The Pawnee Aquifer, Denver-Julesburg Basin, Northeastern Colorado

2017 ◽  
Vol 54 (1) ◽  
pp. 15-32
Author(s):  
Theresa Jehn-Dellaport ◽  
Tammi Renninger

A partially defined and largely unexplored confined aquifer in Colorado, Nebraska, and Wyoming is identified regionally through interpretation of geophysical logs, well drilling, coring, petrographic analysis, and GIS interpretation. The aquifer is a fine-grained arkosic sandstone, with thickness ranging up to 1000 ft in some areas. The aquifer represents a significant water resource for ranching and other development in northeastern Colorado and may be a resource for Wyoming, and Nebraska. Nomenclature for this aquifer is suggested. Water wells penetrating the entire aquifer have produced up to 200 gpm. Water quality data is presented including total dissolved solids, boron, and microbial methane.

2019 ◽  
Vol 20 (1) ◽  
pp. 57-67
Author(s):  
Ernik Yuliana ◽  
Nurhasanah Nurhasanah ◽  
Idha Farida

Reef fish resources are the main catch in Karimunjawa National Park. The fishing activities are feared to have an impact on the sustainability of fish resources inside and outside the conservation area. The purpose of this study is to analyze of the sustainability of reef fish resources (Family Caesionidae) in marine protected area. The study was conducted in Karimunjawa National Park (TNKJ) in Jepara Regency, Central Java, April-September 2017. Data collection was carried out by survey, observation, and deep interview methods, including primary data. Coral fish of the Caesionidae family, which were the object of research, were Caesio cuning and Caesio caerulaurea. Data collection on fish length and weight was carried out six times sampling (for six months). Examples of fish taken from three collectors in Karimunjawa Village. Water quality data was taken for analysis of pH, total dissolved solids (TDS), temperature, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and salinity. Data analysis using FISAT II program and estimation of spawning potential ratio (SPR) using length-based spawning potential ratio analysis. To analyze management aspects of reef fishes, stakeholder analysis was carried out. The research results indicated that Caesio cuning and Caesio caerulaurea had exploitation rate values ​​of 0.69 and 0.61, in the condition of over exploited. The spawning potential ratio (SPR) value are 0.14 and 0.25 (the capacity of adult fish that is ready naturally to spawn is very small). Water quality data is below the water quality standard for marine biota, indicated that the waters of the Karimunjawa National Park was sustainable. The results of stakeholder analysis indicated that there are four parties who are the subject of management. They were fisheries management authorities and Non-Governmental Organizations (NGOs) as work partners of the management authority.   Ikan karang merupakan sumber daya ikan yang menjadi tangkapan utama nelayan di Taman Nasional Karimunjawa. Penangkapan ikan tersebut dikhawatirkan berdampak pada keberlanjutan sumber daya ikan di dalam dan luar kawasan konservasi. Tujuan studi ini adalah menganalisis keberlanjutan sumber daya ikan karang Famili Caesionidae di kawasan konservasi. Studi dilakukan di Taman Taman Nasional Karimunjawa (TNKJ) Kabupaten Jepara, Jawa Tengah, April-September 2017. Pengumpulan data dilakukan dengan metode survei, observasi, dan wawancara dengan mengumpulkan data primer. Ikan karang Famili Caesionidae yang menjadi objek penelitian adalah Caesio cuning dan Caesio caerulaurea. Pengambilan data panjang dan bobot ikan dilakukan empat kali sampling (selama empat bulan). Contoh ikan diambil dari tiga pengepul di Desa Karimunjawa. Data kualitas air diambil untuk analisis pH, total dissolved solids (TDS), suhu, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), dan salinitas. Analisis data menggunakan program FISAT II dan pendugaan spawning potential ratio (SPR) menggunakan analisis length-based spawning potential ratio. Untuk menganalisis aspek pengelolaan, dilakukan analisis stakeholder. Hasil penelitian menunjukkan bahwa Caesio cuning dan Caesio caerulaurea mempunyai nilai laju eksploitasi berturut-turut 0,69 dan 0,61, berada pada kondisi over exploited. Nilai spawning potential ratio (SPR) berturut-turut adalah 0,14 dan 0,25 (kapasitas ikan dewasa yang siap memijah di alam sangat sedikit). Data kualitas air berada di bawah baku mutu perairan untuk biota laut, menunjukkan perairan TNKJ dalam kondisi berlanjut. Hasil analisis stakeholder menunjukkan ada empat pihak yang menjadi subjek pengelolaan, dan semuanya adalah pemegang otoritas pengelolaan perikanan dan Lembaga Swadaya Masyarakat (LSM) sebagai partner kerja otoritas pengelola.


2021 ◽  
Vol 13 (1) ◽  
pp. 517-531
Author(s):  
Abdul Majeed Shar ◽  
Aftab Ahmed Mahesar ◽  
Ghazanfer Raza Abbasi ◽  
Asad Ali Narejo ◽  
Asghar Ali Alias Daahar Hakro

Abstract Nari Formation is considered as one of the most important oil and gas exploration targets. These fine-grained tight sandstone reservoirs face enormous challenges due to their extremely low matrix porosity and permeability. Hence, in this regard, the study was carried out to collect the high-quality data on petrophysical properties along with mineralogy and microstructural characteristics and diagenesis. The experiments performed includes the petrographic study and scanning electron microscopy, and X-ray diffraction analyses. Besides, the measurement of petrophysical properties was carried out to assess the likely influence of the reservoir quality. The petrographic analysis shows predominantly fine- to medium-grained grey samples along with calcite, clay, lithic fragments and iron oxides. Further, the thin-section observations revealed that the quartz is a principal mineral component in all the analysed samples ranging from 52.2 to 92.9%. The bulk volume of clay minerals that range from 5.3 to 16.1% of. The porosity and permeability measured range from 5.08 to 18.56% (average 7.22%) and from 0.0152 to 377 mD (average 0.25 mD), respectively. The main diagenetic processes that affected the sandstones of Nari Formation are mechanical compaction, grain deformation, cementation and quartz dissolution and have played a significant role in influencing the quality of the reservoir rock. Overall, it appears that the primary petrophysical properties (porosity and permeability) were decreased due to the mechanical compaction, lithification, cementation, and framework grain dissolution. Based on the integrated mineralogical, microstructural analysis, and the laboratory-based petrophysical properties, the samples exhibited poor porosity, permeability, and moderate clay content, which indicate that the Nari Formation is a poor quality reservoir.


2000 ◽  
Author(s):  
Kathryn M. Conko ◽  
Margaret M. Kennedy ◽  
Karen C. Rice

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