Geoscience Research Institute

Loma Linda, CA, United States

Geoscience Research Institute

Loma Linda, CA, United States
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Xiao Y.-J.,Peking University | Xiao Y.-J.,Geoscience Research Institute | Li J.-H.,Peking University
Natural Gas Geoscience | Year: 2014

Lishu Depression is an oil-rich depression whose source rocks and reservoirs both are early-Cretaceous formations mainly. Oil and gas was discovered in bedrock buried hill of pre-Mesozoic in recent years and a good exploration prospects is shown in the study area. Based on the analysis of the reservoir-forming factors of buried hill reservoirs in this area, the dark mudstone of Shahezi Formation and Yingcheng Formation of lower Cretaceous with lacustrine facies were considered to be the chief source rock. Gneisses, schist and granites of lower Proterozoic were the main reservoir with fractures as the main reservoir space. Two groups of source rocks exposed directly to the buried hill trap and formed a favorable trap- source configuration. Dark mudstone of lower Cretaceous with lacustrine facies provided a favorable cap rock condition. Four kinds of accumulation modes were summarized which are single side oil-source of Huoshiling Formation, single side oil-source of Shahezi Formation, single side oil-source of Shahezi-Yingcheng Formation and double side oil-source of Shahezi-Yingcheng Formation according to the buried hill reservoir pool-forming feature of Bawu area in Lishu Depression. Single side two oil-sources accumulation mode was the mainly pool-forming type. 16721926 ©, 2014, Science Press. All right reserved.

Nalin R.,Geoscience Research Institute | Bracchi V.A.,University of Milan Bicocca | Basso D.,University of Milan Bicocca | Massari F.,University of Padua
Italian Journal of Geosciences | Year: 2012

Persististrombus latus (GMELIN, 1791) (=Strombus bubonius LAMARCK, 1822), is the most iconic representative of the "Senegalese fauna", a fossil assemblage of tropical water organisms thought to have colonized the Mediterranean Sea during the last interglacial. As such, P. latus has become an important stratigraphic marker of Marine Isotope Stage (MIS) 5.5, allowing the correlation of raised coastal deposits used in studies of sea level variations and tectonic uplift. P. latus is found in shallow marine sediments of Tyrrhenian age (∼124 ka) in several localities of the Italian peninsula. However, despite intensive surveying through the years, the late Pleistocene marine terraces of the Crotone peninsula, which preserve an extensive volume of fossiliferous deposits attributed to MIS 5, have yielded very few specimens of P. latus. This paper reports the finding of several new specimens of P. latus near Isola di Capo Rizzuto, in deposits that had been independently assigned to MIS 5.5, and two specimens from the Capo Colonna terrace, which is thought to correlate with MIS 5.3 or 5.1. The Crotone peninsula, therefore, represents one of the few localities in Italy where multiple stratigraphically distinct P. latus-bearing units can be observed. © Societ̀ Geologica Italiana, Roma 2012.

Muniz F.,Area de Educacion y Cultura | De Gibert J.M.,University of Barcelona | Esperante R.,Geoscience Research Institute
Palaios | Year: 2010

Whale corpses on the modern seafloor host particular communities that benefit from the large amounts of available labile organic matter. The study of these communities has revealed the presence of the siboglinid annelid Osedax that feeds on bone tissue by means of a symbiotic relationship with heterotrophic bacteria. Here we report the presence of tubular borings in a fragment of the neurocranium of a fossil baleen whale found in lower Pliocene rocks of southeastern Spain. They are formally described as Trypanites ionasi isp. n. The fossil borings can be assigned to annelid or sipunculid worms and may constitute the first evidence of an Osedax-like osteophagous behavior in the fossil record of cetaceans. Nevertheless, the definitive assignment to Osedax is not possible until we have more information on the morphology of modern siboglinid borings. © 2010 SEPM (Society for Sedimentary Geology).

Brand L.,Loma Linda University | Urbina M.,Museo de Historia Natural | Chadwick A.,Southwestern Adventist University | DeVries T.J.,University of Washington | Esperante R.,Geoscience Research Institute
Journal of South American Earth Sciences | Year: 2011

The Miocene/Pliocene Pisco Formation of Peru contains a rich marine vertebrate fossil record, providing a unique opportunity for the study of paleoecology and evolution, along with the sedimentological context of the fossils. The lack of a high-resolution stratigraphic framework has hampered such study. In this paper we develop the needed stratigraphy for the areas in the Pisco Formation where most of the vertebrate paleontological research is occurring. In the Ica Valley and in the vicinity of Lomas, series of lithologically or paleontologically unique marker beds were identified. These were walked out and documented with GPS technology. Measured sections connecting these marker beds provide a stratigraphic framework for the areas studied. GPS locations, maps of the marker beds on aerial photographs, and outcrop photographs allow field determination of the stratigraphic positions of study areas. © 2011 Elsevier Ltd.

Esperante R.,Geoscience Research Institute | Poma O.,Union Peruvian University
Spanish Journal of Paleontology | Year: 2015

Two mysticete fossil whales from the upper Miocene of the Pisco Formation in Peru are described that show healed bone-fractures in ribs. One specimen is preserved in a tuffaceous, diatomaceous siltstone and the other specimen is preserved in siltstone. Both specimens are well preserved, mostly articulated and almost complete. Shark teeth were found associated with one of the skeletons, but both specimens lack any trace evidence for the activity of macro-scavengers. We suggest that the cause of bone fracture may have been collision with rocky shores, other whales, or large predators. The fact that the rib fractures healed indicates that the whales did not die due to the bone fractures. Sedimentologic and paleontological evidence indicate that they were rapidly buried in the marine platform with well-oxygenated water. © 2015, Sociedad Española de Paleontolog a.

Nalin R.,Geoscience Research Institute | Ghinassi M.,University of Padua | Basso D.,University of Milan Bicocca
Facies | Year: 2010

A Mid-Pliocene sequence in the sedimentary fill of the Val d'Orcia Basin (Tuscany, Italy) records coeval accumulation of temperate carbonate and siliciclastic deposits in close proximity. This study investigates the role played by local parameters in influencing the spatially discontinuous onset of carbonate sedimentation. Carbonate facies developed during transgression of an irregular coastline and were restricted to the more enclosed portion of an embayment. Coralline red algae were the main carbonate producers and are preserved in the skeletal association as isolated branches, rhodoliths, and incipient bindstone. When comparing the sedimentological attributes of the siliciclastic- and carbonate-dominated deposits, no significant differences are observed. They both appear to have accumulated in shallow-marine areas, subjected to general low-energy conditions punctuated by sporadic higher-energy events. Nevertheless, coastal morphology and bedrock composition at the basin margin created local heterogeneities that were sufficient to induce restricted spatial distribution of the carbonate-producing factory. © Springer-Verlag 2010.

Esperante R.,Geoscience Research Institute | Brand L.R.,Loma Linda University | Chadwick A.V.,Southwestern Adventist University | Poma O.,Union Peruvian University
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2015

The Pisco Formation in Peru contains abundant fossil cetaceans in middle Miocene to lower Pliocene sandstone, siltstone, and tuffaceous and diatomaceous mudstone. Fossil whales are especially abundant in the uppermost diatomaceous units. Most specimens are well articulated or partially disarticulated but associated. Degree of preservation is exceptionally high and uniform among articulated and disarticulated specimens and on the lower and upper surfaces of the bones. Some specimens have baleen preserved in anatomical position. Bones show no evidence of bioerosion by macro- or micro-invertebrates, except for a very limited amount of microbial borings. Diatomaceous layers seem to lack bioturbation. However, bioturbation did occur in a few tuffaceous silty and sandy layers of the lower part of the formation. Shark teeth are found associated with many of the specimens; however, despite abundance of whale skeletons, shark tooth marks are extremely rare. Several lines of evidence indicate that sediments and whales were deposited in a shallow-to-deep shelf environment (an embayment), and not in a beach environment. The thick diatomaceous successions record conditions of strong ocean upwelling indicated by the abundant occurrence of the diatom species Thalassionema nitzschioides. The exceptional preservation of diatom frustules suggests that they reached the seafloor very rapidly and were not successively reworked. The hundreds of whale specimens found, their excellent preservation, and their high degree of articulation make the Pisco Formation fossil whales the best representative assemblage of fossil Mysticeti known so far. The abundance of whale skeletons and other vertebrates in the diatomaceous beds, their excellent preservation, including evidence that soft tissue (baleen) was still present at burial, and the degree of articulation, point to frequent mortalities followed by rapid sedimentation that prevented decay of the skeletons and colonization by invertebrates. Sedimentation rates appear much higher than rates inferred from some other modern and ancient settings where whale skeletons have been found. © 2014 Elsevier B.V.

Bracchi V.A.,University of Milan Bicocca | Bracchi V.A.,Milan Bicocca Local Research Unit | Nalin R.,Geoscience Research Institute | Basso D.,University of Milan Bicocca | Basso D.,Milan Bicocca Local Research Unit
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2016

Coralligenous is the most volumetrically significant type of autochthonous carbonate build-up in the Mediterranean, but its range of morphological variability at the macroscale, and potential link with environmental factors have not been fully documented. Well-preserved examples of coralligenous are exposed in shallow marine carbonate deposits from the Upper Pleistocene Le Castella marine terrace (Southern Italy). The coralligenous build-ups occur in the lower part of an unconformity-bounded, transgressive-regressive sequence. They show high structural and morphological heterogeneity in terms of framework type and build-up size, over a distance of several hundred meters. In northern exposures, coralligenous forms banks up to 4 m high, with a dense, coralline-dominated framework, laterally adjacent to paleo-channels devoid of build-ups and filled by coeval infra-circalittoral biogenic packstone. To the south, build-ups are smaller (up to 1.8 m high), with an open algal framework and local predominance of the coral Cladocora caespitosa as primary framework builder. At both locations, the most important framework-building coralline species is Mesophyllum philippii; Titanoderma pustulatum also occurs. Analysis of sedimentary structures, paleo-topographic indicators, faunal composition of associated mollusk assemblages, and predominance of M. philippii suggest the algal builds-ups grew within a shallow-water, possibly infralittoral setting, competing for space with other biocoenoses. Suitable substrate availability in the form of conglomerate blocks or shell accumulations was the primary factor controlling the inception and spatial distribution of coralligenous. Differences in hydrodynamism and water turbidity determined variability in size and internal composition between the northern and southern locations. To the south, abundant supply of fine suspended sediment resulted in smaller build-ups with more open framework, the growth of which was terminated abruptly by sediment burial. Eventually, relative sea level fall during regression prevented further growth of the coralligenous even in the northern area. This study contributes to a better understanding of the relationship between coralligenous morphology and environmental factors, highlighting the role of suitable substrate availability, turbidity, and sediment burial in influencing spatial and temporal variability of coralligenous assemblages. © 2016 Elsevier B.V.

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