residual adenoma (84% vs. 39%, p<0.05); however, no differences by race were identified. Blacks at both hospitals had significantly more perineural invasion (81% vs. 30%, p<0.05) and Crohn's-like reaction (64% vs. 30%, p<0.05) when compared to white patients, although there was no difference between hospitals. The total number of lymph nodes resected was higher at the university hospital (17.0 vs. 8.9, p<0.001). There were no differences in number of nodes resected at either institution by race. Histopathologic findings did not explain the apparent disparity in survival. The differences in number of nodes harvested may suggest inadequate resection or insufficient recovery of nodes by the pathologist.