ریز رخساره ها محیط رسوبی و بررسی نوسانات عمق دیرینه نهشته های سازند گورپی (بوشهر جنوب باختری ایران).

The purpose of this research is to investigate the microfacies, sedimentary environment and paleodepth fluctuations of the Gurpi Formation sedimentary basin in southwestern Iran. Lithological and facies studies led to the identification of three microfacies related to the deep parts of a basin. The absence of sedimentary evidences such as calcareous turbidities', slip and fall sediments, reef facies, anchoid and pisoid facies characteristic of the edged shelf indicates the deposition of Gurpi Formation in a deep part of the basin. Based on the ratio of the percentage of planktonic foraminifers to benthic foraminifers and the percentage of morphotype 3 and using the formula D = e (3.58718+ (0.03534 × P%)) for the major parts of the Gurpi Formation in the studied sections, a depth between 450 and 602 meter was introduced, which indicates the sedimentation of the facies of this formation in the deep part of the basin. The abundance of planktonic foraminifera such as Oligosteginid and Globotruncana in the facies of this formation indicates that these sediments were deposited in a deep basin, so that the facies of this environment have characteristics related to the deep shelf facies belt. Examining the paleodepth changes of the Gurpi Formation sedimentary basin based on the morphotypes of planktonic foraminifers in the studied sections, indicates that the Gurpi Formation had a regressive trend, and this trend is consistent with the trend of its sedimentary deposits based on the foraminifera morphotypes. The type where the maximum depth of the basin is during the Late-Middle Campanian and Late Maeistrichtian with the expansion of mudstone to wackestone facies and the lowest depth of the sedimentary basin is related to the Santonian to late Campanian with the expansion of wackestone to packstone facies. [ABSTRACT FROM AUTHOR]