• Title/Summary/Keyword: strata and fossil

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Fossil Scaphopods from the Hagjeon Formation and the Duho Formation, the Cenozoic Pohang Basin, Korea (신생대 제3기 포항분지의 학전층과 두호층에서 산출된 굴족류 화석)

  • Kong, Dal Yong;Lee, Seong Joo
    • Korean Journal of Heritage: History & Science
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    • v.45 no.1
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    • pp.218-231
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    • 2012
  • A total of 126 fossil scaphopods (121 specimens from the Hagjeon Formation and 5 specimens from the Duho Formation) were found from the Cenozoic strata, Hagjeon and Duho Formations, Pohang Basin, Korea. Five species belonging two genera (Fissidentalium yokoyamai, F. sp. A, B, and Rhabdus sp. A, B) were classified: the most dominant species is Fissidentalium yokoyamai. The species of Fissidentalium yokoyamai is characterized by curved shell (accuration=3.90%) and very closely spaced longitudinal ribs on shell surfaces, while the species of Rhabdus is a nearly straight shell characterized by concentric growth lines without longitudinal ribs. Identification of two genera is somewhat easy due to such morphological differences but classification at generic level is hard because diagnostic features (e.g., cross section and apical structure) are lost in the most specimens. Consequently, except for Fissidentalium yokoyamai, the rest were classified temporarily as F. sp. A, B, and Rhabdus sp. A, B. Two types of preservation state were recognized: one is three-dimensionally preserved specimen (3D specimen) and the other is compressed specimen. Internal parts of the 3D specimen is filled with clastic sediments identical to the surrounding sediments of the shells, which is not observed in the compressed specimens. It is, thus, concluded that the 3D fossils were originally empty but internal cavity were immediately filled with the sediments, which may have protect from the compaction due to pressure during deposition of the gravelly to coarse sandstone of the Hagjeon Formation.

Content Validity of and Information from Elementary Students' Science Portfolio Assessment (초등학교 과학과 포트폴리오 평가의 내용 타당도 검증 및 학생 포트폴리오에서 파악할 수 있는 정보의 유형)

  • Kim, Chan-Jong;Yoon, Sun-Ah
    • Journal of The Korean Association For Science Education
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    • v.22 no.1
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    • pp.190-203
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    • 2002
  • The purpose of this study is to test content validity of a portfolio assessment and to analyse the information which can be obtained from student portfolios. The content validity of the portfolio was tested against the objectives of each lesson and the emphasis of curriculum. The information was identified from the analysis of student portfolios. Students' portfolios from a fourth grade class in Pyeungteak, Kyeungki-do were used for analysis. The portfolios included students' evidence of learning on (I) Strata, Unit 2 'Strata and Fossil,' and (3) Change of Object by Heat, Unit 4 'Heat and Change of Object'. Fourth-grade science textbooks were also analyzed to understand the base level information for portfolio analysis. Two science education specialists and ten elementary teachers majored in science education took part in this analysis. The results of the analysis showed $70{\sim}100%$ of agreement between the objectives of lesson and portfolio forms. Over 90% of agreement is reached between portfolio forms and the emphasis of the curriculum. Student portfolios revealed much information on comprehension, observation, will to study, and process of learning. They also revealed some information on drawing conclusion, communication. self-direction, progress of learning, self-concept, interaction, and process of learning. As a whole, the information in students' portfolios is similar with that dealt in science textbooks. However, students' portfolios have more information on anticipation, will to study, self-direction, and interaction. On the contrary, science textbook deals more with information on observation, planning inquiry, than students' portfolios. The portfolio assessment examined has very sound content validity. The results also show that much more and various information which can not be obtained from pencil and paper test could be obtained from student portfolios. The use of information, obtained from student portfolios will make it possible understand students' learning. their strength and weakness, hence improve student' science learning.