1,739,808 research outputs found
G-1146-2015-E
No full textG-1146-2015-E CONVOCATORIAS
para Jefes de Departamento de Admisión Escolar; de Certificación;
de Control Documental, y de Servicios Administrativos de la Dirección de Administración
Escolar; Jefe de Departamento de Planeación de la Dirección de Planeación,
y para Jefe de División de Supervisión y Auditoría a Escuelas
de Nivel Medio Superior del Órgano Interno de ControlG-1146-2015-E CONVOCATORIAS
para Jefes de Departamento de Admisión Escolar; de Certificación;
de Control Documental, y de Servicios Administrativos de la Dirección de Administración
Escolar; Jefe de Departamento de Planeación de la Dirección de Planeación,
y para Jefe de División de Supervisión y Auditoría a Escuelas
de Nivel Medio Superior del Órgano Interno de ControlPD
G-1146-2015-E
No full textG-1146-2015-E CONVOCATORIAS
para Jefes de Departamento de Admisión Escolar; de Certificación;
de Control Documental, y de Servicios Administrativos de la Dirección de Administración
Escolar; Jefe de Departamento de Planeación de la Dirección de Planeación,
y para Jefe de División de Supervisión y Auditoría a Escuelas
de Nivel Medio Superior del Órgano Interno de Contro
Stable isotopes of benthic foraminifera from Site ODP 184-1146
No full textWe generated a high resolution (~8 ky) benthic record from a West Pacific marginal basin to investigate the detailed structure and spectral characteristics of deep water isotope fluctuations during the middle Miocene. The benthic record from ODP Site 1146 allows unprecedented resolution of the structure of the middle Miocene delta13C excursion, as well as tighter control on the chronology of climatic events. Spectral analysis of the variance in the delta18O and delta13C records from ODP Site 1146 reveals spectral power concentrated in the eccentricity band (400-, ~100-ky) over the time interval between 13 and 17 Ma. The amplitude evolution in the 400-ky band is strikingly similar to that of the long eccentricity in Laskar's solution. There is an abrupt switch to the obliquity band in the delta18O record at -14.9 Ma, suggesting a shift in the ocean/climate response to orbital forcing (from low latitude eccentricity to high latitude obliquity forcing). The obliquity signal is pervasive in the delta18O record until -13.9 Ma, when a sharp increase in delta18O values indicates a major climatic transition. Comparison of delta18O and delta13C profiles from DSDP Site 588 (SW Pacific Ocean), ODP Site 761 (E Indian Ocean) and ODP Site 1146 (South China Sea) reveals significantly cooler deep water in the NE Indian Ocean throughout the middle Miocene and a restricted deep water exchange between the Pacific Ocean and Indian Ocean
Chemical and isotopic composition of interstitial waters and hydrocarbon composition at ODP Site 184-1146
No full textBottom-simulating reflectors were observed beneath the southeastern slope of the Dongsha Islands in the South China Sea, raising the potential for the presence of gas hydrate in the area. We have analyzed the chemical and isotopic compositions of interstitial water, headspace gas, and authigenic siderite concretions from Site 1146. Geochemical anomalies, including a slight decrease of chlorine concentration in interstitial water, substantial increase of methane concentration in headspace gas, and 18O enrichment in the authigenic siderite concretion below 400 meters below seafloor are probably caused by the decomposition of gas hydrate. The low-chlorine pore fluids contain higher molecular-weight hydrocarbons and probably migrate to Site 1146 along faults or bedded planes
Stable isotopes measured on Miocene benthic foraminifera from ODP sites 202-1237 and 184-1146
No full textOne of the most enigmatic features of Cenozoic long-term climate evolution is the long-lasting positive carbon-isotope excursion or “Monterey Excursion”, which started during a period of global warmth after 16.9 Ma and ended at not, vert, similar 13.5 Ma, approximately 400 kyr after major expansion of the Antarctic ice-sheet. We present high-resolution (1-9 kyr) astronomically-tuned climate proxy records in two complete sedimentary successions from the northwestern and southeastern Pacific (ODP Sites 1146 and 1237), which shed new light on the middle Miocene carbon-isotope excursion and associated climatic transition over the interval 17.1-12.7 Ma. We recognize three distinct climate phases with different imprints of orbital variations into the climatic signals (1146 and 1237 d18O, d13C; 1237 XRF Fe, fraction > 63 µm): (1) climate optimum prior to 14.7 Ma characterized by minimum ice volume and prominent 100 and 400 kyr variability, (2) long-term cooling from 14.7 to 13.9 Ma, principally driven by obliquity and culminating with rapid cryosphere expansion and global cooling at the onset of the last and most pronounced d13C increase, (3) “Icehouse” mode after 13.9 Ma with distinct 100 kyr variability and improved ventilation of the deep Pacific. The “Monterey” carbon-isotope excursion (16.9-13.5 Ma) consists overall of nine 400 kyr cycles, which show high coherence with the long eccentricity period. Superposed on these low-frequency oscillations are high-frequency variations (100 kyr), which closely track the amplitude modulation of the short eccentricity period. In contrast to d13C, the d18O signal additionally shows significant power in the 41 kyr band, and the 1.2 Myr amplitude modulation of the obliquity cycle is clearly imprinted in the 1146 d18O signal. Our results suggest that eccentricity was a prime pacemaker of middle Miocene climate evolution through the modulation of long-term carbon budgets and that obliquity-paced changes in high-latitude seasonality favored the transition into the “Icehouse” climate
Stable oxygen and carbon isotope record of foraminifera of ODP SIte 184-1146
No full textOcean Drilling Program Site 1146 was drilled within a small rift basin on the midcontinental slope of the northern South China Sea. It is located at 19°27.4'N, 116°16.37'E, in 2092 m water depth. This site was drilled to recover records of Asian monsoon variability into the middle Miocene with temporal resolution sufficient for orbital-scale analyses. Here we present oxygen and carbon isotopic measurements of planktonic foraminifers (Globigerinoides ruber) and benthic foraminifers (Uvigerina peregrina and Cibicides wuellerstorfi) as well as a preliminary age model for the top 185 meters composite depth (mcd)
GTS-12 adjusted age models for ODP Site 184-1146
No full textGTS-12 timescale adjusted age models for ODP site 1146 with biostratigraphic (foraminifer) datums
Age and clay mineral analysis and trace element concentrations from ODP Sites 184-1144 and 184-1146
No full textSeismic profiles provide evidence that there has been strong transport by deep-water bottom currents and drift deposition on the northern slope of the South China Sea. Earlier geochemical studies suggest that the drift sediments originated primarily from Taiwan. However, the transport process, history and origin of the deep-water bottom deposition in the northern South China Sea, on both glacial-interglacial and tectonic time scales, remain unclear. Here, we show new high-resolution records of clay minerals, grain size and mass accumulation rate (MAR) of terrigenous materials from Ocean Drilling Program (ODP) Site 1144, together with trace element concentrations in siliciclastic sediments from ODP Site 1146. Combined with other published data, we find that the primary source for sediments at ODP Sites 1144-1148 since 3 Ma is from Taiwan, and not from Pearl River as previously thought. Before 3 Ma, however, sediment source to ODP Sites 1146 and 1148 was mainly from the Pearl River. Increased contribution of terrigenous supply from Taiwan to the northern South China Sea since ~ 3 Ma may be related to the formation of the Taiwan orogen and strengthening of deep-water bottom current transport in the northern South China Sea. Variations in clay mineralogy and sedimentology at ODP Site 1144, located on a sediment drift, shows strong glacial-interglacial cyclicity. This suggests that bottom current deposition is highly dependent on sea-level fluctuations, which control the terrigenous supply to the deep sea
Sedimentary charcoal morphometrics and morphologies of Ocean Drilling Program Site 1146
No full textThe dataset contains sedimentary charcoal morphological and morphometric data, age (ka), depth (mcd), and charcoal accumulation rate ((#·cm)/(mg·Ma)) for Ocean Drilling Project Site 1146 Hole A and C
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