• Economic and Environmental Geology
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• v.50 no.4
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• pp.287-302
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• 2017

The carbonate rocks of the Daegi Formation are composed of the limestone at the upper and lower zones, and the dolomite at the middle zone, in which the upper zone has higher CaO content than others. The colors of carbonate rock in the Daegi Formation can be divided into five types; white, light brown, light gray, gray, and dark gray. The white to light gray colored rocks correspond to the high purity limestone with 53.15 ~ 55.64 wt. % CaO, and the light brown colored rocks contain 20.71 ~ 21.67 wt. % MgO. The bleaching of carbonate rocks are not related to CaO composition of the rocks, as light gray rocks tend to be higher in CaO content than those of the white rocks at the lower zone. The pelitic components are also occasionally increased in white limestone than light grey one. $Al_2O_3$ is one of the most difficult content to remove during hydrothermal processes, so the interpretation that the limestone is purified together with hydrothemral bleaching, has little merit. The wide range (over 16 ‰) of ${\delta}^{18}O_{SMOW}$, smaller variation (within 2 ‰) of ${\delta}^{13}C_{PDB}$ are apparent in both the upper and lower zones, which indicate the Daegi Formation had been affected overall by hydrothermal fluids. The K-Ar isotopic age of hydrothermal alteration in the GMI limestone mine is $85.1{\pm}1.7Ma$. Gradual change from grey through light grey to white limestone is accompaned by lower oxygen stable isotope values, which is major evidence that the hydrothermal effect is the main process of the bleaching. Although the Daegi Formation has suffered from hydrothermal activity and increase in whiteness, there is no clear evidence demonstrating the relationship between bleaching and high purity of limestone. The purification of limestone has nothing to do with the hydrothermal activity in this area. Instead, it should be considered that the change of sedimentary environment related to see-level fluctuation which can prevent deposition of pelitic components especially $Al_2O_3$ contrbuted to the formation of the high purity limestone in the upper zone of the Daegi Formation. Considering the evidences such as increase in CaO content of limestone by depth, gradual change from calcite to dolomite at the lower zones, and occurring the high purity limestone at the upper zone, the interpretation of sequence stratigraphic aspect to the formation of the high purity Daegi limestone appears to be more suitable than that of hydrothermal alteration origin.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.191-202
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• 1995

Purpose: Acute febrile illness in children frequently accompanies with abdominal symptoms such as vomiting, diarrhea, and abdominal pain, even if its etiology is not occured from the gastrointestinal tract. If the etiology of fever was unknown and the fever was accompanied with abdominal symptoms, we should be concerned about whether the etiology of fever was originated from the gastrointestinal tract or interpretated from the abnormality in the gastrointestinal tract. This study was performed to evaluate the diagnostic value of abdominal ultrasonography in patients with fever and abdominal symptoms. Methods: We reviewed retrospectively the medical records of abdominal ultrasonographic (US) findings of 60 cases of acute febrile illness with abdominal symptoms at department of Pediatrics, Ulsan Dongang General Hospital during the period from January 1994 to June 1995. Results: The abnormal abdominal US findings obtained were as follows. 1) The abnormal US findings were seen in 56 cases (93.3%). 2) The most common abnormal US finding was the enlarged mesenteric lymph nodes in 52 cases (86.7%) 3) The enlarged mesenteric lymph nodes with or without intra-abdominal fluid were seen in 30 cases (50.0%) of a wide variety of illnesses, so their diagnostic values were absent. 4) The enlarged mesenteric lymph nodes and splenomegaly with or without ileocecitis were seen in 7 cases. Among them, 4 cases (6.7%) were confirmed as typhoid fever. 5) The US findings in 6 cases of typhoid fever were the enlarged mesenteric lymph nodes in all cases (100%), splenomegaly in 4 cases (66.7%), ileocecitis in 1 case (16.7%), enlarged mesenteric lymph nodes and splenomegaly in 4 cases (66.7%), enlarged mesenteric lymph nodes, splenomegaly and ileocecitis in 1 cases (16.7%). 6) The enlarged mesenteric lymph nodes and the abnormalities around the appendix were seen in 7 cases (11.7%), which were confirmed as appendicitis all. 7) The thickening of wall in urinary bladder was seen in 2 cases (3.3%) of acute cystitis and acute hemorrhagic cystitis. 8) The subtle thickening of wall in colon was seen in 1 cases (1.7%) of shigellosis. Conclusions: The enlarged mesenteric lymph nodes, splenomegaly and ileocolitis on the abdominal ultrasonography in patients with fever and abdominal symptoms aree suggestive findings of typhoid fever. The enlarged mesenteric lymph nodes and the abnormalities around the appendix on abdominal ultrasonography make the rapid diagnosis of acute appendicitis and its complications, when physical examination is difficult in small children and diagnosis of their illnesses is obscure in patients with fever and abdominal pain.