Mesozoic

Mesozoic Triassic 245 Myr Continents begin to drift apart. Early dinosaurs first mammals gymnosperms become dominant diversification of marine invertebrates. Moss extinction at end of period (ca. 75% of all species disappear)... 

Figure 1.62. Location of epithermal-type deposits in Japan (Shikazono and Shimizu, 1988a). 1 Green tuff and subaerial volcanic region of Tertiary/Quaternary ages, 2 Main Paleozoic/Mesozoic sedimentary terranes, 3 Main metamorphic terranes. TTL Tanakura tectonic line, ISTL Itoigawa-Shizuoka tectonic line, MTL Median tectonic line. Open circle epithermal Au-Ag vein-type deposits, solid circle epithermal base metal vein-type deposits, open triangle epithermal Au disseminated-type deposits.

The Yamizo Mountains are mostly occupied by Paleozoic-Mesozoic sedimentary rocks, mainly of Jurassic age (e.g., Sashida et al., 1982) with a small amount of intrusive granitoids of unknown ages. The Paleozoic-Mesozoic sedimentary rocks have been called the Yamizo Formation (Kanomata, 1961). It is composed chiefly of shale, sandstone, alternating beds of shale and sandstone, and a small amount of limestone and chert. The succession of the geologic units and geologic structure of the Yamizo Formation have been left pending due to complex structure such as upturned beds (Kasai, 1978) and submarine land sliding (Aono et al., 1985). 

Aono, H., Sato, T., Matsuda, R, Katsura, Y. and Mariko, Y. (1981) Gravity slidings observable in the Mesozoic of the Yamizo Mountains in northeast Japan. Sci. Kept. Inst. Geosci., Univ. Tsukuba, [B] 2, 17 4. 

The basement rock of the area is composed of the Mesozoic (limestone, chert, and late Tertiary volcanic formation. Osorezan is a composite volcano with caldera structure and post caldera domes. The K-Ar age of strata volcano in the earliest stage and the latest domes are 1 Ma and 0.2 Ma, respectively (Aoki, 1991). 

The area consists of Quaternary late Pliocene pyroclastics and sedimentary rocks. Marine mudstone and sandstone of Mesozoic-lower Tertiary Shimanto Supergroup are overlain by these rocks. Thick (more than 1,000 m) dacitic tuffs interbedded with marine sedimentary rocks of late Pliocene-early Pleistocene age occur. These rocks overlie altered andesite lava and dacitic pyroclastics of Miocene-late Pliocene (Yoshimura et al., 1988). 

Paleozoic-Mesozoic volcanogenic stratiform Cu deposits in Japan which are generally metamorphosed have been called Besshi-type deposits (Kato, 1937) or bedded cupriferous iron sulfide deposits (Kanehira and Tatsumi, 1970). 

Geological characteristics and inferred tectonic settings of Paleozoic to Mesozoic volcanogenic Cu sulfide Besshi-type deposits of Japan (Sato and Kase, 1996)... 

Ceding, T.E. (1991) Carbon dioxide in the atmosphere evidence from Cenozoic and Mesozoic paleosols. Am. J. Sci., 291, 377 00. 

In Chapter 2, a geochemical, geological and mineralogical summary of active subaerial and submarine back-arc basin hydrothermal systems and mineralizations is given. The characteristic features of above-fossil and active subaerial and submarine hydrothermal systems are compared with fossil hydrothermal systems (epithermal vein-type and Kuroko deposits), and the causes for the differences in the characteristic features are considered. Characteristic features of Paleozoic-Mesozoic volcanogenic stratiform Cu deposits (Besshi-type deposits) are compared with those of midoceanic ridge deposits and Kuroko deposits. 

The remaining reptiles are monosmic, i.e. they are MOS-dependent with no functional accessory system. They derive from a secondarily aquatic group of Mesozoic dinosaurs, whose survivals are now represented by Crocodiles, Alligators and Caimans (Howes, 1891 Saint Girons, 1976). In these, the loss of accessory olfaction may have been part of a pre-adaptive trend. Genomic comparisons with the avian OR repertoires could provide some clues on AOS history in their living relatives. 

In addition to the Permian coals there are occurrences of Mesozoic and Tertiary coals in Australia. Mesozoic coals occur in small basins in South Australia, Tasmania, New South Wales and Queensland and vary in rank from brown to bituminous. Perhaps the most notable occurrences in the present context are the Walloon coals in the Clarence-Morton basin in Queensland, e.g. Millmerran bituminous coal (78% carbon, vitrinite plus exinite 90%). ... 

Lepidoptera is the second largest insect group and includes nearly 150,000 described species, which have evolved over 100 million years since the Mesozoic era. For the birth of a new species, it must be isolated from other species by some factor to prevent inter-species crossing. The sex pheromone, which is secreted by the adult (usually by a female moth and sometimes by a male moth or butterfly) for the benefit of a specific partner, plays an important role in reproductive isolation. Therefore, it is no wonder that the chemical structures of the species-specific pheromones exhibit considerable differences. 

Sanchez JA, Coloma P, Perez A (1999) Sedimentary processes related to the groundwater flows from the Mesozoic Carbonate Aquifer of the Iberian Chain in the Tertiary Ebro Basin, northeast Spain. Sediment Geol 129 201-213... 

As a first example, we consider the diagenesis of clastic sandstones in the Gippsland basin, southeastern Australia, basing our model on the work of Harrison (1990). The Gippsland basin is the major offshore petroleum province in Australia. Oil production is from the Latrobe group, a fluvial to shallow marine sequence of Late Cretaceous to early Eocence age that partly fills a Mesozoic rift valley. 

Mesozoic volcanic rocks and coeval intrusive complexes within the Quesnel geotectonic terrain of central British Columbia host several major porphyry copper-gold mines. Exploration for new deposits in this region has been met with limited success, because prospective bedrock is mantled by Late Pleistocene glacial sediment (e.g.,till) and Late Olig-ocene to Pleistocene plateau basalt. 

Ribeiro, A., Quesada, C Dallmeyer, R.D. 1990. Geodynamic evolution of the Iberian massif. In Pre-Mesozoic Geology of Iberia. R. D. Dallmeyer E. M. Garcia (Eds), Springer-Verlag, Berlin, 383-395. 

The Ulsan carbonates (Fig. 1) have long been interpreted as limestone of Paleozoic age or "age unknown" and as the host of a skarn-type iron (magnetite) deposit due to the intrusion of Cretaceous granitic rocks (Park Park 1980 Choi et al. 1999). However, a Paleozoic marine limestone hypothesis fails to explain the spatial association or the relationship between carbonate and ultramafic rocks in a concentric, ellipsoidal shape surrounded by Cretaceous sedimentary, volcanic, and granitic rocks. The sedimentary hypothesis also fails to explain the isolated exposure of a funnel-shaped Paleozoic marine limestone where no marine limestone has been previously observed within the Mesozoic Kyongsang Basin. 

Re-evaluating the origin of the Ulsan carbonates can be very important in understanding the geology and petrogenesis in the Mesozoic Kyongsang Basin, South Korea. This present work is summarized and reviewed from the Yang et al. (2003). 

Fleck, R. J. Criss, R. E. (1985). Strontium and oxygen isotopic variations in Mesozoic and Tertiary plutons of Central Idaho. Contrib. Mineral. Petrol., 90, 291-308. 

Section 8.6.2, the Permian period ended with the largest mass extinction event that has yet occurred on planet Earth. As the ocean began a sustained recovery at the beginning of the Mesozoic era, opportunities likely abounded for the survivors to take over empty ecological niches through evolutionary adaptation. Prior to the advent of planktonic... 

As a specific example of the problem, let us calculate the equilibria for an actual case study a deep water from the Sarcidano region (Sardinia, Italy) in equilibrium with Mesozoic dolomites (Bertorino et al., 1981). The compositions in mEq/1 of water sampled in a drilled well are listed in table 8.8. The in situ temperature is 21 °C we assume here that the in situ T is 25 °C at 1 bar, to simplify calculations. We also assume for the sake of simplicity that the main ion species in solution are HCO3, Mg, Ca, CO3, OH, and H, and that all Ca and Mg are in the ionic forms Ca and Mg. ... 

Table 8.8 Compositions of superficial and deep waters of the Sarcidano region (Sardinia, Italy) equilibriated with Mesozoic dolomite limestones (Bertorino et ah, 1981). Values in mEq/1. C-j- total inorganic carbon in mmol/1.

The mineralized district is restricted by two main strike-slip faults of Kubanan to the east and Posht e Bdam to the west (Fig. la). The host rocks are a thick sequence of Upper Precambrian-Cambrian rhyolite, tuff, alkali granite, syenite, mafic dykes, magnetitite, dolomite, gypsum, limestone, black shale, and sandstone. The Upper Percambrian-Cambrian sequence is overlain unconformably by Mesozoic and... 

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